Department of Medicine, Cardiovascular Division, University of Pennsylvania, Philadelphia, PA, USA.
Circ Heart Fail. 2013 Mar;6(2):233-9. doi: 10.1161/CIRCHEARTFAILURE.112.968230. Epub 2013 Jan 16.
Identifying reversible renal dysfunction (RD) in the setting of heart failure is challenging. The goal of this study was to evaluate whether elevated admission blood urea nitrogen/creatinine ratio (BUN/Cr) could identify decompensated heart failure patients likely to experience improvement in renal function (IRF) with treatment.
Consecutive hospitalizations with a discharge diagnosis of heart failure were reviewed. IRF was defined as ≥20% increase and worsening renal function as ≥20% decrease in estimated glomerular filtration rate. IRF occurred in 31% of the 896 patients meeting eligibility criteria. Higher admission BUN/Cr was associated with in-hospital IRF (odds ratio, 1.5 per 10 increase; 95% confidence interval [CI], 1.3-1.8; P<0.001), an association persisting after adjustment for baseline characteristics (odds ratio, 1.4; 95% CI, 1.1-1.8; P=0.004). However, higher admission BUN/Cr was also associated with post-discharge worsening renal function (odds ratio, 1.4; 95% CI, 1.1-1.8; P=0.011). Notably, in patients with an elevated admission BUN/Cr, the risk of death associated with RD (estimated glomerular filtration rate <45) was substantial (hazard ratio, 2.2; 95% CI, 1.6-3.1; P<0.001). However, in patients with a normal admission BUN/Cr, RD was not associated with increased mortality (hazard ratio, 1.2; 95% CI, 0.67-2.0; P=0.59; p interaction=0.03).
An elevated admission BUN/Cr identifies decompensated patients with heart failure likely to experience IRF with treatment, providing proof of concept that reversible RD may be a discernible entity. However, this improvement seems to be largely transient, and RD, in the setting of an elevated BUN/Cr, remains strongly associated with death. Further research is warranted to develop strategies for the optimal detection and treatment of these high-risk patients.
在心力衰竭的背景下，确定可逆性肾功能障碍（RD）具有挑战性。本研究的目的是评估入院时血尿素氮/肌酐比值（BUN/Cr）升高是否可识别出接受治疗后肾功能（IRF）可能改善的失代偿性心力衰竭患者。
回顾性分析了出院诊断为心力衰竭的连续住院患者。IRF 的定义为估算肾小球滤过率（eGFR）增加≥20%，肾功能恶化定义为 eGFR 降低≥20%。符合入选标准的 896 例患者中，有 31%发生了 IRF。入院时 BUN/Cr 较高与住院期间 IRF 相关（比值比，每增加 10 增加 1.5；95%置信区间 [CI]，1.3-1.8；P<0.001），这种关联在调整基线特征后仍然存在（比值比，1.4；95%CI，1.1-1.8；P=0.004）。然而，较高的入院 BUN/Cr 也与出院后肾功能恶化相关（比值比，1.4；95%CI，1.1-1.8；P=0.011）。值得注意的是，在入院 BUN/Cr 升高的患者中，与 RD（eGFR<45）相关的死亡风险很大（风险比，2.2；95%CI，1.6-3.1；P<0.001）。然而，在入院 BUN/Cr 正常的患者中，RD 与死亡率增加无关（风险比，1.2；95%CI，0.67-2.0；P=0.59；p 交互=0.03）。
入院时 BUN/Cr 升高可识别出接受治疗后可能出现 IRF 的失代偿性心力衰竭患者，为可逆性 RD 可能是一种可识别的实体提供了证据。然而，这种改善似乎在很大程度上是短暂的，并且在 BUN/Cr 升高的情况下，RD 仍然与死亡密切相关。需要进一步研究以制定策略，以最佳地检测和治疗这些高危患者。
