Evaluation of right ventricular performance and impact of continuous positive airway pressure therapy in patients with obstructive sleep apnea living at high altitude

Obstructive Sleep Apnea, Obesity Hypoventilation Syndrome, and Pulmonary Hypertension: A State-of-the-Art Review

The pathophysiological interplay between sleep-disordered breathing (SDB) and pulmonary hypertension (PH) is complex and can involve a variety of mechanisms by which SDB can worsen PH. These mechanistic pathways include wide swings in intrathoracic pressure while breathing against an occluded upper airway, intermittent and/or sustained hypoxemia, acute and/or chronic hypercapnia, and obesity. In this review, we discuss how the downstream consequences of SDB can adversely impact PH, the challenges in accurately diagnosing and classifying PH in the severely obese, and review the limited literature assessing the effect of treating obesity, obstructive sleep apnea, and obesity hypoventilation syndrome on PH.

Acute sleep deprivation: impairment of biventricular function assesed by speckle tracking echocardiography in healthy subjects

OBJECTIVES

Sleep deprivation (SD) has been found to be associated with an increased incidence of adverse cardiovascular disease (CVD) events. The aim of this study was to investigate whether or not acute SD has a pathological effect on the geometry and the systolic and diastolic functions of the right and left heart chambers by standard transthoracic echocardiography (TTE) and speckle tracking echocardiography (STE) in healthy individuals with acute SD.

METHODS

Nurses with no history of acute or chronic diseases underwent TTE and STE after working a night shift, a sleepless period of 24 h and 7 days of normal sleep after the night shift. Measurements of TTE and STE taken in the rested state were compared with those taken after 24 h of sleep deprivation.

RESULTS

The study included 52 nurses (38 women, 73%). The mean age of the study population was 27.9 ± 7.4 years and mean BMI was 24.1 ± 4.8. Left atrial reservoir (51.5 ± 13.5 vs. 45.4 ± 10; p = 0.004), conduit (- 37.3 ± 11.3 vs. - 33.6 ± 7.9; p = 0.01), left ventricular global longitudinal strain (LVGLS, - 22.6 ± 2.4 vs. - 21.3 ± 2.4; p = 0.001), right ventricular global longitudinal strain (RVGLS, - 25.3 ± 3.7 vs. - 23.5 ± 3.9; p = 0.005) and right ventricular free wall longitudinal strain (RVFWSL, - 29.1 ± 4.2 vs. - 27 ± 4.5; p = 0.001) were impaired significantly after SD.

CONCLUSION

This study is the first to investigate the negative effects of acute sleep deprivation on LV and RV strain in healthy adults using echocardiography. The findings showed that acute sleep deprivation leads to deterioration in function of both ventricles and left atrium. Speckle tracking echocardiography demonstrated subclinical diminished heart function.

The role of 3D speckle tracking echocardiography in the diagnosis of obstructive sleep apnea and its severity

There is a consistent relationship between obstructive sleep apnea (OSA) and cardiovascular diseases. It is already recognized that OSA may influence the geometry and function of the right ventricle (RV). This has encouraged the development of echocardiographic evaluation for screening of OSA and its severity. Three-dimensional speckle tracking echocardiography (3D STE) is in assumption better, compared with 2D STE, because it overcomes the standard 2D echo limitations. Thus, the purpose of our study is to evaluate whether 3D STE measurements, could predict the positive diagnosis and severity of OSA. We enrolled 69 patients with OSA and 37 healthy volunteers who underwent a cardiorespiratory sleep study. 2DE was performed in all patients. RVEF and 3D RVGLS were measured by 3DSTE. NT pro BNP plasma level was also assessed in all participants. 3D RV GLS (- 13.5% vs. - 22.3%, p < 0.001) and 3D RVEF (31.9% vs. 50%, p < 0.001) were reduced in patients with OSA, compared with normal individuals. 3D Strain parameters showed better correlation to standard 2D variables, than 3D RVEF. Except for NT pro BNP (p = 0.059), all parameters served to distinguish between severe and mild-moderate cases of OSA. 3D STE may be a reliable and accurate method for predicting OSA. Consequently, 3D RV GLS is a good tool of assessing the RV global function in OSA, because it correlates well with other established measurements of RV systolic function. Furthermore, 3D RV GLS was a precise parameter in identifying severe cases of OSA, while NT pro BNP showed no association.

Obstructive sleep apnea and right ventricular function: A meta-analysis of speckle tracking echocardiographic studies

The authors investigated the association between obstructive sleep apnea (OSA) and right ventricular (RV) systolic dysfunction trough a meta‐analysis of echocardiographic studies providing data on RV mechanics as assessed by longitudinal strain (LS). A systematic search was conducted using PubMed, OVID‐MEDLINE, and Cochrane library databases to search English‐language review papers published from inception to March 31, 2022. Only studies reporting data on RV free‐wall or global LS in patients with OSA of different severity and non‐OSA controls were reviewed. Data of interest were pooled to obtain standard means difference (SMD) with 95% confidence interval (CI). The meta‐analysis included 628 participants (436 with OSA and 192 controls) from eight studies. Compared to controls, RV free wall LS was significantly reduced in the pooled OSA group (SMD 1.02 ± .33, CI:.17/1.24, P < .002); this was also the case for RV global LS (SMD: .72 ± .11, CI: .50/.93, P < .0001). Notably, compared to patients with mild‐OSA those with moderate and severe OSA exhibited significantly lower RV free‐wall LS and global LS values; this was not the case for tricuspid annular plane excursion. In conclusions, both RV free‐wall and global LS are impaired in patients with OSA; deterioration of these indices, unlike TAPSE, was already evident in the early stages and was related to the severity of the syndrome. Thus, RV myocardial strain should be considered to be included in echocardiographic evaluation of OSA patients in order to detect subclinical cardiac damage in these patients regardless of its degree of severity.

