Department of Pulmonary Function Test, School of Medicine, Shanghai Pulmonary Hospital, Tongji University, Shanghai, 200433, China.
Department of Respiratory and Critical Care Medicine, Liaocheng People's Hospital, Liaocheng, 252000, China.
BMC Pulm Med. 2022 Jun 25;22(1):249. doi: 10.1186/s12890-022-02045-4.
End-tidal PCO (PetCO) patterns during exercise testing as well as ventilatory equivalents for CO have been reported for different pulmonary vascular diseases but seldomly for the significant differences in exercise response depending on the etiology of pulmonary hypertension. We aimed to compare PetCO change pattern in IPAH and CTEPH with varying severity during incremental cardiopulmonary exercise testing (CPET).
164 IPAH patients and 135 CTEPH patients referred to Shanghai Pulmonary Hospital between 2012 and 2019 were retrospectively recruited into the study. All patients performed CPET and also underwent right-heart catheterization (RHC). Forty-four healthy subjects also performed CPET and were included as controls.
PetCO was significantly lower in IPAH and CTEPH patients as compared to normal subjects. Moreover, the PetCO did not rise, in fact fell from rest to anaerobic threshold (AT), then further decreased until peak in both IPAH and CTEPH. PetCO value at rest, unloaded, AT and peak were proportionately reduced as the World Health Organization functional class (WHO-Fc) increased in both IPAH and CTEPH patients. The PETCO in IPAH patients had significant differences during all phases of exercise between WHO-Fc I-II and III-IV subgroup. CTEPH also demonstrated significant difference except for PetCO at peak. PetCO values were significantly higher in IPAH during all phases of exercise as compared to CTEPH patients (all P < 0.001). PeakVO%pred correlated significantly with PetCO at rest (r = 0.477, P < 0.001), AT (r = 0.609, P < 0.001) and peak exercise (r = 0.576, P < 0.001) in IPAH. N-terminal natriuretic peptide type-B (NT-proBNP) also correlated markedly with PetCO, with a correlation coefficient of - 0.326 to - 0.427 (all P < 0.001). Additionally, PetCO at rest, at AT and at peak correlated positively with peakVO%pred and showed an inverse correlation with NT-proBNP in CTEPH patients (all P < 0.05).
PetCO during exercise in IPAH and CTEPH patients was significantly different from normal subjects. Moreover, PetCO values were significantly higher in IPAH during all phases of exercise as compared to CTEPH patients (all P < 0.001). PetCO was progressively more abnormal with increasing disease severity according to peakVO%pred and WHO-Fc.
运动试验中呼气末 PCO（PetCO）模式以及 CO 的通气当量已在不同的肺血管疾病中报道，但很少根据肺动脉高压的病因报告运动反应的显著差异。我们旨在比较 IPAH 和 CTEPH 在递增心肺运动试验（CPET）中不同严重程度时 PetCO 的变化模式。
2012 年至 2019 年，回顾性招募了 164 名 IPAH 患者和 135 名 CTEPH 患者至上海肺科医院，并将其纳入研究。所有患者均进行 CPET，并进行右心导管检查（RHC）。44 名健康受试者也进行了 CPET，并被纳入对照组。
与正常受试者相比，IPAH 和 CTEPH 患者的 PetCO 明显降低。此外，PetCO 不仅没有升高，反而从休息到无氧阈（AT）下降，然后在 IPAH 和 CTEPH 患者中进一步下降到峰值。在 IPAH 和 CTEPH 患者中，随着世界卫生组织功能分类（WHO-Fc）的增加，PetCO 在休息、无负荷、AT 和峰值时呈比例降低。在 IPAH 患者中，在 WHO-Fc I-II 与 III-IV 亚组之间，在运动的所有阶段，PETCO 都有显著差异。除了 PetCO 峰值外，CTEPH 也有显著差异。与 CTEPH 患者相比，IPAH 患者在运动的所有阶段的 PetCO 值均显著升高（均 P<0.001）。在 IPAH 中，最大摄氧量百分比预测值（peakVO%pred）与 PetCO 在休息时（r=0.477，P<0.001）、AT 时（r=0.609，P<0.001）和峰值运动时（r=0.576，P<0.001）显著相关。N-末端脑钠肽前体（NT-proBNP）与 PetCO 也有明显相关性，相关系数为-0.326 至-0.427（均 P<0.001）。此外，在 CTEPH 患者中，PetCO 在休息时、AT 时和峰值时与 peakVO%pred 呈正相关，与 NT-proBNP 呈负相关（均 P<0.05）。
IPAH 和 CTEPH 患者运动时的 PetCO 与正常受试者明显不同。此外，与 CTEPH 患者相比，IPAH 患者在运动的所有阶段的 PetCO 值均显著升高（均 P<0.001）。根据 peakVO%pred 和 WHO-Fc，PetCO 随着疾病严重程度的增加而逐渐变得更加异常。
