Left Ventricular Systolic and Diastolic Function in Obstructive Sleep Apnea

Effect of continuous positive pressure ventilation on left ventricular diastolic function E/A ratio in patients with obstructive sleep apnea: a meta-analysis

PURPOSE

Many studies have shown that obstructive sleep apnea (OSA) is related to reduced left ventricular diastolic function. Continuous positive airway pressure (CPAP) is generally recognized as the preferred therapy for OSA. Yet, the effect of CPAP on left ventricular diastolic function in patients with OSA is inconclusive. In order to assess the influence of CPAP on left ventricular diastolic function in patients with OSA, we performed this meta-analysis of clinical experiments.

METHODS

PubMed, Web of Science, OVID, Embase, and Cochrane Library from the establishment of the database to July 6, 2022, were searched for clinical trial data. Inclusion criteria for this meta-analysis were: (1) Patients in the experimental group were diagnosed with OSA by polysomnography; (2) CPAP treatment course ≥ 4 weeks; (3) baseline and follow-up data of the diastolic function parameter E/A ratio were reported in the literature. Exclusion criteria were: (1) Central sleep apnea (CSA); (2) comorbid organic heart diseases such as coronary heart disease; (3) age < 18 years old; (4) conference abstracts or duplicate publications.

RESULTS

After exclusions, 7 studies (2 RCTs and 5 prospective studies) with 473 subjects (225 in the treatment group and 248 in the matched control group) were included in the meta-analysis. Subgroup analysis indicated that after CPAP therapy, the left ventricular (LV) E/A ratio was significantly increased in patients with OSA (weighted mean difference (WMD) = 0.22, 95% CI =  - 0.06-0.38; P = 0.007). Sensitivity analyses showed that the combined results were not influenced by single studies. Publication bias was not significant (Egger's test, P = 0.813).

CONCLUSIONS

The results of this meta-analysis suggest that CPAP may improve the E/A ratio in patients with OSA patients. However, the small number of studies (n = 7) decreases confidence in the findings. Thus, carefully designed randomized controlled trials are needed to confirm the findings.

Effects of Antihypertensive Treatment on Left and Right Ventricular Global Longitudinal Strain and Diastolic Parameters in Patients with Hypertension and Obstructive Sleep Apnea: Randomized Clinical Trial of Chlorthalidone plus Amiloride vs. Amlodipine

Hypertension is highly prevalent in patients with obstructive sleep apnea (OSA), and fluid retention with its nighttime rostral distribution is one potential mechanism. We tested whether or not diuretics differ from amlodipine in their impact on echocardiographic parameters. Patients with moderate OSA and hypertension were randomized to receive diuretics (chlorthalidone plus amiloride) or amlodipine daily for 8 weeks. We compared their effects on left and right ventricular global longitudinal strain (LV-GLS and RV-GLS, respectively), on LV diastolic parameters, and on LV remodeling. In the 55 participants who had echocardiographic images feasible for strain analysis, all echocardiographic parameters were within normal ranges. After 8 weeks, the 24 h blood pressure (BP) reduction values were similar, while most echocardiographic metrics were kept unchanged, except for LV-GLS and LV mass. In conclusion, the use of diuretics or amlodipine had small and similar effects on echocardiographic parameters in patients with moderate OSA and hypertension, suggesting that they do not have important effects on mediating the interaction between OSA and hypertension.

Effects of continuous positive airway pressure therapy on left ventricular performance in patients with severe obstructive sleep apnea

We investigated myocardial performance concerning obstructive sleep apnea (OSA) severity and the benefits of continuous positive airway pressure (CPAP) therapy. In this randomized sham-controlled trial, 52 patients (mean age, 49 years; 92%, males; mean AHI, 59) with severe OSA were randomly assigned to receive either CPAP or sham treatment for 3 months. The severity of OSA was determined using the apnea/hypopnea index (AHI), oxygen desaturation index (ODI), percentage of sleep time below 90% oxygen saturation (T90), and average O₂ saturation during sleep (mean SpO₂). We compared the changes in myocardial work after 3 months of CPAP (n = 26) versus the sham group (n = 26) at rest and during an exercise stress test. Unlike AHI or ODI, indices of hypoxemia including T90 and mean SpO₂ were significantly correlated with global constructive work, as defined by work of left ventricle (LV) that contributes to LV ejection during systole (T90, β = 0.393, p = 0.012; mean SpO₂, β = 0.331, p = 0.048), and global wasted work (GWW), as defined by work of LV that does not contribute to LV ejection (T90, β = 0.363, p = 0.015; mean SpO₂, β =  - 0.370, p = 0.019). After 3 months, GWW decreased (80.0 ± 49.2 to 60.8 ± 26.3, p = 0.009) and global work efficiency increased (94.0 ± 4.5 to 95.7 ± 2.0, p = 0.008) in the CPAP group compared to those in the sham group. At the 3-month follow-up exercise stress echocardiography, worsening of GWW during exercise was significantly decreased in the CPAP group compared to that in the sham group (p = 0.045 at 50 W). Hypoxemia indices were closely associated with myocardial performance in patients with severe OSA. CPAP treatment for 3 months improved left ventricular myocardial performance by decreasing wasted work and increasing work efficacy compared to the sham treatment.

