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

Abstract

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. 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. 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. SHS exposure is associated with a dose-dependent increase in mortality for patients with HF.