Cardiovascular Complications of Obstructive Sleep Apnea in the Intensive Care Unit and Beyond

Impact of obstructive sleep apnea on inpatient outcomes of COVID-19: a propensity-score matching analysis of the US Nationwide Inpatient Sample 2020

Background

Obstructive sleep apnea (OSA) is associated with health complications, but its impact on COVID-19 outcomes is not known. This study investigated the association between OSA and outcomes of hospitalized COVID-19 patients.

Methods

The Nationwide Inpatient Sample 2020 was searched for adults hospitalized for COVID-19. The outcomes of interest were in-hospital mortality, non-routine discharge, prolonged length of stay (LOS), and complications. Patients with OSA were matched to those without OSA in a 1:4 ratio using propensity score matching (PSM) according to age, sex, and major comorbidities.

Results

After PSM, there were 54,900 adult COVID-19 patients consisting of 10,980 with OSA and 43,920 without OSA. The mean age was 63.2 years and 62.8% were male. Patients with OSA had higher odds of respiratory failure (adjusted OR [aOR] = 1.20, 95% confidence interval [CI]: 1.14-1.25), heart failure (aOR = 1.71, 95% CI: 1.60-1.82), and arrhythmias (aOR = 1.18, 95% CI: 1.08-1.30). Conversely, OSA was associated with lower odds of cerebrovascular accidents (CVAs) (aOR = 0.71, 95% CI: 0.62-0.81, p < 0.001), and a reduced likelihood of in-hospital mortality among patients ≥70 years old (aOR = 0.82, 95% CI: 0.75-0.89, p < 0.001) and males (aOR = 0.79, 95% CI: 0.72-0.88, p < 0.001), but not females.

Conclusion

OSA is associated with higher risks of respiratory failure, heart failure, and arrhythmias in patients hospitalized for COVID-19. However, patients with OSA who are ≥70 years old and those who are male are less likely to have CVAs and in-hospital mortality. These findings underscore the complex relationship between OSA and COVID-19. As the study focused on hospitalized patients, the findings may not apply to mild or asymptomatic COVID-19 cases. Future research should include community-based cohorts and prospective studies to better understand this association.

Comparative Efficacy of Continuous Positive Airway Pressure and Antihypertensive Medications in Obstructive Sleep Apnea-Related Hypertension: A Narrative Review

INTRODUCTION

Obstructive sleep apnea (OSA) presents a significant global health concern, affecting a substantial portion of the population, particularly among young and middle-aged adults.

AIM

This review aims to assess the efficacy of continuous positive airway pressure (CPAP) compared to antihypertensive medications in managing OSA-related hypertension.

METHODS

A comprehensive literature search was conducted across multiple databases, yielding studies published from 2000 to March 2024 that investigated CPAP, antihypertensives, or their combination therapy in OSA patients. Six definitive studies were analyzed, including two randomized controlled trials (RCTs), one randomized double-blind placebo-controlled crossover trial, one placebo-controlled trial, one open-label multicenter trial, and one longitudinal cohort study. These studies comprised 939 participants, with intervention durations ranging from four weeks to six months.

RESULTS

Analysis of CPAP monotherapy revealed variable efficacy, with some studies demonstrating significant reductions in 24-hour mean blood pressure and diastolic pressure, while others reported non-significant changes. CPAP therapy combined with antihypertensives showed additive effects, particularly in reducing office blood pressure measurements. Antihypertensive medications, such as valsartan, exhibited superior efficacy in reducing blood pressure compared to CPAP alone. Factors influencing therapy effectiveness included CPAP compliance, patient characteristics, and coexisting comorbidities. Patients with good CPAP adherence experienced greater reductions in blood pressure. The duration of exposure to OSA and the type of hypertension also impacted the therapy response.

CONCLUSION

While CPAP and antihypertensive medications offer significant benefits in managing hypertension among OSA patients, challenges such as CPAP intolerance and medication side effects exist. Personalized treatment considering individual patient factors is crucial for optimal management.

Cardiopulmonary interactions in left heart failure

The primary impact of ventilation and ventilatory efforts on left ventricular (LV) function in left ventricular dysfunction relate to how changes in intrathoracic pressure (ITP) alter the pressure gradients for venous return into the chest and LV ejection out of the chest. Spontaneous inspiratory efforts by decreasing ITP increase both of these pressure gradients increasing venous blood flow and impeding LV ejection resulting in increased intrathoracic blood volume. In severe heart failure states when lung compliance is reduced, or airway resistance is increased these negative swings in ITP can be exacerbated leading to LV failure and acute cardiogenic pulmonary edema. By merely reversing these negative swings in ITP by the use of non-invasive continuous positive airway pressure (CPAP), these profoundly detrimental forces can be immediately reversed, and cardiovascular stability can be restored in moments. This forms the clinical rationale for the immediate use of CPAP for the treatment of acute cardiogenic pulmonary edema. Increasing ITP during positive pressure ventilation decreases the pressure gradients for venous return and LV ejection decreasing intrathoracic blood volume. In a hypovolemic patient even with LV dysfunction this can result in hypotension due to inadequate LV preload. Minor increases in ITP as occur using pressure-limited positive-pressure ventilation primarily reverse the increased LV afterload of negative swings in ITP and if fluid overload was already present, minimally alter cardiac output. The effect of changes in lung volume on LV function are related primarily to its effects on right ventricular (RV) function through changes in pulmonary vascular resistance and overdistention (hyperinflation). In acute lung injury with alveolar collapse, positive pressure ventilation may reduce pulmonary vascular resistance if alveolar recruitment predominates. Hyperinflation, however, impedes diastolic filling while simultaneously increasing pulmonary vascular resistance. Thus, increasing lung volume can reduce RV afterload by reversing hypoxic pulmonary vasoconstriction or increase afterload by overdistention. Hyperinflation can also impede RV filling. All of these processes can be readily identified at the bedside using echocardiography.