In the afternoon session entitled “Clinical Assessment and Research”, chaired by Dr Peter Harper and Dr Ignatios Ikonomidis, results from several studies on alternative tobacco products versus standard cigarette smoking were presented (Day-1 of the Summit).
Konstantinos Farsalinos, MD, MPH, Adjunct Professor, and highly cited researcher presented an update on e-cigarettes research, over the last year.
A “failure in science communication” was the result over the investigation of an outbreak of hundreds of cases of acute inflammatory lung disease observed in the US since July 2019. The disease was named EVALI “E-cigarette or Vaping-Associated Lung Injury”, yet the outbreak was finally linked with Vitamin E. Nevertheless, most people believe that conventional (nicotine) e-cigarettes are the reason for EVALI and THC content is irrelevant.
Disambiguation was needed regarding a research on e-cigarette use and Myocardial Infarction among adults in the US (PATH study), which strongly associated e-cig daily use with cardiovascular disease. Key information about the timing of e-cigarette use and MI was known to the authors, but was not used; as a result, findings were not accurate and the study was retracted, Prof. Farsalinos pointed out.
Prof. Farsalinos also referred to studies among young people, that show e-cigarette use in youth to be mostly experimental and largely confined to smoking youth. At the same time, strong and rapid reduction in youth smoking rate has been observed over the last decade, he noted.
Christelle Haziza, Director Health Science & Biostatistics at Philip Morris, in her talk “The potential to reduce the risk of smoking-related diseases when switching from smoking to the tobacco heating system” presented the results of an exposure response study (ERS), of 12 months overall, in adult healthy smokers who were not willing to quit, and were randomized to THS or to cigarettes. Concurrently, a 12-month smoking cessation study was conducted with adult healthy smokers, willing to quit.
At least 40% of the Smoking Cessation effect was preserved for 5 out of the eight biomarkers of potential harm (BoPH) in smokers who switched to tobacco heating system (THS).
More than 66% of the Smoking Cessation effect was preserved for: HDL-C, white blood cell, FEV1, carboxyhemoglobin, total 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol, 8-epi-prostaglandinF2α; s-intercellular adhesion molecule-1.
This effect provides additional evidence that THS potentially reduces the risk of developing smoking-related diseases in smokers who would otherwise continue smoking.
Charalampos Vlachopoulos, Professor of Cardiology at the Athens Medical School, in his talk presented research that studied the acute effects of heat-not-burn versus standard cigarette smoking in smokers based on various cardiovascular markers.
He stressed that cardiovascular markers are more complicated to test in a preclinical setting because, unlike carcinogens, there is not one particular marker that causes CAD, but a combination of them and, to a large extent, the pathophysiological mechanism is unknown.
Regarding circulating biomarkers, it was found that IQOS (heat-not-burn system, HNBC) emitted far lower levels of potentially harmful carbonyl emissions than a combustible cigarette, but higher levels than an e-cigarette, he said.
He concluded that given the predictive role of arterial stiffness, the finding that HNBC is negatively impactful on aortic stiffness casts doubt on the advocating of smoking HNBC as a risk-reduction product among current smokers for the primary and secondary prevention of cardiovascular diseases, at least in the short-term.
Prof. Giuseppe Biondi Zoccai, Sapienza University of Rome, Italy talked about novel smoking products and cardiovascular risk, and presented results from “Sapienza University of Rome-Vascular Assessment of Proatherosclerotic Effects of Smoking (SUR-VAPES) Study Program”.
Research showed e-cigarettes to be modified risk tobacco products, which may improve cessation rates and persistent abstinence from traditional combustion cigarettes. Nevertheless, electronic cigarettes may have substantial cardiovascular adverse effects, both acutely and long-term, and their use should be considered only for smoking cessation in patients at low cardiovascular risk, and with a specific time for eventual discontinuation, Prof. Biondi Zoccai said.
John Thymis, scientific associate at the University of Athens, presented the results of a study by researchers from the National & Kapodistrian University of Athens and Imperial College, London, UK, on the differential effects of heat-not-burn and conventional cigarettes on coronary flow, myocardial and vascular function.
The study investigated the effects of heated-not-burned tobacco product (HNBC) on endothelial function, arterial stiffness, myocardial deformation, oxidative stress, platelet activation both in an acute context and after 1 month of switching to HNBC use in comparison with traditional cigarette.
Compared to baseline, conventional cigarette smoking acutely increased exhaled CO, and other biomarkers, while no changes were observed after HNBC. Compared to resuming cigarette smoking, switching to for 1-month improved CO and thromboxane B2. In conclusion, HNBCs exert a less detrimental effect on vascular and cardiac function than tobacco cigarettes.