Preoperative cigarette smoking and short-term morbidity and mortality after cardiac surgery: a meta-analysis.

Currently, the choice of whether or not to electively operate on current smokers is varied among cardiothoracic surgeons. This meta-analysis aims to determine whether preoperative current versus ex-smoking status is related to short-term postoperative morbidity and mortality in cardiac surgical patients. Systematic literature searches of the PubMed, MEDLINE and Cochrane databases were carried out to identify all studies in cardiac surgery that investigated the relationship between smoking status and postoperative outcomes. Extracted data were analysed by random effects models. Primary outcomes included 30-day or in-hospital all-cause mortality and pulmonary morbidity. Overall, 13 relevant studies were identified, with 34 230 patients in current or ex-smoking subgroups. There was no difference in mortality (p=0.93). Current smokers had significantly higher risk of overall pulmonary complications (OR 1.44; 95% CI 1.27 to 1.64; p<0.001) and postoperative pneumonia (OR 1.62; 95%  CI 1.27 to 2.06; p<0.001) as well as lower risk of postoperative renal complications (OR 0.82; 95%  CI 0.70 to 0.96; p=0.01) compared with ex-smokers. There was a trend towards an increased risk of postoperative MI (OR 1.29; 95%  CI 0.95 to 1.75; p=0.10). No difference in postoperative neurological complications (p=0.15), postoperative sternal surgical site infections (p=0.20) or postoperative length of intensive care unit stay (p=0.86) was seen. Cardiac surgical patients who are current smokers at the time of operation do not have an increased 30-day mortality risk compared with ex-smokers, although they are at significantly increased risk of postoperative pulmonary complications.