Abstract 12912: Impact of Occult Renal Dysfunction on Early and Late Outcomes following Coronary Artery Bypass Grafting
Background: High serum creatinine is regarded as an independent risk factor for poor outcomes following coronary artery bypass grafting (CABG). However, the impact of "occult renal dysfunction", defined as an impaired creatinine clearance (CCr) with a normal serum creatinine level, still has been unclear. Thus, we sought to investigate the impact of occult renal dysfunction on outcomes after CABG
Methods and Results: Among the patients undergoing first PCI or CABG enrolled in the CREDO-Kyoto Registry (a registry of first-time PCI and CABG patients in Japan), 1560 patients with normal serum creatinine levels undergoing CABG were entered into the study (67 ± 10 y.o.). Patients were divided into two groups based on preoperative CCr estimated with the Cockcroft-Gault equation: 1057 patients with a CCr ≥ 60 mL/min (normal group) and 503 patients with a CCr of < 60 mL/min (occult renal dysfunction group). Ratio of patients with left main disease was similar between the groups (28% vs. 30%, p=0.41), but those with triple-vessel disease was more common in the occult renal dysfunction group (71% vs. 64%, p<0.01). Preoperative creatinine was similar (0.83 ± 0.13 vs. 0.88 ± 0.16 mg/dL), but estimated CCr was different between the groups (86.1 ± 22.5 vs. 51.3 ± 6.6 mL/min, p<0.01). Occult renal dysfunction was associated with high in-hospital mortality (3.2% vs. 1.0%, p<0.01), high stroke rate (2.4% vs. 1.2%, p=0.09), and need for dialysis (2.0% vs. 0.2%, p<0.01). Regarding long-term outcomes, unadjusted all-cause mortality at 1 and 5 years were 1.9% and 7.6% for the normal group, and 5.6% and 17% for the occult renal dysfunction group, respectively (p<0.01). Similarly, multivariate analysis showed that occult renal dysfunction was associated with high overall mortality compared with the normal (hazard ratio [95% confidence interval]: 1.55 [1.00-2.37], p=0.045) and high incidence of composite cardiovascular events (cardiovascular death, myocardial infarction, or stroke: 1.37 [0.99-1.90], p=0.06)
Conclusions: Occult renal dysfunction is an independent risk factor for early and late death, and cardiovascular events in patients undergoing CABG with normal serum creatinine level. Patients with occult renal dysfunction should be carefully operated and followed-up.
- © 2012 by American Heart Association, Inc.