Quitting smoking at any point after the diagnosis of stable coronary artery disease may be linked to a lower risk of major adverse cardiovascular events.
In a study, investigators used a prospective observational CLARIFY registry to analyze the outcomes of 32,378 patients with stable coronary artery disease from 45 countries.
At study inclusion, patients had a mean age of 64.2 ± 10.5 years, 77.6% were male, and the mean time since coronary artery disease diagnosis was 6.5 ± 6.4 years. Patients were categorized as never-smokers (41.3%), former smokers (46.2%), or current smokers (12.5%). Among former smokers who smoked at coronary artery disease diagnosis, 72.8% quit within 1 year, highlighting this as a crucial window for cessation.
The investigators found that quitting smoking after the diagnosis of stable coronary artery disease was associated with a 44% reduction in the risk of major adverse cardiovascular events (MACE) over 5 years, including cardiovascular death or myocardial infarction (adjusted hazard ratio [HR] = 0.56, 95% confidence interval [CI] = 0.42–0.76, P < .001). In contrast, reducing smoking had minimal impact on the MACE risk compared with unchanged smoking habits (adjusted HR = 0.96, 95% CI = 0.74–1.26, P = .78). Each year of continued smoking post–coronary artery disease diagnosis increased the MACE risk by 8% (adjusted HR = 1.08, 95% CI = 1.04–1.12).
Despite the significant risk reduction, former smokers never achieved the low MACE risk of never-smokers, even after years of cessation. Quitters had a 44% lower MACE risk vs continued smokers, regardless of time to cessation postdiagnosis.
"The first year post–[coronary artery disease] diagnosis is a critical period for smoking cessation. Physicians should consistently deliver clear quit smoking messages, stressing the potential to halve MACE risk," suggested lead study author Jules Mesnier.
The investigators recommended cessation strategies, including counseling, behavioral interventions, and pharmacotherapy.
The authors declared having no competing interests.
