Peripheral artery disease (PAD) is a highly prevalent condition affecting 20% of the UK population aged over 60 years (Cea-Soriano et al, 2018; Morley et al, 2018). Atherosclerotic plaques builds up inside arteries, causing them to narrow and reduce blood flow to the limbs (Cea-Soriano et al, 2018; Morley et al, 2018) (Figure 1). More than 50% of patients with PAD are expected to have a major cardiovascular event (myocardial infarction or stroke) or amputation within 5 years of diagnosis (Cea-Soriano et al, 2018; Morley et al, 2018). A low clinical stage of PAD can progress from intermittent claudication to critical limb ischaemia in 21% of patients. PAD is the biggest cause of lower-limb amputation in the UK and 4-27% of people with claudication will need an amputation within 6 years of PAD onset (Sigvant et al, 2016). Ten years ago, the annual treatment cost of PAD in the UK was estimated to be between £774 679 and £1.3 million (National Institute for Health and Care Excellence (NICE), 2013); no more recent figures are available.
Smoking is a key risk factor associated with atherosclerosis and increases the risk of PAD. Cigarette exposure activates various mechanisms that can lead to atherosclerosis, including thrombosis, vascular inflammation, abnormal vascular growth and dyslipidaemia (Benowitz, 2003; Heiss et al, 2008; Flouris et al, 2010). Cigarettes contain more than 4000 chemicals; of these, nicotine in particular can accelerate vascular disease and plaque formation inside vessels (Préfontaine et al, 2006; Lee and Cooke, 2011).
Tobacco use in PAD also has a high financial healthcare burden. A 12-month American observational study of 22 203 patients with PAD revealed that smokers incurred at least $20 000 more in medical expenses than non-smokers (Duval et al, 2015). Similar data from the UK are unavailable.
Smoking cessation is essential for patients with PAD, given that more than 80% of them are current or ex-smokers (NICE, 2020). NICE (2020) recommends evidence-based risk management including robust smoking cessation. Multiple studies have highlighted the importance of smoking cessation in reducing cardiovascular morbidity and mortality, and improving claudication symptoms in patients with PAD (Sigvant et al, 2016). Patients who continue to smoke are at a higher risk of disease progression, amputation, myocardial infarction and death, and have poorer therapeutic outcomes such as graft failure and restenosis after endovascular revascularisation (Willigendael et al, 2005; Fowkes et al, 2013).
Smoking cessation challenges
NICE (2021) recommends that all patients who actively smoke should receive smoking cessation advice at each clinical assessment. Comprehensive smoking cessation programmes have been shown to be more effective and cost-efficient than physician advice alone in helping smokers quit (Suissa et al, 2017). The combination of behavioural therapy, such as motivational interviewing, and pharmacotherapy (nicotine replacement therapy, varenicline and bupropion) can double or triple longer-term abstinence rates and should be offered to all patients, particularly those with PAD (Suissa et al, 2017).
Patients educated about the benefits of tobacco abstinence, including the improvement in claudication symptoms and lower chances of needing invasive treatment, are more motivated to quit (Patel et al, 2018). However, data from Patient-Centered Outcomes Related to Treatment Practices in Peripheral Arterial Disease: Investigating Trajectories (PORTRAIT), a real-world evidence registry collecting data on PAD patients and their adherence, suggest that successful implementation of evidence-based smoking cessation is variable. Despite the background evidence, only 75% of current smokers receive advice to quit smoking or are referred to cessation services and 72% of baseline smokers continue smoking after 12 months (Patel et al, 2018).
Smoking is highly addictive and many patients relapse multiple times before quitting. Smokers with PAD often quit within the first 3 months of their diagnosis (21% quit rate), but can quickly relapse (Patel et al, 2018).
Smoking addiction
Many theories have been drawn up to explain addiction. In the case of smoking, addiction is a need for a substance with physical and psychological withdrawal effects (Figure 2).
Nicotine is the ingredient in cigarettes known to be associated with tobacco addiction (Dani and Heinemann, 1996). Nicotine travels through the bloodstream to reach the brain quickly and stimulates dopamine release (Dani et al, 2001). Dopamine is a hormone related to happiness and pleasure and therefore nicotine is associated with pleasure and good mood (Dani and Heinemann, 1996). Nicotine is active for only a few minutes in the brain and, when it leaves the bloodstream, this results in a craving (Dani and Heinemann, 1996).
The brain operates with reward cues. When a regular smoker decides to quit, their brain does not receive the rewarding effect of nicotine and the person gets withdrawal symptoms (Dani and Heinemann, 1996; Hughes, 2006). These include irritability, low mood, impatience, increased hunger and anxiety (Hughes, 2006). The first month of tobacco abstinence is the hardest as withdrawal symptoms peak within the first week and can last up to 4 weeks (Hughes, 2006). Hence, it is important to support patients during the first month of their quitting attempt.
Many factors can lead someone to start smoking, including social influences as well as cultural and environmental factors (Figure 3) (Scherrer et al, 2012; Reveles et al, 2013). Patients can experience difficulties when quitting as they may feel isolated and no longer ‘part of the group’. To address this, health professionals who recognise a patient's willingness to quit smoking should refer them to smoking cessation specialists who can then offer a tailored plan to those willing to quit.
In the interim, health professionals can provide valuable very brief advice (VBA) on smoking and cessation benefits, as well as encouraging the implementation of the agreed plan. Patients should also be equipped with mechanisms to avoid or manage smoking triggers, such as exercise, which has a positive effect on nicotine cravings and can prevent weight gain (Roberts et al, 2012). For example, if a patient is smoking during their lunch break, they could be encouraged to take a walk with a non-smoking colleague, which is a healthier stress relief method than smoking.
