Akershus Cardiac Examination 4 Study (ACE4)

Akershus Cardiac Examination (ACE) 4 Study: Pragmatic Randomized Controlled Trial of Early Biomarker Measurements and Structured Feedback in Unselected Patients With Tachypnea

Patients hospitalized with tachypnea, defined as respiratory rate ≥20/ min, have substantial mortality and may suffer from different conditions, including acute heart failure (HF). Symptoms of HF can be difficult to identify and ~15% of patients with HF will not be correctly diagnosed by the treating physician in the Emergency Department. Biomarkers like B-type natriuretic peptides and cardiac troponins improve diagnostic accuracy and risk stratification. Whether early, structured biomarker assessment and structured feedback in the patient's electronic health records improve management and outcomes among unselected patients with tachypnea have previously not been explored in a randomized controlled trial.

The main research question of the study is to determine whether early structured biomarker assessment in unselected patients with tachypnea extends the time to the first event for either (1) all-cause readmission or (2) all-cause mortality; i.e. time to the combined endpoint, compared to the current strategy/standard care

Study Overview

• Status: Active, not recruiting
• Conditions: Heart Failure; Tachypnea
• Intervention / Treatment: Other: Early biomarker-based cardiological assessment

• Study Type: Interventional
• Enrollment (Actual): 574
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Norway
  • Lørenskog
    • Lørenskog, Lørenskog, Norway, 1478
      • Akershus University Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Patients ≥18 years old
• Tachypnea (respiratory rate ≥20/min)
• Admission to Departments under the Division of Medicine at Akershus University Hospital, except the Department of Neurology
• <24 h from hospital admittance to inclusion in the study
• Signed written informed consent during the initial phase of the hospitalization

Exclusion Criteria:

• Previously included into the study (in case of patients presenting with a second hospitalization during the study period)
• Known or suspected cancer outside of local control, documented in medical records, at the time of patient inclusion or diagnosed in relation to the index hospitalization
• Neurological condition with short life expectancy; e.g. ALS, documented in medical records during screening prior to study entry
• Other non-cardiac disease with life expectancy below 1 year, documented in medical records during screening prior to study entry
• Obvious non-cardiac cause for tachypnea based on medical records and clinical findings during screening prior to study entry; e.g. anaphylaxis in young patient with known allergy, dyspnea after direct chest trauma, or young patient with fever and positive Covid-19 test on admission.
• Patient assessed as non-Internal Medicine patient; e.g. surgical patient
• Patients unwilling or unable to comply with the protocol, including Glasgow Coma Scale <13 on the time of study inclusion
• Patients that are intubated for invasive ventilatory therapy before or shortly after hospital admission
• History of non-compliance to medical management and patients who are considered potentially unreliable, based on documentation in medical records, during screening prior to study entry
• History or evidence of alcohol or drug abuse with the last 12 months, based on medical records and clinical findings during screening prior to study entry, that will influence study participation
• Any surgical or medical condition, based on medical records and clinical findings during screening prior to study entry, that will impair the ability of the patient to participate in the study

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Early biomarker-based cardiological assessment and structured feedback in the EHR; We will perform cardiac biomarker testing with NT-proBNP and hs-cTnT measurements on emergency department admission in all participants, regardless of randomization status. The results will be provided in the patient's EHR, regardless of randomization status. For patients randomized to the intervention group, we will provide a note in the patient's EHR that includes assessment of probability that myocardial injury or dysfunction are the underlying pathophysiology responsible for tachypnea, as evaluated by the cardiac biomarker algorithm of the study. We will inform on general recommendations for work up and treatment.	Other: Early biomarker-based cardiological assessment; We will perform cardiac biomarker testing with NT-proBNP and hs-cTnT measurements on emergency department admission in all participants, regardless of randomization status. The results will be provided in the patient's EHR, regardless of randomization status. For patients randomized to the intervention group, we will provide a note in the patient's EHR that includes assessment of probability that myocardial injury or dysfunction are the underlying pathophysiology responsible for tachypnea, as evaluated by the cardiac biomarker algorithm of the study. We will inform on general recommendations for work up and treatment.
No Intervention: Standard of care; Routine standard of care according to the treating physician

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Composite of all-cause hospital readmission or all-cause mortality	Composite of all-cause hospital readmission or all-cause mortality after discharge from index hospitalization	12 months after discharge from index hospitalization

