Improved Management of Patients With Recent-Onset Stable Chest Pain (IMPRO)

A Pragmatic, Cluster-randomised Stepped-wedge Trial to Evaluate the Effectiveness of a New Cross-sectoral Form of Care (NVF) in Patients With New-onset Stable Chest Pain and Suspected Coronary Artery Disease (CAD).

In Germany, coronary CT offers an accurate and less burdensome alternative to cardiac catheterisation for evaluating suspected coronary artery disease, but it is still underused. The IMPRO stepped-wedge trial tests a new, nationwide care model (NVF) in 16 regions to improve guideline-based intersectoral implementation of coronary CT and assess its impact on cardiovascular outcomes and healthcare costs. If effective, the model of care (NVF) could be adopted across Germany to enhance care quality while reducing unnecessary procedures and expenses.

Study Overview

• Status: Recruiting
• Conditions: Coronary Artery Disease (CAD)
• Intervention / Treatment: Behavioral: IMPRO - Cross-Sectoral Care Model for Coronary Diagnostics

Detailed Description

In Germany, more than 700,000 patients with chest pain undergo cardiac catheterisation each year. The most common reason is suspected coronary artery disease-the leading cause of death worldwide. Proportionally, more cardiac catheterizations are performed in Germany than in any other country. Coronary computed tomography (coronary CT) is available as an alternative diagnostic method to cardiac catheterization. The advantages of coronary CT include a lower complication rate, greater accuracy in detecting deposits in the coronary arteries, reduced burden for patients, and less procedural effort.

The aim of the partners in the IMPRO project is to optimize the implementation of coronary CT in routine clinical care following the resolution of the Federal Joint Committee on January 18, 2024, while at the same time avoiding overuse. For this purpose, a new model of care will be tested in 16 different regions across 12 federal states in Germany. This model is intended to improve primary and cross-sectoral care for patients with suspected coronary artery disease. The primary goal of the nationwide study is to determine whether the new model of care helps reduce cardiovascular events, such as heart attacks and strokes, in patients with suspected coronary artery disease. The researchers will also analyze how patients respond to this type of treatment and whether it leads to cost savings. The project is funded for 39 months with a total of approximately 9.3 million euros.

If successful, the new model of care could be implemented nationwide to improve the treatment of patients with suspected coronary artery disease and to avoid unnecessary costs for the healthcare system.

• Study Type: Interventional
• Enrollment (Estimated): 3369
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Annika Viniol, Prof. Dr.; Phone Number: +49 6421 28-65120; Email: annika.viniol@staff.uni-marburg.de
• Study Contact Backup: Name: Marc Dewey, Prof. Dr.

