Zhao Tingting, Chen Guanzhong, Zhu Shiyu, Zhao Chengchen, Jin Chunna, Xie Yao, Xiang Meixiang
Department of Cardiology, The Second Affiliated Hospital, Zhejiang University School of Medicine, 310009 Hangzhou, Zhejiang, China.
Rev Cardiovasc Med. 2023 Jul 31;24(8):219. doi: 10.31083/j.rcm2408219. eCollection 2023 Aug.
Mitral regurgitation (MR) has a high prevalence and aggravates hypoperfusion and hypoxia in heart failure (HF). Renal tubular epithelial cells are sensitive to hypoxia, and therefore tubulointerstitial damage is quite common in HF. However, the correlation between tubular dysfunction and MR has not been studied. The aim of this work was to evaluate the prognostic significance of urinary N-acetyl- -d-glucosaminidase (uNAG), a biomarker of renal tubular damage, in patients with HF and MR.
This was a prospective cohort study of 390 patients (mean age 64 years; 65.6% male) with uNAG measurement on admission (expressed as urinary NAG/urinary creatinine) and at least 1 year of follow-up data. The pre-defined primary endpoint was the composite of all-cause mortality or rehospitalization for HF after discharge. Cox regression analysis, restricted cubic splines, and subgroup analysis were used to investigate the prognostic value of uNAG modeled as a categorical (quartiles) or continuous (per SD increase) variable.
A total of 153 (39.23%) patients reached the composite endpoint over a median follow-up time of 1.2 years. The uNAG level correlated with the severity of HF and with the incidence of adverse events. In a multivariable Cox regression model, each SD (13.80 U/g Cr) of increased uNAG was associated with a 17% higher risk of death or HF rehospitalization (95% confidence interval, 2-33%, = 0.022), and a 19% higher risk of HF rehospitalization ( = 0.027). Subgroup analysis revealed the associations between uNAG and poor prognosis were only significant in younger patients ( 65 years) and in patients without obvious cardiovascular comorbidities.
uNAG levels at admission were associated with the risk of adverse outcomes in patients with HF and MR. Additional studies are needed to further investigate the heart-kidney interaction.
二尖瓣反流（MR）患病率高，会加重心力衰竭（HF）时的低灌注和缺氧。肾小管上皮细胞对缺氧敏感，因此肾小管间质损伤在HF中很常见。然而，肾小管功能障碍与MR之间的相关性尚未得到研究。本研究的目的是评估尿N-乙酰-β-D-氨基葡萄糖苷酶（uNAG）（一种肾小管损伤的生物标志物）在HF合并MR患者中的预后意义。
这是一项对390例患者（平均年龄64岁；65.6%为男性）的前瞻性队列研究，患者入院时测量uNAG（以尿NAG/尿肌酐表示），并至少有1年的随访数据。预先定义的主要终点是出院后全因死亡或因HF再次住院的复合终点。采用Cox回归分析、限制性立方样条和亚组分析来研究将uNAG建模为分类变量（四分位数）或连续变量（每标准差增加）时的预后价值。
在中位随访时间1.2年期间，共有153例（39.23%）患者达到复合终点。uNAG水平与HF严重程度及不良事件发生率相关。在多变量Cox回归模型中，uNAG每增加1个标准差（13.80 U/g Cr），死亡或HF再次住院风险升高17%（95%置信区间，2% - 33%，P = 0.022），HF再次住院风险升高19%（P = 0.027）。亚组分析显示，uNAG与预后不良的关联仅在年轻患者（≤65岁）和无明显心血管合并症的患者中显著。
入院时uNAG水平与HF合并MR患者的不良结局风险相关。需要进一步研究以深入探讨心肾相互作用。
