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

Electronic cigarettes for smoking cessation

BACKGROUND

Electronic cigarettes (ECs) are handheld electronic vaping devices which produce an aerosol by heating an e-liquid. Some people who smoke use ECs to stop or reduce smoking, although some organizations, advocacy groups and policymakers have discouraged this, citing lack of evidence of efficacy and safety. People who smoke, healthcare providers and regulators want to know if ECs can help people quit smoking, and if they are safe to use for this purpose. This is a review update conducted as part of a living systematic review.

OBJECTIVES

To examine the effectiveness, tolerability, and safety of using electronic cigarettes (ECs) to help people who smoke tobacco achieve long-term smoking abstinence.

SEARCH METHODS

We searched the Cochrane Tobacco Addiction Group's Specialized Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, and PsycINFO to 1 July 2022, and reference-checked and contacted study authors.  SELECTION CRITERIA: We included randomized controlled trials (RCTs) and randomized cross-over trials, in which people who smoke were randomized to an EC or control condition. We also included uncontrolled intervention studies in which all participants received an EC intervention. Studies had to report abstinence from cigarettes at six months or longer or data on safety markers at one week or longer, or both.

DATA COLLECTION AND ANALYSIS

We followed standard Cochrane methods for screening and data extraction. Our primary outcome measures were abstinence from smoking after at least six months follow-up, adverse events (AEs), and serious adverse events (SAEs). Secondary outcomes included the proportion of people still using study product (EC or pharmacotherapy) at six or more months after randomization or starting EC use, changes in carbon monoxide (CO), blood pressure (BP), heart rate, arterial oxygen saturation, lung function, and levels of carcinogens or toxicants, or both. We used a fixed-effect Mantel-Haenszel model to calculate risk ratios (RRs) with a 95% confidence interval (CI) for dichotomous outcomes. For continuous outcomes, we calculated mean differences. Where appropriate, we pooled data in meta-analyses.

MAIN RESULTS

We included 78 completed studies, representing 22,052 participants, of which 40 were RCTs. Seventeen of the 78 included studies were new to this review update. Of the included studies, we rated ten (all but one contributing to our main comparisons) at low risk of bias overall, 50 at high risk overall (including all non-randomized studies), and the remainder at unclear risk. There was high certainty that quit rates were higher in people randomized to nicotine EC than in those randomized to nicotine replacement therapy (NRT) (RR 1.63, 95% CI 1.30 to 2.04; I2 = 10%; 6 studies, 2378 participants). In absolute terms, this might translate to an additional four quitters per 100 (95% CI 2 to 6). There was moderate-certainty evidence (limited by imprecision) that the rate of occurrence of AEs was similar between groups (RR 1.02, 95% CI 0.88 to 1.19; I2 = 0%; 4 studies, 1702 participants). SAEs were rare, but there was insufficient evidence to determine whether rates differed between groups due to very serious imprecision (RR 1.12, 95% CI 0.82 to 1.52; I2 = 34%; 5 studies, 2411 participants). There was moderate-certainty evidence, limited by imprecision, that quit rates were higher in people randomized to nicotine EC than to non-nicotine EC (RR 1.94, 95% CI 1.21 to 3.13; I2 = 0%; 5 studies, 1447 participants). In absolute terms, this might lead to an additional seven quitters per 100 (95% CI 2 to 16). There was moderate-certainty evidence of no difference in the rate of AEs between these groups (RR 1.01, 95% CI 0.91 to 1.11; I2 = 0%; 5 studies, 1840 participants). There was insufficient evidence to determine whether rates of SAEs differed between groups, due to very serious imprecision (RR 1.00, 95% CI 0.56 to 1.79; I2 = 0%; 8 studies, 1272 participants). Compared to behavioural support only/no support, quit rates were higher for participants randomized to nicotine EC (RR 2.66, 95% CI 1.52 to 4.65; I2 = 0%; 7 studies, 3126 participants). In absolute terms, this represents an additional two quitters per 100 (95% CI 1 to 3). However, this finding was of very low certainty, due to issues with imprecision and risk of bias. There was some evidence that (non-serious) AEs were more common in people randomized to nicotine EC (RR 1.22, 95% CI 1.12 to 1.32; I2 = 41%, low certainty; 4 studies, 765 participants) and, again, insufficient evidence to determine whether rates of SAEs differed between groups (RR 1.03, 95% CI 0.54 to 1.97; I2 = 38%; 9 studies, 1993 participants).  Data from non-randomized studies were consistent with RCT data. The most commonly reported AEs were throat/mouth irritation, headache, cough, and nausea, which tended to dissipate with continued EC use. Very few studies reported data on other outcomes or comparisons, hence evidence for these is limited, with CIs often encompassing clinically significant harm and benefit.

