ECG Triggered Dual Source CT for Non-invasive Pre-operative Cardiac Imaging in Morbid Obese Patients

Coronary arterial disease is a risk factor for bariatric surgery and might be a predictor for later major adverse coronary events. Diagnosis of coronary arterial disease would thus be desirable for obese patients, however percutaneous angiography is an invasive procedure and associated with a certain morbidity in obese patients. In this study the investigators would like to assess whether dual source CT angiography can be used for diagnosis of coronary arterial disease in severely obese patients and which settings yield the best image quality.

Study Overview

• Status: Completed
• Conditions: Obesity, Morbid
• Intervention / Treatment: Radiation: standard protocol; Radiation: enhanced protocol; Radiation: enhanced obesity protocol

Detailed Description

Obesity is a major health problem in many countries and a major risk factor for cardiovascular disease. Extreme obesity can be treated with surgery, however these procedures are associated with a certain surgery-related morbidity which increases with comorbidities, in particular coronary diseases. Thus, preoperative cardiac risk assessment would be desirable, however percutaneous coronary angiography is an invasive procedure with problems and complications in obese patients. A non-invasive alternative would be coronary dual-.source CT angiography (CCTA), however little experience exists in the application of CCTA in morbid obese patients. This study would like to address the following issues:

1. Comparison of image quality of coronary CT angiography using a dual source CT from obese patients using a special protocol (140 kV, 350 mAs) with images from historical controls from normal weight patients with a standard protocol (120 kV, 330 mAs).
2. Prediction of major adverse coronary events. Patients with a coronary stenosis in CCTA will be followed for any major adverse coronary events (details see Outcomes)
3. Is it possible to detect myocardial fat by a reduced CT density. Images from obese patients will be compared to historical controls from normal patients. Furthermore, is the myocardial CT density correlated with the BMI of obese patients?
4. Optimisation of scan protocol. Increasing the scanning angle beyond the standard 90° will reduce the signal noise at the cost of temporal resolution. Various scanning angles with be tested for an optimal combination of signal noise and temporal resolution.
5. Does the long QT-syndrome improve after bariatric surgery? It is assumed that the long QT-syndrome is a consequence of fattening of the myocardia. Is it possible to see a reduction of myocardial fattening and thus an improvement of the long QT-syndrome with CT during the follow-up after bariatric surgery?

• Study Type: Interventional
• Enrollment (Actual): 70
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Switzerland
  • St. Gallen, Switzerland, 9007
    • Cantonal Hospital St Gallen

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• morbid obesity (BMI >35 kg/m²)
• intention to undergo bariatric surgery
• increased risk for coronary artery disease (based on PROCAM score)

Exclusion Criteria:

• kidney insufficiency (serum creatinine >100 µmol/l, creatinine clearance <50 ml/min)
• allergy to iodine containing contrast agents
• hyperthyroidism
• metformin medication
• pregnancy

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: A: standard protocol; Standard dual-source computed tomography coronary angiography protocol	Radiation: standard protocol; tube voltage: 120 kV current time product: 350 mAs/rotation rotation: 90° (with two detectors in a 90° angle); Other Names: dual source computed tomography coronary angiography
Experimental: B: enhanced protocol; enhanced dual-source computed tomography coronary angiography protocol	Radiation: enhanced protocol; tube voltage: 140 kV current time product: 350 mAs/rotation rotation: 90° (with two detectors in a 90° angle); Other Names: dual source computed tomography coronary angiography
Experimental: C: enhanced obesity protocol; enhanced obesity-mode dual-source computed tomography coronary angiography protocol	Radiation: enhanced obesity protocol; tube voltage: 140 kV current time product: 350 mAs/rotation rotation: 180° (with two detectors in a 90° angle); Other Names: dual source computed tomography coronary angiography

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Image quality	Coronary arteries (with at least 1 mm diameter at their origin) were segmented according to the 15-segment model of the American Heart Association (Austen 1975). Subjective image quality was judged for each coronary artery segment on a 4-point scale (Leschka 2007) : = excellent;; = good, minor artifacts;; = fair, moderate artifacts but still diagnostic;; = non-diagnostic	7 days
coronary artery stenosis	Significant coronary artery stenosis was defined as more than 50% narrowing of luminal diameter. Stenosis assessment was performed by a radiologist not involved in image quality assessment.	7 days

