Survival results of postoperative coronary angiogram for treatment of perioperative myocardial ischaemia following coronary artery bypass grafting: a single-centre experience

Abstract

Objectives: Although perioperative myocardial ischaemia (PMI) is a well-known complication following coronary artery bypass grafting (CABG), standard strategies for its diagnosis and treatment are so far not defined. In this study, we sought to evaluate the impact on survival of postoperative coronary angiogram for management of patients with PMI after CABG.

Methods: Overall, 4028 patients underwent isolated CABG in a single-centre institution between January 2006 and September 2013. A total of 168 (4.2%) patients received postoperative coronary angiogram because of diagnosis of PMI. These patients were matched on the basis of gender, age at surgery and date of surgery, with 336 (1:2 ratio) CABG patients without PMI to determine the impact of the PMI management.

Results: A total of 476 grafts were examined (263 venous grafts, 196 internal mammary artery grafts and 17 radial artery grafts). Almost three-quarters of the 168 PMI (74.4%) patients underwent postoperative coronary angiogram within 24 h of surgery. Normal postoperative coronary angiogram, graft failure and new native vessels occlusion were observed in 23.2%, 52.4% and 24.4% of patients, respectively. A total of 30 (17.9%) patients underwent surgical revision of grafts, whereas 60 (35.7%) patients were treated with percutaneous coronary intervention. Eighteen (10.7%) PMI patients died during the hospital stay compared with 6 (1.8%) patients in the non-PMI group. Survival rates at 7 years were 62.5% in the PMI group and 81.1% in non-PMI group (P < 0.001). After multivariable adjustment PMI (P < 0.001; hazard ratio 3.17, 95% confidence interval 2.12-4.73) turned out to be an independent predictor of mortality on follow-up. Moreover, further subanalysis revealed that delayed postoperative coronary angiogram (>24 h after surgery) was an independent predictor of poorer mid-term survival (P = 0.008; hazard ratio 3.62, 95% confidence interval 1.41-9.33).

Conclusions: PMI after CABG is associated with a significantly poorer survival. A prompt postoperative management must always be considered. Further prospective studies are required to confirm our results.

Keywords: Coronary artery bypass grafting; Coronary artery disease; Myocardial infarction.