Study Locations

• Germany
  • Augsburg, Germany, 86156
    • Recruiting
    • Universitätsklinikum Augsburg, Diagnostische und Interventionelle Radiologie und Neuroradiologie
    • Contact: Josua Decker, Dr.; Phone Number: +49 821 400-01; Email: josua.decker@uk-augsburg.de
  • Augsburg, Germany, 86156
    • Recruiting
    • Universitätsklinikum Augsburg, Institut für Allgemeinmedizin
    • Contact: Marco Roos, Prof. Dr.; Phone Number: +49 8214009560; Email: marco.roos@med.uni-augsburg.de
  • Bad Neustadt an der Saale, Germany, 97616
    • Recruiting
    • RHOEN-Klinikum AG, Campus Bad Neustadt, Klinik für Radiologie
    • Contact: Lukas Lehmkuhl, PD Dr.; Phone Number: +49 97716623901; Email: lukas.lemkuhl@campus-nes.de
  • Berlin, Germany, 10098
    • Recruiting
    • Charité-Universitätsmedizin Berlin, Institut für Allgemeinmedizin
    • Contact: Christoph Heintze, Prof. Dr.; Phone Number: +49 30450514226; Email: christoph.heintze@charite.de
  • Berlin, Germany, 10117
    • Recruiting
    • Charité - Universitätsmedizin Berlin, Klinik für Radiologie
    • Contact: Federico Biavati; Phone Number: +49 30 450 627 309; Email: federico.biavati@charite.de
    • Contact: Patrick Asbach, Prof. Dr.; Phone Number: +49 30 450 527510; Email: patrick.asbach@charite.de
  • Cologne, Germany, 50937
    • Recruiting
    • Uniklinik Köln, Institut für Diagnostische und Interventionelle Radiologie
    • Contact: David Maintz, Prof. Dr.; Phone Number: +49 221 478-82035; Email: david.maintz@uk-koeln.de
  • Cologne, Germany, 50937
    • Recruiting
    • Universitätsklinikum Köln, Institut für Allgemeinmedizin
    • Contact: Beate Müller, Prof. Dr.; Phone Number: +49 22147832170; Email: beate.mueller@uk-koeln.de
  • Düsseldorf, Germany, 40225
    • Recruiting
    • Universitätsklinikum Düsseldorf, Institut für Allgemeinmedizin (ifam)
    • Contact: Stefan Wilm, Prof. Dr.; Phone Number: +49 (0)211 / 81- 1 77 71; Email: stefan.wilm@med.uni-duesseldorf.de
  • Düsseldorf, Germany, 40225
    • Recruiting
    • Universitätsklinikum Düsseldorf, Institut für Diagnostische und Interventionelle Radiologie
    • Contact: Gerald Antoch, Prof. Dr.; Phone Number: +49 (0) 211 - 81 17752; Email: Antoch@med.uni-duesseldorf.de
  • Düsseldorf, Germany, 40476
    • Recruiting
    • Röntgeninstitut
    • Contact: Philipp Begemann, PD Dr.; Phone Number: +49 211 49669 1000; Email: p.begemann@roentgeninstitut.de
  • Erlangen, Germany, 91054
    • Recruiting
    • Universitätsklinikum Erlangen, Allgemeinmedizinisches Institut
    • Contact: Thomas Kühlein, Prof. Dr.; Phone Number: +49 91318531140; Email: allgemeinmedizin@uk-erlangen.de
  • Erlangen, Germany, 91054
    • Recruiting
    • Universitätsklinikum Erlangen, Radiologisches Institut
    • Contact: Michael Uder, Prof. Dr.; Phone Number: +49 91318536065; Email: Michael.Uder@uk-erlangen.de
  • Frankfurt, Germany, 60590
    • Recruiting
    • Goethe-Universität Frankfurt am Main, Institut für Allgemeinmedizin
    • Contact: Karola Mergenthal, Dr.; Phone Number: +49 6963014149; Email: mergenthal@allgemeinmedizin.uni-frankfurt.de
  • Giessen, Germany, 35392
    • Recruiting
    • Universitätsklinikum Gießen, Diagnostische und Interventionelle Radiologie und Kinderradiologie
    • Contact: Gabriele Krombach, Prof. Dr.; Phone Number: +49 641 985-41801; Email: gabriele.krombach@uniklinikum-giessen.de
  • Greifswald, Germany, 17475
    • Recruiting
    • Universitätsmedizin Greifswald, Institut für Community Medicine, Abt. Allgemeinmedizin
    • Contact: Jean-Francois Chenot, Prof. Dr.; Phone Number: +49 38348622282; Email: jchenot@uni-greifswald.de
  • Göttingen, Germany, 37073
    • Recruiting
    • Universitätsmedizin Göttingen, Institut für Allgemeinmedizin
    • Contact: Eva Hummers, Prof. Dr.; Phone Number: +49 5513968193; Email: eva.hummers@med.uni-goettingen.de
  • Göttingen, Germany, 37075
    • Recruiting
    • Georg-August-Universität Göttingen, Universitätsmedizin, Institut für Diagnostische und Interventionelle Radiologie
    • Contact: Joachim Lotz, Prof. Dr.; Phone Number: +49 5513968966; Email: joachim.lotz@med.uni-goettingen.de
  • Hamburg, Germany, 20095
    • Recruiting
    • Radiologische Allianz Hamburg
    • Contact: Claas Philip Nähle, Prof. Dr.; Phone Number: +49 40325552141; Email: naehle@radiologische-allianz.de
  • Hamburg, Germany, 20246
    • Recruiting
    • Universitätsklinikum Hamburg-Eppendorf, Institut und Poliklinik für Allgemeinmedizin
    • Contact: Martin Scherer, Prof. Dr.; Phone Number: +49 40741052400; Email: m.scherer@uke.de
  • Jena, Germany, 07747
    • Recruiting
    • Universitätsklinikum Jena, Institut für Diagnostische und Interventionelle Radiologie
