Background: Renal dysfunction is a strong predictor of adverse events in patients with
atrial fibrillation (AF). The
Cokcroft-Gault, Modification of Diet in Renal Disease (MDRD) and Chronic Kidney
Disease-Epidemiology Collaboration (CKD-EPI) equations are available for
estimating the glomerular filtration rate (GFR). No comparisons between these
equations have yet been performed in patients with non-valvular AF concerning
their mid-term prognostic performance.
Methods: Cross-sectional study of 555 consecutive patients with
non-valvular AF undergoing transesophageal echocardiogram. We tested the
prognostic performance of the aforementioned GFR estimation formulae, namely
their ability to predict all-cause mortality (primary endpoint) and major
cardiac adverse or ischemic cerebrovascular events (secondary endpoints) during
an average follow-up of 24 months.
Results: Regarding the primary endpoint, Cockcroft-Gault (AUC=0.749±0.028)
was superior to both MDRD (AUC=0.620±0.035) and CKD-EPI (AUC=0.641±0.034) [p<0.001 both comparisons] while
CKD-EPI was superior to MDRD (p<0.001).
Cockcroft-Gault was marginally superior to both MDRD (AUC=0.673±0.049 vs. AUC=0.595±0.055,
p=0.050) and CKD-EPI (AUC=0.673±0.049
vs. AUC=0.604±0.054, p=0.063) in the
prediction of ischemic cerebrovascular events, while no difference was found
between CKD-EPI and MDRD. Concerning AUC for prediction of MACE,
Cockcroft-Gault was superior to MDRD (p=0.005)
and CKD-EPI (p=0.012), while CKD-EPI
was superior to MDRD (p=0.025). Multivariate
predictive models consistently included Cockcroft-Gault formula along with
CHADS2, excluding the other two equations. Measures of
reclassification revealed a significant improvement in risk stratification for
all studied endpoints with Cockcroft-Gault instead of CKD-EPI.
Conclusions: In patients with
non-valvular AF, the Cockcroft-Gault more appropriately classified individuals
with respect to risk of all-cause mortality, ischaemic cerebrovascular event
and major adverse cardiac event.
Credits: Sérgio Barra; Rui Providência; Catarina Faustino; Luís Paiva; Andreia Fernandes; António Leitão Marques