NEW YORK (Reuters Health) – Patients who develop acute renal failure (ARF) after undergoing coronary artery bypass grafting have a poorer prognosis if the condition doesn’t resolve within a week, according to a new study. CABG patients who don’t have ARF after the procedure do best, so the focus should be on prevention, the researchers say.
Dr. Rajendra H. Mehta, and colleagues at Duke University Medical Center, Durham, North Carolina note in their report in the American Journal of Cardiology that ARF is common after CABG, but “it is not known if the prognosis is different in patients with ARF in whom renal function recovers compared to those without recovery of renal function before discharge.”
To look into that question, the team studied outcomes in 10,415 CABG patients. ARF occurred in 2083 of them (20%), but 703 of these patients had recovery of renal function to baseline levels.
Among patients with no ARF, 30-day mortality (not counting the first week) was 0.6%. Among patients with ARF it was 1.1% in those with recovered renal function and 0.8% in the group without renal recovery — not a significant difference. Median hospital lengths of stay followed a similar pattern: 5, 7 and 8 days, respectively, the researchers found.
Over a median follow-up of 7 years, however, long-term outcomes were significantly worse for patients with ARF who did not have complete recovery of renal function, according to the report.
For example, compared to patients without ARF, the unadjusted hazard ratio for death or rehospitalization was 1.22 for those with ARF and complete recovery but 1.41 for those with ARF with no recovery. Corresponding HRs for death or MI were 1.37 and 1.73, respectively.
These findings, and those of other studies, “suggest that emphasis should be directed toward prevention of ARF after CABG,” the authors observe.
They say that potential strategies might include avoiding nephrotoxic drugs in the perioperative period, delaying surgery if patients have had a large contrast load during cardiac catheterization, and avoiding prolonged hypotension.
However, these and other strategies are aimed at prevention, and it’s not known if attempts to improve recovery of renal function would improve long-term outcomes. “In addition, the best strategy to recover renal function (in the hopes of improving long-term outcomes) in ARF after CABG remains unknown and merits future studies,” Dr. Mehta and colleagues conclude.
Reference:
Impact of Recovery of Renal Function on Long-Term Mortality After Coronary Artery Bypass Grafting
Am J Cardiol 2010.
