Coronary angioplasty in acute myocardial infarction: in which patients is it less likely to obtain an adequate coronary reperfusion?

Introduction. In patients with acute myocardial infarction treated with pri mary angioplasty, the inability to achieve successful coronary reperfusion is associated with higher mortality. The objective of the study was to iden tify which characteristics may predict a lower angiographic success rate in patients with acute myocardial infarction treated with coronary angioplast y. Patients and methods. The study population is constituted by the 790 patien ts with acute myocardial infarction that were treated with angioplasty with in the 12 hours after the onset of symptoms from 1991 to 1999 at our instit ution. A successful anigographic result was considered in presence of a res idual stenosis <50% and a TIMI flow 2 or 3 after the procedure. Results. A successful angiographic result and a final TIMI 3 flow were achi eved in 736 (93.2%) and 652 (82.5%) patients, respectively. In-hospital mor tality was higher in patients with angiographic failure than in those with angiographic successful result (48 vs. 10%; p < 0.01). Age under 65 (91 vs. 95%; p = 0.02), non smoking (90 vs. 96%; p < 0.01), previous infarction (8 7 vs. 94%; p = 0.02), cardiogenic shock (80 vs. 95%; p < 0.01), undetermine d location (67 vs. 93%; p < 0.01), non-inferior location (92 vs. 96%; p = 0 .04), left bundle branch block (64 vs. 94%; p < 0.01), multivessel disease (91 vs. 95%; p = 0.02), left ventricular ejection fraction < 0.40 (89 vs. 9 7%; p < 0.01), no utilization of coronary stenting (90 vs 96%; p < 0.01), a nd use of intraaortic balloon couterpulsation pump (82 vs. 95%; p < 0.01) w ere associated with a lower angiographic success rate. In the multivariable analysis, the following were independent predictors for angiographic failu re: left bundle branch block (odds ratio [OR], 12.95; CI 95%, 3.00-53.90), cardiogenic shock (OR, 4.20; CI 95%, 1.95-8.75), no utilization of coronary stent (OR, 3.44; CI 95%, 1.71-7.37), and previous infarction (OR, 2.82; CI 95%, 1.29-5.90). Conclusion. Coronary angioplasty allows a successful coronary recanalizatio n in most patients with acute myocardial infarction. Some basic characteris tics, however, may identify some subsets in which a successful angiographic result may be more difficult to obtain.