Background

Chronic subclinical hemolysis is frequent in patients implanted with Left Ventricular Assist Device (LVAD) and is associated with adverse outcomes. Consequences of LVADs-induced subclinical hemolysis on kidney structure and function is currently unknown.

Methods

Thirty-three patients implanted with a Heartmate II LVAD (Abbott, Inc, Chicago IL) were retrospectively studied. Hemolysis, Acute Kidney Injury (AKI) and the evolution of estimated Glomerular Filtration Rate were analyzed. Proximal Tubulopathy (PT) groups were defined according to proteinuria, normoglycemic glycosuria, and electrolytic disorders. The Receiver Operating Characteristic (ROC) curve was used to analyze threshold of LDH values associated with PT.

Results

Median LDH between PT groups were statistically different, 688 IU/L [642–703] and 356 IU/L [320–494] in the “PT” and “no PT” groups, respectively p = 0.006. To determine PT group, LDH threshold > 600 IU/L was associated with a sensitivity of 85.7% (95% CI, 42.1–99.6) and a specificity of 84.6% (95% CI, 65.1–95.6). The ROC's Area Under Curve was 0.83 (95% CI, 0.68–0.98). In the “PT” group, patients had 4.2 [2.5–5.0] AKI episodes per year of exposure, versus 1.6 [0.4–3.7] in the “no PT” group, p = 0.03. A higher occurrence of AKI was associated with subsequent development of Chronic Kidney Disease (CKD) (p = 0.02) and death (p = 0.05).

Conclusions

LVADs-induced subclinical hemolysis is associated with proximal tubular functional alterations, which in turn contribute to the occurrence of AKI and subsequent CKD. Owing to renal toxicity of hemolysis, measures to reduce subclinical hemolysis intensity as canula position or pump parameters should be systematically considered, as well as specific nephroprotective therapies.

中文翻译：

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左心室辅助装置引起的溶血与近端肾小管病变有关

背景

植入左心室辅助装置（LVAD）的患者经常发生慢性亚临床溶血，并伴有不良后果。目前尚不清楚LVADs引起的亚临床溶血对肾脏结构和功能的影响。

方法

回顾性研究了33例植入了Heartmate II LVAD的患者（Abbott，Inc，Chicago IL）。分析了溶血，急性肾损伤（AKI）和估计的肾小球滤过率的演变。根据蛋白尿，血糖正常糖尿症和电解质紊乱定义近端肾病（PT）组。接收器工作特性（ROC）曲线用于分析与PT相关的LDH值的阈值。

结果

PT组之间的LDH中位数有统计学差异，“ PT”组和“ no PT”组的688 IU / L [642-703]和356 IU / L [320-494]，p = 0.006。要确定PT组，LDH阈值> 600 IU / L时的敏感性为85.7％（95％CI，42.1-99.6），特异性为84.6％（95％CI，65.1-95.6）。ROC的曲线下面积为0.83（95％CI，0.68-0.98）。在“ PT”组中，患者每年暴露有4.2 [2.5-5.0] AKI发作，而在“无PT”组中，患者为1.6 [0.4-3.7]，p = 0.03。AKI的发生与慢性肾脏病（CKD）的后续发展（p = 0.02）和死亡（p = 0.05）有关。

结论

LVADs引起的亚临床溶血与近端肾小管功能改变有关，这反过来又导致了AKI和随后的CKD的发生。由于溶血的肾脏毒性，应系统地考虑降低亚临床溶血强度的措施，如插管位置或泵参数，以及特定的肾保护疗法。