Extensive endarterectomy of the left anterior descending coronary artery combined with coronary artery bypass grafting.

BACKGROUND

Complete revascularization of a diffusely diseased left anterior descending (LAD) coronary artery can be accomplished by extensive endarterectomy in conjunction with coronary artery bypass grafting (CABG). The present study was designed to assess the safety of the procedure, and which techniques lead to the best short- and long-term results.

METHODS

Between January 1990 and October 1994 106 patients underwent extensive open endarterectomy of the LAD coronary artery combined with CABG at our institution. This group constituted 4.9% of all patients undergoing CABG during this period. The mean age of those studied was 64.4 +/- 9.2 years and 92% were male. In 22 patients (21%) the procedure was a repeat CABG and 12% had had percutaneous transluminal coronary angioplasty prior to the operation. Ninety-one per cent of the patients were in Canadian Cardiovascular Society (CCS) angina class 3 or 4, 91% had three-vessel disease and 36% had unstable angina at the time of surgery. The mean preoperative left ventricular ejection fraction was 53.6 +/- 14.9% (range, 15-80%). The internal mammary artery (IMA) was used to bypass the LAD coronary artery in 40 patients (38%) and a saphenous vein graft (SVG) was used in 66 patients. In 25 of the IMA bypass group an additional venous patch was used (IMA+P).

RESULTS

The overall mortality rate was 9.4% (10 patients), including seven immediate postoperative deaths. When the IMA was used as a conduit the mortality rate was only 5.0%. There were seven (6.6%) postoperative non-fatal myocardial infarctions. There was a low incidence of other postoperative complications, similar to that following CABG without endarterectomy performed during the same period. Multivariate analysis identified emergency operation, two-vessel endarterectomy and female sex as independent risk factors for mortality. Upon follow-up study of 94 hospital survivors (98%), at a mean of 26.5 months (range, 1-48 months), all endarterectomy patients were in CCS class 1 or 2. Seventy-eight patients (83%) had an excellent postoperative exercise tolerance and the left ventricular function was preserved. The 4-year survival rates were 88% and 96% and the cardiac event-free survival rates were 74% and 87% in the SVG and IMA groups respectively.

CONCLUSIONS

Complete revascularization of the diffusely diseased LAD coronary artery can be accomplished by adjunctive open endarterectomy with a degree of operative risk (mortality 9% and incidence of non-fatal myocardial infarction 7%). The immediate and medium-term results are improved when the IMA is used as a conduit, with or without additional venous patch. Independent risk factors for mortality were two-vessel endarterectomy, female sex and emergency operation. The long-term results revealed an overall survival rate of 92% and a cardiac event-free survival rate of 79% at 4 years, as well as excellent functional results.