Medium- and longer-term cardiovascular effects of e-cigarettes in adults making a stop-smoking attempt: a randomized controlled trial

Testing the feasibility of a co-designed intervention, comprising self-managed, home-based, exercise training with embedded behavioural support and compression therapy for people with venous leg ulcers receiving treatment at home (FISCU-II)

BACKGROUND

Venous leg ulcers (VLUs) heal slowly, are painful for patients and are costly for healthcare systems; they also affect patients' quality of life. Previous work suggests that supervised exercise training used in combination with compression therapy may offer clinical benefits. However, a large population of people with VLUs are unable to access such an intervention due to frailty and age.

OBJECTIVES

To assess the feasibility of 'FISCU Home' (a co-designed, 12-week home-based self-managed lifestyle programme based on exercise and behaviour support) as an adjunct therapy to compression in people with VLUs.

METHODS

Forty people with VLUs, receiving treatment at home, were recruited from community nursing and tissue viability teams, and via a newspaper advertisement. Participants were randomized 1 : 1 either to exercise with behaviour support (three times per week) plus compression therapy or compression only. The feasibility of the programme was assessed using progression criteria that included exercise attendance rate, loss to follow-up, patient preference(s) and adverse events (AEs). Baseline assessments were repeated at 12 weeks and 6 months. Secondary outcomes (i.e. ulcer recurrence, healing rate and healing time) were also documented at these intervals. Intervention and healthcare utilization costs were calculated.

RESULTS

The study recruitment rate was 65%, while 75% of the exercise group participants attended all scheduled exercise sessions. All participants completed compression therapy. No serious AEs or exercise-related AEs were reported. Median (interquartile range) ulcer healing time was shorter in the exercise group [29 (7-108) vs. 42 (6-116) weeks].

CONCLUSIONS

The feasibility and acceptability of both a home- and exercise-based lifestyle intervention in conjunction with compression therapy and the study procedures are supported.

Electronic cigarettes for smoking cessation

BACKGROUND

Electronic cigarettes (ECs) are handheld electronic vaping devices which produce an aerosol by heating an e-liquid. 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 safety, tolerability and effectiveness of using electronic cigarettes (ECs) to help people who smoke tobacco achieve long-term smoking abstinence, in comparison to non-nicotine EC, other smoking cessation treatments and no treatment.

SEARCH METHODS

We searched the Cochrane Tobacco Addiction Group's Specialized Register to 1 February 2023, and Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, and PsycINFO to 1 July 2023, and reference-checked and contacted study authors.

SELECTION CRITERIA

We included 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 as these studies have the potential to provide further information on harms and longer-term use. Studies had to report an eligible outcome.

DATA COLLECTION AND ANALYSIS

We followed standard Cochrane methods for screening and data extraction. Critical outcomes were abstinence from smoking after at least six months, adverse events (AEs), and serious adverse events (SAEs). 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 pairwise and network meta-analyses (NMA).

MAIN RESULTS

We included 88 completed studies (10 new to this update), representing 27,235 participants, of which 47 were randomized controlled trials (RCTs). Of the included studies, we rated ten (all but one contributing to our main comparisons) at low risk of bias overall, 58 at high risk overall (including all non-randomized studies), and the remainder at unclear risk. There is high certainty that nicotine EC increases quit rates compared to nicotine replacement therapy (NRT) (RR 1.59, 95% CI 1.29 to 1.93; I2 = 0%; 7 studies, 2544 participants). In absolute terms, this might translate to an additional four quitters per 100 (95% CI 2 to 6 more). There is moderate-certainty evidence (limited by imprecision) that the rate of occurrence of AEs is similar between groups (RR 1.03, 95% CI 0.91 to 1.17; I2 = 0%; 5 studies, 2052 participants). SAEs were rare, and there is insufficient evidence to determine whether rates differ between groups due to very serious imprecision (RR 1.20, 95% CI 0.90 to 1.60; I2 = 32%; 6 studies, 2761 participants; low-certainty evidence). There is moderate-certainty evidence, limited by imprecision, that nicotine EC increases quit rates compared to non-nicotine EC (RR 1.46, 95% CI 1.09 to 1.96; I2 = 4%; 6 studies, 1613 participants). In absolute terms, this might lead to an additional three quitters per 100 (95% CI 1 to 7 more). There is 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 is insufficient evidence to determine whether rates of SAEs differ between groups, due to very serious imprecision (RR 1.00, 95% CI 0.56 to 1.79; I2 = 0%; 9 studies, 1412 participants; low-certainty evidence). Due to issues with risk of bias, there is low-certainty evidence that, compared to behavioural support only/no support, quit rates may be higher for participants randomized to nicotine EC (RR 1.88, 95% CI 1.56 to 2.25; I2 = 0%; 9 studies, 5024 participants). In absolute terms, this represents an additional four quitters per 100 (95% CI 2 to 5 more). There was some evidence that (non-serious) AEs may be more common in people randomized to nicotine EC (RR 1.22, 95% CI 1.12 to 1.32; I2 = 41%, low-certainty evidence; 4 studies, 765 participants) and, again, insufficient evidence to determine whether rates of SAEs differed between groups (RR 0.89, 95% CI 0.59 to 1.34; I2 = 23%; 10 studies, 3263 participants; very low-certainty evidence). Results from the NMA were consistent with those from pairwise meta-analyses for all critical outcomes, and there was no indication of inconsistency within the networks. 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 both 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 due to risk of bias inherent in the study design. 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 the 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. 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.

