A randomized trial comparing the acute coronary, systemic, and environmental effects of electronic vaping cigarettes versus heat-not-burn cigarettes in smokers of combustible cigarettes undergoing invasive coronary assessment: rationale and design of the SUR-VAPES 3 trial.

BACKGROUND Traditional combustible cigarette (TCC) smoking remains a major cause of preventable cardiovascular morbidity and mortality. Modified risk products (MRP) such as electronic vaping cigarettes (EVC) and heat-not-burn cigarettes (HNBC) may be safer than TCC but may still have detrimental oxidative, platelet and vascular effects of particular importance to people with symptomatic coronary artery disease (CAD). METHODS We aim to compare the acute coronary, systemic and environmental effects of two leading MRP in 20 TCC smokers admitted for invasive coronary assessment of CAD and willing to quit or after prior failed quitting attempts. After confirmation at angiography of an intermediate coronary stenosis, coronary flow reserve (CFR) will be appraised. Patients will then be randomized 1:1 to use a single EVC or a single HNBC in the catheterization laboratory, followed by repeat CFR measurement. The primary endpoint will be the change in CFR before and after product use. Quantitative coronary angiography, fractional flow reserve (FFR), and instantaneous wave-free ratio (iFR) will also be measured. EXPECTED RESULTS We expect to accrue results able to: 1) test whether MRP have in general a detrimental impact on coronary vascular function in TCC smokers; 2) test whether EVC have a different impact than HNBC on coronary function; 3) provide ancillary pathophysiologic and translational insights on the acute risk and safety profile of MRP in TCC smokers with established cardiovascular disease, including complex correlations between coronary, cardiac, systemic and environmental effects. In addition, by directly informing participants of their individual results, they will be further empowered to quit TCC. CONCLUSIONS The Sapienza University of Rome-Vascular Assessment of Proatherosclerotic Effects of Smoking (SUR-VAPES) 3 trial will provide important insights into the pathophysiologic cardiovascular impact of EVC and HNBC, also suitable to inform patients and individualize their smoking cessation strategy.