    • Contact: Sebastian Reinartz, Prof. Dr.; Phone Number: +49 3641 9-324831; Email: sebastian.reinartz@med.uni-jena.de
  • Jena, Germany, 07743
    • Recruiting
    • Institut für Allgemeinmedizin des Universitätsklinikums Jena
    • Contact: Jutta Bleidorn, Prof. Dr.; Phone Number: +49 3641/9-395800; Email: Jutta.Bleidorn@med.uni-jena.de
  • Kiel, Germany, 24105
    • Recruiting
    • Christian-Albrechts-Universität zu Kiel, Medizinische Fakultät, Institut für Allgemeinmedizin
    • Contact: Hanna Kaduszckiewicz, Prof. Dr.; Phone Number: +49 43150030101; Email: kaduszkiewicz@allgemeinmedizin.uni-kiel.de
  • Kiel, Germany, 24105
    • Recruiting
    • Universitätsklinikum Schleswig-Holstein, Campus Kiel, Klinik für Radiologie und Neuroradiologie
    • Contact: Marcus Both, Prof. Dr.; Phone Number: 0431 500-16502; Email: Marcus.Both@uksh.de
  • Leipzig, Germany, 04103
    • Recruiting
    • Universität Leipzig, Institut für Allgemeinmedizin
    • Contact: Stefan Lippmann, Dr.; Phone Number: +49 3419715735; Email: Stefan.Lippmann@medizin.uni-leipzig.de
  • Leipzig, Germany, 04103
    • Recruiting
    • Universitätsklinikum Leipzig, Institut für Diagnostische und Interventionelle Radiologie
    • Contact: Timm Denecke, Prof. Dr.; Phone Number: +49 3419717402; Email: Timm.Denecke@medizin.uni-leipzig.de
  • Leipzig, Germany, 04289
    • Recruiting
    • Herzzentrum Leipzig, Abteilung für Diagnostische und Interventionelle Radiologie
    • Contact: Matthias Gutberlet, Prof. Dr.; Phone Number: +49 3418651702; Email: Matthias.gutberlet@helios-gesundtheit.de
  • Lübeck, Germany, 23538
    • Recruiting
    • Universitätsklinikum Schleswig-Holstein, Campus Lübeck, Institut für Allgemeinmedizin
    • Contact: Jost Steinhäuser, Prof. Dr.; Phone Number: +49 45131018000; Email: jost.steinhäuser@uksh.de
  • Lübeck, Germany, 23538
    • Recruiting
    • Universitätsklinikum Schleswig-Holstein, Campus Lübeck, Institut für Radiologie und Nuklearmedizin
    • Contact: Jörg Barkhausen, Prof. Dr.; Phone Number: +49 45150017000; Email: joerg.barkhausen@uksh.de
  • Marburg, Germany, 35043
    • Recruiting
    • Philipps University Marburg, Institut für Allgemeinmedizin
    • Contact: Annika Viniol, Prof. Dr.; Phone Number: +4964212865120; Email: annika.viniol@staff.uni-marburg.de
  • Rostock, Germany, 18057
    • Recruiting
    • Universitätsmedizin Rostock, Institut für Allgemeinmedizin
    • Contact: Ralf Michael Jendyk, Prof. Dr.; Phone Number: +49 381 4942480; Email: ralf.jendyk@med.uni-rostock.de
  • Rostock, Germany, 18057
    • Recruiting
    • Universitätsmedizin Rostock, Institut für Diagnostische und Interventionelle Radiologie, Kinder- und Neuroradiologie
    • Contact: Felix Meinel, Prof. Dr.; Phone Number: +49 3814949275; Email: felix.meinel@med.uni-rostock.de
  • Tübingen, Germany, 72076
    • Recruiting
    • Universitätsklinikum Tübingen, Diagnostische und Interventionelle Radiologie, Department für Radiologie
    • Contact: Konstantin Nikolaou, Prof. Dr.; Phone Number: +49 70712982087; Email: Konstantin.Nikolaou@med.uni-tuebingen.de
  • Tübingen, Germany, 72076
    • Recruiting
    • Universitätsklinikum Tübingen, Institut für Allgemeinmedizin & Interprofessionelle Versorgung
    • Contact: Stefanie Joos, Prof. Dr.; Phone Number: +49 7071 29-85213; Email: stefanie.joos@med.uni-tuebingen.de
  • Ulm, Germany, 89081
    • Recruiting
    • Universitätsklinikum Ulm, Institut für Allgemeinmedizin
    • Contact: Anne Barzel, Prof. Dr.; Phone Number: +49 73150057901; Email: anne.barzel@uni-ulm.de
  • Ulm, Germany, 89081
    • Recruiting
    • Universitätsklinikum Ulm, Klinik für Diagnostische und Interventionelle Radiologie
    • Contact: Meinrad Beer, Prof. Dr.; Phone Number: +49 73150061001; Email: meinrad.beer@uniklinik-ulm.de
  • Wiesbaden, Germany, 65185
    • Recruiting
    • radiomed Gemeinschaftspraxis für Radiologie und Nuklearmedizin
    • Contact: Stefanie Bitschnau, Dr.; Phone Number: +49 61190017117; Email: bitschnau@radiomed-praxis.de
  • Wiesbaden, Germany, 65189
    • Recruiting
    • RNS Gemeinschaftspraxis für Radiologie und Strahlentherapie
    • Contact: Ralf Bauer, Prof. Dr.; Phone Number: +49 611 - 56589-1400; Email: ralfwbauer@aol.com
  • Würzburg, Germany, 97080
    • Recruiting
    • Universität Würzburg, Institut für Allgemeinmedizin
    • Contact: Ildikó Gágyor, Prof. Dr.; Phone Number: +49 931-201-47802; Email: gagyor_i@ukw.de
  • Würzburg, Germany, 97080
    • Recruiting
    • Universitätsklinkum Würzburg, Institut für Diagnostische und Interventionelle Radiologie
    • Contact: Thorsten Bley, Prof. Dr.; Phone Number: +49 93120134001; Email: Bley_T@ukw.de

