Relation of Echocardiographic Characteristics of the Right-Sided Heart With Incident Heart Failure and Mortality in Patients With Sleep-Disordered Breathing and Preserved Left Ventricular Ejection Fraction

Assessment of right ventricular remodeling and dysfunction in obstructive sleep apnea syndrome: a prospective monocentric study

BACKGROUND

Obstructive sleep apnea (OSA) is a common sleep-related disorder that has been implicated in many serious cardiovascular diseases including cardiac remodeling and dysfunction. Since most investigations have focused on the left heart, little is known on right ventricular (RV) involvement in OSA. The role of the RV in the management of cardiovascular outcomes has become increasingly recognized. Early detection of subtle signs of RV dysfunction and remodeling in patients with OSA is crucial for optimal medical care.

PURPOSE

We aimed to investigate the effect of OSA and its severity on the RV structure and function using conventional echocardiography.

METHODS

We conducted a cross-sectional analytical study including patients with OSA who did not have heart failure or chronic pulmonary disease comparing them to controls without OSA. All patients underwent respiratory polygraphy at the Pneumology Department and standard echocardiography performed by the same blinded cardiologist at the Cardiology Department of Taher Sfar University Hospital.

RESULTS

A total of 139 patients with OSA and 45 controls were enrolled in the study. Amonth the patients, there were 32% (n = 44) with mild, 20% (n = 28) with moderate, and 48% (n = 67) with severe OSA. Sixty-three percent of the study population were women. The mean age was 54.1 ± 11.0 years. Early RV dilatation was present in the mild disease stage (RVID = 42.0 ± 7.7 mm vs. 32.4 ± 5.5 mm in controls; p < 0.0001) without obvious RVH. The systolic pulmonary artery pressure was significantly higher in patients with OSA (31.2 ± 8.2 vs. 20.9 ± 9.8; p < 0.0001). Tricuspid annular plane systolic excursion was borderline normal and significantly lower in patients with OSA (17.7 ± 4.7 vs. 26.0 ± 5.7, p < 0.0001). In multivariate analysis, an OSA was independently associated with RV remodeling (OR: 0.257, 95% CI [0.114-0.582], p = 0.001) but not with RV dysfunction.

CONCLUSION

OSA was independently associated with structural alterations of RV early in the disease course, suggesting that the reversibility of these deleterious effects requires earlier detection and initiation of treatment.

Deterioration of biventricular strain is an early marker of cardiac involvement in confirmed sarcoidosis

AIMS

Risk assessment of developing cardiac involvement in systemic sarcoidosis can be challenging because of limited data. Recently, attention has been given to left ventricular and right ventricular (LV and RV) involvement in cardiac sarcoidosis (CS) and its prevalence, relevance, and prognostic value. The aim of this study was to assess the role of biventricular strain to predict prognosis in confirmed sarcoidosis patients.

METHODS AND RESULTS

LV and RV longitudinal strains (LSs) were evaluated by 2D speckle tracking in 139 consecutive confirmed sarcoidosis patients without other pre-existing structural heart diseases, and 52 age- and gender-matched control subjects. The primary endpoint was CS-related events (cardiac death or development of cardiac involvement). Sarcoidosis without cardiac involvement had significantly lower LV and RV free wall LS compared with control subjects. Basal LS had a higher area under the curve for differentiation of sarcoidosis in patients without cardiac involvement compared to control (cut-off value: -18% with 89% sensitivity and 69% specificity). During a median period of 50 months, the occurrence of CS-related events was observed in 20 patients. In a multivariate analysis, basal LV LS and RV free wall LS were associated with the events [hazard ratio (HR) 0.72, P < 0.001 and HR: 0.83, P = 0.006, respectively]. Patients with impaired biventricular function had significantly shorter event-free survival than those with preserved biventricular function (P < 0.001).

CONCLUSION

Deterioration of biventricular strain was associated with CS-related events. This information might be useful for clinical evaluation and follow-up in sarcoidosis.

