Introduction and methods

A Randomized Controlled Trial Evaluating the Efficacy and Safety of e-cigarettes for Smoking Cessation

Presented at ACC.20 by Mark J. Eisenberg (Montreal, QC, Canada)

e-Cigarettes are used by many smokers in an attempt to quit smoking and improve health outcomes. However, whether e-cigarettes are safe and effective for smoking cessation still remains poorly understood.

The present study was a multicenter trial performed at 17 sites in Canada which evaluated the efficacy and safety of e-cigarettes in participants of the general population. Participants (n=376) were active smokers (≥10 cigarettes/day) motivated to quit smoking. They were randomized to e-cigarettes containing nicotine plus counseling (n=128), e-cigarettes not containing nicotine plus counseling (n=127), or counseling alone (n=121). They were told to smoke the e-cigarettes as much as they felt they needed over the 12-week treatment period. In addition, all groups received around 100 minutes of individual counseling that included guidance on quitting smoking. Primary endpoint was point prevalence smoking abstinence at 12 weeks, defined as self-reported abstinence over the past 7 days combined with biochemical validation using exhaled carbon monoxide ≤10 ppm. Secondary endpoint measures further included reduction in cigarettes/day. Safety of e-cigarettes was measured by monitoring the occurrence of side effects, AEs and SAEs.

Main results

• At 12 weeks, quit rates were 21.9% for nicotine E-cigarettes users, 16.5% for non-nicotine E-cigarettes users, and 9.1% for those with counseling alone (for nicotine e-cigarettes vs. counseling alone, RR: 2.4, 95% CI: 1.3-4.6; for non-nicotine e-cigarettes vs. counseling alone, RR: 1.9, 95% CI: 1.0-3.8).

• Mean difference in cigarettes smoked per day at week 12 was for nicotine e-cigarettes users vs. those with counseling alone -5.7 (95% CI: -8.0 to -3.3) and for non-nicotine e-cigarettes users vs. those with counseling alone -3.6 (95% CI: -6.3 to -1.0).

• Few SAEs were reported (nicotine e-cigarettes 0.7%, non-nicotine e-cigarettes 3.1%, counseling alone 1.7%). One participant in the nicotine e-cigarettes group had a chronic obstructive pulmonary disease exacerbation. There were no cases of e-cigarette, or Vaping, product use Associated Lung Injury (EVALI).

Conclusion

Smoking nicotine e-cigarettes combined with individual counseling for 12 weeks increases smoking abstinence and decreases daily cigarette use compared to counseling alone. Smoking non-nicotine e-cigarettes also has benefits compared to counseling alone. Few SAEs occurred, however additional safety data is needed. Longer-term follow-up data will determine if benefits of e-cigarettes persist over time.

Discussion

There is a desperate need of well-designed studies and real-world data regarding efficacy and safety of e-cigarettes, according to Eugene Yang, MD (Bellevue, WA, USA). He observed that the results of the present study clearly showed a small benefit with short term follow-up, and that these results are intriguing and important. He added however that longer-term follow-up is needed to evaluate additional potential risks of adverse events. Furthermore, e-cigarette intervention should be compared to already approved strategies, typically nicotine-replacement therapy or pharmacological therapy. According to Yang , these already have proven benefits of improving relapse rates over extended periods of time (4-6-12 months).

Yang also expressed his concerns about the possibility that, with the use of e-cigarettes, one bad habit is substituted for another. Some studies that compared e-cigarette therapy to nicotine-replacement therapy found that 1 year after study enrollment participants still used e-cigarettes. In light of emerging data about potential hazards of e-cigarettes (increasing CV risk and pulmonary disease), caution is needed with use of e-cigarette therapies.

– Our coverage of ACC.20 is based on the information provided during the congress –

Watch a video by prof. Eisenberg