Impact of renal dysfunction on 1-year mortality after acute myocardial infarction

Survival after acute myocardial infarction (MI) is linked to multiple factors, including mild or severe chronic kidney dysfunction. The aim of this study was to determine to what extent a reduction in glomerular filtration rate (GFR) influences 1-year mortality when risk level at admission and quality of care are taken into account.

A prospective registry was carried out in a geographically delimited area, including all patients admitted with a diagnosis of acute MI over a 6-month period. The GFR was calculated from serum creatinine levels, and patients were stratified into 3 groups: GFR1 >59 mL/min per 1.73 m2, GFR2 >29 and <60 mL/min per 1.73 m2, and GFR3 <30 mL/min per 1.73 m2. A risk index based on initial presentation was calculated. Inhospital and discharge treatments were recorded, taking into account possible contraindications. Patients were followed up for 1 year to assess all-cause mortality rate.

A total of 754 patients were included, 333 ST-elevation MI and 421 non-ST-elevation MI. Overall 1-year mortality was 11.5%. Patients with impaired GFR were older, with more comorbidities, and received fewer effective therapies (less reperfusion, glycoprotein IIb/IIIa receptor inhibitors, early angiography, beta-blockers, and statins). One-year mortality increased as GFR decreased: GFR1 2.3% (5/215), GFR2 9.4% (31/328), and GFR3 24.2% (51/211) (P < .001 for trend). By multivariable logistic regression, a significant association was found between 1-year mortality and risk index (odds ratio [OR] 1.41, 95% CI 1.16-1.71 per 10% increase in risk index), GFR (OR 0.97, 95% CI 0.95-0.98 per additional GFR unit), use of beta-blockers (OR 0.15, 95% CI 0.05-0.50 for users), and early coronary angiography (OR 0.26, 95% CI 0.32-0.66 for patients submitted to angiography).

In patients with acute MI, decreased GFR is associated with higher mortality, and this relation remains strong after adjustment for the level of risk at admission and the effective treatments used.