Association Between Right Ventricular Contractile Function and Cardiac Events in Isolated Postcapillary and Combined Pre- and Postcapillary Pulmonary Hypertension

BACKGROUND

Recent studies have shown that patients with combined pre- and postcapillary pulmonary hypertension (CpcPH) had worse outcomes than those with isolated postcapillary pulmonary hypertension (IpcPH). However, the prognostic factors including right ventricular (RV) function have not been well documented. The aim of this study was to assess the differentiation of PH phenotypes, using echocardiography, and the association between RV longitudinal strain and cardiac events.

METHODS AND RESULTS

We prospectively recruited consecutive patients who had undergone right heart catheterization. The primary endpoint was cardiovascular death or readmission due to heart failure. We included 137 patients with Group 2 PH. A RV longitudinal strain of 17% was sensitive (85%) and specific (70%) to determine the CpcPH. During a median period of 31 months, 43 patients experienced the primary endpoint during follow-up. In a multivariate analysis, RV longitudinal strain was associated with the primary endpoint in both CpcPH and IpcPH (HR: 0.84, P = 0.003; HR: 0.86, P = 0.001).

CONCLUSIONS

Lower RV longitudinal strain was independently associated with worse outcomes in CpcPH and IpcPH. RV longitudinal strain may play a prognostic role in PH phenotypes.

The epidemiology of obstructive sleep apnoea and cardiovascular disease

Obstructive sleep apnoea, the most common form of sleep-disordered breathing, is highly prevalent in patients with cardiovascular disease. The last 30 years has seen a plethora of large scale epidemiological studies investigating the relationship between sleep apnoea and cardiovascular outcomes. This review highlights the key epidemiological studies addressing the links between sleep apnoea and hypertension, cardiac arrhythmias, cerebrovascular disease, coronary artery disease, heart failure and pulmonary hypertension, with a particular focus on some of the most recent reports.

Physiological and Biological Responses to Short-Term Intermittent Hypobaric Hypoxia Exposure: From Sports and Mountain Medicine to New Biomedical Applications

In recent years, the altitude acclimatization responses elicited by short-term intermittent exposure to hypoxia have been subject to renewed attention. The main goal of short-term intermittent hypobaric hypoxia exposure programs was originally to improve the aerobic capacity of athletes or to accelerate the altitude acclimatization response in alpinists, since such programs induce an increase in erythrocyte mass. Several model programs of intermittent exposure to hypoxia have presented efficiency with respect to this goal, without any of the inconveniences or negative consequences associated with permanent stays at moderate or high altitudes. Artificial intermittent exposure to normobaric hypoxia systems have seen a rapid rise in popularity among recreational and professional athletes, not only due to their unbeatable cost/efficiency ratio, but also because they help prevent common inconveniences associated with high-altitude stays such as social isolation, nutritional limitations, and other minor health and comfort-related annoyances. Today, intermittent exposure to hypobaric hypoxia is known to elicit other physiological response types in several organs and body systems. These responses range from alterations in the ventilatory pattern to modulation of the mitochondrial function. The central role played by hypoxia-inducible factor (HIF) in activating a signaling molecular cascade after hypoxia exposure is well known. Among these targets, several growth factors that upregulate the capillary bed by inducing angiogenesis and promoting oxidative metabolism merit special attention. Applying intermittent hypobaric hypoxia to promote the action of some molecules, such as angiogenic factors, could improve repair and recovery in many tissue types. This article uses a comprehensive approach to examine data obtained in recent years. We consider evidence collected from different tissues, including myocardial capillarization, skeletal muscle fiber types and fiber size changes induced by intermittent hypoxia exposure, and discuss the evidence that points to beneficial interventions in applied fields such as sport science. Short-term intermittent hypoxia may not only be useful for healthy people, but could also be considered a promising tool to be applied, with due caution, to some pathophysiological states.

Treatment of sleep-disordered breathing in heart failure impacts cardiac remodeling: Insights from the CAT-HF Trial

BACKGROUND

Sleep-disordered breathing (SDB), including central and obstructive sleep apnea, is a marker of poor prognosis in heart failure (HF) and may worsen cardiac dysfunction over time. Treatment of SDB with adaptive servoventilation (ASV) may reverse pathologic cardiac remodeling in HF patients.

