Background: Atrial fibrillation (AF) is common in hemodialysis patients and contributes to increased mortality. We aimed to examine heart rate variability triangular index (HRVI) in hemodialysis patients with AF as it has recently been reported to predict mortality in AF patients without kidney disease.

Methods: A total of 88 patients on hemodialysis with a medical history of AF or newly diagnosed AF underwent 24-h electrocardiography recordings. The primary endpoint of cardiovascular mortality was recorded during a median follow up of 3.0 years. Risk prediction was assessed by Cox regression, both unadjusted and adjusted for the Charlson Comorbidity Index and the Cardiovascular Mortality Risk Score.

Results: Median age was 76 years, median dialysis vintage was 27 months. Altogether, 22 and 44 patients died due to cardiovascular and non-cardiovascular causes. In 55% of patients AF was present during the recording. Kaplan-Meier plots of HRVI quartiles suggested a non-linear association between HRVI, cardiovascular, and all-cause mortality which was confirmed in non-linear Cox regression analysis. Adjusted linear Cox regression revealed a hazard ratio of 6.2 (95% CI: 2.1–17.7, p = 0.001) and 2.2 (95% CI: 1.3–3.8, p = 0.002) for the outer quartiles (combined first and fourth quartile) for cardiovascular and all-cause mortality, respectively. Patients in the first quartile were more likely to have sinus rhythm whereas patients in the fourth quartile were more likely to have AF.

Conclusions: We found a U-shaped association between HRVI and mortality in hemodialysis AF patients. The results might contribute to risk stratification independent of known risk scores in hemodialysis AF patients.

背景：心房颤动（AF）在血液透析患者中​​很常见，并导致死亡率增加。我们的目的是检查患有 AF 的血液透析患者的心率变异性三角指数 (HRVI)，因为最近有报道称它可以预测无肾脏疾病的 AF 患者的死亡率。

方法：对88例有房颤病史或新诊断房颤的血液透析患者进行24小时心电图记录。心血管死亡率的主要终点是在中位随访 3.0 年期间记录的。风险预测通过 Cox 回归进行评估，未针对 Charlson 合并症指数和心血管死亡风险评分进行调整和调整。

结果：中位年龄为 76 岁，中位透析时间为 27 个月。总共有 22 名和 44 名患者因心血管和非心血管原因死亡。 55% 的患者在记录过程中出现房颤。 HRVI 四分位数的 Kaplan-Meier 图表明 HRVI、心血管疾病和全因死亡率之间存在非线性关联，这一点在非线性 Cox 回归分析中得到了证实。调整后的线性 Cox 回归显示，外四分位数（第一和第四四分位数的组合）的风险比为 6.2（95% CI：2.1–17.7，p = 0.001）和 2.2（95% CI：1.3–3.8，p = 0.002）。分别是心血管死亡率和全因死亡率。第一个四分位数的患者更有可能患有窦性心律，而第四个四分位数的患者更有可能患有房颤。

结论：我们发现血液透析房颤患者的 HRVI 与死亡率之间存在 U 形关联。结果可能有助于独立于血液透析房颤患者已知风险评分的风险分层。