From the Guidelines
Low dose nicotine may have theoretical cardioprotective effects, though this remains controversial and unproven for clinical application. Some laboratory studies suggest that nicotine at low doses might stimulate angiogenesis (formation of new blood vessels), activate protective cellular pathways, and provide some protection against ischemia-reperfusion injury. The mechanism appears to involve nicotinic acetylcholine receptors that can trigger cellular survival pathways and reduce oxidative stress in cardiac tissue, as noted in a study published in The Lancet Respiratory Medicine 1. However, these potential benefits must be weighed against nicotine's well-documented harmful effects, including increased heart rate, blood pressure, and vasoconstriction, which can worsen cardiovascular outcomes.
Currently, there is insufficient evidence to recommend nicotine for cardioprotection in clinical practice, and its overall cardiovascular risk profile remains negative. The theoretical cardioprotective effects observed in laboratory settings have not translated into proven clinical benefits in humans, and nicotine-containing products should not be used for heart protection. It is essential to consider the findings of the most recent and highest quality study, which in this case is from 2022 1, indicating that while nicotine may have some anti-inflammatory effects, its use is highly addictive and has several adverse cardiopulmonary effects.
Key points to consider include:
- Nicotine's potential to stimulate the cholinergic anti-inflammatory response and activate the parasympathetic nervous system to release acetylcholine, modulating the immune response 1.
- The activation of the α7 nAChR suppresses nuclear factor-κB-dependent transcriptional events, leading to downregulation of cytokine production and an attenuated response to inflammatory triggers 1.
- Insufficient epidemiological or experimental evidence exists to support the assertion that nicotine might decrease the hyperinflammatory response in people with COVID-19 1.
- Nicotine replacement shows no adverse effect on outcomes in patients with cardiac disease, as noted in the 2016 European guidelines on cardiovascular disease prevention in clinical practice 1.
In clinical practice, the use of nicotine for cardioprotection is not recommended due to its negative overall cardiovascular risk profile and the lack of proven clinical benefits. Instead, established methods for reducing cardiovascular risk, such as smoking cessation programs and evidence-based treatments for cardiovascular disease, should be prioritized.
From the Research
Theoretical Cardioprotective Effects of Low-Dose Nicotine
- The available evidence suggests that low-dose nicotine may have theoretical cardioprotective effects, particularly when used as a replacement therapy for smoking cessation 2, 3, 4.
- Studies have shown that nicotine replacement therapy (NRT) is associated with a lower risk of cardiovascular events compared to continued smoking 5, 3, 4.
- The cardiovascular effects of nicotine are dose-dependent, and low-dose nicotine may not increase the risk of cardiovascular events in patients with underlying coronary artery disease 3, 4.
- Transdermal nicotine patches have been shown to be safe and effective in promoting smoking cessation in patients with coronary artery disease, without increasing the risk of myocardial ischemia or arrhythmia 4.
Comparison with Smoking and Other Nicotine Replacement Therapies
- The risks of NRT are significantly lower than those associated with continued smoking 2, 5, 3.
- Nicotine replacement therapy is considered a reasonable choice for smoking cessation, particularly when compared to other medications such as bupropion and varenicline, which have been associated with serious adverse effects 5.
- Electronic cigarettes, which deliver nicotine without combustion of tobacco, may pose a low cardiovascular risk, at least with short-term use, in healthy users 6.
Key Findings and Implications
- The available evidence suggests that low-dose nicotine may have theoretical cardioprotective effects, particularly when used as a replacement therapy for smoking cessation 2, 3, 4.
- Healthcare professionals should consider the potential benefits and risks of NRT when recommending it to patients with established cardiovascular disease 2, 5, 3.