METHODS

The Cardiovascular Improvements with Minute Ventilation-targeted Adaptive Servo-Ventilation Therapy in Heart Failure (CAT-HF) trial randomized patients with acute decompensated HF and confirmed SDB to either optimal medical therapy (OMT) or treatment with ASV and OMT. Patients with reduced ejection fraction (HFrEF) or preserved EF (HFpEF) were included. Echocardiograms, performed at baseline and 6 months, assessed cardiac size and function and evaluated cardiac remodeling over time. The CAT-HF trial was stopped early in response to the SERVE-HF trial, which found increased mortality among HFrEF patients with central sleep apnea treated with ASV.

RESULTS

Of the 126 patients enrolled prior to trial cessation, 95 had both baseline and 6-month echocardiograms (77 HFrEF and 18 HFpEF). Among HFrEF patients, both treatment arms demonstrated a significant increase in EF: +4.3% in the ASV group (.0004) and +4.6% in OMT alone (P = .007) and a significant decrease in LV end-systolic volume index: -9.4 mL/m² in the ASV group (P = .01) and -8.6 mL/m² in OMT alone (P = .003). Reductions in left atrial (LA) volume and E/e' were greater in the ASV arm, whereas patients receiving OMT alone demonstrated more improvement in right ventricular function. HFpEF patients treated with ASV also had a decrease in LA size that was greater than those receiving OMT alone. Although there were significant intragroup changes within the ASV + OMT and OMT-alone groups, there were no significant intergroup differences at 6 months.

CONCLUSIONS

Significant reverse LV remodeling was seen among HFrEF patients with SDB regardless of treatment allocation. Substantial reductions in LA volume among HFrEF and HFpEF patients receiving ASV suggest that ASV treatment may also improve diastolic function and warrant further investigation.

Right Ventricular Function and Beneficial Effects of Cardiac Rehabilitation in Patients With Systolic Chronic Heart Failure

BACKGROUND

It has been recognized that a comprehensive cardiac rehabilitation (CR) program improves mortality in patients with chronic heart failure. On the other hand, the magnitude of the improvement in exercise capacity after CR differs among individuals. The aim of this study was to assess the echocardiographic determinants of responders to CR using preload stress echocardiography.

METHODS

We prospectively enrolled 58 chronic heart failure patients with reduced left ventricular ejection fraction (aged 62 ± 11 years; 69% male; left ventricular ejection fraction 43% ± 7%) who had received optimized medical treatment in a CR program for 5 months. We performed preload echocardiographic studies using leg positive pressure (LPP) to assess the echocardiographic parameters during preload augmentation. We defined 41 patients as a development cohort to assess the predictive value of echocardiographic variables. Next, we validated results in the remaining 17 patients as a validation cohort.

RESULTS

In the development cohort, significant improvement in peak oxygen uptake (VO₂) (>10%) after CR was observed in 58% patients. In a multivariable logistic regression model, the significant predictor of improvement in exercise capacity was right ventricular (RV) strain during LPP (odds ratio: 3.96 per 1 standard deviation; P = 0.01). An RV strain value of -16% during LPP had a good sensitivity of 0.79 and a specificity of 0.71 to identify patients with improvement in peak VO₂. In the validation cohort, an optimal cutoff value of RV strain value was the same (area under the curve: 0.77, sensitivity: 0.78, specificity: 0.65).

CONCLUSIONS

RV strain during LPP may be an echocardiographic parameter for assessing beneficial effects of CR.

The relationship between pulmonary hypertension and obstructive sleep apnea

PURPOSE OF REVIEW

Although obstructive sleep apnea (OSA)-associated pulmonary hypertension is not uncommon and carries a worse prognosis if left untreated, it is less well recognized by clinicians. This review provides information on prevalence, pathophysiology, clinical presentation, treatment, and prognosis of pulmonary hypertension in OSA.

RECENT FINDINGS

The prevalence of pulmonary hypertension in OSA ranges from 17 to 53%. The underlying pathophysiology is complex and yet to be fully understood. Continuous positive airway pressure has been proven to be efficacious in the treatment of OSA-associated pulmonary hypertension.

SUMMARY

There is still lack of research in this field. We look forward to more well designed studies to help us understand this disease entity better.