Original article Impact of the time to reperfusion on early outcomes in patients with acute myocardial infarction undergoing primary angioplasty

Abstract

Background: The ACC/AHA guidelines for management of patients with ST-elevation myocardial infarction (STEMI) have recommended primary PCI (pPCI) as the preferred reperfusion therapy, when it can be performed in a timely fashion, within 90-110 min from the first contact with medical personnel. The impact of treatment delays on outcomes in patients undergoing pPCI has been controversial.
Aim: To evaluate the impact of time delays on in-hospital mortality and on the frequency of cardiac events during 30 days after STEMI.
Methods: 1723 patients were stratified on the basis of their time delays: from symptom onset until balloon inflation. The patients were divided into 4 groups: group 1 (311 patients) – time from symptom onset <90 min; group 2 (731 patients) – time delays of 90-180 min; group 3 (535 patients) – time delays of 180-360 min, and group 4 (146 patients) – time from symptom onset >360 min.
Results: The median time delay was 268.5±206 min, the median door to balloon time was 36.12±11.2 min. The patients with longer time delays (group 4) were older, more often were women, and had a higher frequency of diabetes, anterior MI and Killip class 4. During hospitalisation, 70 (4.1%) patients died. In-hospital mortality was significantly higher in group 4 (13.6%) than in other groups. Complications of STEMI such as cardiogenic shock considerably influenced mortality (45.6%). During a 30-day follow- -up, the patients with cardiogenic shock and the elderly had an increased risk of cardiac events. Also, time delays >360 min and failed pPTCA were independent adverse risk factors in multivariate regression analysis.
Conclusion: Delays in time to pPCI have an impact on outcomes, especially in those treated >6 hours from the onset of symptoms.