Smoking is greatest predictor of recurrent cardiac events among young myocardial infarction survivors

Continuing to smoke following a myocardial infarction is the most powerful predictor for recurrent cardiac events among survivors age 35 years or younger.
In particular, patients who continue to smoke have approximately three times the risk for future heart problems ( e.g., cardiac death, a repeat heart attack or revascularization due to clinical deterioration ) compared to those who quit smoking after the first acute myocardial infarction ( AM I).
This higher risk was independent of the type of treatment, presence of other cardiovascular risk factors ( e.g., high cholesterol, high blood pressure, diabetes mellitus or body mass index ) and even the function of the left ventricle ( ejection fraction), which is a well-established, strong predictor of future cardiac events.

Of the 135 subjects in this study, more than half ( 56 percent ) continued smoking after having a heart attack, and one out of three patients developed a cardiac event during this time period ( 3 deaths, 30 acute coronary syndromes, and 11 revascularizations ).
Almost half ( 45 percent ) of persistent smokers ( on average 20 cigarettes per day ) suffered from cardiac events, while only 18 percent of quitters suffered an event during the follow-up period.

Patients were recruited between 1997 and 2001 from two large hospitals in Athens, Greece, and followed for up to ten years. Three out of four patients were overweight or obese when they had their first myocardial infarction; high cholesterol was the second most prevalent risk factor ( behind smoking status ) among these patients ( 70 percent had cholesterol levels above 200 mg/dl ).

A previous study by researchers at University General Hospital Attikon in Greece, found that the majority of patients ( 95 percent ) experiencing a myocardial infarction before the age of 36 years were smokers. This translated to a 6-fold increased risk of AMI before 36 years of age compared to non-smokers, regardless of the presence of high cholesterol, high blood pressure or diabetes mellitus.

Source: American College of Cardiology, 2008


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