BARCELONA — North Americans and Europeans have been presenting with milder acute MIs for the last 2 decades, and a new Swedish study suggests the declining popularity of smoking may be a factor.
The study, which involved 121,032 consecutive admissions for acute MI to Swedish coronary care units in 1996–2004, showed smoking was an independent predictor of presentation with a more extensive ST-elevation MI (STEMI) rather than a non-ST-elevation MI (NSTEMI), Dr. Lena Bjorck reported at the joint congress of the European Society of Cardiology and the World Heart Federation.
Smoking is known to promote coagulation and interfere with thrombolysis. Because thrombosis plays a key role in MI, smoking might be expected to result in increased likelihood of a larger STEMI when MI occurs, said Dr. Bjorck of Sahlgrenska University Hospital, Goteborg, Sweden.
Thirty-five percent of the acute MI patients, who were gleaned from the Register of Information and Knowledge about Swedish Heart Intensive Care Admissions, presented with STEMI; 27% of the STEMI patients were current smokers, as were just 19% in the NSTEMI group. The trend was strongest in patients under age 65. Some 44% of men and 54% of women under 65 who presented with STEMI were current smokers, compared with 34% of men and 37% of women with NSTEMI.
In a multivariate analysis, current smoking was an independent predictor of STEMI in patients with MI. Men younger than 65 years who presented with MI and were current smokers were 40% more likely than nonsmokers to have STEMI; women who were current smokers were 90% more likely. Older men who smoked were 22% more likely than nonsmokers to present with STEMI, and older women who were current smokers were 54% more likely.