Clinical characteristics of dialysis patients with acute myocardial infarction in the United States: a collaborative project of the United States Renal Data System and the National Registry of Myocardial Infarction

Abstract

Background: Acute myocardial infarction (AMI) is catastrophic for dialysis patients. This study set out to determine the clinical characteristics of dialysis patients hospitalized for AMI in the United States.

Methods and results: This retrospective cohort study used data from the US Renal Data System (USRDS) database (n=1,285,177) and the third National Registry of Myocardial Infarction (NRMI 3) (n=537,444). AMI hospitalizations from April 1, 1998, through June 30, 2000, were identified using International Classification of Diseases, 9th edition, clinical modification, codes 410, 410.x, 410.x0, and 410.x1. The 9418 unique dialysis patients identified with AMI hospitalizations in the USRDS database were cross-matched with the NRMI registry, creating a cohort for analysis that consisted of 3049 matching patients. Clinical characteristics of dialysis and nondialysis (n=534,395) AMI patients were compared by use of the chi2 test. Of clinical significance, 44.8% of dialysis patients were diagnosed as not having acute coronary syndrome on admission, versus 21.2% of nondialysis patients; 44.4% presented with chest pain, versus 68.3% of nondialysis patients; and 19.1% had ST elevation, versus 35.9% of nondialysis patients. Cardiac arrest was twice as frequent for dialysis patients (11.0% versus 5.0%), and in-hospital death was nearly so (21.3% versus 11.7%). In a logistic regression model, the odds ratio for in-hospital death for dialysis versus nondialysis patients was 1.498 (95% CI, 1.340 to 1.674).

Conclusions: Dialysis patients hospitalized for AMI differ strikingly from nondialysis patients, which possibly explains their poor outcomes. Intensive efforts for early, accurate recognition of AMI in dialysis patients are warranted.