According to a study presented today at the ESC 2024 Congress, patients with stable coronary heart disease who stopped smoking at any time after their diagnosis reduced their risk of a major event by almost 50%. In contrast, the impact on cardiovascular risk was minimal in patients who reduced their smoking habits.

The international CLARIFY registry (prospective, observational, longitudinal registry for patients with stable coronary artery disease) investigated the influence of smoking behavior on cardiovascular events in patients with coronary artery disease. The registry included 32,378 patients with this disease. The occurrence of a major adverse cardiovascular event (MACE), defined as cardiovascular death or myocardial infarction, during the 5-year observation period was analyzed.

Patients were enrolled in the study an average of 6.5 years after their diagnosis of coronary heart disease: at enrollment, 13,366 patients (41.3%) had never smoked, 14,973 (46.2%) were former smokers, and 4,039 (12.5%) were current smokers. Of the former smokers who smoked at the time of diagnosis of coronary heart disease, 72.8% quit smoking within the following year, while only 27.2% quit in subsequent years.

Interestingly, the first year after diagnosis was the critical window for quitting. At the time of diagnosis, we should emphasize the importance of quitting and support patients in this challenge.”

Dr. Jules Mesnier, study author, Bichat-Claude Bernard Hospital, Paris, France

In patients who stopped smoking after being diagnosed with coronary heart disease, their cardiovascular outcome improved significantly, regardless of when they quit smoking. The risk of MACE decreased by 44% (adjusted hazard ratio (HR) 0.56; 95% confidence interval (CI) 0.42–0.76; p

Dr. Mesnier concluded: “I like to tell my patients that it is never too early or too late to quit smoking. However, the sooner a patient stops, the better the reduction in cardiovascular risk. And it is not enough to cut down on smoking. During any medical procedure, smokers must receive short, clear messages that make it clear to them that they need to quit. Telling patients that they can reduce their risk of a later serious event or death by half – as we have shown here – is a powerful message.”

Measures to promote smoking cessation include brief counseling, counseling and behavioral interventions, and drug therapy.