The effect of coronary artery bypass grafting on specific causes of long-term mortality in the Bypass Angioplasty Revascularization Investigation

Objectives

We sought to examine the effect of revascularization with coronary artery bypass grafting on specific causes of death in the Bypass Angioplasty Revascularization Investigation cohort. Although the effect of coronary revascularization on long-term mortality has been previously described, there are limited data describing its effect on specific causes of death in patients with coronary artery disease. Evaluation of cause of death might help elucidate disease mechanisms and be useful for developing treatment strategies.

Methods

In the Bypass Angioplasty Revascularization Investigation randomized trial and registry, 3610 patients underwent initial revascularization with coronary artery bypass grafting or balloon angioplasty and were followed for an average of 7.7 years. Causes of all deaths were classified by an independent committee.

Results

Among 3610 revascularized patients, 2239 underwent coronary artery bypass grafting as an initial or subsequent procedure. Over 7.7 years of follow-up, 3% of all patients died of sudden cardiac death, 3% died of myocardial infarction–related death, 2% died of congestive heart failure and other cardiac causes, and 9% died of noncardiac causes. Coronary artery bypass grafting (vs no coronary artery bypass grafting) was associated with a significantly lower risk of sudden cardiac death (relative risk, 0.60; P = .01) but was not significantly associated with any other causes of long-term mortality.

Conclusions

In the Bypass Angioplasty Revascularization Investigation coronary artery bypass grafting significantly decreased the risk of sudden cardiac death but not any other cause of long-term mortality. Because major risk factors for sudden cardiac death have historically favored a revascularization strategy of coronary artery bypass grafting over angioplasty, evaluation of the current practice of extending angioplasty as an alternative to coronary artery bypass grafting in similar high-risk subgroups is paramount.

CTSNet classification: 23, 28

Abbreviations and Acronyms: CABG, coronary artery bypass grafting, CAD, coronary artery disease, CHF, congestive heart failure, CI, confidence interval, ECG, electrocardiography, EF, ejection fraction, MI, myocardial infarction, PCI, percutaneous coronary intervention, PTCA, percutaneous transluminal coronary angioplasty, RR, relative risk