AUTHORS' CONCLUSIONS

There is high-certainty evidence that ECs with nicotine increase quit rates compared to NRT and moderate-certainty evidence that they increase quit rates compared to ECs without nicotine. Evidence comparing nicotine EC with usual care/no treatment also suggests benefit, but is less certain. More studies are needed to confirm the effect size. Confidence intervals were for the most part wide for data on AEs, SAEs and other safety markers, with no difference in AEs between nicotine and non-nicotine ECs nor between nicotine ECs and NRT. Overall incidence of SAEs was low across all study arms. We did not detect evidence of serious harm from nicotine EC, but longest follow-up was two years and the number of studies was small. The main limitation of the evidence base remains imprecision due to the small number of RCTs, often with low event rates, but further RCTs are underway. To ensure the review continues to provide up-to-date information to decision-makers, this review is a living systematic review. We run searches monthly, with the review updated when relevant new evidence becomes available. Please refer to the Cochrane Database of Systematic Reviews for the review's current status.

An Overview of the Molecular Mechanisms Associated with Myocardial Ischemic Injury: State of the Art and Translational Perspectives

Cardiovascular disease is the leading cause of death in western countries. Among cardiovascular diseases, myocardial infarction represents a life-threatening condition predisposing to the development of heart failure. In recent decades, much effort has been invested in studying the molecular mechanisms underlying the development and progression of ischemia/reperfusion (I/R) injury and post-ischemic cardiac remodeling. These mechanisms include metabolic alterations, ROS overproduction, inflammation, autophagy deregulation and mitochondrial dysfunction. This review article discusses the most recent evidence regarding the molecular basis of myocardial ischemic injury and the new potential therapeutic interventions for boosting cardioprotection and attenuating cardiac remodeling.

Endothelium in Coronary Macrovascular and Microvascular Diseases

ABSTRACT

The endothelium plays a pivotal role in the regulation of vascular tone by synthesizing and liberating endothelium-derived relaxing factors inclusive of vasodilator prostaglandins (eg, prostacyclin), nitric oxide (NO), and endothelium-dependent hyperpolarization factors in a distinct blood vessel size-dependent manner. Large conduit arteries are predominantly regulated by NO and small resistance arteries by endothelium-dependent hyperpolarization factors. Accumulating evidence over the past few decades has demonstrated that endothelial dysfunction and coronary vasomotion abnormalities play crucial roles in the pathogenesis of various cardiovascular diseases. Structural and functional alterations of the coronary microvasculature have been coined as coronary microvascular dysfunction (CMD), which is highly prevalent and associated with adverse clinical outcomes in many clinical settings. The major mechanisms of coronary vasomotion abnormalities include enhanced coronary vasoconstrictive reactivity at epicardial and microvascular levels, impaired endothelium-dependent and endothelium-independent coronary vasodilator capacities, and elevated coronary microvascular resistance caused by structural factors. Recent experimental and clinical research has highlighted CMD as the systemic small artery disease beyond the heart, emerging modulators of vascular functions, novel insights into the pathogenesis of cardiovascular diseases associated with CMD, and potential therapeutic interventions to CMD with major clinical implications. In this article, we will summarize the current knowledge on the endothelial modulation of vascular tone and the pathogenesis of coronary macrovascular and microvascular diseases from bench to bedside, with a special emphasis placed on the mechanisms and clinical implications of CMD.

