Departamento de Psicobiologia, Universidade Federal de São Paulo, São Paulo, Brazil.
Sleep Laboratory, Bethesda North Hospital, Cincinnati, Ohio.
J Clin Sleep Med. 2021 Sep 1;17(9):1875-1880. doi: 10.5664/jcsm.9396.
Patients with congestive heart failure (CHF) frequently exhibit an elevated ratio of minute ventilation over CO output (VE/VCO slope) while undergoing exercise tests. One of the factors contributing to this elevated slope is an increased chemosensitivity to CO in that this slope significantly correlates with the slope of the ventilatory response to CO rebreathing at rest. A previous study in patients with CHF and central sleep apnea showed that the highest VE/VCO slope during exercise was associated with the most severe central sleep apnea. In the current study, we tested the hypothesis that in patients with CHF and obstructive sleep apnea (OSA), the highest VE/VCO slope is also associated with the most severe OSA. If the hypothesis is correct, then it implies that in CHF, augmented instability in the negative feedback system controlling breathing predisposes to both OSA and central sleep apnea.
This preliminary study involved 70 patients with stable CHF and a spectrum of OSA severity who underwent full-night polysomnography, echocardiography, and cardiopulmonary exercise testing. Peak oxygen consumption and the VE/VCO slope were calculated.
There was significant positive correlation between the apnea-hypopnea index and the VE/VCO slope ( = .359; = .002). In the regression model, involving the relevant variables of age, body mass index, sex, VE/VCO slope, peak oxygen consumption, and left ventricular ejection fraction, the apnea-hypopnea index retained significance with VE/VCO.
In patients with CHF, the VE/VCO slope obtained during exercise correlates significantly to the severity of OSA, suggesting that an elevated CO response should increase suspicion for the presence of severe OSA, a treatable disorder that is potentially associated with excess mortality.
Registry: ClinicalTrials.gov; Name: Comparison Between Exercise Training and CPAP Treatment for Patients With Heart Failure and Sleep Apnea; URL: https://clinicaltrials.gov/ct2/show/record/NCT01538069; Identifier: NCT01538069.
Bittencourt L, Javaheri S, Servantes DM, Pelissari Kravchychyn AC, Almeida DR, Tufik S. In patients with heart failure, enhanced ventilatory response to exercise is associated with severe obstructive sleep apnea. 2021;17(X):1875-1880.
患有充血性心力衰竭（CHF）的患者在进行运动试验时常表现出分钟通气量与 CO 输出比（VE/VCO 斜率）升高。导致这种斜率升高的因素之一是对 CO 的化学敏感性增加，因为该斜率与静息时 CO 再呼吸时通气反应的斜率显著相关。之前一项关于 CHF 合并中枢性睡眠呼吸暂停患者的研究表明，运动时最高的 VE/VCO 斜率与最严重的中枢性睡眠呼吸暂停相关。在本研究中，我们检验了这样一个假设，即在 CHF 合并阻塞性睡眠呼吸暂停（OSA）患者中，最高的 VE/VCO 斜率也与最严重的 OSA 相关。如果该假设成立，那么这意味着在 CHF 中，控制呼吸的负反馈系统的不稳定性增加，导致 OSA 和中枢性睡眠呼吸暂停。
这项初步研究纳入了 70 名患有稳定型 CHF 和不同严重程度 OSA 的患者，他们接受了整夜多导睡眠图、超声心动图和心肺运动测试。计算最大摄氧量和 VE/VCO 斜率。
呼吸暂停低通气指数与 VE/VCO 斜率呈显著正相关（ =.359； =.002）。在包含年龄、体重指数、性别、VE/VCO 斜率、最大摄氧量和左心室射血分数等相关变量的回归模型中，呼吸暂停低通气指数与 VE/VCO 斜率仍然有显著相关性。
在 CHF 患者中，运动时获得的 VE/VCO 斜率与 OSA 的严重程度显著相关，这表明 CO 反应的升高应增加对严重 OSA 的怀疑，严重 OSA 是一种可治疗的疾病，可能与死亡率增加有关。
注册处：ClinicalTrials.gov；名称：心力衰竭伴睡眠呼吸暂停患者的运动训练与 CPAP 治疗比较；网址：https://clinicaltrials.gov/ct2/show/record/NCT01538069；标识符：NCT01538069。
Bittencourt L, Javaheri S, Servantes DM, Pelissari Kravchychyn AC, Almeida DR, Tufik S. 在心力衰竭患者中，增强的运动通气反应与严重的阻塞性睡眠呼吸暂停相关。 2021;17(X):1875-1880.