Nocturnal hypoxia indexes are associated with left ventricular remodeling and diastolic dysfunction in obstructive sleep apnea patients

BACKGROUND AND OBJECTIVE

Obstructive sleep apnea (OSA) is associated with heart derangements detected at echocardiography as higher left ventricular mass index (LVMI), higher left ventricular end-diastolic diameter, lower left ventricular ejection fraction (LVEF), and impaired diastolic function. However, the currently used parameter to define OSA diagnosis and severity, the apnea/hypopnea index (AHI), poorly predicts cardiovascular damage, cardiovascular events, and mortality. Our study aimed to assess if other polygraphic indices of OSA presence and severity, in addition to AHI, might better predict echocardiographic cardiac remodeling.

METHODS AND RESULTS

We enrolled two cohorts of individuals referred for suspected OSA to the outpatient facilities of the IRCCS Istituto Auxologico Italiano, Milano, and of the Clinica Medica 3, Padova. All patients underwent home sleep apnea testing and echocardiography. Based on the AHI the cohort was divided into no-OSA (AHI<15 events/hour) and moderate-severe OSA (AHI≥15 events/hour). We recruited 162 patients and found that compared to patients with no-OSA, those with moderate-severe OSA showed higher LV remodeling [left ventricular end-diastolic volume (LVEDV) 48.4 ± 11.5 ml/m2 vs. 54.1 ± 14.0 ml/m2, respectively, p = 0.005] and lower LVEF (65.3 ± 5.8% vs. 61.6 ± 7.8%, respectively, p = 0.002), whereas we could not find any difference in LVMI and early and late ventricular filling velocity ratio (E/A). At multivariate linear regression analysis two polygraphic hypoxic burden-related markers were independent predictors of LVEDV and E/A, i.e., the percentage of time with O2 saturation below 90% (β = 0.222) and ODI (β = -0.422), respectively.

CONCLUSIONS

Our study shows that nocturnal hypoxia-related indexes were associated with left ventricular remodeling and diastolic dysfunction in OSA patients.

Defining the impact of continuous positive airway pressure therapy on diastolic function in adults with moderate-to-severe obstructive sleep apnea

Although studies have shown that continuous positive airway pressure (CPAP) therapy to treat obstructive sleep apnea improves left ventricular diastolic function, modifiers of improvement are unknown. We explored race and pre-treatment 24-h non-dipping blood pressure status as modifiers of improved diastolic function. Participants (N = 220) with obstructive sleep apnea (apnea-hypopnea index ≥15 events/h) and hypertension were recruited to a cohort study that examined effects of 3-month CPAP therapy on 24-h blood pressure. Those who completed echocardiogram at baseline and follow-up were included in this analysis. Diastolic function parameters (E, A, e', E/A, E/e') were assessed. Race was categorised to African American versus others. Participants were categorised as nocturnal dippers (night-time blood pressure decrease by ≥10%) versus non-dippers. We compared changes in parameters of diastolic function by race and nocturnal dipping status. A total of 92 participants were included. They were men (86%), African American (67.4%), and current smoker (29.5%). Mean apnea-hypopnea index was 32.9 events/h. Mean CPAP usage was 3.15 h/day. After 3 months of CPAP treatment, there were significant improvements in measures of diastolic function: a median (interquartile range [IQR]) increase in E velocity by 4.00 (-5.75 to 13.75) cm/s, an increase in e' by 2.00 (0-4.00) cm/s, and a decrease in the E/e' ratio by 1.74 (-4.27 to 0.00) at follow-up (p < 0.05). These changes did not differ by race or nocturnal dipping status. Improvements in diastolic function after CPAP therapy did not differ by race or nocturnal dipping status. Further studies are needed to understand predictors of CPAP effects on diastolic function.

Subclinical left ventricular myocardial dysfunction in patients with obstructive sleep apnea syndrome: insights from noninvasive left ventricular myocardial work analysis

BACKGROUND

Obstructive sleep apnea syndrome (OSAS) is associated with various cardiovascular diseases and has aroused public concern. Early detection for declining myocardial function is of great significance. This study was aimed at noninvasively evaluating the subclinical left ventricular (LV) myocardial dysfunction with LV pressure-strain loop (PSL) in patients with OSAS having normal LV ejection fraction.