Cardiovascular medicine: a year in review

Cardiovascular medicine is facing several challenges in the current era, dominated by the rapid spread of a previously unknown virus around the world. Indeed, the 2020 COVID-19 pandemic set the course of cardiovascular science and education in an extraordinary way, hogging the attention of the medical community. Notably, while COVID-19 impacted research progress, there has been considerable effort in exploring topics of great interest, from the management of acute coronary syndromes to new horizons in the treatment of heart failure, from novelties in the surgical treatment of cardiovascular disease to new data on implantable cardiac devices, and from new diagnostic applications of multimodal imaging techniques to relevant basic science findings. Minerva Cardiology and Angiology, formerly Minerva Cardioangiologica, has strived to inform its readers on these topics and novelties, aiming for a succinct yet poignant melding of timeliness and accuracy. Accordingly, the purpose of this narrative review is to highlight and summarize the major research and review articles published during 2020. In particular, we provide a broad overview of the novelties identifying six major areas of interest in the field of cardiovascular sciences in which new evidences have contributed to improving prevention, diagnosis and treatment of heart and vessels diseases.

Electronic cigarettes for smoking cessation

BACKGROUND

Electronic cigarettes (ECs) are handheld electronic vaping devices which produce an aerosol formed by heating an e-liquid. Some people who smoke use ECs to stop or reduce smoking, but some organizations, advocacy groups and policymakers have discouraged this, citing lack of evidence of efficacy and safety. People who smoke, healthcare providers and regulators want to know if ECs can help people quit and if they are safe to use for this purpose. This is an update conducted as part of a living systematic review.

OBJECTIVES

To examine the effectiveness, tolerability, and safety of using electronic cigarettes (ECs) to help people who smoke tobacco achieve long-term smoking abstinence.

SEARCH METHODS

We searched the Cochrane Tobacco Addiction Group's Specialized Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, and PsycINFO to 1 May 2021, and reference-checked and contacted study authors. We screened abstracts from the Society for Research on Nicotine and Tobacco (SRNT) 2021 Annual Meeting.   SELECTION CRITERIA: We included randomized controlled trials (RCTs) and randomized cross-over trials, in which people who smoke were randomized to an EC or control condition. We also included uncontrolled intervention studies in which all participants received an EC intervention. Studies had to report abstinence from cigarettes at six months or longer or data on safety markers at one week or longer, or both.

DATA COLLECTION AND ANALYSIS

We followed standard Cochrane methods for screening and data extraction. Our primary outcome measures were abstinence from smoking after at least six months follow-up, adverse events (AEs), and serious adverse events (SAEs). Secondary outcomes included the proportion of people still using study product (EC or pharmacotherapy) at six or more months after randomization or starting EC use, changes in carbon monoxide (CO), blood pressure (BP), heart rate, arterial oxygen saturation, lung function, and levels of carcinogens or toxicants or both. We used a fixed-effect Mantel-Haenszel model to calculate risk ratios (RRs) with a 95% confidence interval (CI) for dichotomous outcomes. For continuous outcomes, we calculated mean differences. Where appropriate, we pooled data in meta-analyses.

