title: Usefulness of Low Cardiac Index to Predict Sleep-Disordered Breathing in Chronic Thromboembolic Pulmonary Hypertension.
abstract: Patients with chronic thromboembolic pulmonary hypertension (CTEPH) often have substantial right ventricular dysfunction. The resulting low cardiac index might predispose to sleep disordered breathing (SDB) by increasing ventilatory instability. The prevalence of SDB and potential association with impaired cardiac index was examined in patients with CTEPH. Patients referred for evaluation for pulmonary thromboendarterectomy surgery were recruited. Subjects underwent a sleep study, unless already using positive airway pressure therapy. Hemodynamic data were obtained from contemporaneous right-sided cardiac catheterization. A total of 49 subjects were included. SDB-defined as ongoing positive airway pressure use or apnea-hypopnea index (AHI) ≥5/h-was found in 57% of subjects. SDB was generally mild in severity, with respiratory events mainly consisting of hypopneas. Cardiac index was found to be significantly lower in subjects with SDB than those without (2.19 vs 2.55 L/min/m(2); p = 0.024), whereas no differences were observed in other characteristics. Additionally, cardiac index was independently predictive of AHI. In a subgroup of subjects with an elevated percentage of central events, both cardiac index and lung to finger circulation time correlated with AHI. In conclusion, SDB is prevalent in patients with CTEPH and might decrease with treatments that improve cardiac index.
authors.affiliation: Division of Pulmonary, Department of Medicine, Critical Care and Sleep Medicine, University of California, San Diego, California. Electronic address: j1orr@ucsd.edu.
authors.forename: Jeremy E
authors.initials: JE
authors.lastname: Orr
authors.affiliation: Division of Pulmonary, Department of Medicine, Critical Care and Sleep Medicine, University of California, San Diego, California.
authors.forename: William R
authors.initials: WR
authors.lastname: Auger
authors.affiliation: Division of Pulmonary, Department of Medicine, Critical Care and Sleep Medicine, University of California, San Diego, California.
authors.forename: Pamela N
authors.initials: PN
authors.lastname: DeYoung
authors.affiliation: Division of Pulmonary, Department of Medicine, Critical Care and Sleep Medicine, University of California, San Diego, California.
authors.forename: Nick H
authors.initials: NH
authors.lastname: Kim
authors.affiliation: Division of Pulmonary, Department of Medicine, Critical Care and Sleep Medicine, University of California, San Diego, California.
authors.forename: Atul
authors.initials: A
authors.lastname: Malhotra
authors.affiliation: Division of Pulmonary, Department of Medicine, Critical Care and Sleep Medicine, University of California, San Diego, California.
authors.forename: Robert L
authors.initials: RL
authors.lastname: Owens
mesh_terms: D015992:Body Mass Index; D002140:California / Q000453:epidemiology; D002303:Cardiac Output, Low; D002908:Chronic Disease; D005260:Female; D006801:Humans; D006976:Hypertension, Pulmonary / Q000150:complications*; D008297:Male; D008875:Middle Aged; D017286:Polysomnography; D011237:Predictive Value of Tests; D015995:Prevalence; D011655:Pulmonary Embolism / Q000150:complications*; D012720:Severity of Illness Index; D020181:Sleep Apnea, Obstructive / Q000150:complications* / Q000175:diagnosis* / Q000453:epidemiology / Q000503:physiopathology