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Age ≥30 years
• Suspected CAD with stable chest pain
• Ability to give informed consent

Exclusion Criteria:

• Known or previously treated (with PCI or CABG) obstructive CAD (defined as at least one coronary diameter stenosis ≥50%)
• Acute coronary syndrome
• Negative invasive coronary angiography or coronary CT within the last 5 years
• Already enrolled in the study
• Not covered by statutory health insurance
• Unable to give consent

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: Randomized
• Interventional Model: Sequential Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
No Intervention: Usual Care; Usual diagnostic and treatment procedures for suspected coronary artery disease according to national guideline (NVL KHK 2024), without structured cross-sectoral coordination or quality feedback.
Experimental: IMPRO Program; Participants in this arm will receive the IMPRO cross-sectoral care model (NVF) for patients presenting with stable chest pain and suspected coronary artery disease (CAD). The program integrates general practitioners and certified cardiac CT centres to improve diagnostic indication, shared decision-making, and reporting quality.	Behavioral: IMPRO - Cross-Sectoral Care Model for Coronary Diagnostics; The intervention consists of structural and procedural components designed to improve cross-sectoral coordination in the diagnostic work-up of patients with suspected coronary artery disease (CAD). It builds upon the 2024 National Disease Management Guideline (NVL KHK 2024) and comprises three main components: (1) evidence-based initial assessment and indication for imaging diagnostics, (2) shared decision-making between primary care physicians, radiologists, and patients, and (3) quality-assured CT imaging and structured reporting in certified centres. Participating sites receive structured training, feedback, and centralized quality monitoring.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Major Adverse Cardiovascular Events (MACE)	Composite endpoint: Major Adverse Cardiovascular Events (MACE) including cardiovascular death, myocardial infarction, stroke, and procedure-related complications from diagnostic testing and subsequent management/therapy in the two randomization groups. Procedure-related complications (major and minor) are defined in the subsequent outcome measure and include events occurring during or within 48 hours after CT or ICA or related tests or revascularization procedures.	From enrolment to 12 months for primary MACE analysis in the G-BA-funded IMPRO trial; extended follow-up to 5 years for MACE (cardiovascular death, myocardial infarction, stroke) excluding procedure-related complications; data at 3, 12 months and 5 years

