Door-to-balloon time in patients undergoing primary angioplasty and therapeutic decision on acute myocardial infarction

Objectives

In the treatment of acute myocardial infarction (MI), the time delay to achieve reperfusion of the infarction-related artery has been linked to survival rates. Primary or direct angioplasty has been found to be an excellent means of achieving reperfusion in acute ST-elevation MI compared to thrombolytic therapy in randomized trials. However, no mortality benefit of primary angioplasty over thrombolysis was observed in several registries, in which delays in performing primary angioplasty were longer. Our objectives were to evaluate the door-to-balloon time (DBT) in our institution and investigate its relationship with clinical and prognostic variables.

Methods

We studied, retrospectively, 67 patients submitted to primary angioplasty, from January 1999 to November 2000. We divided our patient population into two groups. Group A (GA) included patients with DBT less than 120 min and group B (GB) patients with DBT greater or equal to 120 min. We evaluated several clinical variables, such as left ventricular ejection fraction (LVEF) on their first echocardiogram during hospitalization, admission Killip classification, in-hospital length of stay (LOS) and major cardiovascular events (MACE) during hospitalization and up to 6-month follow-up (in 23 patients).

Results

The median DBT was 132 min and the mean was 165 min, with a standard deviation of 137 min for all the cases. We had 32 patients in the GA and 35 patients (52%) in the GB. We observed four in-hospital deaths, all in GB. The mean LVEF was 53.1 ± 9% in GA and 46.1 ± 13% in GB (P = 0.059). Admission Killip class greater than 1 was noted in three patients of each group. The in-hospital LOS was similar for both groups (GA=8.35 ± 4 and GB=8.33 ± 4 days; NS). In-hospital events occurred in eight patients of GA (25%) and seven patients of GB (20%; NS). Only five follow-up events occurred during the first 6 months, three events in GA patients and two in GB patients (NS).

Conclusion

DBT greater than or equal to 2 h are common and in our population it occurred in more than half of the primary angioplasties. Greater than 2 h DBTs were associated with a trend to larger left ventricular dysfunction early after MI. Monitoring and measures to reduce DBT are crucial for the potential prognosis improvement offered by primary angioplasty and for the broadening of its use in the management of acute MI.