August 1, 1992Open Access
View Full PaperEffect of completeness of revascularization on long-term outcome of patients with three-vessel disease undergoing coronary artery bypass surgery. A report from the Coronary Artery Surgery Study (CASS) Registry.
Key Result
Complete revascularization (grafts to ≥3 vessels) improved 6-year survival compared to 2 vessels in patients with severe angina and ejection fraction <0.35 (69% vs 45%, p=0.04).
Study Design
Type
Cohort (n=3,372)
Multicenter
Yes
Structured PICO
Does complete revascularization improve survival and event-free survival in patients with three-vessel coronary disease undergoing coronary artery bypass surgery?
P
Population
3,372 nonrandomized surgical patients from the Coronary Artery Surgery Study (CASS) Registry with three-vessel coronary disease undergoing coronary artery bypass surgery. Group 1 (n=894) had class I or II angina; Group 2 (n=2,478) had class III or IV angina.
I
Intervention
Complete revascularization (grafts to three or more vessels)
C
Comparator
Incomplete revascularization (grafts to one or two vessels)
O
Outcome
Survival and event-free survival (composite of death, myocardial infarction, definite angina, or reoperation)composite
Complete revascularization during CABG in patients with three-vessel disease provides the greatest survival and event-free survival benefits to those with severe angina and left ventricular dysfunction.
Main Result
Absolute Event Rate: 69% vs 45%
p-value: p=0.04
Abstract
BACKGROUND: Complete revascularization after coronary artery bypass surgery is a logical goal and improves symptomatic outcome and survival. However, the impact of complete revascularization in patients with three-vessel coronary disease with varying severities of angina and left ventricular dysfunction has not been clearly defined. METHODS AND RESULTS: The study was performed as a retrospective analysis of 3,372 nonrandomized surgical patients from the Coronary Artery Surgery Study (CASS) Registry who had three-vessel coronary disease. Group 1 (894 patients) had class I or II angina (Canadian Cardiovascular Society criteria) and group 2 (2,478 patients) had class III or IV angina. In group 1, adjusted cumulative 4-year survivals according to the number of vessels bypassed were 85% (one vessel), 94% (two vessels), 96% (three vessels), and 96% (more than three vessels) (log rank, p = 0.022). Adjusted event-free survival (death, myocardial infarction, definite angina, or reoperation) was not influenced by the number of vessels bypassed, nor was the anginal status among patients remaining alive after 5 years. In group 2, adjusted cumulative 5-year survivals were 78% (one vessel), 85% (two vessels), 90% (three vessels), and 87% (more than three vessels) (log rank, p = 0.074). Adjusted event-free survivals after 6 years were 23% (one vessel), 23% (two vessels), 29% (three vessels), and 31% (more than three vessels) (p = 0.025); at 5 years, those with more complete revascularization were more likely to be asymptomatic or free of severe angina. Among group 2 patients with ejection fractions less than 0.35, 6-year survival was 69% for those with grafts to three or more vessels versus 45% for those with grafts to two vessels (p = 0.04). Placing grafts to three or more vessels was independently associated with improved survival and event-free survival in group 2 but not group 1 patients. The case-fatality rates among 529 patients experiencing a myocardial infarction during follow-up was significantly higher for patients with less complete revascularization. CONCLUSIONS: Complete revascularization (grafts to three or more vessels) in patients with three-vessel coronary disease appears to most benefit those with severe angina and left ventricular dysfunction.