Department of Cardiology, Nagoya University Graduate School of Medicine, Nagoya, Japan; Department of Cardiology, Nagoya Ekisaikai Hospital, Nagoya, Japan.
Department of Cardiology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
J Cardiol. 2020 Jun;75(6):689-696. doi: 10.1016/j.jjcc.2019.12.016. Epub 2020 Jan 27.
Heart failure (HF) is a hypercatabolic state that promotes branched-chain amino acid (BCAA) catabolic activity in the heart and skeletal muscle and reduces protein synthesis in the liver. Consequently, plasma free aromatic amino acids (AAAs) are increased. We investigated the prognostic value of the BCAA/AAA ratio (Fischer's ratio, FR) in patients with HF.
We enrolled 157 consecutive patients hospitalized for worsening HF (81 men, 76 women; mean ± SD age 75 ± 14 years). Plasma BCAA levels (i.e. total leucine, isoleucine, valine) and AAA levels (i.e. total tyrosine, phenylalanine) were measured at a time when the patients were stabilized (at discharge). FR was calculated as the combined plasma BCAA levels divided by the AAA level. Cardiac events were defined as a composite of cardiac death and hospitalization for worsening HF.
The patients were divided into two groups based on the median FR (high-FR group: FR ≥ 3.1, n = 78; low-FR group: FR < 3.1, n = 79). Compared with the high-FR group, low-FR patients were older, had more prior hospitalizations for HF, lower albumin and cholinesterase levels, and lower geriatric nutritional risk index (GNRI). Altogether, 46 cardiac events occurred during the follow-up period (221 ± 135 days), including 14 cardiac deaths and 32 hospitalizations for worsening HF. In a Kaplan-Meier survival analysis, the low-FR group had more cardiac events than the high-FR group (log-rank, p < 0.001). The best cut-off value of FR was determined as 2.9 in the receiver operating characteristic curve for cardiac events. A multivariate Cox proportional hazards regression analysis showed that being in the low-FR group was an independent determinant of cardiac events from parameters of liver function tests and GNRI.
FR might be useful for predicting future cardiac events in patients with HF, reflecting nutritional status which cannot be assessed by liver function tests and GNRI.
心力衰竭（HF）是一种高分解代谢状态，会促进心脏和骨骼肌中支链氨基酸（BCAA）的分解代谢活性，并减少肝脏中的蛋白质合成。因此，血浆游离芳香族氨基酸（AAA）增加。我们研究了 BCAA/AAA 比值（Fischer 比，FR）在 HF 患者中的预后价值。
我们纳入了 157 例因 HF 恶化住院的连续患者（81 名男性，76 名女性；平均年龄 75±14 岁）。在患者稳定时（出院时）测量血浆 BCAA 水平（即总亮氨酸、异亮氨酸、缬氨酸）和 AAA 水平（即总酪氨酸、苯丙氨酸）。FR 计算为血浆 BCAA 水平的总和除以 AAA 水平。心脏事件定义为心脏死亡和因 HF 恶化住院的复合事件。
根据 FR 的中位数将患者分为两组（高 FR 组：FR≥3.1，n=78；低 FR 组：FR<3.1，n=79）。与高 FR 组相比，低 FR 组患者年龄较大，HF 住院次数较多，白蛋白和胆碱酯酶水平较低，老年营养风险指数（GNRI）较低。随访期间共发生 46 例心脏事件（221±135 天），包括 14 例心脏死亡和 32 例 HF 恶化住院。在 Kaplan-Meier 生存分析中，低 FR 组的心脏事件多于高 FR 组（对数秩检验，p<0.001）。FR 的最佳截断值在心脏事件的受试者工作特征曲线中确定为 2.9。多变量 Cox 比例风险回归分析显示，在肝功能试验和 GNRI 参数中，低 FR 组是心脏事件的独立决定因素。
FR 可能有助于预测 HF 患者未来的心脏事件，反映了不能通过肝功能试验和 GNRI 评估的营养状况。
