The Association Between Secondhand Smoke Exposure and Survival for Patients With Heart Failure

Background: The effect of secondhand tobacco smoke (SHS) exposure on patients with heart failure (HF) is uncertain. We investigated the association of mortality with SHS exposure for patients with HF. Methods: Nonsmokers with clinical HF were enrolled from 2003 to 2008 in a single-center longitudinal cohort study. The effect of SHS exposure determined by high-sensitivity urinary cotinine on mortality was estimated by multivariable proportional hazards modeling. Results: Mortality was assessed after median 4.3 years. Of 202 patients, enrollment urinary cotinine levels were below the limit of detection for 106 (52%) considered unexposed to SHS. The median detectable cotinine was 0.47 ng/mL (interquartile range: [0.28, 1.28]). Participants were 41% female, 65 +/- 17 years old, and 57% white race. Elevated cotinine was associated with increased mortality after multivariate adjustment: hazard ratio (HR) per 1 ng/mL increase in urinary cotinine: 1.15, 95% confidence interval (CI): 1.08-1.23, P < .001. Higher age (HR per 5-year increase: 1.32, 95% CI: 1.22-1.43, P < .001), male sex (HR vs female: 1.52, 95% CI: 1.02-2.28, P = .040), and New York Heart Association class (HR for class III vs I: 2.91, 95% CI: 1.71-4.99, P < .001) were also associated with mortality. Conclusions: SHS exposure is associated with a dose-dependent increase in mortality for patients with HF.