Influence of vessel size on early and late outcomes after primary angioplasty for acute myocardial infarction.

Small vessel size is associated with worse outcomes after elective angioplasty, but the effect of vessel size on outcomes after primary angioplasty for acute myocardial infarction has not been studied. We evaluated outcomes in 1,490 consecutive patients treated with primary angioplasty comparing patients with small (< 3.0 mm) versus large ( 3.0 mm) vessels. Outcomes were worse in patients with small vessels with lower procedural success rates (92% versus 96%; p = 0. 002), higher rates of reinfarction (5.5% vs. 3.4%; p = 0.07), more late reocclusion (12.5% vs. 4.1%; p = 0.002), less improvement in ejection fraction (1.8% vs. 4.2%; p = 0.04), lower follow-up ejection fraction (53.7% vs. 56.5%; p = 0.03), and higher 30-day and late mortality (12.5% vs. 6.4%; p = 0.0002). The higher mortality can be explained by a higher baseline risk profile combined with worse procedural results and higher rates of reocclusion and reinfarction. These data stress the importance of developing new strategies to improve procedural and late outcomes after primary angioplasty in patients with small vessels.