Impact of Coronary Collateral Circulation of Perioperative Myocardial Damage in High-Risk Patients Undergoing Coronary Artery Bypass Grafting Surgery.

Background: Coronary collateral circulation (CCC) is a small vascular formation that allows the connection between the different parts of an epicardial vessel or other vessels. The presence of collateral circulation contributes positively to the course of coronary artery disease (CAD). The aim of this study was to investigate the effect of collateral circulation on myocardial injury and clinical outcomes during coronary artery bypass grafting (CABG) in a high-risk patient group.

Methods: 386 patients who underwent isolated CABG under cardiopulmonary bypass (CPB) were included in the study. Patients were divided into two groups according to the Rentrop scores (n = 225 poor CCC group; and n = 161 good CCC group). Myocardial injury and postoperative clinical results were evaluated as endpoints.

Results: The mean age was 62.9 ± 7.5 years, and 61.6% of all patients were male. Postoperative 30-day mortality rate was significantly higher in poor CCC group (4 [1.7%] and 1 [0.6%], P < .001). The frequency of postoperative intraaortic balloon pump (IABP) use (5 [2.2%] and 1 [0.6%], P < .001), low cardiac output syndrome (LCOS) (28 [12.4%] and 10 [6.2%], P < .001) and postoperative atrial fibrillation (35 [15.6%] and 16 [9.9%], P = .038) were significantly higher in poor CCC group. 12th and 24th hour CK-MB and cTn-I values were found to be significantly lower in the good CCC group.

Conclusion: It is inevitable that the CPB circuit and operation have devastating effects on myocardium in CABG operations. The presence of CCC reduces postoperative myocardial injury, low cardiac output syndrome, and mortality rates.