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Total medical care costs (Ct) from the perspective of society	Cumulative healthcare costs that can be mapped from primary data	3 months, 12 months, 5 years
Prospective Primary Safety Endpoint: Procedure-related Complications	Rate of procedure-related complications by diagnostic imaging modality and by interventional/surgical treatments (PCI, CABG). Includes major and minor complications. Major complications: events occurring during or within 48 hours after CT or ICA or related tests or revascularization procedures, including death, nonfatal myocardial infarction, nonfatal stroke, complications prolonging hospitalization ≥24 hours, coronary/aortic dissection, cardiogenic shock, cardiac tamponade, retroperitoneal bleeding, cardiac arrhythmia (ventricular tachycardia/fibrillation), or cardiac arrest. Minor complications: events occurring during or within 48 hours after CT or ICA or related tests or revascularization procedures not meeting major criteria, including hematoma or secondary bleeding at the puncture site, bradycardia, angina pectoris without myocardial infarction, allergic reaction to contrast media, hypotension requiring treatment, infection, thrombosis, or arteriovenous fistula.	3 months and 12 months
Indication quality	1) Agreement of the diagnostic decision with the pre-test probability (PTP, below 15%, 15-50%, above 50% criterion) with the National Health Services guidelines for suspected coronary artery disease and the statistical distribution of PTP values across the scale (NVL KHK 2024), measured using the updated DISCHARGE PTP calculator in the two randomisation groups, 2) Agreement of the mean pre-test probability with the prevalence of obstructive coronary artery disease (CAD) defined as at least one at least 50% coronary artery diameter stenosis on coronary computed tomography angiography (CTA) and/or invasive coronary angiography (ICA) in the two randomisation groups.	From enrollment to 12 months (with follow-up data collection at baseline, 3 months, 12 months)
Functional test rates	Rate of functional tests performed during the follow-up period (stress electrocardiography (ECG), cardiac stress magnetic resonance imaging (MRI), stress echocardiography, stress myocardial perfusion single-photon emission CT (SPECT), myocardial stress perfusion positron emission tomography (PET)) in the two randomisation groups.	From enrollment to 12 months and 5 years (with follow-up data collection at 3 months, 12 months and 5 years)
Revascularization rates	Rate of coronary artery revascularisations (percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG)) performed during the follow-up period in the two randomisation groups.	From enrollment to 12 months and 5 years (with follow-up data collection at 3 months, 12 months and 5 years)
Coronary CT angiography (CTA) rates	Rate of coronary CT performed during the follow-up period in the two randomisation groups.	From enrollment to 12 months and 5 years (with follow-up data collection at 3 months, 12 months and 5 years)
Invasive coronary angiography (ICA) rates	Rate of ICA procedures performed during the follow-up period in the two randomisation groups.	From enrollment to 12 months and 5 years (with follow-up data collection at 3 months, 12 months and 5 years)
Invasive coronary angiography (ICA) results	Rate of diagnostic findings on the ICA procedures performed in the two randomisation groups (obstructive or non-obstructive CAD or no signs of CAD) to assess the yield of ICA defined as the proportion of ICAs performed in both randomisation groups demonstrating obstructive CAD.	From enrolment to 12 months and 5 years (with follow-up data collection at 3 months, 12 months and 5 years)
Coronary CT angiography (CTA) results	Rate of diagnostic findings on the CTA procedures performed in the two randomisation groups (obstructive or non-obstructive CAD or no signs of CAD) to assess the yield of CTA defined as the proportion of CTAs performed in both randomisation groups demonstrating obstructive CAD.	From enrolment to 12 months and 5 years (with follow-up data collection at 3 months, 12 months and 5 years)
Hospitalization due to chest pain	Rate of hospitalisations due to chest pain during the follow-up period in the two randomisation groups.	From enrollment to 12 months and 5 years (with follow-up data collection at 3 months, 12 months and 5 years)
Emergency department visits due to chest pain	Rate of emergency department visits due to chest pain during the follow-up period in the two randomisation groups.	From enrollment to 12 months and 5 years (with follow-up data collection at 3 months, 12 months and 5 years)
Assessability of coronary CTs	Proportion of non-diagnostic coronary CTs in the two randomisation groups.	From enrollment to 12 months (with follow-up data collection at 3 months, 12 months)
Radiation exposure	Estimated radiation exposure of cardiac imaging tests including coronary CT, ICA, SPECT, and PET in the two randomisation groups in millisieverts (mSv).	From enrollment to 12 months and 5 years (with follow-up data collection at 3 months, 12 months and 5 years)
Quality of life questionnaire	EQ-5D-5L: validated questionnaire with five dimensions (mobility, self-care, usual activities, pain/discomfort and anxiety/depression) and 5 levels (no problems, slight problems, moderate problems, severe problems and extreme problems) in the two randomisation groups.	From enrollment to 3 months, 12 months and 5 years (with follow-up data collection at baseline 3 months, 12 months and 5 years)
Seattle Angina Questionnaire	SAQ-7 questionnaire (short version): disease-specific health status instrument for coronary artery disease (CAD) with seven items from the physical limitations, angina frequency, and quality of life domains in the two randomisation groups.	From enrollment to 3 months, 12 months and 5 years (with follow-up data collection at baseline 3 months, 12 months and 5 years)
Total medical care costs (Ct) from the statutory health insurance perspective	Cumulative healthcare costs that can be mapped from routine health insurance data.	3 months, 6 months
Cost-effectiveness ratio (ICER) based on routine data collected by health insurers	ΔCt/ΔMACE: The calculated total costs are compared with MACE (primary endpoint). The results are presented as the incremental cost-effectiveness ratio (ICER). Data sources are routine data and patient survey distributed by the health insurers.	3 months, 6 months
Cost-effectiveness ratio (ICER) based on health care utilisation data	ΔCt/ΔMACE: The calculated total costs are compared with MACE (primary endpoint) in the two randomisation groups. The results are presented as the incremental cost-effectiveness ratio (ICER). Data source is primary health care utilisation data in the two randomisation groups.	3 months, 12 months, 5 years
Cost-utility ratio (ICUR) based on routine data collected by health insurers	ΔCt/ΔQALYs: The calculated total costs are compared with quality of life (secondary endpoint), measured using the standardised and validated EQ-5D-5L. The results are presented as the incremental cost-utility ratio (ICUR). Data sources are routine data and patient survey distributed by health insurers.	3 months and 6 months
Cost-utility ratio (ICUR) based on health care utilisation data	ΔCt/ΔQALYs: The calculated total costs are compared with quality of life (secondary endpoint), measured using the standardised and validated EQ-5D-5L. The results are presented as the incremental cost-utility ratio (ICUR). Data sources are primary data and patient quality of life survey in the two randomisation groups.	3 months, 12 months, 5 years

