[Glomerular filtration rate: which formula should be used in patients with myocardial infarction?]

There is disagreement regarding the best method for assessing renal dysfunction in patients with myocardial infarction (MI). This study aims to compare two commonly used formulas for measuring glomerular filtration rate (GFR) (Cockcroft-Gault [CG] and modification of diet in renal disease [MDRD]) in terms of predicting extent of coronary artery disease (CAD) and short- and long-term cardiovascular risk.

We studied 452 patients admitted to a cardiac intensive care unit (ICU) with MI (age 69.01±13.64 years; 61.7% male, 38.5% diabetic) and followed for two years. CG and MDRD GFR estimates were compared in terms of prediction of CAD extent, in-hospital mortality risk and cardiovascular risk during follow-up.

GFR <60ml/min/1.73 m(2) using the MDRD formula was associated with a tendency for more extensive CAD (2.70 affected segments vs. 2.20, p=0.052) and higher two-year mortality risk (p<0.001, OR 3.84, 95% CI 2.04-7.22) and risk for reinfarction (p<0.001, OR 4.09, 95% CI 2.00-8.39), decompensated heart failure (DHF) (p<0.001, OR 3.95, 95% CI 2.04-7.66) and combined cardiovascular endpoints (p=0.001, OR 2.47, 95% CI 1.47-4.17). Using the CG formula, GFR<60ml/min/1.73 m(2) only predicted higher risk for DHF (p=0.016, OR 4.5, 95% CI 1.11-16.57), despite a tendency for more overall combined cardiovascular endpoints (p=0.09, OR 2.84). Both formulas predicted in-hospital mortality.

This study confirmed the value of GFR in predicting various cardiovascular endpoints in patients with MI. Compared to the CG formula, the MDRD formula was significantly more accurate in predicting the severity of CAD and two-year CV risk in patients admitted to the ICU with MI.