NEW YORK (Reuters) -- Smoking may hasten a heart attack by as much as 10 years, according to an Israeli study of smokers and nonsmokers.
Although smokers actually recovered better from heart attack than nonsmokers, the authors said the earlier risk of heart attack far outweighs any protective benefit and urged readers not to view the findings in a positive light.
The study appears in the November 15 issue of the Journal of the American College of Cardiology.
The authors, led by Dr. Shmuel Gottlieb, even suggest that one of the reasons that smokers have better outcomes may be their younger age at the time of the heart attack.
A total of 367 smokers and 632 nonsmokers who suffered a heart attack were studied. Nonsmokers had more complications, including triple the rate of congestive heart failure and cardiogenic shock. Gottlieb and colleagues from the Bikur Cholim Hospital in Jerusalem studied the patients as part of the Israeli Thrombolytic Survey Group.
Smokers were more likely to receive clot-busting therapy and invasive coronary interventions, probably because they were younger and more likely to respond to such therapy than nonsmokers, the researchers wrote. Smokers also had smaller areas of damage to their heart after the heart attack than nonsmokers. This damaged area, called an infarction, is used to assess survival. The smaller the infarction size, the better the outcome.
Researchers have been puzzled for years by study findings showing that smokers are more likely to survive a heart attack than their nonsmoking peers. In this study, that theory certainly appeared to be true, with 21.5% of nonsmokers dying within six months of their heart attack compared to only 7.9% of smokers.
But when Gottlieb and colleagues adjusted the data to take into account age and age-related factors at the time of the attack, the differences between the two groups disappeared, leaving no advantage for smokers. The average age of nonsmokers in the study was 67 years versus 57 years for smokers.
Gottlieb said that the message of the study is not that smoking improves prognosis after a heart attack, but that it actually causes heart attacks earlier. "If you want to smoke, fine, but you will have a heart attack 10 years earlier than a nonsmoker," he said. He added that efforts to discourage smoking should continue.
SOURCE: Journal of the American College of Cardiology (1996;28:1506-1513)