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Image noise	Image noise was determined as the standard deviation of the attenuation value in a region of 1 sq cm that was placed in the ascending aorta. The average of the attenuation in the left and right coronary artery were used for further calculations.	7 days
Signal-to-noise ratio (SNR)	SNR was determined by dividing mean attenuation by image noise	7 days
contrast-to-noise ratio (CNR)	Vessel contrast was calculated as the difference in the mean attenuation (in Hounsfield units) between the contrast-enhanced vessel lumen and the mean attenuation in the adjacent perivascular tissue. Attenuations were measured in a region in the proximal segment of the right coronary artery and in the left main artery, and were defined as large as possible, whereas avoiding calcifications and plaques. CNR was calculated as vessel contrast divided by image noise (Husmann 2006, Lembcke 2004).	7 days
Major adverse cardiovascular events (MACE)	Any of the following events: death; non fatal myocardial infarction; late revascularization with percutaneous coronary intervention; coronary artery bypass grafting	7 years

Collaborators and Investigators

• Sponsor: Cantonal Hospital of St. Gallen
• Investigators: Principal Investigator: Sebastian Leschka, MD, Cantonal Hospital St. Gallen

Publications and helpful links

General Publications

• Austen WG, Edwards JE, Frye RL, Gensini GG, Gott VL, Griffith LS, McGoon DC, Murphy ML, Roe BB. A reporting system on patients evaluated for coronary artery disease. Report of the Ad Hoc Committee for Grading of Coronary Artery Disease, Council on Cardiovascular Surgery, American Heart Association. Circulation. 1975 Apr;51(4 Suppl):5-40. doi: 10.1161/01.cir.51.4.5. No abstract available.
• Leschka S, Scheffel H, Desbiolles L, Plass A, Gaemperli O, Valenta I, Husmann L, Flohr TG, Genoni M, Marincek B, Kaufmann PA, Alkadhi H. Image quality and reconstruction intervals of dual-source CT coronary angiography: recommendations for ECG-pulsing windowing. Invest Radiol. 2007 Aug;42(8):543-9. doi: 10.1097/RLI.0b013e31803b93cf.
• Husmann L, Alkadhi H, Boehm T, Leschka S, Schepis T, Koepfli P, Desbiolles L, Marincek B, Kaufmann PA, Wildermuth S. Influence of cardiac hemodynamic parameters on coronary artery opacification with 64-slice computed tomography. Eur Radiol. 2006 May;16(5):1111-6. doi: 10.1007/s00330-005-0110-4. Epub 2006 Jan 28.
• Lembcke A, Wiese TH, Schnorr J, Wagner S, Mews J, Kroencke TJ, Enzweiler CN, Hamm B, Taupitz M. Image quality of noninvasive coronary angiography using multislice spiral computed tomography and electron-beam computed tomography: intraindividual comparison in an animal model. Invest Radiol. 2004 Jun;39(6):357-64. doi: 10.1097/01.rli.0000123316.10765.6c.

Study record dates

Study Major Dates

• Study Start: December 1, 2007
• Primary Completion (Actual): December 1, 2015
• Study Completion (Actual): December 1, 2015

Study Registration Dates

• First Submitted: June 14, 2016
• First Submitted That Met QC Criteria: June 14, 2016
• First Posted (Estimate): June 16, 2016

Study Record Updates

• Last Update Posted (Estimate): June 17, 2016
• Last Update Submitted That Met QC Criteria: June 16, 2016
• Last Verified: June 1, 2016

More Information

Terms related to this study

• Keywords: obesity; prognosis; bariatric surgery; dual source CT; coronary CT angiography; gastric bypass surgery; coronary arterial disease; major adverse coronary event
• Additional Relevant MeSH Terms: Overnutrition; Nutrition Disorders; Overweight; Body Weight; Obesity; Obesity, Morbid
• Other Study ID Numbers: RAD0701

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
• product manufactured in and exported from the U.S.: No