956-116 The Reperfusion Strategy Does Affect Outcome When Nonsmokers Present with Acute Myocardial Infarction: A PAMI Substudy

Abstract

In the reperfusion era thrombolytic trials reported a “smoker's paradox” in which a favorable clinical outcome was noted in smokers. This was thought to be due in part to the hypercoagulable state with smoking, resulting in a more thrombotic coronary occlusion which responds well to thrombolysis. To determine whether the type of reperfusion strategy affects outcome in smokers vs. nonsmokers, we evaluated 395 patients (pts) who were randomized to tPA vs. primary PTCA in the PAMI study of whom 168 were smokers (SM) and 128 never smoked (NS). The combined in-hospital outcome including death, recurrent MI or recurrent ischemia was similar in SM and NS (p = 0.12) despite univariate analysis revealing that SM were younger (65 vs. 55 yrs, p < 0.001) and less likely to be female (20 vs. 41%, P < 0.001) compared with NS. Stratifying the data according to reperfusion modality, smokers treated with tPA did significantly better than NS (p = 0.04); a difference that did not exist in the PTCA group (SM vs NS, p = 0.69). Multivariate analysis revealed that NS treated with PTCA had less recurrent ischemia (11 vs. 33%, p = 0.004) and combined mortality or recurrent MI (7 vs 18%, P = 0.05) compared with those treated with tPA. At 6 months, NS treated with PTCA vs. tPA continued to have fewer deaths or recurrent MI. (11 vs. 24%, P = 0.07). Conversely, treatment strategy in SM did not significantly affect hospital outcomes; recurrent ischemia (12 vs. 23%, P = 0.07) and mortality combined with recurrent MI (6 vs. 8%, P = 0.55) in PTCA and tPA groups. The statistical significance of these associations is maintained when controlling for age and gender. Nonsmokers presenting with acute MI have a significantly better outcome after treatment with primary angioplasty. Even when controlling for age and gender the reperfusion strategy affects outcome in NS, a difference not seen in SM. These data add further support to the hypothesis that nonsmokers have a more atherosclerotic occlusion which may explain why they benefit from primary angioplasty more than thrombolysis.