METHODS

We enrolled 200 patients with OSAS who visited the Beijing Chaoyang Hospital between February 2021 and December 2021. According to the apnea-hypopnea index (AHI), patients were divided into mild, moderate, and severe groups. The global longitudinal strain (GLS) of the left ventricle was analyzed by two-dimensional speckle tracking echocardiography. The LV PSL was used to assess global work index (GWI), global constructive work (GCW), global waste work (GWW), and global work efficiency (GWE), and comparisons were made among groups.

RESULTS

GLS was significantly lower in the severe group than in mild and moderate group. GWI, GCW, and GWE were lower in the severe group than in mild and moderate groups. GWW was significantly higher in the severe group than in the mild group. GLS, GWI, and GWE were moderately correlated with AHI (Spearman's ρ = -0.468, -0.321, and -0.319, respectively; P < 0.001), whereas GCW and GWW showed a weak correlation with AHI (Spearman's ρ = -0.226 and 0.255 respectively; P < 0.001). Multiple regression analyses revealed AHI was independently associated with GWI after adjusting for SBP, GLS, e', etc. AHI was independently associated with GCW after adjusting for SBP, GLS, etc. CONCLUSIONS: The LV PSL is a new technique to noninvasively detect myocardial function deterioration in patients with OSAS and preserved LV ejection fraction. Increased severity of OSAS was independent associated with both decreased GWI and GCW.

Sleep Apnoea and Heart Failure

Heart Failure (HF) and Sleep-Disordered-Breathing (SDB) are two common conditions that frequently overlap and have been studied extensively in the past three decades. Obstructive Sleep Apnea (OSA) may result in myocardial damage, due to intermittent hypoxia increased sympathetic activity and transmural pressures, low-grade vascular inflammation and oxidative stress. On the other hand, central sleep apnoea and Cheyne-Stokes respiration (CSA-CSR) occurs in HF, irrespective of ejection fraction either reduced (HFrEF), preserved (HFpEF) or mildly reduced (HFmrEF). The pathophysiology of CSA-CSR relies on several mechanisms leading to hyperventilation, breathing cessation and periodic breathing. Pharyngeal collapse may result at least in part from fluid accumulation in the neck, owing to daytime fluid retention and overnight rostral fluid shift from the legs. Although both OSA and CSA-CSR occur in HF, the symptoms are less suggestive than in typical (non-HF related) OSA. Overnight monitoring is mandatory for a proper diagnosis, with accurate measurement and scoring of central and obstructive events, since the management will be different depending on whether the sleep apnea in HF is predominantly OSA or CSA-CSR. SDB in HF are associated with worse prognosis, including higher mortality than in patients with HF but without SDB. However, there is currently no evidence that treating SDB improves clinically important outcomes in patients with HF, such as cardiovascular morbidity and mortality.

Obstructive sleep apnea increases the risk of cardiovascular damage: a systematic review and meta-analysis of imaging studies

BACKGROUND

We aimed to perform a systematic review and meta-analysis of the association between obstructive sleep apnea (OSA) and cardiac as well as coronary impairment evaluated using imaging modalities. Finding of this study will provide more robust evidence regarding OSA-induced cardiovascular damage.

METHODS

We systematically searched through PubMed, EMBASE, and Cochrane library databases for relevant literatures on the association between OSA and cardiovascular damage evaluated using imaging modalities, and manually searched the references of selected articles for additional relevant articles. For each clinical parameter relevant to the meta-analysis, we first evaluated the methodological heterogeneity of the relevant studies and thereafter pooled the data together using fixed effect or random effect model. The difference in the relevant indices of cardiovascular damage between OSA patients and controls was evaluated using the standardized mean difference.

RESULTS

Of the 82 articles included in the final systematic analysis, 20 studies explored the association between OSA and coronary atherosclerosis. OSA patients had higher rate of coronary atherosclerosis assessed by coronary artery calcification score and plaque volume. Moreover, the severity of OSA and coronary atherosclerosis displayed a positive correlation. The rest of the studies (n = 62) evaluated cardiac alterations in OSA patients. According to the inclusion and exclusion criteria, 46 studies yielding 3082 OSA patients and 1774 controls were pooled for the meta-analysis. For left cardiac structure and function, OSA patients exhibited significantly wider left atrial diameter; higher left atrium volume index; wider left ventricular end-systolic diameter, left ventricular end-diastolic diameter, and left ventricular mass; higher left ventricular mass index; wider interventricular septum diameter and posterior wall diameter; and higher left ventricular myocardial performance index (all p < 0.05). In addition, compared with controls, left ventricular ejection fraction was significantly decreased in OSA patients (p = 0.001). For right cardiac structure and function, OSA patients displayed a significant increase in right ventricular diameter and right ventricular myocardial performance index (both p < 0.001). Finally, compared with controls, OSA patients displayed significant decrease in tricuspid annular plane systolic excursion and RV fractional area change (p = 0.001).

