Optimal periods for coronary artery bypass surgery on working heart in patients with stenosis of left main coronary artery and acute coronary syndrome

Introduction: The treatment strategies of patients with stenosis of the left main coronary artery (LMCA) and acute coronary syndrome (ACS) is being debated. One of the key problems is the selection of the optimal time for coronary artery bypass surgery (CABS) in these patients.

Aim: To analyze different periods of revascularization of the myocardium by CABS on a working heart in patients with LMCA stenosis and ACS.

Materials and methods: A prospective analysis of treatment of 112 patients with LMCA stenosis (> 50%) and ACS was performed. Patients were divided to three groups depending on the time of surgical treatment: upto 7 days after occurrence of ACS, 18 (16.1%, group1) patients; 8–14 days, 38 (33.9%, group2) patients; > 14 days, 56 (50%, group3) patients. The average time of ACS-CABS in all patients was 15 days. The groups were comparable in terms of the main preoperative parameters, except for EuroSCORE II and GRACE scale that were predominant in the early periods of CABS.

Results:  LMCA subocclusion (stenosis > 90%) with coexistence of anginal syndrome at rest was observed in more than half of patients with surgery upto 7 days (56%, p=0.019). The surgery duration, blood loss through drains, number of days in the resuscitation unit, duration of artificial lung ventilation, and use of vasopressor support were not significantly different. The revascularization index was higher in surgeries conducted within 7 days than in surgeries performed within 8–14 days (2.33 ± 0.59 versus 1.89 ± 0.65, p=0.02). The evaluation of the dynamics of the functional parameters of the myocardium showed a greater increase in ejection fraction in group1 when compared with group3 after surgery (p=0.036). In the evaluation of the end-diastolic volume of the left ventricle, the average reductions were 16 mL, 14 mL, and 8.5 mL, respectively, without any significant differences among the groups. The rate of intrahospital lethality was highest in group3 (.4%), followed by group2 (2.6%). No fatal outcomes were noted in surgeries conducted in upto 7 days (p> 0.050).

Conclusion: Early CABS performed upto 7 days have similar immediate results to delayed ones and considerably improves the contractile ability of the myocardium in patients with ACS and LMCA stenosis.