MAIN RESULTS

We included 61 completed studies, representing 16,759 participants, of which 34 were RCTs. Five of the 61 included studies were new to this review update. Of the included studies, we rated seven (all contributing to our main comparisons) at low risk of bias overall, 42 at high risk overall (including all non-randomized studies), and the remainder at unclear risk. There was moderate-certainty evidence, limited by imprecision, that quit rates were higher in people randomized to nicotine EC than in those randomized to nicotine replacement therapy (NRT) (risk ratio (RR) 1.53, 95% confidence interval (CI) 1.21 to 1.93; I2 = 0%; 4 studies, 1924 participants). In absolute terms, this might translate to an additional three quitters per 100 (95% CI 1 to 6). There was low-certainty evidence (limited by very serious imprecision) that the rate of occurrence of AEs was similar (RR 0.98, 95% CI 0.80 to 1.19; I2 = 0%; 2 studies, 485 participants). SAEs were rare, but there was insufficient evidence to determine whether rates differed between groups due to very serious imprecision (RR 1.30, 95% CI 0.89 to 1.90: I2 = 0; 4 studies, 1424 participants). There was moderate-certainty evidence, again limited by imprecision, that quit rates were higher in people randomized to nicotine EC than to non-nicotine EC (RR 1.94, 95% CI 1.21 to 3.13; I2 = 0%; 5 studies, 1447 participants). In absolute terms, this might lead to an additional seven quitters per 100 (95% CI 2 to 16). There was moderate-certainty evidence of no difference in the rate of AEs between these groups (RR 1.01, 95% CI 0.91 to 1.11; I2 = 0%; 3 studies, 601 participants). There was insufficient evidence to determine whether rates of SAEs differed between groups, due to very serious imprecision (RR 1.06, 95% CI 0.47 to 2.38; I2 = 0; 5 studies, 792 participants). Compared to behavioural support only/no support, quit rates were higher for participants randomized to nicotine EC (RR 2.61, 95% CI 1.44 to 4.74; I2 = 0%; 6 studies, 2886 participants). In absolute terms this represents an additional six quitters per 100 (95% CI 2 to 15). However, this finding was of very low certainty, due to issues with imprecision and risk of bias. There was some evidence that non-serious AEs were more common in people randomized to nicotine EC (RR 1.22, 95% CI 1.12 to 1.32; I2 = 41%, low certainty; 4 studies, 765 participants), and again, insufficient evidence to determine whether rates of SAEs differed between groups (RR 1.51, 95% CI 0.70 to 3.24; I2 = 0%; 7 studies, 1303 participants).  Data from non-randomized studies were consistent with RCT data. The most commonly reported AEs were throat/mouth irritation, headache, cough, and nausea, which tended to dissipate with continued use. Very few studies reported data on other outcomes or comparisons, hence evidence for these is limited, with CIs often encompassing clinically significant harm and benefit.

AUTHORS' CONCLUSIONS

There is moderate-certainty evidence that ECs with nicotine increase quit rates compared to NRT and compared to ECs without nicotine. Evidence comparing nicotine EC with usual care/no treatment also suggests benefit, but is less certain. More studies are needed to confirm the effect size. Confidence intervals were for the most part wide for data on AEs, SAEs and other safety markers, with no difference in AEs between nicotine and non-nicotine ECs. Overall incidence of SAEs was low across all study arms. We did not detect  evidence of harm from nicotine EC, but longest follow-up was two years and the  number of studies was small. The main limitation of the evidence base remains imprecision due to the small number of RCTs, often with low event rates, but further RCTs are underway. To ensure the review continues to provide up-to-date information to decision-makers, this review is now a living systematic review. We run searches monthly, with the review updated when relevant new evidence becomes available. Please refer to the Cochrane Database of Systematic Reviews for the review's current status.

A novel algorithm for the computation of the diastolic pressure ratio in the invasive assessment of the functional significance of coronary artery disease

BACKGROUND

Invasive functional assessment is a mainstay in the management of patients with coronary artery disease (CAD), but there is uncertainty on the comparative accuracy of diagnostic indices of functional significance. We aimed to validate the diagnostic performance of a novel non-hyperemic diastolic pressure ratio (dPR).

METHODS

We performed a retrospective analysis including two separate registries (VERIFY 2, Latina, Italy) of patients in whom functional indices were measured for lesions with angiographically moderate severity. On top of fractional flow reserve, distal coronary pressure (Pd)/aortic pressure (Pa) ratio, instantaneous wave-free ratio (iFR) and diastolic pressure ratio (dPR) were computed using a novel dedicated algorithm over 4 consecutive beats. Agreement/discrepancy between indexes was appraised Bland-Altman analysis, area under the receiver operating characteristic curve (AUC), and unsupervised machine learning.

