Author + information
- Received June 22, 2019
- Revision received August 22, 2019
- Accepted September 23, 2019
- Published online December 16, 2019.
- Jacob George, MDa,∗ (, )@UoDMedicine,
- Muhammad Hussain, MSca,
- Thenmalar Vadiveloo, PhDb,
- Sheila Ireland, BSca,
- Pippa Hopkinson, BSca,
- Allan D. Struthers, MDa,
- Peter T. Donnan, PhDb,
- Faisel Khan, PhDc,∗ and
- Chim C. Lang, MDa,∗
- aDivision of Molecular and Clinical Medicine, University of Dundee, Ninewells Hospital and Medical School, Dundee, United Kingdom
- bPopulation Health and Genomics Division, University of Dundee, Ninewells Hospital and Medical School, Dundee, United Kingdom
- cDivision of Systems Medicine, University of Dundee, Ninewells Hospital and Medical School, Dundee, United Kingdom
- ↵∗Address for correspondence:
Dr. Jacob George, Division of Molecular and Clinical Medicine, Mailbox 2, Ninewells Hospital and Medical School, Dundee, United Kingdom.
Background E-cigarette (EC) use is increasing exponentially worldwide. The early cardiovascular effects of switching from tobacco cigarettes (TC) to EC in chronic smokers is unknown. Meta-analysis of flow-mediated dilation (FMD) studies indicate 13% lower pooled, adjusted relative risks of cardiovascular events with every 1% improvement in FMD.
Objectives This study sought to determine the early vascular impact of switching from TC to EC in chronic smokers.
Methods The authors conducted a prospective, randomized control trial with a parallel nonrandomized preference cohort and blinded endpoint of smokers ≥18 years of age who had smoked ≥15 cigarettes/day for ≥2 years and were free from established cardiovascular disease. Participants were randomized to EC with nicotine or EC without nicotine for 1 month. Those unwilling to quit continued with TC in a parallel preference arm. A propensity score analysis was done to adjust for differences between the randomized and preference arms. Vascular function was assessed by FMD and pulse wave velocity. Compliance with EC was measured by carbon monoxide levels.
Results Within 1 month of switching from TC to EC, there was a significant improvement in endothelial function (linear trend β = 0.73%; 95% confidence interval [CI]: 0.41 to 1.05; p < 0.0001; TC vs. EC combined: 1.49%; 95% CI: 0.93 to 2.04; p < 0.0001) and vascular stiffness (−0.529 m/s; 95% CI: −0.946 to −0.112; p = 0.014). Females benefited from switching more than males did in every between-group comparison. Those who complied best with EC switch demonstrated the largest improvement. There was no difference in vascular effects between EC with and without nicotine within the study timeframe.
Conclusions TC smokers, particularly females, demonstrate significant improvement in vascular health within 1 month of switching from TC to EC. Switching from TC to EC may be considered a harms reduction measure. (Vascular Effects of Regular Cigarettes Versus Electronic Cigarette Use [VESUVIUS]; NCT02878421; ISRCTN59133298)
↵∗ Drs. Khan and Lang contributed equally to this work and are joint last authors.
The VESUVIUS (Vascular Effects of Regular Cigarettes Versus Electronic Cigarette Use) trial was funded by the British Heart Foundation (grant PG/15/64/31681); and supported by Immunoassay Biomarker Core Laboratory, University of Dundee, the Tayside Medical Sciences Centre, and the NHS Tayside Smoking Cessation Service. The funder had no role in the study design, data collection, data analysis, data interpretation, writing of the report, or in the decision to submit for publication. Dr. Donnan has received research grants from AbbVie, Shire, and Gilead Sciences. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- Received June 22, 2019.
- Revision received August 22, 2019.
- Accepted September 23, 2019.
- 2019 The Authors