Smoking cessation and vascular endothelial function

Smoking is associated with vascular endothelial dysfunction. It is thought that smoking impairs vascular endothelial function through a decrease in nitric oxide bioavailability induced by activation of oxidative stress and inflammation. Endothelial dysfunction can be improved or augmented by appropriate interventions including pharmacotherapy, administration of supplements and lifestyle modifications. Although there have not been many studies, the effects of smoking cessation on endothelial function have been shown. In those studies, it was shown that smoking cessation does not always have a positive effect on vascular endothelial function. In this review, I will focus on the role of smoking in endothelial function and the effects of smoking cessation on endothelial function. Smoking impairs vascular endothelial function and leads to atherosclerosis. Smoking cessation is expected to improve vascular endothelial function. Effects of smoking cessation on endothelial function are not always consistent. Further studies are needed to determine whether smoking cessation directly improves endothelial function. NO indicates nitric oxide.

Varied effects of tobacco smoke and e-cigarette vapor suggest that nicotine does not affect endothelium-dependent relaxation and nitric oxide signaling

Chronic smoking causes dysfunction of vascular endothelial cells, evident as a reduction of flow-mediated dilation in smokers, but the role of nicotine is still controversial. Given the increasing use of e-cigarettes and other nicotine products, it appears essential to clarify this issue. We studied extracts from cigarette smoke (CSE) and vapor from e-cigarettes (EVE) and heated tobacco (HTE) for their effects on vascular relaxation, endothelial nitric oxide signaling, and the activity of soluble guanylyl cyclase. The average nicotine concentrations of CSE, EVE, and HTE were 164, 800, and 85 µM, respectively. At a dilution of 1:3, CSE almost entirely inhibited the relaxation of rat aortas and porcine coronary arteries to acetylcholine and bradykinin, respectively, while undiluted EVE, with a 15-fold higher nicotine concentration, had no significant effect. With about 50% inhibition at 1:2 dilution, the effect of HTE was between CSE and EVE. Neither extract affected endothelium-independent relaxation to an NO donor. At the dilutions tested, CSE was not toxic to cultured endothelial cells but, in contrast to EVE, impaired NO signaling and inhibited NO stimulation of soluble guanylyl cyclase. Our results demonstrate that nicotine does not mediate the impaired endothelium-dependent vascular relaxation caused by smoking.

Assessing the effect of regular swimming exercise on the micro- and macrovascular physiology of older adults (ACELA II study)

Introduction: Cardiovascular disease (CVD) remains the main cause of death in the Western world. Our recent findings demonstrate potential CVD risk reduction in older adults who undertake regular swimming exercise. Nevertheless, it remains unknown whether an exercise intervention based on swimming is feasible and effective prior to a wider implementation of a CVD risk prevention strategy. Methods: This was a pragmatic, two-group, randomised controlled trial. A total of 40 older adults were randomly split into two groups (n = 20 per group). The swimming exercise group consisted of participants who engaged in swimming exercise (2-3 days/week, for 8 weeks). The control group did not perform any exercise. Flow-mediated dilation (%FMD) was the primary outcome. Secondary outcomes included raw cutaneous vascular conductance. Feasibility outcomes (e.g., recruitment, adherence, and attrition rates) were also assessed. Results: Statistically significant macrovascular (%FMD; swimming group: 9.8% ± 4.2%, p <0.001; control group: 4.6% ± 2.5%) and microvascular function (raw cutaneous vascular conductance; swimming group: 4.1 ± 0.9, p <0.01; control group: 3.2 ± 1.1) improvements were observed in the swimming group compared to the control group. Compliance to twice and thrice weekly in an 8-week swimming exercise was 92.6% and 88.4%, respectively, with no dropouts. Conclusion: Our 8-week, community-based, pragmatic swimming exercise intervention is a feasible and effective exercise programme that could be implemented in older adults for the prevention of age-related CVD. These findings suggest that swimming exercise could significantly reduce CVD risk in older adults, and a large research clinical trial is warranted to establish these findings.

Health effects of e-cigarettes and their use for smoking cessation from a vascular perspective

Tobacco consumption is one of the most important risk factors for cardiovascular disease. Despite all efforts to curb any form of smoking, the number of e-cigarette users is still rising more than tabacco smoking decreases. E-cigarettes are often advertised as less harmful than regular cigarettes and helpful for smoking cessation. But e-cigarettes are not risk-free and their use causes vascular damage. There is concern about long-term health risks of e-cigarettes or when non-smokers use them as first nicotine contact. Furthermore, their use for smoking cessation is discussed controversially. To optimize treatment and medical counselling of current smokers and e-cigarette users, we present an evidence-based overview of the most important issues of e-cigarette use from a vascular medicine point of view. The key messages are presented as a position statement of the German Society of Vascular Medicine and endorsed by the European Society of Vascular Medicine.