The Effects of Continuous Positive Airway Pressure on Myocardial Energetics in Patients With Heart Failure and Obstructive Sleep Apnea
Keiichiro Yoshinaga, MD, PhD*,1,
Ian G. Burwash, MD, FRCPC*,
Judith A. Leech, MD, FRCP(C) ,
Haissam Haddad, MD, FRCPC, FACC*,
Chris B. Johnson, MD, FRCPC*,
Robert A. deKemp, PhD*,
Linda Garrard, RN, BScN*,
Li Chen, MSc*,
Kathryn Williams, MS*,
Jean N. DaSilva, PhD* and
Rob S.B. Beanlands, MD, FRCPC, FACC*,2,*
* Division of Cardiology, University of Ottawa Heart Institute, Ottawa, Canada
Ottawa Hospital Sleep Medicine Centre, Ottawa, Canada.
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Figure 1 Example of Myocardial Time-Activity Data From an 11C Acetate Positron Emission Tomography Acquisition
A monoexponential function fit to the myocardial clearance yields a clearance rate constant; kmono represents the rate of oxidative metabolism and reflects myocardial oxygen consumption.
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Figure 2 Effects of Short-Term CPAP Application
Stroke volume index, myocardial oxidative metabolism (kmono), and work metabolic index (WMI) at rest and during short-term continuous positive airway pressure (CPAP) administration. *p = 0.031, p = 0.063 (trend). LV = left ventricular.
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Figure 3 Effects of 6 Weeks of CPAP on Oxidative Metabolism and on Efficiency
(A) kmono at baseline and after 6 weeks of CPAP therapy. *p = 0.078 (trend); (B) WMI at baseline and after 6 weeks of CPAP therapy. *p = 0.031. OSA = obstructive sleep apnea; other abbreviations as in Figure 2.
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Figure 4 Percent Change in Myocardial Efficiency
Percent change of WMI from baseline to 6 weeks after CPAP therapy in group I (with obstructive sleep apnea [OSA]) and in group II (control). *p = 0.044 versus group II (control). Abbreviations as in Figure 2.
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