Effect of reperfusion modality on outcome in nonsmokers and smokers with acute myocardial infarction (a Primary Angioplasty in Myocardial Infarction [PAMI] Substudy)

We analyzed the 395 patients randomized into the Primary Angioplasty in Myocardial Infarction (PAMI) trial to receive tissue plasminogen activator (tPA) or to undergo primary percutaneous transluminal coronary angioplasty (PTCA) for acute myocardial infarction (AMI). Of these, 168 were current smokers and 128 had never smoked. Univariate analyses of baseline characteristics and outcome, including death, recurrent AMI, and recurrent ischemia, were done by chi-square analysis. Multivariate stratified analysis was then performed controlling for age and gender, which were found to be confounders of outcome. The combined in-hospital outcomes of death, recurrent AMI, and recurrent ischemia were similar for smokers and nonsmokers (p = 0.12). When stratified according to treatment modality, nonsmokers treated with PTCA had a lower frequency of death and nonfatal recurrent AMI (7% vs 18%; p = 0.05), in-hospital ischemia (11% vs 33%; p = 0.004), or the combined event (13% vs 40%; p = 0.001). At 6 months, nonsmokers treated with PTCA continued to have a lower incidence of death or nonfatal recurrent AMI (11% vs 24%; p = 0.07) compared with tPA. Conversely, in smokers, the treatment strategy did not significantly affect hospital outcomes: recurrent ischemia (12% vs 23%; p = 0.07), death and recurrent AMI (6% vs 8%; p = 0.55), or the combined event (15% vs 25%; p = 0.12). The statistical significance of these associations was maintained when multivariate analysis controlling for age and gender was used. Thus, nonsmokers presenting with AMI had a significantly better outcome when treated with primary angioplasty; these differences were not seen in smokers.