Elsevier

Heart Rhythm

Volume 11, Issue 5, May 2014, Pages 822-827
Heart Rhythm

Smoking is associated with an increased risk of first and recurrent ventricular tachyarrhythmias in ischemic and nonischemic patients with mild heart failure: A MADIT-CRT substudy

https://doi.org/10.1016/j.hrthm.2014.02.007Get rights and content

Background

Limited data exist regarding the proarrhythmic effects of smoking.

Objective

To evaluate the relationship between smoking and the risk of first and recurrent ventricular tachyarrhythmias (VTAs) in patients with mild heart failure.

Methods

The risk of a first and recurrent appropriate implantable cardioverter-defibrillator therapy for VTAs or death was compared between nonsmokers (n = 465), past smokers (n = 780), and current smokers (n = 197) in patients with ischemic and nonischemic cardiomyopathy who were enrolled in the Multicenter Automatic Defibrillator Implantation Trial-Cardiac Resynchronization Therapy study.

Results

The cumulative probability of a first VTA or death was significantly higher in current smokers than in past and nonsmokers (P < .001). Multivariate analysis showed that current smokers had a significantly higher risk of first ventricular tachycardia/ventricular fibrillation or death (hazard ratio [HR] 1.51; 95% confidence interval [CI] 1.14–2.01; P = .005) and a higher risk for first ventricular tachycardia/ventricular fibrillation episode (HR 1.54, 95% CI 1.12–2.13, P = .008) than did nonsmokers. Past smokers had a risk of first VTAs or death similar to that of nonsmokers (HR 1.01; 95% CI 0.80–1.27; P = .953). In comparison to nonsmokers, the risk of recurrent VTAs was significantly higher in the total cohort of patients (HR 1.54; 95% CI 1.21–1.95; P < .001) and in the subgroups of patients with ischemic and nonischemic cardiomyopathy (HR 1.48; 95% CI 1.03–2.13; P = .035).

Conclusions

Current smokers with left ventricular dysfunction and mild heart failure are at a significantly higher risk of VTAs or death than are past smokers and nonsmokers. Smoking is associated with a significant increase in the risk of recurrent VTAs in both patients with ischemic and nonischemic cardiomyopathy.

Introduction

Patients with ischemic and nonischemic left ventricular dysfunction are at an increased risk for sudden cardiac death caused by ventricular tachyarrhythmias (VTAs).1, 2 Smoking has been linked to increased morbidity and mortality in patients at high risk for cardiac disease.3, 4

Smoking has several deleterious effects that may result in ventricular proarrhythmias, including nicotine-induced surge in catecholamines.5, 6 It has previously been shown that continued cigarette smoking is associated with an increased risk of VTAs in patients with an ischemic cardiomyopathy and moderate symptoms of heart failure enrolled in the Multicenter Automatic Defibrillator Implantation Trial II.7

The effect of smoking on the risk of VTAs in patients with mild symptoms of heart failure and particularly in those with nonischemic cardiomyopathy has not been well characterized. We aimed to evaluate the relationship between smoking and the risk for VTAs in patients with mild heart failure. We hypothesized that cigarette smoking may be associated with an increased risk for VTAs and death in patients with mild heart failure with either ischemic or nonischemic cardiomyopathy enrolled in the Multicenter Automatic Defibrillator Implantation Trial-Cardiac Resynchronization Therapy (MADIT-CRT) study.

Section snippets

Study population

The design and results from the MADIT-CRT study have previously been published.8 Briefly, 1820 patients enrolled at 110 hospitals in the United States, Canada, and Europe were randomized in a 3:2 ratio to receive cardiac resynchronization therapy–defibrillator (CRT-D) or an implantable cardioverter-defibrillator (ICD) therapy. Patients of either sex who were at least 21 years of age were enrolled if they had ischemic cardiomyopathy (New York Heart Association [NYHA] functional class I or II) or

Results

The baseline characteristics of the 1442 study patients stratified by smoking status are summarized in Table 1. Compared with nonsmokers, past and current smokers were more likely to be men and they more often had prior myocardial infarction and ischemic cardiomyopathy with NYHA class I or II heart failure symptoms. Furthermore, past and current smokers were less likely to have a left bundle branch block than were nonsmokers. Mean QRS durations were similar between the 3 smoking categories as

Discussion

In the present study, we evaluated the relationship between smoking and the risk for VTAs in patients with ischemic and nonischemic cardiomyopathy who have mild symptoms of heart failure. We have shown that current smokers with left ventricular dysfunction and mild heart failure symptoms have significantly increased risk for VTAs than do past smokers and nonsmokers. Furthermore, after having a first VTA event, both ischemic and nonischemic smokers were at an increased risk for recurrent VTAs

Conclusions

In patients with left ventricular dysfunction and mild symptoms of heart failure, current smokers have a higher risk of VTAs than do past and nonsmokers. Past smokers have an arrhythmia risk profile similar to that of nonsmokers. Current smoking significantly increases the risk of recurrent VT/VF events in patients with ischemic and nonischemic cardiomyopathy. These findings suggest a strong proarrhythmic effect of smoking, and therefore smoking cessation should be strongly encouraged in mild

References (22)

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  • Cited by (0)

    The MADIT-CRT study was supported by an unrestricted research grant from Boston Scientific, St Paul, MN, to the University of Rochester Medical Center.

    Dr Moss has received research grant from Boston Scientific. Dr Huang has received consulting fees/honoraria from St Jude Medical; he is on speakers bureau for Biotronik. Dr Huang has also received research grants from Medtronic, Boston Scientific, St Jude Medical, and Biotronik as well as fellowship support from Biotronik, Medtronic, Boston Scientific, and St Jude Medical. Dr Ruwald is a Mirowski-Moss Awardee. Dr Zareba has received research grant from Boston Scientific.

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