Influence of treatment delay on infarct size and clinical outcome in patients with acute myocardial infarction treated with primary angioplasty

Abstract

Objectives: The purpose of this analysis was to determine the influence of an additional treatment delay inherent in transfer to an angioplasty center for primary angioplasty of patients with acute myocardial infarction who are first admitted to hospitals without angioplasty facilities.

Background: Several randomized trials have demonstrated the benefits of primary angioplasty in acute myocardial infarction. In recent years, increasing numbers of patients with myocardial infarction, initially admitted to hospitals without angioplasty facilities are transported to our hospital for primary angioplasty. However, the additional delay due to the transport may have a deleterious effect on infarct size and clinical outcome.

Methods: In a three-year period (December 1993 to November 1996), 207 consecutive patients who were transferred for primary angioplasty were analyzed in a matched comparison with non-transferred patients. Matching criteria were age, sex, infarct location, presentation delay and Killip class.

Results: Patients who were transferred had an additional median delay of 43 min. This resulted in a more extensive enzymatic infarct size and a lower ejection fraction measured at 6 months. The rate of angioplasty success defined as TIMI grade 3 flow, and the 6-month mortality rate (7%) were comparable in both groups.

Conclusions: The additional delay had a deleterious effect on myocardial salvage, reflected by a larger infarct size and a lower left ventricular function. However, the patency rate and 6-month clinical outcome were not affected by this delay.