Zhang Haojie, Yan Menghuan, Li Feng, Chen Qi, Lu Rui, Wang Ziyu, Zheng Xuan, Zhang Gangcheng
Center of Structural Heart Disease Zhongnan Hospital of Wuhan University Wuhan China.
Key Laboratory of Artificial Micro-Structures of Ministry of Education, School of Physics and Technology Wuhan University Wuhan China.
Pulm Circ. 2025 Jun 25;15(2):e70120. doi: 10.1002/pul2.70120. eCollection 2025 Apr.
Pulmonary hypertension (PH) is a life-threatening condition frequently associated with exertional dyspnea. It remains diagnostically challenging due to limitations in current screening modalities. While the 6-min walk test (6MWT) has been applied for risk stratification in confirmed PH, its potential role in screening remains unexplored. This retrospective cohort study investigated the diagnostic utility of 6MWT-derived parameters in 180 patients with exertional dyspnea. PH diagnosis was confirmed by right heart catheterization with the definition of mean pulmonary artery pressure > 20 mmHg. Among 79 PH patients (43.9%), a significantly reduced 6-min walk distance (6MWD) was observed compared to non-PH patients (469.5 ± 106.4 m vs. 509.8 ± 74.9 m, = 0.019). Continuous physiological monitoring revealed that the SpO₂ trough and the heart rate (HR) peak occurred at different time points during 6MWT. Propensity score-matched case-control analysis further demonstrated greater exercise-induced desaturation of SpO from the rest to minimal levels (ΔSpO₂ : 9 ± 9% vs. 4 ± 6%, < 0.001) and exaggerated HR response from the rest to maximal levels (ΔHR : 51±21bpm vs. 34±14bpm, < 0.001) in PH patients. Multivariable analysis identified ΔSpO₂ ≥ 5% (AUC = 0.715, 95% CI: 0.640-0.852; < 0.001) and ΔHR ≥ 42 bpm (AUC = 0.740, 95% CI: 0.656-0.823; < 0.001) as independent predictors of PH. The number of these predictors discriminated the risk of PH in dyspneic patients. A risk-stratification model incorporating these thresholds demonstrated improved predictive value for PH screening, with a C-statistic of 0.786 (95% CI: 0.710-0.863, < 0.001). These findings suggest that parameters derived from the 6MWT, particularly exercise-induced SpO₂ desaturation and HR response, may facilitate noninvasive PH screening in exertional dyspneic patients.
肺动脉高压（PH）是一种常与劳力性呼吸困难相关的危及生命的疾病。由于当前筛查方式存在局限性，其诊断仍具有挑战性。虽然6分钟步行试验（6MWT）已用于确诊PH患者的风险分层，但其在筛查中的潜在作用仍未得到探索。这项回顾性队列研究调查了6MWT衍生参数在180例劳力性呼吸困难患者中的诊断效用。通过右心导管检查确诊PH，定义为平均肺动脉压>20 mmHg。在79例PH患者（43.9%）中，与非PH患者相比，观察到6分钟步行距离（6MWD）显著缩短（469.5±106.4米对509.8±74.9米，P = 0.019）。连续生理监测显示，SpO₂谷值和心率（HR）峰值在6MWT期间出现在不同时间点。倾向评分匹配的病例对照分析进一步表明，PH患者从静息到最低水平的运动诱发SpO₂去饱和更大（ΔSpO₂：9±9%对4±6%，P<0.001），从静息到最高水平的HR反应更夸张（ΔHR：51±21次/分对34±14次/分，P<0.001）。多变量分析确定ΔSpO₂≥5%（AUC = 0.715，95%CI：0.640 - 0.852；P<0.001）和ΔHR≥42次/分（AUC = 0.740，95%CI：0.656 - 0.823；P<0.001）为PH的独立预测因素。这些预测因素的数量可区分呼吸困难患者的PH风险。纳入这些阈值的风险分层模型对PH筛查的预测价值有所提高，C统计量为0.786（95%CI：0.710 - 0.863，P<0.001）。这些发现表明，6MWT衍生的参数，特别是运动诱发的SpO₂去饱和和HR反应，可能有助于对劳力性呼吸困难患者进行无创PH筛查。
