Evaluation of varenicline usage on ventricular repolarization after smoking cessation

The Effect of Obesity on Repolarization and Other ECG Parameters

Background: Overweight and obesity are important risk factors in the development of cardiovascular diseases. New repolarization markers, such as the Tpeak-Tend interval and JTpeak intervals, have not yet been profoundly studied in obese patients. The study aims to analyze whether, in patients with obesity and overweight, repolarization markers, including the Tpeak-Tend interval, are prolonged and simultaneously check the frequency of other ECG pathologies in a 12-lead ECG in this group of patients. Methods: A study group consisted of 181 adults (90 females and 91 males) with overweight and first-class obesity. The participants completed a questionnaire, and the ECG was performed and analyzed. Results: When analyzing the classic markers, only QT dispersion was significantly higher in obese people. The Tpeak-Tend parameter (97.08 ms ± 23.38 vs. 89.74 ms ± 12.88, respectively), its dispersion, and JTpeak-JTend parameters were statistically significantly longer in the obese group than in the controls. There were also substantial differences in P-wave, QRS duration, and P-wave dispersion, which were the highest in obese people. Tpeak-Tend was positively correlated with body mass and waist circumference, while JTpeak was with BMI, hip circumference, and WHR. Tpeak/JT was positively correlated with WHR and BMI. In backward stepwise multiple regression analysis for JTpeak-WHR, type 2 diabetes and smoking had the highest statistical significance. Conclusions: Only selected repolarization markers are significantly prolonged in patients with class 1 obesity and, additionally, in this group, we identified more pathologies of P wave as well as prolonged QRS duration.

Abrupt versus gradual smoking cessation with pre-cessation varenicline therapy for Chinese treatment-seeking smokers: A retrospective, observational, cohort study

INTRODUCTION

This study aimed to explore the efficacy of abrupt and gradual smoking cessation with pre-cessation varenicline therapy.

METHODS

A total of 278 smokers who experienced moderate-to-severe nicotine dependence and visited a Chinese smoking cessation outpatient clinic from March 2017 to February 2021 were enrolled. This was a retrospective, observational, cohort study. Participants were divided into two groups by the cessation strategy they received: the abrupt cessation group (n=139, tobacco was not controlled during the first 3 weeks before the target cessation date and smoking was entirely discontinued on the 22nd day) and the gradual cessation group (n=139, tobacco was gradually reduced in the first 3 weeks before the target cessation date and smoking was discontinued on the 22nd day). The abstinence rates were compared between groups (7-day point prevalence abstinence rates at 1, 3 and 6 months post-treatment; and 1-month and 3-month continuous abstinence rates of 6-month follow-up). Possible factors that influence efficacy, reasons for smoking cessation failure, and associated adverse events were also analyzed.

RESULTS

No significant difference in the 7-day point prevalence abstinence rates at 1, 3 and 6 months post-treatment was observed between the groups (p>0.05). The 1-month continuous abstinence rate of the gradual cessation group was higher than that of the abrupt cessation group (51.1% vs 31.7%; χ²=10.812, p=0.001). The 3-month continuous abstinence rate of the gradual cessation group was also higher than that of the abrupt cessation group (42.4% vs 27.3%; χ²=6.983, p=0.008). Abrupt cessation was a risk factor for successful smoking cessation than gradual cessation (AOR=2.39; 95% CI: 1.15–3.85, p=0.013),the motivation of ‘prevention and treatment of own diseases’ reduced the risk of incomplete abstinence (AOR=0.87; 95% CI: 0.38–0.99, p=0.049). The incidence of adverse events was higher in the abrupt cessation group than in the gradual cessation group. The incidence rates of nausea and insomnia were statistically significant differences.

CONCLUSIONS

Compared with abrupt cessation, gradual smoking cessation with pre-cessation varenicline therapy produced higher abstinence rates and relatively milder withdrawal symptoms.

Evaluation of varenicline usage on ventricular repolarization after smoking cessation

BACKGROUND

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.

METHODS

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.

RESULTS

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.