Impact of Cholesterol Level on Long-term Coronary Bypass Graft Patency

Chinese University of Hong Kong

Overview

This single-centre cross-sectional study aims to ascertain the impact of dyslipidemia on long-term graft patency after coronary artery bypass grafting (CABG).

All consecutive patients who underwent CABG from 1st January 2007 to 31st December 2008 at the Prince of Wales Hospital were eligible for entry. Graft patency will be determined by computed tomography coronary angiogram. The severity of stenosis will be classified by the Fitzgibbon classification system. The levels of individual lipid profile subcomponents, namely LDL-C, high-density lipoprotein cholesterol (HDL-C), total cholesterol and triglycerides (TG) will be obtained. A plot of lipid profile subcomponent measurements against time will be compiled and the area under the curve is calculated to estimate gross exposure after CABG. Average lipid exposure is calculated by dividing the gross exposure by the number of days lapsed between the first and last lipid profile measurements. The association between average cholesterol target attainment and graft patency will then be determined.

Study Type

OBSERVATIONAL

Conditions

Coronary Artery Disease Bypass Graft Stenosis Dyslipidemias Bypass Graft Occlusion Coronary Bypass Graft Stenosis Coronary Artery Stenosis Hyperlipidemia Hypercholesterolemia

Interventions

Computed tomography coronary angiogramRADIATION

Preparation * Rate control with oral beta-blockers or calcium channel blockers to achieve the target heart rate of 60 to 70 beats per minute * Sublingual Nitroglycerin to be given on table if not contraindicated, 5 minutes prior to scanning * 18G angiocath at a large antecubital vein for intravenous contrast injection Scanning procedure Contrast CT angiogram (Retrospective gating) * Contrast medium and injection protocol: 75ml Omnipaque 350 with 50ml saline chaser * Automatic triggering started at the aorta of the level of left main coronary artery when the relative reached 100 * Scanning coverage: From the thoracic inlet to diaphragm

Eligibility

Sex: ALLMin age: 18 Years

Medical Language ↔ Plain English

Inclusion Criteria: \- All consecutive patients on record who underwent coronary artery bypass graft surgery in 2007 and 2008 Exclusion Criteria: * Death * Single vessel LIMA-LAD anastomosis only * Concomitant valve and aortic procedures * Concomitant repair of post-infarct ventricular septal rupture * Defaulted follow-up * Informed consent cannot be obtained * Intermediate to high risk for contrast nephropathy, defined as estimated glomerular filtration rate less than 45 ml/min/1.73m2 or serum creatinine level \<1.5 mg/dL (based on American College of Radiology criteria for diagnostic computed tomography risk) * Pregnancy

Locations (1)

Prince of Wales Hospital

Hong Kong, Hong Kong

Outcomes

Primary Outcomes

Graft patency

Graft patency as assessed by computed tomographic coronary angiogram, using Fitzgibbon classification

Time frame: Immediately after CTCA

Secondary Outcomes

Actuarial cardiac events

Events attributable to cardiac causes as adjudicated by the investigators, including congestive heart failure, ischaemic cardiomyopathy, myocardial infarction, ventricular arrhythmias, recurrent angina

Time frame: Immediately after CTCA

Data from ClinicalTrials.gov

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