Congestive Heart Failure? ASV Machine can be Harmful – a Study
On Wednesday, May 13, 2015, ResMed released a field safety notice for Congestive Heart Failure patients currently being treated for central sleep apnea syndrome with adaptive servo-ventilation (ASV) machine – a more sophisticated version of continuous positive pressure machine (CPAP).
In particular, if you have shortness of breath, chronic heart failure and a reduced left ventricular ejection fraction (LVEF ≤ 45% – a measure of your heart’s squeezing function), using ASV may be harmful. Based upon the early results of the randomized controlled SERVE-HF study, for this particular at-risk population, there is a 33.5% increased risk of cardiovascular death, compared to control patients who are not on ASV therapy (absolute annual risk: 10% in ASV patients vs. 7.5% in control group).
What should you do?
Only you and your physician can determine the best course of action.
Work with your family physician, your cardiologist, and your sleep doctor to determine the best course of action. We first make sure that you do have Central Sleep Apnea. We have ordered for several patients a repeat diagnostic sleep study to determine this. Your cardiologist may repeat an echocardiogram to assess your ejection fraction – the squeezing function of your heart. If you do have central sleep apnea and a weak heart, Other evidence-based therapies for CSA might include CPAP or oxygen, but long-term outcome studies for these therapies are not conclusive either.
Please remember that these findings do not apply to Obstructive Sleep Apnea and to the use of Continuous Positive Airway Pressure use, which in fact have been shown to reduce the risk of uncontrolled blood pressure, stroke, heart attack, atrial fibrillation, drowsy driving, and sudden death.
Thank You. God Bless You.
Sleep Well, Live Well.