Is CPAP cardioprotective?

Two studies presented at ERS 2023 demonstrated the potential of a continuous positive airway pressure (CPAP) machine to address cardiovascular (CV) risks in individuals with obstructive sleep apnoea (OSA).

Reduction in risk of CV death

To evaluate the effects of CPAP on major CV events in a real-world setting, researchers conducted a population-based study on OSA patients who have stopped CPAP use in 2011 and had no further CPAP prescriptions thereafter until 2015 (n=3,638; median age 66.5 years, 71.5 percent male). This cohort was matched with a similar group of individuals who have continued to use CPAP until at least 2015 or their death. [ERS 2023, abstract OA3290]

During a median follow-up of 4.5 years, after adjusting for age, sex, and key comorbidities, those on continued CPAP treatment had a lower risk of CV death than those who stopped (hazard ratio [HR], 0.66).

A similar trend in favour of CPAP continuation was seen for CV hospitalizations (HR, 0.82) and a composite of CV deaths and hospitalizations (HR, 0.80).

“[These suggest] a moderate but significant protective effect of CPAP on major CV events,” said the researchers, led by Dr Jordi de Batlle from Institut de Recerca Biomèdica de Lleida, Spain. “[The findings] contrast with the results of randomized controlled trials tackling this issue and highlights the importance of including real-world patients in the studies.”

“Our results suggest that CPAP treatment can help most OSA patients by preventing CV problems such as heart disease and stroke. This is a plus, as CPAP treatment already helps most OSA patients by reducing sleepiness and improving their quality of life,” he continued.

“Based on these findings, we should encourage people with OSA to keep using their CPAP machines,” de Batlle added.

“[R]esearch using real-world data [has shown] that CPAP adherence is one of the key predictors for reducing CV risk and for better outcomes in general,” commented Professor Sophia Schiza, secretary of the ERS group assembly on sleep-disordered breathing, who was not involved in the study.

“Therefore, there is a need for individualized treatment plans, patient engagement, educational activities, and close treatment follow-up to increase adherence to long-term treatment and improve outcomes for patients,” Schiza continued.

Potential for plaque reduction

In a small pilot study, CPAP appeared to outshine the weight loss drug liraglutide in terms of CV benefit. In this proof-of-concept trial, 30 patients (mean age 50 years, 80 percent male) with moderate-to-severe OSA underwent a CT coronary angiogram to evaluate signs of narrowing in the blood vessels. Participants were randomized to treatment with CPAP, liraglutide, or both for 24 weeks. [ERS 2023, abstract OA3287]

More than half of the participants showed signs of coronary artery disease in their first CT scan. They underwent a repeat scan at the end of week 24.

Low-density coronary artery plaque volume markedly dropped in the CPAP (from 571 to 334 mm³) and combination therapy arms (from 401 to 278 mm³) but not in the liraglutide arm.

“CPAP works by keeping patients’ airways open while they sleep. This stops fluctuations in oxygen levels in the blood that can exacerbate CV disease,” said Dr Cliona O’Donnell from the University College Dublin, Ireland.

Although this is a pilot study and firm conclusions cannot be drawn, the study did show improvements in some early signs of CV disease with CPAP treatment, O’Donnell noted. She called for further evaluation in larger studies to ascertain the current findings.