CONCLUSION

Overall, this systematic review and meta-analysis provides imaging evidence in support that OSA patients are at a higher risk of developing coronary atherosclerosis and display cardiac remodeling and dysfunction.

Obstructive sleep apnoea syndrome and left ventricular hypertrophy: a meta-analysis of echocardiographic studies

AIM

We investigated the association between obstructive sleep apnoea (OSA) and subclinical cardiac organ damage through a meta-analysis of echocardiographic studies that provided data on left ventricular hypertrophy (LVH), assessed as a categorical or continuous variable.

DESIGN

The PubMed, OVID-MEDLINE, and Cochrane library databases were systematically analyzed to search English-language articles published from 1 January 2000 to 15 August 2019. Studies were detected by using the following terms: 'obstructive sleep apnea', 'sleep quality', 'sleep disordered breathing', 'cardiac damage', 'left ventricular mass', 'left ventricular hypertrophy', and 'echocardiography'.

RESULTS

Meta-analysis included 5550 patients with OSA and 2329 non-OSA controls from 39 studies. The prevalence of LVH in the pooled OSA population was 45% (CI 35--55%). Meta-analysis of studies comparing the prevalence of LVH in participants with OSA and controls showed that OSA was associated with an increased risk of LVH (OR = 1.70, CI 1.44-2.00, P < 0.001). LV mass was significantly increased in patients with severe OSA as compared with controls (SMD 0.46 ± 0.08, CI 0.29-0.62, P < 0.001) or with mild OSA. This was not the case for studies comparing patients with unselected or predominantly mild OSA and controls (0.33 ± 0.17, CI -0.01 to 0.67, P = 0.057).

CONCLUSION

The present meta-analysis expands previous information on the relationship between OSA and echocardiographic LVH, so far based on individual studies. The overall evidence strongly suggests that the likelihood of LVH increases with the severity of OSA, thus exhibiting a continuous relationship.

Heart failure in adult congenital heart disease: tetralogy of Fallot

The number of rTOF patients who survive into adulthood is steadily rising, with currently more than 90% reaching the third decade of life. However, rTOF patients are not cured, but rather have a lifelong increased risk for cardiac and non-cardiac complications. Heart failure is recognized as a significant complication. Its occurrence is strongly associated with adverse outcome. Unfortunately, conventional concepts of heart failure may not be directly applicable in this patient group. This article presents a review of the current knowledge on HF in rTOF patients, including incidence and prevalence, the most common mechanisms of heart failure, i.e., valvular pathologies, shunt lesions, left atrial hypertension, primary left heart and right heart failure, arrhythmias, and coronary artery disease. In addition, we will review information regarding extracardiac complications, risk factors for the development of heart failure, clinical impact and prognosis, and assessment possibilities, particularly of the right ventricle, as well as management strategies. We explore potential future concepts that may stimulate further research into this field.

The effects of cardiac stretch on atrial fibroblasts: Analysis of the evidence and potential role in atrial fibrillation

Atrial fibrillation (AF) is an important clinical problem. Chronic pressure/volume overload of the atria promotes AF, particularly via enhanced extracellular matrix (ECM) accumulation manifested as tissue fibrosis. Loading of cardiac cells causes cell-stretch that is generally considered to promote fibrosis by directly activating fibroblasts, the key cell-type responsible for ECM-production. The primary purpose of this article is to review the evidence regarding direct effects of stretch on cardiac fibroblasts, specifically: (i) the similarities and differences among studies in observed effects of stretch on cardiac-fibroblast function; (ii) the signaling-pathways implicated; and (iii) the factors that affect stretch-related phenotypes. Our review summarizes the most important findings and limitations in this area and gives an overview of clinical data and animal models related to cardiac stretch, with particular emphasis on the atria. We suggest that the evidence regarding direct fibroblast activation by stretch is weak and inconsistent, in part because of variability among studies in key experimental conditions that govern the results. Further work is needed to clarify whether, in fact, stretch induces direct activation of cardiac fibroblasts and if so, to elucidate the determining factors to ensure reproducible results. If mechanical load on fibroblasts proves not to be clearly profibrotic by direct actions, other mechanisms like paracrine influences, the effects of systemic mediators and/or the direct consequences of myocardial injury or death, might account for the link between cardiac stretch and fibrosis. Clarity in this area is needed to improve our understanding of AF pathophysiology and assist in therapeutic development.

