Isolated bypass grafting of the left internal thoracic artery to the left anterior descending coronary artery: Late consequences of incomplete revascularization

Objective: Multiple strategies to achieve some degree of myocardial revascu larization are available. In some, less complete revascularization is accep ted to limit invasiveness. To examine the issues of incomplete revasculariz ation, we assessed the long-term impact of additional non-left anterior des cending coronary artery stenoses in patients undergoing only grafting of th e left internal thoracic artery to the left anterior descending coronary ar tery. Methods: A total of 2067 patients underwent primary isolated grafting of th e left internal thoracic artery to the left anterior descending coronary ar tery from 1971 to 1997. Of these, 26% and 13% had 2- and 3-system disease, respectively. Multivariable analyses of survival and reintervention were pe rformed in the hazard function domain for 27,683 patient-years of follow-up (mean 14 +/- 6.7). Results: Survival was 99%, 88%, and 62% at 1, 10, and 20 years. Right coron ary artery or left circumflex system disease of 50% or more (P = .02) and p articularly high-grade (greater than or equal to 70%) left circumflex (P = .01) and proximal right coronary artery disease (P = .01), as well as any d egree of left main trunk stenosis (P < .0001), were associated with reduced long-term survival. Compared with 75% 20-year survival in patients with no non-left anterior descending disease, those with either left circumflex or left main trunk disease experienced a 44% survival, and those with proxima l right coronary artery disease, 42%. The most common stated reason for inc omplete revascularization was small vessel size. Freedom from reinterventio n was 89% and 65% at 10 and 20 years, respectively. High-grade left main tr unk disease, but, in contrast, mid or distal disease of the right coronary artery, and not left circumflex disease, were risk factors for reinterventi on, Conclusions: These findings call into question the long-term appropriatenes s of interventions whose strategy includes leaving unrevascularized segment s in territories not in the distribution of the left anterior descending co ronary artery.