BACKGROUND Estimated glomerular filtration rate (eGFR) based on serum creatinine (sCr) improves early after left ventricular assist device (LVAD) implantation but subsequently declines. Although sCr is a commonly accepted clinical standard, cystatin C (CysC) has shown superiority in assessment of renal function in disease states characterized by muscle wasting. Among patients with an LVAD, we aimed to (1) longitudinally compare CysC-eGFR and sCr-eGFR, (2) assess their predictive value for early postoperative outcomes, and (3) investigate mechanisms which might explain potential discrepancies. METHODS A prospective cohort (n=116) with CysC and sCr concurrently measured at serial time points, and a retrospective cohort (n=91) with chest computed tomography performed within 40 days post-LVAD were studied. In the prospective cohort, the primary end point was a composite of in-hospital mortality, renal replacement therapy, or severe right ventricular failure. In the retrospective cohort, muscle mass was estimated using pectoralis muscle area indexed to body surface area (pectoralis muscle index). RESULTS In the prospective cohort, sCr-eGFR significantly improved early post-LVAD and subsequently declined, whereas CysC-eGFR remained stable. CysC-eGFR but not sCr-eGFR predicted the primary end point: odds ratio per 5 mL/(min·1.73 m2) decrease 1.16 (1.02-1.31) versus 0.99 (0.94-1.05). In retrospective cohort, for every 5 days post-LVAD, a 6% decrease in pectoralis muscle index was observed (95% CI, 2%-9%, P=0.003). After adjusting for time on LVAD, for every 1 cm2/m2 decrease in pectoralis muscle index, there was a 4% decrease in 30-day post-LVAD sCr (95% CI, 1%-6%, P=0.004). CONCLUSIONS Initial improvement in sCr-eGFR is likely due to muscle wasting following LVAD surgery. CysC may improve assessment of renal function and prediction of early postoperative outcomes in patients with an LVAD.

中文翻译：

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用半胱氨酸蛋白酶抑制剂C-基于肌酐的肾功能评估和左心室辅助装置患者的早期结果预测。

背景技术基于血清肌酐（sCr）的估计肾小球滤过率（eGFR）在左心室辅助装置（LVAD）植入后早期有所改善，但随后下降。尽管sCr是公认的临床标准，但是在以肌肉萎缩为特征的疾病状态中，胱抑素C（CysC）在评估肾功能方面显示出优越性。在LVAD患者中，我们旨在（1）纵向比较CysC-eGFR和sCr-eGFR，（2）评估其对术后早期结局的预测价值，（3）研究可能解释潜在差异的机制。方法研究在连续时间点同时测量CysC和sCr的前瞻性队列（n = 116），并在LVAD后40天内进行胸部CT回顾性队列（n = 91）。在预期的同类中，主要终点是院内死亡率，肾脏替代疗法或严重右心衰竭的综合指标。在回顾性队列中，使用与身体表面积相关的胸大肌面积（胸肌指数）估算肌肉质量。结果在预期队列中，sCr-eGFR在LVAD早期明显改善，随后下降，而CysC-eGFR保持稳定。CysC-eGFR而非sCr-eGFR预测了主要终点：每5 mL /（min·1.73 m2）的优势比下降1.16（1.02-1.31），而0.99（0.94-1.05）。在回顾性队列研究中，LVAD后每5天观察到胸肌指数下降6％（95％CI，2％-9％，P = 0.003）。调整LVAD时间后，胸肌指数每下降1 cm2 / m2，LVAD sCr在30天后下降4％（95％CI，1％-6％，P = 0.004）。结论sCr-eGFR的最初改善可能是由于LVAD手术后肌肉浪费所致。CysC可能会改善LVAD患者的肾功能评估和术后早期结局的预测。