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

Abstract

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.