The effects of smoking and drinking on all-cause mortality in patients with dilated cardiomyopathy: a single-center cohort study

SUBJECT: Recent studies have shown that smoking and drinking are associated with poorer outcomes in patients with cardiomyopathy. The purpose of this study was to determine all-cause mortality in dilated cardiomyopathy (DCM) associated with smoking and drinking. METHODS: An observational cohort study was undertaken in DCM patients from November 2003 to September 2011. A total of 1118 patients were enrolled, with a mean follow-up of 3.5 ± 2.3 years. Standard demographics were obtained, and transthoracic echocardiography and routine blood testing were performed shortly after admission. Outcome assessment was based on the all-cause death after admission. RESULTS: The patients were divided into three groups: non-smokers (n = 593), mild-to-moderate smokers (n = 159) and heavy smokers (n = 366). The all-cause mortality rates showed no differences between the three groups (23.8, 20.8 and 24 %, respectively; log-rank χ (2) = 1.281, P = 0.527). There was also no significant difference in mortality between non-drinkers (n = 747), mild drinkers (n = 142) and moderate drinkers (n = 229) (23.7, 23.2 and 22.3 %, respectively; log-rank χ (2) = 2.343, P = 0.310). In the Cox analysis, neither the smoking (HR 0.971, P = 0.663) nor the drinking status (HR 0.891, P = 0.140) was a significant independent predictor of all-cause mortality in patients with DCM. CONCLUSION: In conclusion, there were no significant differences in mortality between the smoking- and drinking-related patient groups, indicating no effect of smoking and drinking on all-cause mortality in patients with DCM in the present large-scale study.