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

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ClinicalTrials.gov Identifier: NCT02802579
Recruitment Status : Completed
First Posted : June 16, 2016
Last Update Posted : June 17, 2016
Sponsor:
Information provided by (Responsible Party):
Sebastian Leschka, MD, Cantonal Hospital of St. Gallen

Brief Summary:
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.

Condition or disease Intervention/treatment Phase
Obesity, Morbid Radiation: standard protocol Radiation: enhanced protocol Radiation: enhanced obesity protocol Not Applicable

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?

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 70 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple (Participant, Care Provider, Outcomes Assessor)
Primary Purpose: Diagnostic
Official Title: ECG Triggered Dual Source CT for Non-invasive Pre-operative Cardiac Imaging in Morbid Obese Patients
Study Start Date : December 2007
Actual Primary Completion Date : December 2015
Actual Study Completion Date : December 2015

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 Name: 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 Name: 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 Name: dual source computed tomography coronary angiography




Primary Outcome Measures :
  1. Image quality [ Time Frame: 7 days ]

    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) :

    1. = excellent;
    2. = good, minor artifacts;
    3. = fair, moderate artifacts but still diagnostic;
    4. = non-diagnostic

  2. coronary artery stenosis [ Time Frame: 7 days ]
    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.


Secondary Outcome Measures :
  1. Image noise [ Time Frame: 7 days ]
    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.

  2. Signal-to-noise ratio (SNR) [ Time Frame: 7 days ]
    SNR was determined by dividing mean attenuation by image noise

  3. contrast-to-noise ratio (CNR) [ Time Frame: 7 days ]
    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).

  4. Major adverse cardiovascular events (MACE) [ Time Frame: 7 years ]

    Any of the following events:

    • death
    • non fatal myocardial infarction
    • late revascularization with percutaneous coronary intervention
    • coronary artery bypass grafting



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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Criteria

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

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT02802579


Locations
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Switzerland
Cantonal Hospital St Gallen
St. Gallen, Switzerland, 9007
Sponsors and Collaborators
Cantonal Hospital of St. Gallen
Investigators
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Principal Investigator: Sebastian Leschka, MD Cantonal Hospital St. Gallen

Publications:
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Responsible Party: Sebastian Leschka, MD, Attending Physician, Cantonal Hospital of St. Gallen
ClinicalTrials.gov Identifier: NCT02802579     History of Changes
Other Study ID Numbers: RAD0701
First Posted: June 16, 2016    Key Record Dates
Last Update Posted: June 17, 2016
Last Verified: June 2016
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No
Keywords provided by Sebastian Leschka, MD, Cantonal Hospital of St. Gallen:
obesity
dual source CT
coronary CT angiography
prognosis
bariatric surgery
gastric bypass surgery
coronary arterial disease
major adverse coronary event
Additional relevant MeSH terms:
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Obesity, Morbid
Obesity
Overnutrition
Nutrition Disorders
Overweight
Body Weight
Signs and Symptoms