Effect of Obstructive Sleep Apnea and Positive Airway Pressure Therapy on Cardiac Remodeling as Assessed by Cardiac Biomarker and Magnetic Resonance Imaging in Nonobese and Obese Adults

It is unknown whether obesity modifies the effect of obstructive sleep apnea (OSA) and positive airway pressure (PAP) therapy on cardiac remodeling and NT-proBNP (N-terminal pro-B-type natriuretic peptide) levels. We compared NT-proBNP and cardiac magnetic resonance imaging in adults without OSA (n=56) and nonobese (n=73; body mass index <30 kg/m²) and obese (n=136; body mass index ≥30 kg/m²) adults with OSA. We also investigated these traits in nonobese (n=45) and obese (n=78) participants with OSA adherent to 4 months of PAP treatment. At baseline, left ventricular mass to end-diastolic volume ratio, a measure of left ventricular concentricity, was greater in both nonobese and obese participants with OSA compared with those without OSA. Participants with OSA and obesity exhibited reduced phasic right atrial function. No significant differences in baseline NT-proBNP were observed across groups. The effect of PAP treatment on NT-proBNP and left atrial volume index was significantly modified by obesity. In nonobese participants, PAP therapy was associated with a decrease in NT-proBNP (P<0.0001) without a change in left atrial volume index, whereas in obese participants, PAP was associated with an increase in left atrial volume index (P=0.006) without a change in NT-proBNP. OSA was associated with left ventricular concentric remodeling independent of obesity and right atrial dysfunction in participants who were obese. PAP treatment was associated with reduced NT-proBNP in nonobese participants with OSA, but left atrial enlargement in obese participants with OSA, suggesting that PAP-induced reduction in BNP release (which is known to occur during obstructive apnea episodes) may lead to volume retention in obese participants with OSA. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01578031.

Obstructive sleep apnoea, intermittent hypoxia and heart failure with a preserved ejection fraction

Obstructive sleep apnoea (OSA) is recognised to be a potent risk factor for hypertension, coronary heart disease, strokes and heart failure with a reduced ejection fraction. However, the association between OSA and heart failure with a preserved ejection fraction (HFpEF) is less well recognised. Both conditions are very common globally.It appears that there are many similarities between the pathological effects of OSA and other known aetiologies of HFpEF and its postulated pathophysiology. Intermittent hypoxia induced by OSA leads to widespread stimulation of the sympathetic nervous system, renin-angiotensin-aldosterone system and more importantly a systemic inflammatory state associated with oxidative stress. This is similar to the consequences of hypertension, diabetes, obesity and ageing that are the common precursors to HFpEF. The final common pathway is probably via the development of myocardial fibrosis and structural changes in collagen and myocardial titin that cause myocardial stiffening. Thus, considering the pathophysiology of OSA and HFpEF, OSA is likely to be a significant risk factor for HFpEF and further trials of preventive treatment should be considered.

Effect of long term CPAP therapy on cardiac parameters assessed with cardiac MRI

The obstructive sleep apnoea syndrome (OSAS) is a disorder with a high prevalence and is associated with an elevated cardiovascular risk and increased morbidity and mortality. For longitudinal studies and functional analysis cardiac MRI is regarded as the gold standard. Aim of this study was to evaluate the long-term effect of continuous positive airway pressure (CPAP) therapy on cardiac functional parameters with cardiac Magnetic Resonance Imaging (cMRI). 54 patients with OSAS (mean apnea hypopnea index-AHI: 31) were prospectively enrolled in this study and cMRI was performed before and after 7 months of CPAP therapy. Data were acquired on a 1.5 T MRI and right and left ventricular cardiac function were analysed. CPAP treatment was considered compliant when used ≥ 4 h per night. 24-h blood pressure was measured at baseline and follow up. 33 patients could be assigned to the compliance group. Left ventricular stroke volume (LV SV) and right ventricular ejection fraction (RV EF) improved significantly with CPAP therapy (LV SV from 93 ± 19 to 99 ± 20 ml, p = 0.02; RV EF from 50 ± 6 to 52 ± 6%, p = 0.04). All other cardiac parameters did not change significantly while mean systolic and diastolic blood pressure improved significantly (p < 0.01). 21 patients were assigned to the non-compliance group and were considered as a control group. There were no relevant differences in cardiac parameters between baseline and follow up examination in these patients. CPAP therapy seems to improve LV SV, RV EF, systolic and diastolic blood pressure in OSAS patients, but reproducibility of our results need to be confirmed in a larger patient population.

Hypertension as a Road to Treatment of Heart Failure with Preserved Ejection Fraction

PURPOSE OF REVIEW

Hypertension heralds the diagnosis of heart failure (HF) with preserved ejection fraction (HFpEF) in 75-85% of cases and shares many of its adverse outcomes as well as its acute and chronic symptoms. This review provides important new data about the pathophysiology and mechanisms that connect hypertension and HFpEF as well as therapy used in both conditions.

