Early and five-year results for coronary artery bypass grafting. A benchmark for percutaneous transluminal coronary angioplasty

Abstract

Patients currently undergoing coronary artery bypass grafting will likely have worse early and late results because of the selection of patients with fewer risk factors for percutaneous transluminal coronary angioplasty. Therefore, until the results of randomized prospective studies are available, angioplasty should also be compared to bypass grafting before the era of angioplasty to facilitate current comparison with bypass grafting. To obtain these data, I analyzed 500 consecutive patients (aged 33 to 79 years [58 +/- 10 SD], 20% [100/500] female, and 60% [300/500] with three vessel disease) undergoing first-time coronary bypass without associated procedures between late 1976 and mid-1980. Intermittent aortic cross-clamping (for each distal graft) was used for revascularization of all arteries 1.0 mm in internal diameter or larger with stenoses of 50% or greater. This strategy resulted in complete revascularization in 99.8% of patients, averaging 3.2 +/- 1.2 distal grafts per patient. The hospital mortality rate was 0.2% (1/500). The incidence of low output syndrome necessitating pressors (0.8%) or intraaortic balloon pump support (0.2%) was 1% (5/500). Perioperative myocardial infarction rate based on new Q waves was 2.2% (11/500). All but three patients (99.4%) were contacted at 5 years or later with respect to repeat coronary bypass or angioplasty and survival. The survival rate at 5 years, including hospital deaths, was 92.7% +/- 1.2% (70% confidence limits) for cardiac deaths, 89.8% +/- 1.4% for all deaths, and 89.8% +/- 1.4% for all deaths plus three patients lost to follow-up. Approximately 40 factors were screened univariately to determine their effect on survival and survival free from repeat intervention. Multivariate analysis revealed, as in other series, that decreased left ventricular function (ejection fraction less than 50%) was the predominant determinant of decreased 5-year survival for both cardiac death and total mortality. At 5 years, the freedom from reintervention was 97.7% +/- 0.7%. Factors associated with repeat intervention were younger age (52 +/- 11 years versus 58 +/- 10, p less than 0.05) and fewer grafts (2.3 +/- 1.0 versus 3.3 +/- 1.2, p less than 0.01) because of less severe disease (three vessel disease 31% versus 60%, p less than 0.05). These results provide a benchmark for angioplasty which should attain a hospital mortality rate of under 1%, a periprocedure myocardial infarction rate under 3%, and a 5-year survival rate of approximately 90% with more than 95% of survivors free of repeat intervention in unselected patients, not cohorts with primarily single vessel disease.