RESULTS

A total of 525 lesions from 479 patients were included. The novel dPR was highly correlated with iFR (R²=0.99, P<0.001), with a mean difference of -0.004±0.014. The diagnostic performance of dPR (best cutoff value: ≤0.89) against iFR was as follows: accuracy =96%; sensitivity =94%; specificity =97%; positive-predictive value =94%; and negative-predictive value =96%. Additionally, AUC to predict iFR≤0.89 was 0.99, which was significantly higher than that of Pd/Pa (0.97, P<0.001). In the iFR range of 0.85-0.93 ("grey zone"), the diagnostic performance was well maintained (accuracy =91%; sensitivity =87%; specificity =93%; and AUC=0.96). Results were supported also by unsupervised learning analysis.

CONCLUSIONS

This multicenter registry suggests this novel dPR algorithm provides results that are numerically equivalent to iFR. Pending further studies, physicians may consider using this novel dPR algorithm to gauge the functional significance of a coronary lesion.

Electronic cigarettes for smoking cessation

BACKGROUND

Electronic cigarettes (ECs) are handheld electronic vaping devices which produce an aerosol formed by heating an e-liquid. Some people who smoke use ECs to stop or reduce smoking, but some organizations, advocacy groups and policymakers have discouraged this, citing lack of evidence of efficacy and safety. People who smoke, healthcare providers and regulators want to know if ECs can help people quit and if they are safe to use for this purpose. This is an update of a review first published in 2014.

OBJECTIVES

To examine the effectiveness, tolerability, and safety of using electronic cigarettes (ECs) to help people who smoke achieve long-term smoking abstinence.

SEARCH METHODS

We searched the Cochrane Tobacco Addiction Group's Specialized Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, and PsycINFO to 1 February 2021, together with reference-checking and contact with study authors.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) and randomized cross-over trials in which people who smoke were randomized to an EC or control condition. We also included uncontrolled intervention studies in which all participants received an EC intervention. To be included, studies had to report abstinence from cigarettes at six months or longer and/or data on adverse events (AEs) or other markers of safety at one week or longer.

DATA COLLECTION AND ANALYSIS

We followed standard Cochrane methods for screening and data extraction. Our primary outcome measures were abstinence from smoking after at least six months follow-up, adverse events (AEs), and serious adverse events (SAEs). Secondary outcomes included changes in carbon monoxide, blood pressure, heart rate, blood oxygen saturation, lung function, and levels of known carcinogens/toxicants. We used a fixed-effect Mantel-Haenszel model to calculate the risk ratio (RR) with a 95% confidence interval (CI) for dichotomous outcomes. For continuous outcomes, we calculated mean differences. Where appropriate, we pooled data from these studies in meta-analyses.

