Evaluation of varenicline usage on ventricular repolarization after smoking cessation

Varenicline, which is a selective partial agonist of the alpha4-beta2 nicotinic acetylcholine receptor, is used for the smoking cessation pharmacotherapy. Cardiovascular adverse effects have been reported after varenicline usage in patients who stop smoking. We investigated the effect of varenicline usage on ventricular repolarization after smoking cessation.

In this prospective cohort study, we evaluated the cardiac arrhythmic effects of varenicline by comparing smoking patients (n = 214) before and after varenicline usage. Varenicline administered patients were also compared to ex-smoker individuals (n = 50) who quit smoking without varenicline usage in terms of ventricular repolarization parameters.

After calculated according to Fridericia's and Framingham's formulas, QTc intervals were significantly increased when patients compared before and after smoking cessation with varenicline (402.9 ± 24.5 ms vs. 409.1 ± 25.0 ms p < 0.001 and 376.5 ± 15.2 ms, vs. 380.6 ± 13.5 ms; p < 0.001, respectively). There was no arrhythmic event during the follow-up. The change in Tp-e and QTc following varenicline usage was negatively correlated with the smoking packet/year. (ρ: -0.443, p < 0.001 and ρ = -0.601, p < 0.001) CONCLUSION: Varenicline usage was demonstrated to prolong ventricular repolarization parameters similar to animal studies. Varenicline may have a role to predispose cardiac dysrhythmias after utilization in smoking cessation.