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

Abstract

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.