Symptom-onset-to-balloon time and mortality in patients with acute myocardial infarction treated by primary angioplasty

OBJECTIVES The aim of the study was to evaluate the relationship between symptom-onset-to-balloon time and one-year mortality in patients with ST-segment elevation myocardial infarction (STEMI) treated by primary angioplasty.

BACKGROUND Despite the prognostic implications demonstrated in patients with STEMI treated with thrombolysis, the impact of time-delay on prognosis in patients undergoing primary angioplasty has yet to be established.

METHODS Our study population consisted of 1,791 patients with STEMI treated by primary angioplasty from 1994 to 2001. All clinical, angiographic and follow-up data were collected. Subanalyses were conducted according to patient risk profile at presentation and preprocedural Thrombolysis In Myocardial Infarction (TIMI) flow.

RESULTS A total of 103 patients (5.8%) had died at one year. Symptom-onset-to-balloon time was significantly associated with the rate of postprocedural TIMI 3 flow (p = 0.012), myocardial blush grade (p = 0.033), and one-year mortality (p = 0.02). A stronger linear association between symptom-onset-to-balloon time and one-year mortality was observed in non-low-risk patients (p = 0.006) and those with preprocedural TIMI flow 0 to 1 (p = 0.013). No relationship was found between door-to-balloon time and mortality. At multivariate analysis, a symptom-onset-to-balloon time >4 h was identified as an independent predictor of one-year mortality (p <0.05).

CONCLUSIONS This study shows that, in patients with STEMI treated by primary angioplasty, symptom-onset-to-balloon time, but not door-to-balloon time, is related to mortality, particularly in non-low-risk patients and in the absence of preprocedural anterograde flow. Furthermore, a symptom-onset-to-balloon time >4 h was identified as independent predictor of one-year mortality. (C) 2003 by the American College of Cardiology Foundation.