Influence of incomplete revascularisation on the outcomes of coronary artery bypass grafting in patients with ischaemic heart disease

Background. At the present time there is no agreement regarding effect of revascularisation volume on long-term results of coronary artery bypass grafting. According to some reports, incomplete revascularisation, compared with complete revascularisation, affects survival and increases the frequency of adverse cardiovascular events. Other researchers do not find such differences. Aim. This study aimed to assess the influence of incomplete revascularisation on the long-term results of coronary bypass surgery and to determine its predictors. Methods. A total of 243 patients with coronary artery disease who underwent microscope-assisted coronary artery bypass surgery were categorised into two groups. Group I included those with complete revascularisation (n = 152), while group II included those with incomplete revascularisation (n = 91). When assigning patients to groups, the volume of achieved myocardial revascularisation was determined according to the patency of grafts. The groups were compared by the late survival and by the frequency of major cardiovascular events. Logistic regression was used to analyse predictors of incomplete revascularisation. Results. The median of follow-up (interquartile range) was 802 days (426–1487 days). Survival in group 1 at 1, 3 and 5 years after surgery was 98%, 98% and 89%, respectively, while in group 2, it was 90%, 86%, and 86%, respectively (p = 0.024). Freedom from major cardiovascular events (death, myocardial infarction, repeated revascularisation, stroke) in group 1 after 1, 3 and 5 years was 91%, 89% and 77%, respectively, and in group 2, it was 78%, 68% and 68%, respectively (p = 0.005). It was revealed that diabetes mellitus (odds ratio [OR] = 1.45, 95% confidence interval [CI] = 1.01–2.09), arteriosclerosis of arteries of two or more localisations (OR = 1.63, CI = 1.15–2.31), number of lesions in circumflex artery system (OR = 2.48, CI = 1.86–3.31), number of lesions in anterior descending artery system (OR = 1.61, CI = 1.14–2.28) and the diameter of the target coronary artery is less than 1.5 mm (OR = 1.3, CI = 1.22–2.38) are independent predictors of incomplete myocardial revascularisation during coronary artery bypass grafting. Male gender (OR = 0.61, CI = 0.41–0.91) and increased body mass index were associated with a reduced risk of incomplete revascularisation (OR = 0.96, CI = 0.93–0.99). Conclusion. Incomplete revascularisation worsens the prognosis after coronary bypass surgery, and is accompanied by an increase in the frequency of adverse cardiovascular events and a decrease in long-term survival. The risk of incomplete revascularisation increases in patients with diabetes mellitus, common manifestations of atherosclerosis, number of lesions in the left coronary system, as well as with a small diameter of the target coronary arteries. Male gender and increased body mass index were associated with a reduced risk of incomplete revascularisation. Received 15 June 2020. Revised 23 July 2020. Accepted 24 July 2020. Funding: The study did not have sponsorship. Conflict of interest: Authors declare no conflict of interest.