Clinical Research Directory

ASV Effects on Myocardial Energetics and Sympathetic Nerve Function in Heart Failure and Sleep Apnea.

Obstructive sleep apnea (OSA), central sleep apnea (CSA) and heart failure (HF) are states of metabolic demand and sympathetic nervous system (SNS) activation. In patients with sleep apnea and HF, continuous positive airway pressure (CPAP) initially may reduce left ventricular (LV)stroke volume (SV) but subsequently improves and LV function. This may relate to an early beneficial effect on myocardial energetics through early reduction in metabolic demand that subsequently leads to improved efficiency of LV contraction. However, it is not clear whether long-term adaptive servo-ventilation (ASV) favorably affects cardiac energetics. Any such benefit may also relate to reduced sympathetic nervous system (SNS) activation. However its effect on myocardial SNS function is also not well studied. In a pilot study we demonstrated early (6 week) beneficial effects of CPAP in patients with OSA and HF. The current proposal (AMEND) is a unique substudy of the recently funded ADVENT-HF trial (Adaptive Servo Ventilation for Therapy of Sleep Apnea in HeartFailure) (NCT01128816; CIHR; D. Bradley, PI). We propose to evaluate the long-term (6 month) effects of ASV on daytime 1) oxidative metabolism; 2) the work metabolic index (WMI) as an estimate of mechanical efficiency; 3) myocardial sympathetic nerve (SN) pre-synaptic function; and 4) heart rate (HR) variability in patients with HF and coexisting OSA or CSA. In conjunction with echocardiographic measures of LV stroke work, positron emission tomography (PET) derived \[11C\] acetate kinetics will be used as a measure of oxidative metabolism, to determine the WMI. \[11C\] hydroxyephedrine (HED) retention will be used to measure cardiac SN pre-synaptic function. Primary Hypotheses: In patients with chronic stable HF and CSA or OSA without excessive daytime sleepiness (EDS), long-term (6-month) ASV therapy yields: 1. Beneficial effects on daytime myocardial metabolism leading to a reduction in the rate of oxidative metabolism as measured by \[11C\]acetate kinetics using PET imaging; 2. Improvement in energy transduction from oxidative metabolism to stroke work as measured by an increase in the daytime work-metabolic index.

remedē System Therapy Study

The purpose of this non-randomized post market study is to collect clinical data on the safety and effectiveness of the remedē System in a real-world setting.

Belgian Central Sleep Apnea REgistry

This study evaluates different factors that determine the treatment choice and treatment compliance in patients with central sleep apnea. All patients will receive routine care (registry).

Interface Selection for Adaptive Servo Ventilation

The purpose of this study is to compare the effects of nasal and oronasal interfaces during ASV treatment on sleep efficiency and sleep architecture. Therefore, patients starting treatment with ASV, will be randomized between two groups. In the first group, patients will use a nasal interface during the first night and an oronasal interface during the second night. In the second group, patients will use an oronasal mask first and a nasal mask during the second night. The results of this trial will have major impact on future clinical practice as it would deliver prediction rules to choose the correct interface immediately.

Long-term Observation of PAP-therapy With Telemonitoring: Telemedicine Registry TelePAP

Telemonitoring for Positive Airway Pressure (PAP) therapy might help to establish and maintain long-term therapy adherence and thus support the beneficial effects of PAP therapy on long-term outcomes.