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Prognostic validation of the Marburg Heart Score (MHS)	The MHS is a well validated and established diagnostic clinical prediction rule estimating the clinical probability of coronary heart disease in patients presenting with chest pain in primary care. However, the prognostic value has not been evaluated so far. For this secondary analysis, we will calculate the rate of coronary events (death, lethal and non-lethal myocardial infarctions), stratified by the MHS score values.	3 months and 12 months
Initiation or Intensification of Statin Therapy	Proportion of patients in whom lipid-lowering therapy is newly initiated or escalated (dose increase or switch to high-intensity statin) following diagnostic evaluation.	3 months, 12 months, and 5 years
No-Show Rate	Proportion of scheduled diagnostic imaging appointments (CTA or ICA) not attended by the patient without prior cancellation.	3 months and 12 months
Patient acceptance of informed consent, preparation and procedural aspects of the test performed	Patient acceptance of informed consent, preparation, procedural aspects of the tests performed and patient acceptance of the management recommendations.	3 months and 12 months
Gender differences regarding all aspects of medical history	Gender differences regarding all aspects of medical history will be collected at baseline and follow-up. Data will be analysed in regards to occurrence of MACE and MICE in all genders.	Baseline, 3 months and 12 months
Process Evaluation - Intervention (TIDieR Checklist)	TIDieR Checklist is used to describe the complex intervention	Study beginning (planned intervention); End of study (potentially shaped intervention)
Comparison of incidental findings on CT	Analysis of prevalence of a) non-coronary cardiac causes of symptoms (such as aortic dissection, valve disease, pericarditis) or b) non-cardiac causes of symptoms (such as thrombus, pulmonary embolism, pleural effusion, pneumonia, hiatal hernia) on CT in the two randomisation groups.	3 months, 12 months, 5 years
Effects of incidental findings on CT	Influence of non-coronary cardiac and non-cardiac findings on MACE, non-cardiac events and Quality of Life (QoL) measured using EQ-5D-5L in the two randomisation groups.	3 months, 12 months, 5 years
Malignant incidental findings	Rate for malignancy in pulmonary nodules seen on CT (reference standard: biopsy results in the two randomisation groups, Positron Emission Tomography (PET) findings, or progression versus no change or regression on follow-up CT).	3 months, 12 months, 5 years
Rate of death from cancer	Rate of death from cancer in both randomisation groups.	5 years
Rates of unnecessary follow-up procedures.	Composite outcome: Rates of unnecessary follow-up procedures such as examinations, biopsies, or surgeries performed based on non-coronary findings on CT in the two randomisation groups.	3 months, 12 months, 5 years
Analysis of coronary CT site versus core lab and interobserver core lab readings	Analysis of interobserver variability (site vs. core lab and interobserver in the core lab) of reading for the presence of coronary stenosis (obstructive CAD) and plaques on CTA (types, characteristics, volumes etc.).	3 months, 12 months
Association between plaque characterisation and quantification by core lab and MACE	Association between plaque characterisation and quantification by core lab and MACE (with and without inclusion of procedure-related complications).	5 years
Image quality of Computed Tomography by core lab read	Image quality of coronary CT by core lab read (manual and automated): comparison of the two randomisation groups. This analysis involves also an analysis of the heart rate during CT and the use of oral and intravenous betablockers before CTA in the two randomisation groups.	3 months, 12 months, 5 years
Noise in Computed Tomography Angiography	Noise in CTA imaging in the two randomisation groups and the factors it depends on, for instance adherence vs. non-adherence to scan protocol.	3 months, 12 months, 5 years
Aortic valve calcification and fibrosis on CT to predict MACE and need for TAVR or SAVR	Quantitative assessment of aortic valve calcification and fibrosis on CT to predict the occurrence of major adverse cardiovascular events (MACE) and the future need for transcatheter aortic valve replacement (TAVR) or surgical aortic valve replacement (SAVR). This outcome includes the following objectives: 1. To automate the measurement of fibrotic and calcified aortic valve characteristics on CT; 2. To assess the concordance between anatomical fibrocalcific aortic valve thickening and functional haemodynamics as measured by echocardiography, and to predict rapid hemodynamic progression; 3. To develop and validate an integrated patient risk score for predicting clinical outcomes.	3 months, 12 months, 5 years
Correlation of a zero-calcium score by CT and MACE	Analysis of prevalence of MACE in correlation to a calcium score (CS) of zero: the prognostic value of a calcium score of zero.	3 months, 12 months, 5 years
Characterisation of plaques	The characterisation of plaques (type and composition) by CT core lab in relation to cardiac risk factors at baseline in all patients who underwent CT.	baseline
Influence of statin treatment on plaque development.	Risk factors for and influence of statin treatment on plaque progression or regression in patients who had follow-up cardiac CT done.	3 months, 12 months
Gender differences in MACE, procedural complications, and examination results.	Comparison of MACE, procedural complications, and examination results (rate of coronary artery disease, PCI rate adjusted for CAD prevalence, occurrence of adverse events, stress tests used, patient acceptance) in women and men in the two randomisation groups.	3 months, 12 months, 5 years
Age differences in MACE, procedural complications, and examination results.	Comparison of MACE, procedural complications, and examination results (rate of coronary artery disease, PCI rate adjusted for CAD prevalence, occurrence of adverse events, stress tests used, patient acceptance) in both randomisation groups in patient a) under 65 years, b) between 65 and 75 years and c) over 75 years.	3 months, 12 months, 5 years
Differences in MACE, procedural complications, and examination results in patients living with and without diabetes mellitus.	Comparison of MACE, procedural complications, and examination results (rate of coronary artery disease, PCI rate adjusted for CAD prevalence, occurrence of adverse events, stress tests used, patient acceptance) in patients with and without diabetes mellitus in the two randomisation groups.	3 months, 12 months, 5 years
Differences in MACE, procedural complications, and examination results between patients of different body mass index (BMI) groups.	Comparison of MACE, procedural complications, and examination results (rate of coronary artery disease, PCI rate adjusted for CAD prevalence, occurrence of adverse events, stress tests used, patient acceptance) in patients with BMI a) under 25, b) between 25 and 30 and c) over 30 in the two randomisation groups.	3 months, 12 months, 5 years
Differences in MACE, procedural complications, and examination results between patients with different smoking habits.	Comparison of MACE, procedural complications, and examination results (rate of coronary artery disease, PCI rate adjusted for CAD prevalence, occurrence of adverse events, stress tests used, patient acceptance) in patients with different smoking habits (current smokers, current non-smokers, never-smokers) in the two randomisation groups.	3 months, 12 months, 5 years
Differences in MACE, procedural complications, and examination results between patients with quality of life (QoL) reductions versus patients with no changes in QoL.	Comparison of MACE, procedural complications, and examination results (rate of coronary artery disease, PCI rate adjusted for CAD prevalence, occurrence of adverse events, stress tests used, patient acceptance) in patients with significant QoL reductions versus patients with no changes in QoL in the two randomisation groups.	3 months, 12 months, 5 years
Differences in MACE, procedural complications, and examination results between pre- and post-menopausal women.	Comparison of MACE, procedural complications, and examination results (rate of coronary artery disease, PCI rate adjusted for CAD prevalence, occurrence of adverse events, stress tests used, patient acceptance) in pre- and post-menopausal women in the two randomisation groups.	3 months, 12 months, 5 years
Differences in coronary plaque characteristics determined by Computed Tomography in pre- and post-menopausal women.	Differences of coronary plaque characteristics determined by CT including parameters like coronary plaque assessment, including calcified, mixed and non-calcified plaques, remodelling index, ring-sign, spotty calcification in pre- and post-menopausal women.	3 months, 12 months