MAIN RESULTS

We included 56 completed studies, representing 12,804 participants, of which 29 were RCTs. Six of the 56 included studies were new to this review update. Of the included studies, we rated five (all contributing to our main comparisons) at low risk of bias overall, 41 at high risk overall (including the 25 non-randomized studies), and the remainder at unclear risk. There was moderate-certainty evidence, limited by imprecision, that quit rates were higher in people randomized to nicotine EC than in those randomized to nicotine replacement therapy (NRT) (risk ratio (RR) 1.69, 95% confidence interval (CI) 1.25 to 2.27; I2 = 0%; 3 studies, 1498 participants). In absolute terms, this might translate to an additional four successful quitters per 100 (95% CI 2 to 8). There was low-certainty evidence (limited by very serious imprecision) that the rate of occurrence of AEs was similar) (RR 0.98, 95% CI 0.80 to 1.19; I2 = 0%; 2 studies, 485 participants). SAEs occurred rarely, with no evidence that their frequency differed between nicotine EC and NRT, but very serious imprecision led to low certainty in this finding (RR 1.37, 95% CI 0.77 to 2.41: I2 = n/a; 2 studies, 727 participants). There was moderate-certainty evidence, again limited by imprecision, that quit rates were higher in people randomized to nicotine EC than to non-nicotine EC (RR 1.70, 95% CI 1.03 to 2.81; I2 = 0%; 4 studies, 1057 participants). In absolute terms, this might again lead to an additional four successful quitters per 100 (95% CI 0 to 11). These trials mainly used older EC with relatively low nicotine delivery. There was moderate-certainty evidence of no difference in the rate of AEs between these groups (RR 1.01, 95% CI 0.91 to 1.11; I2 = 0%; 3 studies, 601 participants). There was insufficient evidence to determine whether rates of SAEs differed between groups, due to very serious imprecision (RR 0.60, 95% CI 0.15 to 2.44; I2 = n/a; 4 studies, 494 participants). Compared to behavioral support only/no support, quit rates were higher for participants randomized to nicotine EC (RR 2.70, 95% CI 1.39 to 5.26; I2 = 0%; 5 studies, 2561 participants). In absolute terms this represents an increase of seven per 100 (95% CI 2 to 17). However, this finding was of very low certainty, due to issues with imprecision and risk of bias. There was no evidence that the rate of SAEs differed, but some evidence that non-serious AEs were more common in people randomized to nicotine EC (AEs: RR 1.22, 95% CI 1.12 to 1.32; I2 = 41%, low certainty; 4 studies, 765 participants; SAEs: RR 1.17, 95% CI 0.33 to 4.09; I2 = 5%; 6 studies, 1011 participants, very low certainty). Data from non-randomized studies were consistent with RCT data. The most commonly reported AEs were throat/mouth irritation, headache, cough, and nausea, which tended to dissipate with continued use. Very few studies reported data on other outcomes or comparisons and hence evidence for these is limited, with confidence intervals often encompassing clinically significant harm and benefit.

AUTHORS' CONCLUSIONS

There is moderate-certainty evidence that ECs with nicotine increase quit rates compared to ECs without nicotine and compared to NRT. Evidence comparing nicotine EC with usual care/no treatment also suggests benefit, but is less certain. More studies are needed to confirm the size of effect, particularly when using modern EC products. Confidence intervals were for the most part wide for data on AEs, SAEs and other safety markers, though evidence indicated no difference in AEs between nicotine and non-nicotine ECs. Overall incidence of SAEs was low across all study arms. We did not detect any clear evidence of harm from nicotine EC, but longest follow-up was two years and the overall number of studies was small. The evidence is limited mainly by imprecision due to the small number of RCTs, often with low event rates. Further RCTs are underway. To ensure the review continues to provide up-to-date information, this review is now a living systematic review. We run searches monthly, with the review updated when relevant new evidence becomes available. Please refer to the Cochrane Database of Systematic Reviews for the review's current status.

Heat-not-burn tobacco products: an emerging threat to cardiovascular health

Cigarette smoking is at all-time lows globally, but the use of electronic cigarettes has increased profoundly. Recent reports of electronic cigarette or vaping use-associated lung injury may lead individuals to explore novel methods of nicotine consumption, such as heat-not-burn devices. IQOS from Philip Morris, a heat-not-burn device, became available for purchase in the United States in October 2019. Philip Morris claims that 8.8 million people have abandoned traditional cigarettes in favor of IQOS; however, evidence suggests that it may act as a gateway or complement to cigarette smoking, rather than a replacement. Surveys indicate that 96% of Korean IQOS users also smoke cigarettes, and 45% of Italian users of IQOS had never smoked cigarettes. In the United States, Canada, and England, susceptibility of youth to trying IQOS was slightly lower than electronic cigarettes, but higher than cigarette smoking. Heat-not-burn products produce mainstream and second-hand emissions of harmful chemicals, including nicotine, particulate matter, benzene, acrolein, and tobacco-specific nitrosamines. The levels of these emissions, despite being less than those of traditional cigarettes, are potentially harmful to cardiovascular health. A study of current smokers showed similar acute effects of heat-not-burn tobacco products and traditional cigarettes on heart rate, blood pressure, and arterial stiffness. Rats exposed to IQOS had similar vascular endothelial function impairment to those exposed to cigarettes. Heat-not-burn aerosol exposure of cultured macrophages elicited increased oxidative stress, although less than that induced by cigarette smoke. Further studies are needed to better understand the cardiovascular effects of heat-not-burn tobacco products.

