[Independent association of smoking with postoperative cardiac events and thirty-day mortality]

Abstract

Background: Few studies have demonstrated the association of smoking, as an independent risk factor, with postoperative cardiac events.

Objective: To evaluate the association of smoking, as an independent variable, with postoperative cardiovascular complications and 30-day mortality in noncardiac surgeries.

Methods: A retrospective cohort from a general hospital was studied, which included 1,072 patients stratified as current smokers (n=265), ex-smokers (n=335) and nonsmokers (n=472). These three groups were analyzed regarding the combined cardiovascular outcomes in the postoperative period (infarction, pulmonary edema, arrhythmia with hemodynamic instability, unstable angina and cardiac death) and 30-day mortality. The Chi-square test and logistic regression were used, considering a p value < 0.05 as statistically significant.

Results: When current smokers are compared to ex-smokers and nonsmokers, the combined cardiovascular outcomes in the postoperative period and the 30-day mortality were, respectively: 71 (6.6%) and 34 (3.2%). The current smokers and ex-smokers presented 53 (8.8%) combined cardiac events, whereas the nonsmokers presented 18 (3.8%), with p = 0.002. Regarding mortality, current smokers and ex-smokers presented 26 (4.3%), whereas nonsmokers presented 8 (1.7%), p = 0.024. At the multivariate analysis, age range, emergency surgery, heart failure, left ventricular overload, myocardial revascularization and ventricular extrasystoles were independently associated with perioperative cardiovascular events, whereas age range, emergency surgery, heart failure, laboratory alterations, history of hepatopathy, surgeries due to neoplasia and smoking were associated with 30-day mortality in the postoperative period.

Conclusion: Current smoking was independently associated with 30-day mortality in high-risk noncardiac surgeries, but not to postoperative cardiac events.