Differences of epicardial adipose tissue (EAT) characteristics determined by Computed Tomography between pre- and post-menopausal women and association with MACE.	Differences of epicardial adipose tissue characteristics determined by CT including parameters like EAT volume, EAT density, EAT radiomics (adjusted for coronary calcium score, age and body surface area) and their relation to MACE and CAD.	3 months, 12 months
Pretest Probability in patients receiving CTA	Comparison of the pretest probability between the two randomisation groups in patients receiving CTA to determine success of the intervention in regard to indication for CTA.	3 months and 12 months
Updated DISCHARGE calculator	Recalibration of the DISCHARGE calculator based on the results of the trial. Calibration will be done nationwide across Germany and regionally. Both versions will be compared.	3 months, 12 months, 5 years
Prognostic validation of the DISCHARGE Calculator.	The DISCHARGE Calculator is based on the well validated COME-CCT Calculator and was calibrated on the DISCHARGE trial data. However, the prognostic value has not been evaluated so far. For this secondary analysis, we will calculate the rate of MACE and any subset within MACE, stratified by the DISCHARGE Calculator.	3 months, 12 months, 5 years
Bayesian analysis - Differences in rate of MACE and additional secondary outcomes in the two randomization groups.	Bayesian evaluation of the different rates of major adverse cardiovascular events (MACE) and secondary outcomes in the two randomization groups. The primary analysis assesses whether the intervention reduces 12-month MACE compared with standard care in patients with suspected chronic CAD. Secondary outcomes are analysed using Bayesian methods.	12 months
MACE differences between the two randomisation groups depending on if patients were recruited in the primary care setting or in CT centres.	Does recruitment in primary care setting versus in CT centres impact the rate of MACE within the two randomisation groups and between the two randomisation groups?	12 months
Time to Final Diagnosis	Time from first clinical presentation with stable chest pain (recruitment) to documented final diagnostic classification (obstructive CAD, non-obstructive CAD, or no signs of CAD or no need to further investigate as the chest pain is clearly noncardiac) in the two randomisation groups	3 months and 12 months
Documentation of Pre-test Probability	Proportion of patients with documented pre-test probability assessment prior to diagnostic CT and ICA in the two randomisation groups	3 months and 12 months
Documentation of Clinical Decision Rationale	Proportion of patients with documented justification for the selected diagnostic strategy (e.g., CTA-first, functional testing, direct ICA) in the two randomisation groups.	3 months and 12 months
Multistep Diagnostic Pathway Rate	Proportion of patients undergoing more than one sequential non-therapeutic diagnostic tests (e.g., CTA → stress imaging → ICA) in the two randomisation groups.	3 and 12 months
Structured Reporting	Proportion of structured quantitative CTA reports according to QCI consensus statement and the results of the ISCHEMIA trial (no CAD-RADS) in the two randomisation groups.	3 months and 12 months
Inclusion of Patient-Friendly Summary in Imaging Report	Proportion of CTA reports that include a standardised patient-friendly summary explaining results, cardiovascular risk implications, and recommended next steps in plain language in the two randomisation groups.	3 months and 12 months
Geographic Subgroup Analysis of All Study Outcomes by Cluster Region	All primary, secondary, and pre-specified study outcomes will be analysed according to predefined cluster regions within the stepped-wedge design to assess regional heterogeneity of intervention effects in the two randomisation groups.	3 months, 12 months and 5 years
Geographic Subgroup Analysis of All Study Outcomes by Federal State (Bundesland)	All primary, secondary, and pre-specified study outcomes will be analysed across German federal states (Bundesländer) to assess regional heterogeneity of intervention effects in the two randomisation groups.	3 months, 12 months and 5 years
Geographic Subgroup Analysis of All Study Outcomes by Cardinal Region (North, South, East, West)	All primary, secondary, and pre-specified study outcomes will be analysed according to aggregated cardinal regions of Germany (North (Hamburg, Kiel/Lübeck, Göttingen), South (Augsburg, Erlangen, Würzburg/Bad Neustadt, Ulm, Tübingen), East (Rostock/Greifswald, Berlin/Brandenburg, Jena, and Leipzig), and West (Düsseldorf, Wiesbaden/Frankfurt, Marburg/Gießen, Köln) to explore broad geographic variation of intervention effects in the two randomisation groups..	3 months, 12 months and 5 years
Process Evaluation - Context Description	Questionnaire for sociodemographic and characteristics of primary care and CT centres. Interviews regarding contextual factors that shape how the intervention works; and that affect (or may be affected by) implementation, intervention mechanisms and outcomes. Causal mechanisms present within the context which act to sustain the status quo or potentiate effects by comparing the two randomisation groups.	Questionnaire at initiation; Interview/Focusgroup-discussion
Process Evaluation - Implementation (Delivery)	How is delivery achieved; training, resources, etc. Participation of at least 1 person/clinic; Positive online-evaluation (emotion, readiness to present again in the clinic, grading (as in school grades), open feedback, self-evaluated competency in the two randomisation groups.	Ongoing documentation; Online questionnaire after training
Process Evaluation - Implementation/Normalization (Sustainability)	NoMad-survey for long-term implementation (normalisation); Implementation questionnaire and interviews with Elements: Integration in every-day routine, knowledge of guideline, involvement of cardiologists in the two randomisation groups.	End of intervention phase
Process Evaluation - Mechanisms of Impact	Multiple provenances of data and acquisition time-points to test mechanisms of impact: Questionnaire on the use of a pre-test probability calculator; Questionnaire on use of decision aids; Questionnaires on structure of radiology reports; Qualitative experiences of all involved person-groups in the two randomisation groups.	Ongoing
Time to Imaging	Time from first clinical presentation with stable chest pain (recruitment) to first documented diagnostic imaging procedure.	3 months and 12 months
Quantitative coronary artery plaque quantification using AI assisted software	Development and/or testing of an automated coronary artery plaque quantification tool for total plaque volume, calcified plaque volume, and noncalcified plaque volume with high diagnostic accuracy and predictive value for MACE.	3 months, 12 months, and 5 years
Automated High Risk Plaque Quantification	Development and/or testing of an automated high risk plaque (HRP) quantification tool with high diagnostic accuracy and predictive value for MACE.	baseline, 3 and 12 months
Automated cardiac and multi-organ Total Segmentator for imaging biomarker quantification	Development and/or testing of an automated Total Segmentator tool for quantitative imaging biomarker extraction, aiming to achieve high diagnostic accuracy and predictive value for major adverse cardiovascular events (MACE). This includes the development and validation of a dedicated cardiac Total Segmentator for detailed segmentation of cardiac structures, as well as a complementary multi-organ segmentation model to enable integrated assessment of cardiac and extracardiac imaging biomarkers relevant to cardiovascular risk. The approach will evaluate the performance of these models in terms of segmentation accuracy, robustness, and their ability to improve prediction of MACE.	baseline, 3 and 12 months
Interobserver variability in quantitative coronary artery plaque analysis	We aim to determine if the elements of the NVF have an impact on interobserver variability in CT in the intervention phase compared to the control phase by comparing the two randomisation groups.	baseline, 3 and 12 months
Automated segment-based tool for coronary artery calcium (CAC) quantification	Fully automated quantification of coronary artery calcium on CT on the vessel- and segment level, and its prognostic ability for major adverse cardiovascular events (MACE).	baseline, 3 and 12 months
Rate of CABG procedures planned on CT versus planned on ICA	Are there more coronary artery bypass grafting (CABG) procedures being planned on CT (rather than ICA) in the intervention phase compared to the control phase? This will be assessed by the proportion of patients undergoing ICA after CT for planning of CABG.	baseline, 3 and 12 months