Comparative Indoor Pollution from Glo, Iqos, and Juul, Using Traditional Combustion Cigarettes as Benchmark: Evidence from the Randomized SUR-VAPES AIR Trial

Modified risk products (MRP) such as electronic vaping cigarettes (EVC) and heat-not-burn cigarettes (HNBC) are appealing alternatives to combustion cigarettes. Limited between- and within-device comparative data are available on MRP. We aimed at comparing indoor particulate matter (PM) emissions measured in a randomized trial enforcing standardized smoking sessions, testing different devices and flavors of MRP, using traditional combustion cigarettes (TCC) as benchmark. Overall, MRP yielded significantly lower levels of indoor PM in comparison to TCC (with median PM levels during smoking for MRP < 100 μg/m³, and for TCC > 1000 μg/m³). Despite this, significant differences among MRP were found, with Iqos appearing associated with a significantly lower burden of emissions for all the monitored fractions of PM, including total PM (all p < 0.05). Precisely, during use, PM ≤1 µm (PM₁) emissions were 28 (16; 28) μg/m³ for Glo, 25 (15; 57) μg/m³ for Iqos, and 73 (15; 559) μg/m³ for Juul (p < 0.001 for Glo vs. Iqos, p < 0.001 for Glo vs. Juul, and p = 0.045 for Iqos vs. Juul). Exploratory within-MRP analyses suggested significant differences between flavors, favoring, for instance, Ultramarine for Glo, Bronze for Iqos, and Mango for Juul, even if results varied substantially according to individual smoker. In conclusion, leading MRP have significantly less intense and persistent effects on indoor pollution in comparison to TCC. Yet, when focusing solely on MRP, between-product and between-flavor differences appear, with quantitative estimates suggesting lower polluting effects with Iqos. These results, if confirmed externally, could be used to individualize product and flavor choice to minimize the untoward effects of EVC and HNBC on indoor pollution.

Vaping Cardiovascular Health Risks: an Updated Umbrella Review

Purpose of Review

Modified risk products (MRP) such as electronic vaping cigarettes (EVC) and heat-not-burn cigarettes (HNBC) are alternatives to traditional combustion cigarettes (TCC) with an expanding consumer base. Yet, their cardiovascular health risks are still unclear. We aimed to summarize the evidence base on this topic by conducting an updated umbrella review.

Recent Findings

We identified 7 systematic reviews, totaling 183 studies and reports, ranging from in vitro and in animal studies to clinical studies in apparently healthy volunteers and patients at risk of cardiovascular disease. Overall, acute EVC use was associated with several toxic effects at molecular, cellular, tissue, organ, and system level. In addition, EVC impacted adversely on blood pressure (BP) management, caused tachycardia, and worsened arterial stiffness. Finally, EVC use was associated with an increased risk of adverse clinical events, including atrial fibrillation and myocardial infarction, even if the causal link is still debated. Most reviews highlighted that the detrimental impact of EVC was of lesser magnitude of that of TCC. In addition, the differential impact of liquids and nicotine was not clearly disentangled. Finally, no review included studies on HNBC.

Summary

The present umbrella review suggests that EVC, and likely HNBC, despite clearly causing an increase in overall cardiovascular risk, may represent a temporary lesser evil than TCC in a risk-reduction or risk-modification strategy, aiming for eventual abstinence from all tobacco or nicotine products.