A research study was conducted on patients with sleep apnea both with and without coronary disease. Prior to therapy with CPAP, N-terminal brain natriuretic peptide (NT-proBNP) was measured. In the group with sleep apnea, the levels were elevated. Elevated NT-proBNP may be a marker of ischemia as well as increased myocardial wall stress.
Ventricular myocytes are also the major source of synthesis and secretion of cardiac NT-proBNP. In response to increased myocardial wall stress due to volume or pressure-overload states, NT-proBNP levels are elevated in cardiac failure. Natriuretic peptide production is also upregulated in the area adjacent to ischemic myocardium.
In the study, the authors found significant drops in the levels of NT-proBNP after therapy with CPAP in the group with associated coronary artery disease, but not in those with normal coronaries. They also ob-served significant decreases in nocturnal ST segment depression in the coronary group on CPAP.
This study clearly demonstrates the positive effects treating sleep apnea with CPAP can have on myocardial function. The authors postulate it is probably the result of two variables that can be represented by elevated NT-proBNP. The first is a decrease in oxygen consumption or an increase in the supply of oxygen to vulnerable myocardial cells. The second is a decrease in hemodynamic stress due to a decrease in preload and after-load.
Summarized by: Robert S. Rosenberg, DO, FCCP, is the medical director of the Sleep Disorders Center of Prescott Valley, Arizona and sleep medicine consultant for Mountain Heart Health Services in Flagstaff, Arizona. Dr. Rosenberg is Board Certified in Sleep Medicine, Pulmonary Medicine, and Internal Medicine. His book Sleep Soundly Every Night, Feel Fantastic Every Day is a best seller. Dr Rosenberg’s latest book is The Doctor’s Guide to Sleep Solutions for Stress & Anxiety. Visit Dr Rosenberg’s website www.AnswersForSleep.com which offers a wealth of information on sleep topics.
In conclusion, patients with coronary artery disease need to be screened carefully for sleep apnea. It is obvious from this and other studies that treatment of sleep apnea can have very positive effects on the course of coronary artery disease.
Natriuretic Peptide and High-Sensitive Troponin T Concentrations Correlate with Effectiveness of Short-Term CPAP in Patients with Obstructive Sleep Apnea and Coronary Artery Disease
Ralf Strehmel, Misa Valo, and Claudius Teupe
Clinical Medicine Insights: Circulatory, Respiratory and Pulmonary Medicine,