Combined Impact of Age and Estimated Glomerular Filtration Rate on In-Hospital Mortality After Percutaneous Coronary Intervention for Acute Myocardial Infarction (from the American College of Cardiology National Cardiovascular Data Registry)

Age and chronic kidney disease are major risk factors for poor cardiovascular outcome; however, renal function is often estimated on the basis of serum creatinine levels, and advanced renal impairment may be hidden behind near normal creatinine levels. We assessed the impact of estimated glomerular filtration rate (GFR) on in-hospital mortality in young (<65 years old), old (65 to 84 years old), and very old (≥85 years old) patients undergoing percutaneous coronary intervention (PCI) for acute myocardial infarction. The adjusted risk of death was calculated in 169,826 patients from the American College of Cardiology National Cardiovascular Data Registry undergoing primary PCI for acute myocardial infarction. Younger patients had fewer co-morbidities, higher estimated GFR, less frequent multivessel disease, and lower unadjusted mortality rates than older patients (p <0.0001 for all comparisons). However, the adjusted risk of in-hospital mortality for patients with severe renal insufficiency (estimated GFR <30 ml/min/1.73 m²) compared with those with normal renal function (estimated GFR ≥60 ml/min/1.73 m²) was higher in young patients (adjusted odds ratio = 7.58, 95% confidence interval 6.18 to 9.29) than old (adjusted odds ratio = 4.75, 95% confidence interval 4.14 to 5.45) and very old patients (adjusted odds ratio = 3.50, confidence interval 2.50 to 4.89). In conclusion, severe renal insufficiency is associated with a greater risk of in-hospital mortality in young than old and very old patients after primary PCI. Risk stratification for patients with acute myocardial infarction should incorporate an assessment of renal function with estimated GFR values rather than absolute serum creatinine levels as done in the currently utilized risk scoring algorithms.