Impact of smoking on the outcomes of minimally invasive direct coronary artery bypass.

backgroundTobacco smoking has been associated with an increased risk of complications after conventional coronary surgery. However, the impact of smoking on the risk of postoperative complications in minimally invasive coronary surgery is yet to be studied. We aimed to analyze the impact of the preoperative smoking status on the short- and long-term outcomes of minimally invasive direct coronary artery bypass grafting (MIDCAB) in the context of isolated surgical revascularization or in association with percutaneous coronary intervention.

methodsThis was a retrospective observational study of all patients undergoing MIDCAB at our institution between 2006 and 2020. Patients were divided into three groups: active smokers, ex-smokers who have quit smoking for at least 1 month before surgery, and non-smokers. The groups were compared using conventional statistical methods. Multivariate analysis was then performed where significant differences were found to eliminate bias.

resultsThroughout the study period, 541 patients underwent MIDCAB, of which 135 (25%) were active smokers, 183 (34%) were ex-smokers, and 223 (41%) were non-smokers. Smokers presented for surgery at a younger age (p < 0.0001), more frequently with a history of myocardial infarction (p < 0.001), peripheral artery disease (p < 0.001) and chronic obstructive pulmonary disease (p < 0.0001). Using multivariate analysis, active smoking was determined to be a significant risk factor for the need of urgent revascularization (odds ratio 2.36 [1.00-5.56], p = 0.049) and the composite of pulmonary complications (including pneumothorax, respiratory infection, respiratory dysfunction, subcutaneous emphysema and exacerbation of chronic obstructive pulmonary disease; odds ratio 2.84 [1.64-4.94], p < 0.001). Preoperative smoking status did not influence the long-term survival (p = 0.83).

conclusionsIn our study, active smokers presented for MIDCAB at a younger age and more often with signs of atherosclerotic disease (history of myocardial infarction and peripheral artery disease). Active smoking was found to be the most significant risk factor for postoperative pulmonary complications, and is also associated with a more frequent need for urgent surgery at diagnosis. Long-term postoperative survival is not affected by the preoperative smoking status.