title: Effects of continuous positive airway pressure treatment on coronary vasoreactivity measured by (82)Rb cardiac PET/CT in obstructive sleep apnea patients.
abstract: OBJECTIVE
  Obstructive sleep apnea syndrome (OSA) increases the risk of cardiovascular disease. We aimed at evaluating the effect of continuous positive airway pressure (CPAP) treatment on coronary endothelium-dependent vasoreactivity in OSA patients by quantifying myocardial blood flow (MBF) response to cold pressure testing (CPT).
  
  
  METHODS
  In the morning after polysomnography (PSG), all participants underwent a dynamic (82)Rb cardiac positron emitting tomography/computed tomography (PET/CT) scan at rest, during CPT and adenosine stress. PSG and PET/CT were repeated at least 6 weeks after initiating CPAP treatment. OSA patients were compared to controls and according to response to CPAP. Patients' characteristics and PSG parameters were used to determine predictors of CPT-MBF.
  
  
  RESULTS
  Thirty-two untreated OSA patients (age 58 ± 13 years, 27 men) and 9 controls (age 62 ± 5 years, 4 men) were enrolled. At baseline, compared to controls (apnea-hypopnea index (AHI) = 5.3 ± 2.6/h), untreated OSA patients (AHI = 48.6 ± 19.7/h) tend to have a lower CPT-MBF (1.1 ± 0.2 mL/min/g vs. 1.3 ± 0.4 mL/min/g, p = 0.09). After initiating CPAP, CPT-MBF was not different between well-treated patients (AHI <10/h) and controls (1.3 ± 0.3 mL/min/g vs. 1.3 ± 0.4 mL/min/g, p = 0.83), but it was lower for insufficiently treated patients (AHI ≥10/h) (0.9 ± 0.2 mL/min/g vs. 1.3 ± 0.4 mL/min/g, p = 0.0045). CPT-MBF was also higher in well-treated than in insufficiently treated patients (1.3 ± 0.3 mL/min/g vs. 0.9 ± 0.2 mL/min/g, p = 0.001). Mean nocturnal oxygen saturation (β = -0.55, p = 0.02) and BMI (β = -0.58, p = 0.02) were independent predictors of CPT-MBF in OSA patients.
  
  
  CONCLUSIONS
  Coronary endothelial vasoreactivity is impaired in insufficiently treated OSA patients compared to well-treated patients and controls, confirming the need for CPAP optimization.
authors.affiliation: Department of Nuclear Medicine and Molecular Imaging, Lausanne University Hospital, Rue du Bugnon 46, 1011, Lausanne, Switzerland.|Department of Radiology, Lausanne University Hospital, Lausanne, Switzerland.
authors.forename: Vincent
authors.initials: V
authors.lastname: Dunet
authors.affiliation: Center for Investigation and Research in Sleep (CIRS), Department of Pneumology, Lausanne University Hospital, Lausanne, Switzerland.
authors.forename: Vincianne
authors.initials: V
authors.lastname: Rey-Bataillard
authors.affiliation: Department of Nuclear Medicine and Molecular Imaging, Lausanne University Hospital, Rue du Bugnon 46, 1011, Lausanne, Switzerland.
authors.forename: Gilles
authors.initials: G
authors.lastname: Allenbach
authors.affiliation: Center for Investigation and Research in Sleep (CIRS), Department of Pneumology, Lausanne University Hospital, Lausanne, Switzerland.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Beysard
authors.affiliation: Center for Investigation and Research in Sleep (CIRS), Department of Pneumology, Lausanne University Hospital, Lausanne, Switzerland.
authors.forename: Alban
authors.initials: A
authors.lastname: Lovis
authors.affiliation: Department of Nuclear Medicine and Molecular Imaging, Lausanne University Hospital, Rue du Bugnon 46, 1011, Lausanne, Switzerland. John.Prior@chuv.ch.
authors.forename: John O
authors.initials: JO
authors.lastname: Prior
authors.affiliation: Center for Investigation and Research in Sleep (CIRS), Department of Pneumology, Lausanne University Hospital, Lausanne, Switzerland.
authors.forename: Raphael
authors.initials: R
authors.lastname: Heinzer
mesh_terms: D000328:Adult; D000368:Aged; D045422:Continuous Positive Airway Pressure; D003326:Coronary Circulation / Q000502:physiology; D003331:Coronary Vessels / Q000503:physiopathology*; D004730:Endothelium, Vascular / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D017286:Polysomnography; D049268:Positron-Emission Tomography; D012413:Rubidium; D020181:Sleep Apnea, Obstructive / Q000503:physiopathology* / Q000628:therapy*; D014057:Tomography, X-Ray Computed; D014655:Vascular Resistance / Q000502:physiology*
chemical_list: D012413:Rubidium
keywords: Continuous positive airway pressure; Endothelial function; Obstructive sleep apnea; PET