RECENT FINDINGS

The traditional model of HFpEF pathophysiology emphasizes the role of hypertension causing increased afterload on the left ventricle (LV), leading to LV hypertrophy (LVH) and subsequent LV diastolic dysfunction. Recent work has provided valuable insights into the mechanisms underlying the transition from hypertension to HFpEF, showing that the pathophysiology extends beyond LVH and diastolic dysfunction. An evolving paradigm suggests that HFpEF is inflammatory in nature with multifactorial pathophysiology, affected by age-related changes and comorbidities. Hypertension shares many of the proinflammatory mechanisms of HFpEF. Furthermore, hypertension precedes HFpEF in the majority of cases. Because of its clinically heterogeneous nature, development of standardized therapies for HFpEF has been challenging. As there are standardized approaches to hypertension, we suggest that similar approaches be used for the treatment of HFpEF, including medical and non-medical therapies. With medical therapies, a treat-to-target blood pressure (BP) strategy could be employed, such as systolic BP < 130 mmHg. With non-medical therapies, approaches to deal with physical inactivity, obesity, and sleep apnea could be used. Due to its heterogeneity, delineation of standardized therapies for HFpEF has been challenging. Focusing on the tremendous overlap of hypertensive heart disease with HFpEF, it is proposed that approaches currently used to guide therapies for hypertension be applied to the treatment of HFpEF.

Risk of Obstructive Sleep Apnea and Echocardiographic Parameters

BACKGROUND

Obstructive sleep apnea (OSA) is a chronic progressive disorder with high mortality and morbidity rate, associated with cardiovascular diseases (CVD), especially heart failure (HF). The pathophysiological changes related to OSA can directly affect the diastolic function of the left ventricle.

OBJECTIVES

To assess the association of the risk of OSA, evaluated by the Berlin Questionnaire (BQ), and echocardiographic (ECHO) parameters related to diastolic dysfunction in individuals without HF assisted in primary care.

METHODS

A cross-sectional study that included 354 individuals (51% women) aged 45 years or older. All individuals selected were submitted to an evaluation that included the following procedures: consultation, filling out the BQ, clinical examination, laboratory examination and transthoracic Doppler echocardiography (TDE). Continuous data are presented as medians and interquartile intervals, and categoric variables in absolute and relative frequencies. The variables associated with risk of OSA and at the 0.05 level integrated the gamma regression models with a log link function. A value of p < 0.05 was considered an indicator of statistical significance. Exclusion criteria were presence of HF, to fill out the BQ and patients with hypertension and obesity not classified as high risk for OSA by other criteria. All individuals were evaluated on a single day with the following procedures: medical appointment, BQ, laboratory tests and ECHO.

RESULTS

Of the 354 individuals assessed, 63% were classified as having high risk for OSA. The patients with high risk for OSA present significantly abnormal diastolic function parameters. High risk for OSA confirmed positive and statistically significant association, after adjustments, with indicators of diastolic function, such as indexed left atrium volume LAV-i (p = 0.02); E'/A' (p < 0.01), A (p = 0.02), E/A (p < 0.01).

CONCLUSION

Our data show that patients at high risk for OSA present worsened diastolic function parameters measured by TDE.

Echocardiographic Changes with Positive Airway Pressure Therapy in Obesity Hypoventilation Syndrome. Long-Term Pickwick Randomized Controlled Clinical Trial

Rationale: Obesity hypoventilation syndrome (OHS) has been associated with cardiac dysfunction. However, randomized trials assessing the impact of long-term noninvasive ventilation (NIV) or continuous positive airway pressure (CPAP) on cardiac structure and function assessed by echocardiography are lacking.Objectives: In a prespecified secondary analysis of the largest multicenter randomized controlled trial of OHS (Pickwick Project; N = 221 patients with OHS and coexistent severe obstructive sleep apnea), we compared the effectiveness of three years of NIV and CPAP on structural and functional echocardiographic changes.Methods: At baseline and annually during three sequential years, patients underwent transthoracic two-dimensional and Doppler echocardiography. Echocardiographers at each site were blinded to the treatment allocation. Statistical analysis was performed using a linear mixed-effects model with a treatment group and repeated measures interaction to determine the differential effect between CPAP and NIV.Measurements and Main Results: A total of 196 patients were analyzed: 102 were treated with CPAP and 94 were treated with NIV. Systolic pulmonary artery pressure decreased from 40.5 ± 1.47 mm Hg at baseline to 35.3 ± 1.33 mm Hg at three years with CPAP, and from 41.5 ± 1.56 mm Hg to 35.5 ± 1.42 with NIV (P < 0.0001 for longitudinal intragroup changes for both treatment arms). However, there were no significant differences between groups. NIV and CPAP therapies similarly improved left ventricular diastolic dysfunction and reduced left atrial diameter. Both NIV and CPAP improved respiratory function and dyspnea.Conclusions: In patients with OHS who have concomitant severe obstructive sleep apnea, long-term treatment with NIV and CPAP led to similar degrees of improvement in pulmonary hypertension and left ventricular diastolic dysfunction.Clinical trial registered with www.clinicaltrials.gov (NCT01405976).

