Decreasing hospital mortality between 1994 and 1998 in patients with acute myocardial infarction treated with primary angioplasty but not in patients treated 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)

Abstract

OBJECTIVESWe investigated changes in the clinical outcome of primary angioplasty and thrombolysis for the treatment of acute myocardial infarction (AMI) from 1994 to 1998.BACKGROUNDPrimary angioplasty for the treatment of AMI is a sophisticated technical procedure that requires experienced personnel and optimized hospital logistics. Growing experience with primary angioplasty in clinical routine and new adjunctive therapies may have improved the outcome over the years.METHODSThe pooled data of two German AMI registries: the Maximal Individual Therapy in AMI (MITRA) study and the Myocardial Infarction Registry (MIR) were analyzed.RESULTSOf 10,118 lytic eligible patients with AMI, 1,385 (13.7%) were treated with primary angioplasty, and 8,733 (86.3%) received intravenous thrombolysis. Patients characteristics were quite balanced between the two treatment groups, but there was a higher proportion of patients with a prehospital delay of >6 h in those treated with primary angioplasty. The proportion of an in-hospital delay of more than 90 min significantly decreased in patients treated with primary angioplasty over the years (p for trend = 0.015, multivariate 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 significantly 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 trend 0.175, multivariate OR for each year: 1.02, 95% CI: 0.94– 1.11).CONCLUSIONSCompared with thrombolysis the clinical results of primary angioplasty for the treatment of AMI improved from 1994 to 1998. This indicates a beneficial effect of the growing experience and optimized hospital logistics of this technique over the years.