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Hospital length of stay	Hospital length of stay during the index hospitalization	From admission to discharge of index hospitalization, assessed up to 12 months
Length of stay in Intensive Care Unit/Medical Intensive Care Unit/Cardiac Intensive Care Unit	Length of stay in Intensive Care Unit/Medical Intensive Care Unit/Cardiac Intensive Care Unit during the index hospitalization	From admission to discharge of index hospitalization, assessed up to 12 months
30-day all-cause readmission	30-day all-cause readmission after discharge from index hospitalization	30-days after discharge from index hospitalization
Time to all-cause readmission	Time to first all-cause readmission after discharge from index hospitalization	12 months after discharge from index hospitalization
Number of all-cause readmission	Number of all-cause readmissions after discharge from index hospitalization	12 months after discharge from index hospitalization
All-cause mortality	Time to all-cause mortality after discharge from index hospitalization	12 months after discharge from index hospitalization
Total cost of hospitalization	Total cost of hospitalization	From admission to discharge of index hospitalization, assessed up to 12 months
All-cause mortality	All-cause mortality during the index hospitalization	From admission to discharge of index hospitalization, assessed up to 12 months
Difference in cardiac biomarker concentrations during index hospitalization	Difference in the cardiac troponin T and/or I and B-type natriuretic peptide and/or N-terminal pro-B-type natriuretic peptide concentrations from hospital admission to discharge	From admission to discharge of index hospitalization, assessed up to 12 months
Difference in guideline-defined medical therapy for heart failure	Difference in guideline-defined medical therapy for heart failure, as defined by international guidelines, at discharge after index hospitalization	From admission to discharge of index hospitalization, assessed up to 12 months
Cost-utility	Cost-utility for the intervention strategy	From admission to discharge of index hospitalization, assessed up to 12 months

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Assessing primary and secondary outcomes with patients stratified by concentrations of NT-proBNP measured at admission	We will assess all the primary and secondary outcomes of the study in patients stratified according to concentrations of NT-proBNP (< 300 ng/L, 300-449ng/L, 450-899ng/L, 900-1799ng/L, >1799ng/L) measured at admission of the index hospitalization	From admission to discharge of index hospitalization, assessed up to 12 months
Assessing primary and secondary outcomes with patients stratified by concentrations of cardiac troponin T measured at admission	We will assess all the primary and secondary outcomes of the study in patients stratified according to concentrations of cardiac troponin T (<10ng/L, 10-89ng/L), >89ng/L) measured at admission of the index hospitalization	From admission to discharge of index hospitalization, assessed up to 12 months
Assessing accuracy for HF2FPEF score assessed during index hospitalization for diagnosing heart failure with preserved ejection fraction	Using c-statistics, we will assess the diagnostic accuracy of the H2FPEF score assessed during index hospitalization to predict heart failure with preserved ejection fraction in the total cohort of study patients	From admission to discharge of index hospitalization, assessed up to 12 months
Assessing accuracy for HFA-PEFF score for diagnosing heart failure with preserved ejection fraction	Using c-statistics, we will assess the diagnostic accuracy of the HFA-PEFF score assessed during index hospitalization to predict heart failure with preserved ejection fraction in the total cohort of study patients	From admission to discharge of index hospitalization, assessed up to 12 months
Assessing accuracy for NT-proBNP measured at hospital admission for diagnosing heart failure with preserved ejection fraction	Using c-statistics, we will assess the diagnostic accuracy of continuous concentrations of NT-proBNP measured at hospital admission to predict heart failure with preserved ejection fraction in the total cohort of study patients	From admission to discharge of index hospitalization, assessed up to 12 months
Assessing accuracy for cardiac troponin T measured at hospital admission for diagnosing heart failure with preserved ejection fraction	Using c-statistics, we will assess the diagnostic accuracy of continuous concentrations of cardiac troponin T measured at hospital admission to predict heart failure with preserved ejection fraction in the total cohort of study patients	From admission to discharge of index hospitalization, assessed up to 12 months
Assessing primary and secondary outcomes in the subgroup of patients classified as hospitalized due to heart failure	We will assess all the primary and secondary outcomes of the study in the subgroup of patients with heart failure as the adjudicated cause of tachypnea.	From admission to discharge of index hospitalization, assessed up to 12 months
Assessing primary and secondary outcomes in the subgroups of patients with heart failure with reduced ejection fraction, heart failure with mildly reduced ejection, and heart failure with preserved ejection fraction	We will assess all the primary and secondary outcomes of the study in the subgroups of patients with heart failure with reduced ejection fraction, heart failure with mildly reduced ejection, and heart failure with preserved ejection fraction as the adjudicated cause of tachypnea.	From admission to discharge of index hospitalization, assessed up to 12 months

Collaborators and Investigators

• Sponsor: University Hospital, Akershus
• Collaborators: University of Oslo
• Investigators: Principal Investigator: Magnus N Lyngbakken, MD PhD, University Hospital, Akershus

Study record dates

Study Major Dates

• Study Start (Actual): March 3, 2023
• Primary Completion (Actual): March 20, 2025
• Study Completion (Estimated): December 1, 2038

Study Registration Dates

• First Submitted: January 5, 2023
• First Submitted That Met QC Criteria: January 24, 2023
• First Posted (Actual): January 26, 2023

Study Record Updates

• Last Update Posted (Actual): April 28, 2026
• Last Update Submitted That Met QC Criteria: April 23, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: biomarker; echocardiography; heart failure; tachypnea
• Additional Relevant MeSH Terms: Cardiovascular Diseases; Heart Diseases; Respiratory Tract Diseases; Respiration Disorders; Signs and Symptoms, Respiratory; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Heart Failure; Tachypnea
• Other Study ID Numbers: 2015/1273

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

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