Subclinical impairment of dynamic left ventricular systolic and diastolic function in patients with obstructive sleep apnea and preserved left ventricular ejection fraction

Background

Hypoxia affects myocardial oxygen supply resulting in subclinical cardiac dysfunction in obstructive sleep apnea (OSA) patients, with cardiovascular complications being associated with increased oxidative burst (OB). The aims of our study were to assess left ventricular (LV) dynamic myocardial deformation and diastolic reserve at rest and upon exercise, along with OB determination in this patients subset.

Methods

Conventional echocardiography, Doppler myocardial imaging and LV 2D speckle tracking echocardiography were performed in 55 OSA patients with preserved LV ejection fraction (EF) and 35 age and sex-comparable healthy controls. Peripheral OB levels were evaluated by flow cytometry.

Results

Despite comparable LVEF, LV global longitudinal strain (GLS) was significantly reduced in OSA at rest (− 13.4 ± 3.8 vs − 18.4 ± 3.3 in controls, P <  0.001) and at peak exercise (− 15.8 ± 2.6 vs − 23.4 ± 4.3, P <  0.001). Systolic pulmonary artery pressure (sPAP) and E/E′ ratios increase during effort were higher in OSA than in controls (ΔsPAP 44.3% ± 6.4 vs 32.3% ± 5.5, P <  0.0001, and ΔE/E’ 87.5% ± 3.5 vs 25.4% ± 3.3, P <  0.0001, respectively). The best correlate of E/E′ at peak stress was peak exertion capacity (r = − 0.50, P <  0.001). OB was also increased in OSA patients (P = 0.001) but, unlike OSA severity, was not associated with LV diastolic dysfunction.

Conclusions

Evaluation of diastolic function and myocardial deformation during exercise is feasible through stress echocardiography. OSA patients with preserved LVEF show subclinical LV systolic dysfunction, impaired LV systolic and diastolic reserve, reduced exercise tolerance, and increased peripheral levels of OB. Therapy aimed at increasing LV diastolic function reserve might improve the quality of life and exercise tolerability in OSA patients.

Cardiac output measured by transthoracic echocardiography and Swan-Ganz catheter. A comparative study in mechanically ventilated patients with high positive end-expiratory pressure

Objective

To compare cardiac output measurements by transthoracic echocardiography and a pulmonary artery catheter in mechanically ventilated patients with high positive end-expiratory pressure. To evaluate the effect of tricuspid regurgitation.

Methods

Sixteen mechanically ventilated patients were studied. Cardiac output was measured by pulmonary artery catheterization and transthoracic echocardiography. Measurements were performed at different levels of positive end-expiratory pressure (10cmH₂O, 15cmH₂O, and 20cmH₂O). The effect of tricuspid regurgitation on cardiac output measurement was evaluated. The intraclass correlation coefficient was studied; the mean error and limits of agreement were studied with the Bland-Altman plot. The error rate was calculated.

Results

Forty-four pairs of cardiac output measurements were obtained. An intraclass correlation coefficient of 0.908 was found (p < 0.001). The mean error was 0.44L/min for cardiac output values between 5 and 13L/min. The limits of agreement were 3.25L/min and -2.37L/min. With tricuspid insufficiency, the intraclass correlation coefficient was 0.791, and without tricuspid insufficiency, 0.935. Tricuspid insufficiency increased the error rate from 32% to 52%.

Conclusions

In patients with high positive end-expiratory pressure, cardiac output measurement by transthoracic echocardiography is comparable to that with a pulmonary artery catheter. Tricuspid regurgitation influences the intraclass correlation coefficient. In patients with high positive end-expiratory pressure, the use of transthoracic echocardiography to measure cardiac output is comparable to invasive measures.

The Effect of Obstructive Sleep Apnea on 3-Year Outcomes in Patients Who Underwent Orthotopic Heart Transplantation

Despite the well-known association between obstructive sleep apnea (OSA) and cardiovascular disease, there is a paucity of data regarding OSA in orthotopic heart transplant (OHT) recipients and its effect on clinical outcomes. Hence, we sought to determine the association between OSA, as detected by polysomnography, and late graft dysfunction (LGD) after OHT. In this retrospective review of consecutive OHT recipients from 2012 to 2014 at our center, we examined LGD, i.e., graft failure >1 year after OHT, through competing risks analysis. Due to small sample size and event counts, as well as preliminary testing which revealed statistically similar demographics and outcomes, we pooled patients who had treated OSA with those who had no OSA. Of 146 patients, 29 (20%) had untreated OSA, i.e., OSA without use of continuous positive airway pressure therapy, at the time of transplantation. Patients with untreated OSA were significantly older, heavier, and more likely to have baseline hypertension than those with treated/no OSA. Although there were no differences between groups in regard to short-term complications of acute kidney injury, cardiac allograft vasculopathy, or primary graft dysfunction, there were significant differences in the occurrence of LGD. Those with untreated OSA were at 3 times the risk of developing LGD than those with treated/no OSA (hazard ratio 3.2; 95% confidence interval 1.3 to 7.9; p = 0.01). Because OSA is a common co-morbidity of OHT patients and because patients with untreated OSA have an elevated risk of LGD, screening for and treating OSA should occur during the OHT selection period.