Collaborators and Investigators

• Sponsor: Philipps University Marburg
• Collaborators: Gemeinsamer Bundesaussschuss
• Investigators: Principal Investigator: Annika Viniol, Prof. Dr., Philipps-Universität Marburg, Institut für Allgemeinmedizin

Publications and helpful links

General Publications

• DISCHARGE Trial Group; Maurovich-Horvat P, Bosserdt M, Kofoed KF, Rieckmann N, Benedek T, Donnelly P, Rodriguez-Palomares J, Erglis A, Stechovsky C, Sakalyte G, Cemerlic Adic N, Gutberlet M, Dodd JD, Diez I, Davis G, Zimmermann E, Kepka C, Vidakovic R, Francone M, Ilnicka-Suckiel M, Plank F, Knuuti J, Faria R, Schroder S, Berry C, Saba L, Ruzsics B, Kubiak C, Gutierrez-Ibarluzea I, Schultz Hansen K, Muller-Nordhorn J, Merkely B, Knudsen AD, Benedek I, Orr C, Xavier Valente F, Zvaigzne L, Suchanek V, Zajanckauskiene L, Adic F, Woinke M, Hensey M, Lecumberri I, Thwaite E, Laule M, Kruk M, Neskovic AN, Mancone M, Kusmierz D, Feuchtner G, Pietila M, Gama Ribeiro V, Drosch T, Delles C, Matta G, Fisher M, Szilveszter B, Larsen L, Ratiu M, Kelly S, Garcia Del Blanco B, Rubio A, Drobni ZD, Jurlander B, Rodean I, Regan S, Cuellar Calabria H, Boussoussou M, Engstrom T, Hodas R, Napp AE, Haase R, Feger S, Serna-Higuita LM, Neumann K, Dreger H, Rief M, Wieske V, Estrella M, Martus P, Dewey M. CT or Invasive Coronary Angiography in Stable Chest Pain. N Engl J Med. 2022 Apr 28;386(17):1591-1602. doi: 10.1056/NEJMoa2200963. Epub 2022 Mar 4.
• Jung-Henrich J, Schlossler K, Uebel T, Chikhradze N, Suslow A, Lindner N, Fahrenkrog S, Kraft J, Hummers E, Vollmar HC, Gagyor I, Heider D, Konig HH, Donner-Banzhoff N. Development and implementation of a treatment pathway to reduce coronary angiograms - lessons from a failure. BMC Health Serv Res. 2024 Apr 25;24(1):527. doi: 10.1186/s12913-024-10904-5.
• Dewey M, Rief M, Martus P, Kendziora B, Feger S, Dreger H, Priem S, Knebel F, Bohm M, Schlattmann P, Hamm B, Schonenberger E, Laule M, Zimmermann E. Evaluation of computed tomography in patients with atypical angina or chest pain clinically referred for invasive coronary angiography: randomised controlled trial. BMJ. 2016 Oct 24;355:i5441. doi: 10.1136/bmj.i5441.

Helpful Links

• IMPRO - Innovatives Management für Patientinnen und Patienten mit erstmals aufgetretenen stabilen Thoraxschmerzen

Study record dates

Study Major Dates

• Study Start (Actual): April 1, 2026
• Primary Completion (Estimated): March 1, 2028
• Study Completion (Estimated): March 1, 2028

Study Registration Dates

• First Submitted: March 10, 2026
• First Submitted That Met QC Criteria: March 10, 2026
• First Posted (Actual): March 17, 2026

Study Record Updates

• Last Update Posted (Actual): April 7, 2026
• Last Update Submitted That Met QC Criteria: April 1, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: Percutaneous Coronary Intervention; Shared Decision Making; computed tomography; health services research; Coronary Heart Disease; Coronary Angiography; Evidence-Based Practice; Coronary Artery Disease (CAD); stepped-wedge trial; Health Care Quality Assurance
• Additional Relevant MeSH Terms: Vascular Diseases; Cardiovascular Diseases; Heart Diseases; Arteriosclerosis; Arterial Occlusive Diseases; Myocardial Ischemia; Coronary Artery Disease; Coronary Disease
• Other Study ID Numbers: 01NVF24302

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES

IPD Plan Description

Data sharing will be performed through with the GUIDE-IT platform (Guide to Data Sharing of Imaging Trials, www.guideit.org), which will allow access for researcher according to the GUIDE-IT data sharing rules and governance as well as application processes. After completion of the study, pseudonymised data will be made available for scientific reuse. This will comprise clinical data, including clinical endpoints at 3 and 12 months as well as 5 years, and imaging data (cardiac CT scans in DICOM format).

Specifically:

• Demographic data: age category, gender, weight, height.
• Health data: Clinical data (diagnoses, medical history, physical examinations, vital signs, concomitant medication, laboratory parameters, cardiological parameters: ECG, etc.)
• Image data: Computed tomography scans
• Questionnaire data (quality of life (EQ-5-DL), angina (SAQ-7))

• IPD Sharing Time Frame: Data will be shared after completion of the IMPRO study for a maximum period of 30 years.
• IPD Sharing Access Criteria: Access to pseudonymized data will only be granted to those who submit an application to the dissemination committee (members of the consortium leadership of the participating studies). The provided pseudonymized data comprise both clinical data, including clinical endpoints at 3 and 12 months as well as at 5 years, and imaging data (cardiac CT scans in DICOM format). The study proposal must include: The proposed study's overview, rationale, aims and analysis methods, plans for dissemination of results and names of those wishing to access data, and how is the data going to be stored and for how long.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No