Reoperative coronary artery bypass surgery. Improved preservation of myocardial function with retrograde cardioplegia.

BACKGROUND

Cardiac-related mortality remains high for reoperative coronary artery bypass graft surgery (rCABG) compared with first-time surgery (fCABG). Retrograde cardioplegia (RC) has been suggested but not proven to improve the results for rCABG.

METHODS AND RESULTS

We therefore reviewed the records of 240 consecutive patients who had undergone rCABG at our institution since 1988. The interval to reoperation was 9.1 +/- 4.2 years (mean +/- SD), with a range from 0.2 to 18 years. Only 46% of grafts were patent at the time of rCABG. The incision to cardiopulmonary bypass (CPB), incision to cross-clamp (XCL), and XCL per graft time intervals were significantly prolonged compared with 100 consecutive fCABG patients operated on during the same time period. Blood utilization was also significantly increased in rCABG compared with fCABG patients. Overall operative mortality was 5.8% and 0% for rCABG and fCABG patients, respectively (P < .05). High-risk criteria (emergency surgery, angina at rest requiring intravenous nitroglycerin or intra-aortic balloon pump [IABP] support [urgent surgery], recent [<21 days] myocardial infarction, or ejection fraction < 30%) were noted in 136 rCABG patients (57%) and 28 fCABG patients (28%) (P < .001). Profound postoperative myocardial dysfunction (postoperative IABP dependence) occurred in only one of 104 low-risk patients (1%), compared with 14 of 136 high-risk patients (10%) (P < .005). Operative mortality was noted in 13 high-risk patients (9.5%) compared with one low-risk patient (1%) (P < .005). RC was used in 80 patients without complication. Postoperative IABP dependence developed in only 2 of 53 high-risk/RC patients (3.8%) compared with 12 of 83 high-risk/non-RC patients (14.5%) (P < .05). At follow-up, rCABG and fCABG patients enjoyed similar symptomatic improvement.

CONCLUSIONS

We conclude that retrograde cardioplegia, possibly by minimizing the increased ischemia associated with rCABG, improves the results of rCABG, specifically in regard to preventing profound myocardial dysfunction in high-risk patients.