Continuous Positive Airway Pressure for the Treatment of Supine Hypertension and Orthostatic Hypotension in Autonomic Failure

Abstract

BACKGROUND: Supine hypertension affects most patients with orthostatic hypotension (OH) due to autonomic failure, but it is often untreated for fear of worsening OH. We hypothesized that increasing intrathoracic pressure with continuous positive airway pressure (CPAP) had a Valsalva-like blood-pressure-lowering effect that could be used to treat nocturnal supine hypertension in these patients, while reducing nocturnal pressure diuresis and improving daytime OH. METHODS: In Protocol 1, we determined the acute hemodynamic effects of increasing levels of CPAP (0, 4, 8, 12, and 16 cm H 2 O, 3 minutes each) in 26 patients with autonomic failure and supine hypertension studied while awake and supine. In Protocol 2 (n=11), we compared the effects of overnight therapy with CPAP (8–12 cm H 2 O for 8 hours) versus placebo on nocturnal supine hypertension, nocturnal diuresis and daytime OH in a 2-night crossover study. RESULTS: In Protocol 1, acute CPAP (4–16 cm H 2 O) decreased systolic blood pressure in a dose-dependent manner (maximal drop 22±4 mmHg with CPAP 16) due to reductions in stroke volume (−16+3%) and cardiac output (−14±3%). Systemic vascular resistance and heart rate remained unchanged. In Protocol 2, overnight CPAP lowered nighttime systolic blood pressure (maximal change −23±5 versus placebo −1±7 mmHg; P =0.023) and was associated with lower nighttime diuresis (609±84 versus placebo 1004±160 mL; P =0.004) and improved morning orthostatic tolerance (AUC upright SBP 642±121 versus placebo 410±109 mmHg*min; P =0.014). CONCLUSIONS: CPAP is a novel nonpharmacologic approach to treat the supine hypertension of autonomic failure while improving nocturia and daytime OH. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT03312556.

Orthostatic Hypotension in Adults With Hypertension: A Scientific Statement From the American Heart Association

“…134,135 In contrast, small proof-of-concept clinical studies have shown that sleeping in a head-up tilt position, application of local passive heat (water-recirculating heated mattress), and continuous positive airway pressure (at levels used in sleep apnea) control nocturnal hypertension (as effectively as antihypertensives), reduce nocturia, and improve early-morning OH (Figure 4). 131,132 Unfortunately, to be effective, sleeping in a head-up tilt position requires levels of tilt of at least 12° (≈16-in elevation of the head of the bed), which is not practical, tolerable, or safe. Both local heat and continuous positive airway pressure reduce cardiac output by increasing venous capacitance through skin vasodilation or splanchnic venous pooling, respectively.…”

“…Interventions were tested on a series of single-night, placebo-controlled crossover, proof-of-concept studies. 131,132 Outcomes were monitored from 8 pm to 8 am , followed by a 10-minute standing test in the morning. A single oral dose of each medication was given at 8 pm ; nitroglycerin (NTG) patch was applied from 8 pm to 6 am; and local heat and continuous positive airway pressure (CPAP) were applied from 10 pm to 6 am .…”

“…Figure 4. Effect of different antihypertensive medications and nonpharmacological interventions on nocturnal hypertension, diuresis, and morning orthostatic tolerance in patients with supine hypertension and OH.Interventions were tested on a series of single-night, placebo-controlled crossover, proof-of-concept studies 131,132. Outcomes were monitored from 8 pm to 8 am, followed by a 10-minute standing test in the morning.…”

Non-Pharmacological Treatment of Autonomic Dysfunction in Parkinson’s Disease and Other Synucleinopathies

“…A heating pad set at 40-42 • C placed over the abdomen for 2-h effectively lowered overnight BP in patients with supine hypertension [52]. A novel nonpharmacological approach to treating supine hypertension is the overnight use of continuous positive airway pressure (8-12 cm H 2 O), which lowered nighttime BP, was associated with lower nighttime diuresis, and improved symptoms of nOH in the morning [53].…”