The Role of Sleep Apnea in the Acute Exacerbation of Heart Failure

Target population:

Patients admitted to the OSU Heart Hospital with ADHF routinely undergo a cardiorespiratory sleep study to identify OSA. Patients with ADHF who are newly diagnosed with OSA during the same hospital stay are eligible for this study.

Enrollment:

Given the presence of significant previously unrecognized OSA in 62% of patients hospitalized with ADHF, we expect to need to screen 270 patient volunteers to recruit 170 patients with OSA.

Eligibility for randomization: The criteria for ADHF is admission diagnosis of heart failure; a chief complaint of dyspnea; and ejection fraction of 45% or less. Additionally, elevated left ventricular pressure as indicated by at least one sign and one symptom of volume overload (pedal edema, crackles, consistent chest X-ray, increased left ventricular end-diastolic diameter, or elevated BNP level) is required [46].

Inclusion criteria

• Previously unrecognized OSA with an Apnea Hypopnea Index (AHI) > 15 events per hour on the attended in-hospital sleep study. Patients with apnea index of less than 5 events / hour are excluded (see design consideration for rationale)
• Projected length of stay 3 days or more on the morning following the cardio-respiratory sleep study
• Ongoing or planned targeted treatment for heart failure including one of the following: IV diuretics, IV infusion of inotropes or vasodilators, or planned revascularization, or device therapy

Exclusion criteria

• Patients who are already diagnosed with OSA
• Patients with Central Sleep Apnea
• Patients with diastolic only heart failure
• Cardiogenic shock and hemodynamic instability with MAP less than 55 mmHg off vasopressors, or concurrently on vasopressor treatment, left ventricular assist devices, or intra-aortic Balloon Pump. Inotropic agents will not constitute an exclusion criterion. Patients will be eligible once off vasopressors.
• Acute respiratory failure or insufficiency defined by P/F (PaO2/FIO2) ratio less than 250, or FIO2 requirement more than 50%
• Overt neurological deficit
• Renal failure requiring renal replacement therapy; Patients will not be excluded if they were undergoing ultra-filtration for volume removal
• Patients scheduled for procedures that will interfere with post randomization measurement: This includes scheduled coronary bypass surgery, or expected left ventricular assist device placement.
• Patients who arrived from a long-term care facility or expected to be discharged to one; and patients who have very poor functional outcome precluding ability to use the CPAP device independently.
• Patients on long term or "bridging" inotropic infusion, or short life expectancy due to concomitant illness