Determinants of mortality after myocardial infarction in patients with advanced renal dysfunction

Previous studies using administrative data have shown high mortality in patients with renal failure requiring dialysis after acute myocardial infarction (AMI). There has been little investigation into the mortality after AMI in those with advanced renal disease who are not on dialysis therapy. We analyzed a prospective coronary care unit registry of 1,724 patients with ST segment elevation myocardial infarction admitted over an 8-year period at a single tertiary-care center. Those not on chronic dialysis therapy were stratified into groups based on corrected creatinine clearance, with cutoff values of 46.2, 63.1, and 81.5 mL/min/72 kg. Dialysis patients (n = 47) were considered as a fifth comparison group. Older age, black race, diabetes, hypertension, previous coronary disease, and heart failure were incrementally more common across increasing renal dysfunction strata. There were also graded increases in the relative risk for atrial and ventricular arrhythmias, heart block, asystole, development of pulmonary congestion, acute mitral regurgitation, and cardiogenic shock. Primary angioplasty, thrombolysis, and beta-blockers were used less often across the risk strata (P < 0.0001 for all trends). There was an early mortality hazard (age-adjusted relative risk, 8.76; P < 0.0001) for those with renal dysfunction but not on dialysis therapy for the first 60 months, followed by graded decrements in survival across increasing renal dysfunction strata. The excess mortality in this population appears to be mediated through arrhythmias, adverse hemodynamic events, and the lower use of mortality-reducing therapy.