A substantial proportion of patients with congestive heart failure of ischemic origin will benefit from revascularization. Much evidence now supports the use of coronary artery bypass grafting (CABG) in such patients, who fall into two main groups:
Patients with instrumental or clinical evidence of ischemia. Randomized trials of medical vs surgical treatment in myocardial ischemia (mainly stable angina) show an inverse relationship between the survival benefit of CABG and preoperative left ventricular function: the poorer the ventricular function, the greater the benefit. Although these trials have included few patients with an ejection fraction <40% and none with heart failure, it seems reasonable to assume that patients with systolic dysfunction will also benefit.
Patients with viable myocardium. There is increasing evidence that revascularization in such patients pro-
Louie HW, Laks H, Milgalter E, et al. Ischemic cardiomyopathy. Criteria for coronary revascularization and cardiac transplantation. Circulation. 1991 ;84 (Suppl):lll290-lll295.
Pasquet A, Robert A, D Hondt AM, Dion R, Melin JA, Vanover-schelde JL Prognostic value of myocardial ischemia and viability in patients with chronic left ventricular ischemic dysfunction. Circulation. 1999;100:141 -148. Picano E, Sicari R, Landi P, et al. Prognostic value of myocardial viability in medically treated patients with global left ventricular dysfunction early after an acute uncomplicated myocardial infarction: a dobutamine stress echocardiographic study. Circulation. 1998;98:1078-1084.
Ivides a significantly better prognosis than medical therapy. The negative prognostic impact of a low preoperative ejection fraction is also significantly reduced if substantial viable myocardium can be demonstrated before surgery. Even so, the level of evidence supporting revascularization in heart failure patients with viable myocardium remains rather low, according to the recently published guidelines (2001). As stated in the analysis by the United States Society of Thoracic Surgeons database (www.ctsnet.org/doc/4743), a strong negative correlation remains between operative mortality and left ventricular ejection fraction. Strict preoperative risk stratification before surgery is mandatory.
In patients with severe left ventricular dysfunction, post-CABG survival is similar to that after heart transplantation. Off-pump revascularization and percutaneous angioplasty may lower the risks of the revascularization procedure. Controlled trials on this issue are pending.
Remme WJ, Swedberg K. Guidelines for the diagnosis and treatment of chronic heart failure. Task Force for the Diagnosis and Treatment of Chronic Heart Failure, European Society of Cardiology. Eur Heart J. 2001 ;22:1527-1560. Sicari R, Ripoii A, Picano E, et ai. The prognostic value of myocardial viability recognized by low dose dipyridamole echocardiography in patients with chronic ischaemic left ventricular dysfunction. Eur Heart J. 2001;22:837-844. Yusuf S, Zucker D, Peduzzi P, et al. Effect of coronary artery bypass graft surgery on survival: overview of 10-year results from randomised trials by the Coronary Artery Bypass Surgery Trialists Collaboration. Lancet. 1994;344:563-570.
management; surgical revascularization; myocardial viability; coronary artery bypass grafting