Cockcroft-Gault is better than the Modification of Diet in Renal Disease study formula at predicting outcome after a myocardial infarction: data from the Swedish Web-system for Enhancement and Development of Evidence-based care in Heart disease Evaluated According to Recommended Therapies (SWEDEHEART).
BACKGROUND
The aim was to examine whether the Modification of Diet in Renal Disease (MDRD) or the Cockcroft-Gault (CG) formula is better at predicting prognosis in myocardial infarction (MI) patients.


METHODS
All consecutive MI patients entered in a nationwide registry between 2003 and 2006 with glomerular filtration rate (eGFR) estimated by both the MDRD and CG formula (N = 36,137) were analyzed.


RESULTS
Cockcroft-Gault classified a larger proportion of patients as having at least a moderate (39.8% vs 31.1%, P < .001) or at least a severe renal dysfunction (7.6% vs 4.4%, P < .001) compared with the MDRD. The largest difference between the estimations was seen when patients were divided according to gender, age, and weight, where CG estimated a lower eGFR in women, the elderly, and those with low body weight. In a receiver operating characteristic analysis, CG had a stronger association to 1-year mortality (area under the curve 0.78, 95% CI 0.77-0.79) than MDRD (area under the curve 0.73, 95% CI 0.72-0.74). Within each renal function stage classified with the MDRD, there were patients identified with the CG as having both a worse renal function and a higher mortality. After multivariable adjustment, CG predicted 1-year mortality better than the MDRD (renal failure vs normal renal function: hazard ratio 3.00, 95% CI 2.42-3.71 with the CG; hazard ratio 2.56, 95% CI 2.10-3.11 with the MDRD).


CONCLUSIONS
Cockcroft-Gault is better than the MDRD equation at predicting mortality after a MI. This is mainly explained by differences in the coefficients and variables included in the eGFR equations, and less to differences in various subgroups of patients.
Szummer
Karolina
K
Department of Medicine, Section of Cardiology, Huddinge, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden. karolina.szummer@karolinska.se
Lundman
Pia
P
Jacobson
Stefan H
SH
Lindbäck
Johan
J
Stenestrand
Ulf
U
Wallentin
Lars
L
Jernberg
Tomas
T
D000368:Aged; D000369:Aged, 80 and over; D004032:Diet / Q000592:standards*; D019317:Evidence-Based Medicine / Q000379:methods*; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007674:Kidney Diseases / Q000178:diet therapy* / Q000209:etiology / Q000503:physiopathology; D008297:Male; D016347:Medical Records Systems, Computerized; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications / Q000453:epidemiology / Q000628:therapy*; D011379:Prognosis; D012015:Reference Standards; D012189:Retrospective Studies; D013548:Sweden / Q000453:epidemiology