Data Sheet 2_Excess ventilation and chemosensitivity in patients with inefficient ventilation and chronic coronary syndrome or heart failure: a case–control study.pdf

BackgroundIn patients with chronic coronary syndromes (CCS), increased ventilation/carbon dioxide production (V̇E/V̇CO2) slope has been found to predict disease progression and mortality, similarly to patients with heart failure (HF); however, increased chemosensitivity, a well-established predictor for mortality in patients with HF, has rarely been assessed in patients with CCS.
MethodPatients with CCS, HF with reduced ejection fraction (EF < 50%), healthy controls (45+ years), and young healthy adults (<35 years) were recruited. For patients, a V̇E/V̇CO2 slope ≥36 was an inclusion criterion. The Duffin rebreathing method was used to determine the resting end-expiratory partial pressure of carbon dioxide (PETCO2), ventilatory recruitment threshold (VRT), and slope (sensitivity) during a hyperoxic (150 mmHg O2) and hypoxic (50 mmHg O2) rebreathing test to determine the central and peripheral chemosensitivity.
ResultsIn patients with CCS, HF, controls, and young healthy adults, median V̇E/V̇CO2 slopes were 40.2, 41.3, 30.5, and 28.0, respectively. Both patient groups had similarly reduced hyperoxic VRT (at PETCO2 42.1 and 43.2 mmHg) compared to 46.0 and 48.8 mmHg in the control and young healthy adults. Neither hypoxic VRT nor hyper- or hypoxic slopes were significantly different in patients compared to controls. Both patient groups had lower resting PETCO2 than controls, but only patients with HF had increased breathing frequency and rapid shallow breathing at rest.
ConclusionIn patients with HF and/or CCS and excess ventilation, central chemoreflex VRT was reduced independently of the presence of HF. Low VRTs were related to resting excess ventilation in patients with CCS or HF; however, rapid shallow breathing at peak exercise was present only in patients with HF.
Clinical trial registration numberNCT05057884.

【背景】在慢性冠状动脉综合征（chronic coronary syndromes, CCS）患者中，通气/二氧化碳生成斜率（V̇E/V̇CO2 slope）升高已被证实可预测疾病进展与死亡风险，这一点与心力衰竭（heart failure, HF）患者类似；但作为心力衰竭患者中公认的死亡风险预测因子的化学敏感性升高，在慢性冠状动脉综合征患者中却极少被评估。
【方法】本研究纳入了慢性冠状动脉综合征（CCS）患者、射血分数降低型心力衰竭（heart failure with reduced ejection fraction, EF < 50%）患者、健康对照受试者（年龄≥45岁）以及年轻健康成年人（年龄<35岁）。入组患者需满足V̇E/V̇CO2斜率≥36的纳入标准。本研究采用达夫因复吸法（Duffin rebreathing method），通过高氧（150 mmHg O₂）与低氧（50 mmHg O₂）复吸试验，测定受试者静息状态下的呼气末二氧化碳分压（end-expiratory partial pressure of carbon dioxide, PETCO2）、通气募集阈值（ventilatory recruitment threshold, VRT）以及斜率（敏感性），以此评估中枢与外周化学敏感性。
【结果】慢性冠状动脉综合征患者、心力衰竭患者、健康对照受试者以及年轻健康成年人的V̇E/V̇CO2斜率中位数分别为40.2、41.3、30.5与28.0。与健康对照受试者（46.0 mmHg）和年轻健康成年人（48.8 mmHg）相比，两个患者组的高氧通气募集阈值均显著降低（对应呼气末二氧化碳分压分别为42.1 mmHg与43.2 mmHg）。与健康对照受试者相比，两个患者组的低氧通气募集阈值以及高氧/低氧斜率均无显著差异。两个患者组的静息呼气末二氧化碳分压均低于健康对照受试者，但仅心力衰竭患者存在静息呼吸频率升高以及浅快呼吸表现。
【结论】在存在通气过度的心力衰竭（HF）和/或慢性冠状动脉综合征（CCS）患者中，中枢化学反射通气募集阈值的降低与心力衰竭的存在无关。慢性冠状动脉综合征或心力衰竭患者的低通气募集阈值与静息通气过度相关；然而，运动峰值期的浅快呼吸仅见于心力衰竭患者。
临床试验注册号：NCT05057884