Hospital therapy traditions influence long-term survival in patients with acute myocardial infarction.
BACKGROUND
Differences in therapy and outcome among hospitals have been reported, but these studies have seldom used adjustment for differences in patient characteristics. The objective was to investigate the differences in treatment of acute myocardial infarction (AMI) among different hospitals within 1 country and the possible causes and outcomes of these differences.


METHODS
Prospective cohort study using data from the Register of Information and Knowledge about Swedish Heart Intensive care Admissions (RIKS-HIA) on 32,954 consecutive primary admissions of patients with AMI admitted to the intensive coronary care units of 67 Swedish hospitals in 1999-2000. An activity index was calculated for each hospital based on the hospital's ranking regarding proportion of performed examination or given therapy among the AMI patients.


RESULTS
After adjustment for 24 background characteristics, there were few significant deviations among hospitals in the proportion treated with acute reperfusion, antiplatelets, beta-blockers, or angiotensin-converting enzyme (ACE) inhibitors. However, 3- to 10-fold differences existed among hospitals in the proportion of patients treated with intravenous beta-blockers, intravenous nitroglycerin, intravenous or subcutaneous anticoagulants, and lipid-lowering medication, and even larger discrepancies in echocardiography and revascularization within 14 days. There was a strong (r = 0.69, P < .001) correlation between hospital activity index between the years and a correlation between the hospital's activity index and 1-year mortality (r = -0.30, P = .014). There was no correlation between hospital size and activity index.


CONCLUSIONS
Even after adjustment for differences in patient characteristics, there are differences between the hospital treatment cultures for patients with AMI that persists over time. Concerning everywhere-available treatment options, the treatment activity is independent of the size of the center. A more active treatment tradition is associated with a lower short- and long-term mortality in AMI patients.
Stenestrand
Ulf
U
Department of Cardiology, University Hospital of Linköping, Sweden. stenestrand@riks-hia.se
Lindbäck
Johan
J
Wallentin
Lars
L
D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use; D000368:Aged; D015906:Angioplasty, Balloon, Coronary; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000627:therapeutic use; D000925:Anticoagulants / Q000627:therapeutic use; D015331:Cohort Studies; D001026:Coronary Artery Bypass; D004452:Echocardiography; D005260:Female; D006493:Heparin / Q000627:therapeutic use; D006742:Hospital Bed Capacity; D006761:Hospitals; D006801:Humans; D000960:Hypolipidemic Agents / Q000627:therapeutic use; D008297:Male; D009203:Myocardial Infarction / Q000401:mortality / Q000628:therapy*; D005996:Nitroglycerin / Q000627:therapeutic use; D016019:Survival Analysis; D013548:Sweden; D015912:Thrombolytic Therapy
D000319:Adrenergic beta-Antagonists; D000806:Angiotensin-Converting Enzyme Inhibitors; D000925:Anticoagulants; D000960:Hypolipidemic Agents; D006493:Heparin; D005996:Nitroglycerin