Decreasing hospital mortality between 1994 and 1998 in patients with acutemyocardial infarction treated with primary angioplasty but not in patientstreated with intravenous thrombolysis - Results from the pooled data of the Maximal Individual Therapy in acute myocardial infarction (MITRA) Registry and the Myocardial Infarction Registry (MIR)

OBJECTIVES We investigated changes in the clinical outcome of primary angio plasty and thrombolysis for the treatment of acute myocardial infarction (A MI) from 1994 to 1998. BACKGROUND Primary angioplasty for the treatment of AMI is a sophisticated technical procedure that requires experienced personnel and optimized hospi tal logistics. Growing experience with primary angioplasty in clinical rout ine and new adjunctive therapies may have improved the outcome over the yea rs. METHODS The pooled data of two German AMI registries: the Maximal Individua l Therapy in AMI (MITRA) study and the Myocardial Infarction Registry (MIR) were analyzed. RESULTS Of 10,118 lytic eligible patients with AMI, 1,385 (13.7%) were trea ted with primary angioplasty, and 8,733 (86.3%) received intravenous thromb olysis. Patients characteristics were quite balanced between the two treatm ent groups, but there was a higher proportion of patients with a prehospita l delay of >6 h in those treated with primary angioplasty. The proportion o f an in-hospital delay of more than 90 min significantly decreased in patie nts treated with primary angioplasty over the years (p fur trend = 0.015, m ultivariate odds ratio [OR] for each year of the observation period = 0.84, 95% confidence Interval [CI]: 0.73-0.96) but did not change significantly in patients treated with thrombolysis. Hospital mortality decreased signifi cantly in the primary angioplasty group (p = 0.003 for trend; multivariate OR for each year = 0.73, 95% CI: 0.58-0.93). However, for patients treated with thrombolysis, hospital mortality did not change significantly (p for t rend 0.175, multivariate OR for each year: 1.02, 95% CI: 0.94-1.11). CONCLUSIONS Compared with thrombolysis the clinical results of primary angi oplasty for the treatment of AMI improved from 1994 to 1998. This indicates a beneficial effect of the growing experience and optimized hospital logis tics of this technique over the years. (C) 2000 by the American College of Cardiology.