Impact of multivessel disease on infarct size among STEMI patients undergoing primary angioplasty

Background: Although primary angioplasty achieves Thrombolysis In Myocardial Infarction (TIMI) 3 flow in most patients with ST-elevation myocardial infarction, epicardial recanalization does not guarantee optimal perfusion in a large proportion of patients. Multivessel disease has been demonstrated to be associated with impaired survival, however its impact on infarct size has not been largely investigated, that therefore is the aim of the current study. Methods: Our population is represented by 827 STEMI patients undergoing primary PCI. Infarct size was evaluated at 30 days by technetium-99m-sestamibi. Results: Multivessel disease was observed in 343 patients (41.5%). It was associated with older age (65 [57-74] vs 63 [53-71], p<0.001), higher rate of previous MI (6.4% vs 2.5%, p=0.005), longer ischemia time evaluated as continuous variable (210 [155-280] min vs 196 [145-270] min, p=0.065) or percentage of patients with ischemia time >3h (63.7% vs 56.4%, p=0.038), and a trend in more cardiogenic shock (5.5% vs 2.9%, p=0.055). Patients with multivessel disease received more often Abciximab (92.1% vs 88.4%, p<0.001), Intra-aortic balloon pump (6.4% vs 1.9%, p<0.001). No differences were observed in other clinical or angiographic characteristics. In particular, multivessel disease did not affect the rate of postprocedural TIMI 3 flow (90.9% vs 93.4%, p=0.18) and ST-segment resolution (52.4% vs 54.9%, p=0.48). Multivessel disease did not affect infarct size (12.7% [4.5%-24.9%] vs 12.3% [4%-24.1%], p=0.58). Similar results were observed in subanalyses without any significant interaction for each variable (anterior infarct location (p int=0.23), gender (p int=0.9), age (p int=0.7), diabetes (pint=0.15)). The absence of any impact of multivessel disease on infarct size was confirmed when the analysis was conducted according to the percentage of patients with infarct size above the median, even after correction for baseline characteristics, such as age, previous MI, ischemia time, use of Gp IIb-IIIa inhibitors, cardiogenic shock, ischemia time (OR [95% CI]=1.09 [0.82-1.45], p=0.58). Conclusions: This study shows that among STEMI patients undergoing primary PCI multivessel disease does not affect infarct size.