ESC Congress 2024: Quitting smoking halves cardiovascular risk in coronary artery disease patients
New research reveals that patients with stable coronary artery disease who quit smoking at any point after diagnosis can reduce their risk of major cardiovascular events by nearly 50%. The study, presented at ESC Congress 2024, also found that merely reducing smoking habits had minimal impact on cardiovascular risk.
Smoking cessation crucial for heart health
The CLARIFY registry (prospeCtive observational LongitudinAl RegIstry oF patients with stable coronary arterY disease) assessed the impact of smoking status on cardiovascular events in patients with coronary artery disease. This international study included 32,378 patients and analysed the occurrence of major adverse cardiovascular events (MACE), defined as cardiovascular death or myocardial infarction, over a 5-year follow-up period.
At the time of inclusion in the study, which occurred an average of 6.5 years after coronary artery disease diagnosis, 41.3% of patients had never smoked, 46.2% were former smokers, and 12.5% were current smokers. Notably, among former smokers who were active smokers at the time of diagnosis, 72.8% quit within the first year, while only 27.2% quit in subsequent years.
Dr Jules Mesnier of Hospital Bichat-Claude Bernard, Paris, France, the study’s lead author, emphasised the significance of this finding: “Interestingly, the first year after diagnosis was the crucial window for quitting. At the time of diagnosis, we should emphasise the importance of quitting and support patients in this challenge.”
Timing of cessation and risk reduction
The research demonstrated that patients who quit smoking after their coronary artery disease diagnosis significantly improved their cardiovascular outcomes, regardless of when they quit. These ex-smokers experienced a 44% reduction in the risk of MACE (adjusted HR 0.56; 95% CI 0.42–0.76; p<0.001).
In contrast, smokers who merely reduced their smoking habits did not significantly alter their risk of MACE compared to those who maintained their smoking levels (adjusted HR 0.96; 95% CI 0.74–1.26; p=0.78).
The study also revealed that for each additional year of active smoking after diagnosis, the risk of MACE increased by 8% (adjusted HR 1.08; 95% CI 1.04–1.12 per year).
Long-term impact of smoking history
Despite the significant risk reduction achieved by quitting, the research showed that former smokers never quite reached the cardiovascular risk level of those who had never smoked, even after years of cessation. This finding underscores the lasting impact of smoking on cardiovascular health.
Implications for patient care
Dr Mesnier highlighted the importance of these findings for patient care: “I like to tell my patients that it is never too soon or too late to stop smoking, though the sooner a patient stops, the better to lower cardiovascular risk. And it is not enough to reduce smoking. Short, clear messages are needed for smokers at every medical intervention highlighting the need to quit. Telling patients they can cut their risk of a subsequent major event or death by half – as we have shown here – is a powerful message.”
The study’s findings reinforce the importance of implementing effective measures to promote smoking cessation. Current guidelines recommend a multifaceted approach, including brief advice, counselling, behavioural interventions, and pharmacological therapy.
This research provides valuable insights into the potential impact of smoking cessation interventions. By emphasising the significant risk reduction associated with quitting smoking, healthcare providers can offer patients a compelling reason to overcome this challenging but crucial lifestyle change.
- The abstract “Trajectories in smoking habits and outcomes in patients with stable coronary artery disease” was presented at ESC Congress 2024 on 30 August in the session ‘Epidemiology and risk factors in cardiovascular disease‘.