The impact of continuous positive airway pressure on cardiac mechanics: Findings from a meta-analysis of echocardiographic studies

Current evidence on the effects of continuous positive airway pressure (CPAP) on cardiac mechanics in patients with obstructive sleep apnea (OSA) is based on a few single studies. The authors investigated this topic through a meta‐analysis of speckle tracking echocardiography (STE) studies that provided data on left ventricular (LV) and right ventricular (RV) mechanics as assessed by global longitudinal strain (GLS). The PubMed, OVID‐MEDLINE, and Cochrane library databases were systematically analyzed to search English‐language review papers published from inception to January 31, 2022. Studies were identified by crossing the following terms: “obstructive sleep apnea”, “sleep quality”, “sleep disordered breathing”, “continuous positive airway pressure therapy”, “noninvasive ventilation”, “left ventricular hypertrophy”, “systolic dysfunction”, “global longitudinal strain”, “left ventricular mechanics”, “right ventricular mechanics”, “echocardiography” and “STE echocardiography”. The meta‐analysis, including a total of 337 patients with OSA from nine studies (follow‐up 2–24 months) showed a significant GLS improvement in both LV and RV after CPAP, standard mean difference (SMD) being 0.51±0.08, CI:0.36–0.66, p = .0001 and 0.28±0.07, CI:0.15–0.42, p = .0001), respectively. Corresponding SMD values for LV ejection fraction (LVEF) and tricuspid annular plane systolic excursion (TAPSE) were 0.20±0.06, CI:0.08–0.33, p = .001 and 0.08±0.06, CI: ‐0.04/0.20, p = .21. Our meta‐analysis suggests that: I) CPAP treatment exerts beneficial effects on biventricular function in patients with OSA; II) the assessment of cardiac mechanics by STE should be routinely recommended for monitoring cardiac function in this setting, due to limitations of conventional echocardiography in evaluating biventricular performance.

Association of Pulmonary Artery Pulsatility Index With Adverse Cardiovascular Events Across a Hospital-Based Sample

BACKGROUND

The pulmonary artery pulsatility index (PAPi), calculated from the ratio of the pulmonary artery pulse pressure to right atrial pressure, is a predictor of right ventricular failure after inferior myocardial infarction and left ventricular assist device implantation. Whether PAPi is associated with adverse outcomes across a heterogeneous population is unknown.

METHODS

We examined consecutive patients undergoing right heart catheterization between 2005 and 2016 in a hospital-based cohort. Multivariable Cox models were utilized to examine the association between PAPi and all-cause mortality, major adverse cardiac events, and heart failure hospitalizations.

RESULTS

We studied 8285 individuals (mean age 63 years, 39% women) with median PAPi across quartiles 1.7, 2.8, 4.2, and 8.7, who were followed over a mean follow-up of 6.7±3.3 years. Patients in the lowest PAPi quartile had a 60% greater risk of death compared with the highest quartile (multivariable-adjusted hazard ratio, 1.60 [95% CI, 1.36-1.88], P<0.001) and a higher risk of major adverse cardiac events and heart failure hospitalizations (hazard ratio, 1.80 [95% CI, 1.56-2.07], P<0.001 and hazard ratio, 2.08 [95% CI, 1.76-2.47], P<0.001, respectively). Of note, patients in quartiles 2 and 3 also had increased risk of cardiovascular events compared with quartile 4 (multivariable P<0.05 for all).

CONCLUSIONS

Compared with the highest PAPi quartile, patients in PAPi quartiles 1 to 3 had a greater risk of all-cause mortality, major adverse cardiac events, and heart failure hospitalizations, with greatest risk observed in the lowest quartile. A low PAPi, even at values higher than previously reported, may serve an important role in identifying high-risk individuals across a broad spectrum of cardiovascular disease.

Speckle tracking echocardiography in heart failure development and progression in patients with apneas

Obstructive (OA) and central apneas (CA) are highly prevalent breathing disorders that have a negative impact on cardiac structure and function; while OA promote the development of progressive cardiac alterations that can eventually lead to heart failure (HF), CA are more prevalent once HF ensues. Therefore, the early identification of the deleterious effects of apneas on cardiac function, and the possibility to detect an initial cardiac dysfunction in patients with apneas become relevant. Speckle tracking echocardiography (STE) imaging has become increasingly recognized as a method for the early detection of diastolic and systolic dysfunction, by the evaluation of left atrial and left and right ventricular global longitudinal strain, respectively. A growing body of evidence is available on the alterations of STE in OA, while very little is known with regard to CA. In this review, we discuss the current knowledge and gap of evidence concerning apnea-related STE alterations in the development and progression of HF.