How nurses can support patients
Every patient contact matters, and all smokers should receive cessation advice at every appointment. NICE guidance (2021) suggests that primary care and community healthcare providers should be able to provide smokers with VBA that takes less than 30 seconds.
As PAD is a common condition, community nurses will see a significant number of patients in their practice. Thus, nurses should be able to identify when patients require referral to a service that can provide more in-depth, evidence-based tobacco cessation interventions.
The principles of the National Centre for Smoking Cessation and Training (NCSCT) VBA are (NICE, 2021):
- Ask all patients if they smoke
- Advise on the best way to stop
- Act: provide a referral or offer behavioural support and drug treatment.
Health professionals can enhance their knowledge and skills in advising patients on smoking cessation by completing a concise VBA training module provided by the NCSCT. Given the sensitivity of the topic and the potential for patients to feel pressured or judged, VBA offers an efficient and effective approach to discussing smoking.
Offering VBA at every appointment is recommended, given that patients' circumstances and readiness to quit smoking may change over time (NICE, 2021).
How about e-cigarettes?
E-cigarette use is becoming more popular. It is now the most favoured method of quitting smoking in the UK, with 27% of smokers using them compared to 18% using nicotine replacement therapy (NICE, 2021). Vaping products are similar to nicotine replacement therapy, as they provide clean nicotine, without exposure to harmful substances such as the tar included in cigarettes or carbon monoxide, a toxic byproduct of smoking.
However, the cardiovascular risk of e-cigarette use is still unclear. Data from the PATH study (Population Assessment of Tobacco and Health), a US 5-year longitudinal cohort study (2013-2019), did not identify a significant difference in the risk of CVD events in e-cigarette smokers compared to cigarette smokers (Berlowitz et al, 2022). In addition, combining smoking with vaping does not reduce the risk of CVD events (Berlowitz et al, 2022), so patients should quit both to reduce their risk.
A lot of PAD patients vape and ask health professionals for advice on this. Public Health England (2021) has recognised that vaping is significantly less harmful than smoking and NICE guidance (2021) suggests that patients should not be discouraged from using e-cigarettes as a smoking abstinence method and should receive appropriate education. However, recent literature supports health professionals advising individuals against e-cigarettes, given the significant damage these can cause to the heart, blood vessels and lungs (Kuntic et al, 2020).
Author's study findings
As part of the author's pre-doctoral fellowship, she completed a survey of 105 PAD patients attending a vascular outpatient appointment at a large London university hospital, aiming to identify the rates of patient adherence to non-invasive (best medical therapy, smoking abstinence and exercise) guideline-recommended therapy. Patients were eligible to participate in the study if they had a PAD diagnosis, were aged over 18 years, could speak English and had mental capacity. All patients consented before taking part in the survey and the study received ethical approval.
Most participants had a history of smoking (96/105; 91.4%). However, only a minority (21/105) had been referred to smoking cessation services by their GP and even fewer had attended a programme.
Of the ex-smokers cohort (70/105), only 16 had been referred by their clinician to a stop-smoking programme and only five of these patients attended the programme and managed to quit smoking in that way.
As for the current smokers (26/105), only six of them were willing to quit smoking for good. The rest of them compromised by smoking an average of five cigarettes per day and believing that such a small number of cigarettes would not harm them. Of the six current smokers willing to quit, five had been referred to smoking cessation services, and four were attending a programme; one patient relapsed back to smoking.
When patients were asked to give a reason for not attending a smoking cessation programme, a high number reported that ‘it does not work’. Some patients said they were aware of the smoking risks but were willing to face them and continue enjoying smoking.
Although all current smokers were advised to quit smoking, none of them had been referred to smoking cessation services by their vascular clinician or given brief cessation advice. Moreover, in most cases, it had not been explained why smoking cessation is essential for vascular preservation. Therefore, patients reported not being convinced by their clinicians.
Future research
There is a plethora of studies recording longer-term abstinence in patients with cancer or heart disease but very limited data on vascular patients. Existing studies have limited follow-up to 12 months after advising patients to quit smoking. Therefore, prospective clinical trials that assess smoking cessation interventions in PAD patients and measure long-term smoking abstinence are needed.
Moreover, the barriers to providing tobacco cessation support need to be identified so we can support patients better (Patel et al, 2018). Studies exploring PAD patients' health beliefs and barriers to quitting smoking are limited. Qualitative research is ideal for exploring complex matters such as smoking cessation and the views patients may have about the reasons for their behaviour, as well as their sense-making about how tobacco cessation interventions may work for them. Therefore, more qualitative research is needed to understand the barriers to tobacco abstinence from a patient's perspective and address these before moving to external factors.
Conclusion
Smoking is the most prevalent risk factor for atherosclerosis. Cessation is necessary for patients with PAD to delay the disease progression and improve their claudication symptoms.
More than 80% of PAD patients have a smoking history and 78% of patients continue to smoke 12 months after their diagnosis. Referral to smoking cessation is poor and patients are not convinced about the benefits of tobacco abstinence.
Smoking is a complex behaviour, associated with social and cultural determinants. Health professionals should act as patient advocates and work with patients to tackle the barriers to quitting smoking and ensure successful tobacco abstinence.
KEY POINTS
- Patients with peripheral artery disease (PAD) who continue to smoke have increased cardiovascular risk and more vascular complications
- Smoking is a complex behaviour, affected by multiple social and environmental factors
- The very brief advice intervention is the best way to raise the subject of smoking
- Only a minority of patients with PAD attend smoking cessation services
- Understanding the barriers to smoking cessation in patients with PAD is essential
CPD reflective questions
- What causes someone to start smoking?
- What are the barriers to quitting smoking in patients with cardiovascular disease in your area?
- What do you need to consider when you offer smoking cessation advice to a patient? How do you feel about the use of very brief advice within your practice?