Cardiovascular Center, Division of Cardiology, Department of Internal Medicine, Korea University Guro Hospital, Korea University College of Medicine, Seoul, Korea.
Korean J Intern Med. 2023 Jul;38(4):514-525. doi: 10.3904/kjim.2022.375. Epub 2023 Jun 20.
BACKGROUND/AIMS: Cardiorespiratory fitness (CRF), as measured by maximal oxygen consumption (VO2max), is an important independent predictive factor of cardiovascular outcomes in patients with heart failure (HF). However, it is unclear whether conventional equations for estimating CRF are applicable to patients with HF with preserved ejection fraction (HFpEF).
This study included 521 patients with HFpEF (EF ≥ 50%) whose CRF was directly measured by cardiopulmonary exercise test using a treadmill. We developed a new equation (Kor-HFpEF) for half of the patients in the HFpEF cohort (group A, n = 253) and validated it for the remaining half (group B, n = 268). The accuracy of the Kor-HFpEF equation was compared to that of the other equations in the validation group.
In the total HFpEF cohort, the directly measured VO2max was significantly overestimated by the FRIEND and ACSM equations (p < 0.001) and underestimated by the FRIEND-HF equation (p <0.001) (direct 21.2 ± 5.9 mL/kg/min; FRIEND 29.1 ± 11.8 mL/kg/min; ACSM 32.5 ± 13.4 mL/kg/min; FRIEND-HF 14.1 ± 4.9 mL/kg/min). However, the VO2max estimated by the Kor-HFpEF equation (21.3 ± 4.6 mL/kg/min) was similar to the directly measured VO2max (21.7 ± 5.9 mL/kg/min, p = 0.124), whereas the VO2max estimated by the other three equations was still significantly different from the directly measured VO2max in group B (all p < 0.001).
Traditional equations used to estimate VO2max were not applicable to patients with HFpEF. We developed and validated a new Kor-HFpEF equation for these patients, which had a high accuracy.
背景/目的：心肺适能（CRF），以最大摄氧量（VO2max）衡量，是心力衰竭（HF）患者心血管结局的重要独立预测因素。然而，尚不清楚用于估计 CRF 的传统方程是否适用于射血分数保留的心力衰竭（HFpEF）患者。
本研究纳入了 521 例 HFpEF（EF≥50%）患者，他们的 CRF 通过跑步机心肺运动试验直接测量。我们为 HFpEF 队列的一半患者（A 组，n=253）开发了一个新方程（Kor-HFpEF），并对另一半患者（B 组，n=268）进行了验证。在验证组中比较了 Kor-HFpEF 方程的准确性。
在整个 HFpEF 队列中，FRIEND 和 ACSM 方程显著高估了直接测量的 VO2max（p<0.001），而 FRIEND-HF 方程则低估了直接测量的 VO2max（p<0.001）（直接测量 21.2±5.9 mL/kg/min；FRIEND 29.1±11.8 mL/kg/min；ACSM 32.5±13.4 mL/kg/min；FRIEND-HF 14.1±4.9 mL/kg/min）。然而，Kor-HFpEF 方程估计的 VO2max（21.3±4.6 mL/kg/min）与直接测量的 VO2max 相似（21.7±5.9 mL/kg/min，p=0.124），而其他三个方程估计的 VO2max 在 B 组中仍与直接测量的 VO2max 显著不同（均 p<0.001）。
用于估计 VO2max 的传统方程不适用于 HFpEF 患者。我们为这些患者开发并验证了一个新的 Kor-HFpEF 方程，其准确性较高。