Prevalence, Clinical Profile, and In-Hospital Outcomes of Sleep-Disordered Breathing in Patients Undergoing Transcatheter Aortic Valve Implantation in Japan

Background: The prevalence, patient profile, and outcomes of sleep-disordered breathing (SDB) in aortic stenosis (AS) remain unknown, especially in East Asia.

Methods and Results: One hundred and eighty-one AS patients undergoing transcatheter aortic valve implantation (TAVI) were enrolled. Sixty-one patients (33.7%) had SDB, and lower stroke volume index was an independent determinant of SDB. Incidence of in-hospital stroke after TAVI was higher in the SDB group.

Conclusions: SDB is associated with left ventricular systolic dysfunction in Japanese AS patients referred for TAVI. SDB was highly associated with the incidence of stroke as a procedural complication.

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.

Effects of continuous positive airway pressure therapy on left ventricular diastolic function: a randomised, sham-controlled clinical trial

Continuous positive airway pressure (CPAP) therapy may decrease left ventricular (LV) loads and improve myocardial oxygenation. In this study, we investigated the effect of CPAP on LV diastolic function compared with sham treatment in patients with severe obstructive sleep apnoea (OSA).

This 3-month prospective single-centre randomised sham-controlled trial analysed 52 patients with severe OSA. Patients were randomly assigned (1:1) to receive either CPAP or sham treatment for 3 months. The main investigator and patients were masked to the trial randomisation. The primary end-point was change of early diastolic mitral annular (e′) velocity over the 3-month period. Secondary end-points were pulse wave velocity (PWV), 24-h ambulatory blood pressure (BP) and variables of ventricular-vascular coupling at 3 months.

After 3 months of follow-up, CPAP treatment significantly increased the e′ velocity, and was greater than the sham treatment (0.65±1.70 versus −0.61±1.85 cm·s−1, p=0.014). The PWV, 24-h mean diastolic BP, night-time diastolic BP, arterial elastance index and ventricular-vascular coupling index after 3 months of follow-up decreased significantly in the CPAP group.

In patients with severe OSA, CPAP treatment for 3 months improved LV diastolic function more than sham treatment, and was accompanied by improvements in arterial stiffness and ventricular-vascular coupling.

Rationale and Design for a Monocentric Prospective Study: Sleep Apnea Diagnosis Using a Novel Pacemaker Algorithm and Link With Aldosterone Plasma Level in Patients Presenting With Diastolic Dysfunction (SAPAAD Study)

Previous studies showed good agreement between pacemaker respiratory disturbance index (RDI) and polysomnography for diagnosis of severe sleep apnea (SA). The aim of this study is to investigate the diagnostic accuracy of RDI compared with apnea-hypopnea index (AHI) from a cardiorespiratory sleep study for the diagnosis of severe SA within patients requiring a pacemaker and meeting diastolic dysfunction criteria. Secondary objectives are as follows: correlation between plasma aldosterone level and SA severity, diagnostic accuracy of RDI for moderate SA, prevalence of SA among patients with diastolic dysfunction, occurrence of arrhythmias, and improvement of RDI with continuous positive airway pressure therapy. We designed a monocentric prospective nonrandomized study of prevalent cases to include 68 patients with a 6-month follow-up. Both RDI and AHI will be compared 2 months after implantation and after 1 month of continuous positive airway pressure treatment in patients with severe SA. This is the first study that examines diagnostic accuracy of pacemaker algorithm for the diagnosis of SA and correlation with plasma aldosterone levels in patients with diastolic dysfunction. Protocol version: V04. 04/04/2017 Trial registration: ClinicalTrials.gov NCT02751021.

Left ventricular torsion in patients with obstructive sleep apnoea before and after continuous positive airway pressure therapy: assessment by two-dimensional speckle tracking echocardiography

BACKGROUND

The purpose of the present study was to evaluate how obstructive sleep apnoea (OSA) influences left ventricular (LV) torsion and whether nasal continuous positive airway pressure (CPAP) therapy has any impact on LV torsion in OSA patients with established cardiovascular risk factors.

METHODS

LV torsion was assessed by two-dimensional speckle tracking echocardiography (STE) in 162 participants without overt cardiovascular disease. The participants were categorized according to the apnoea-hypopnea index (AHI) as controls and mild, moderate and severe OSA patients. Forty-three patients with AHI greater than 30 were enrolled to receive CPAP therapy for 24 weeks. Twenty-eight patients received CPAP therapy effectively (compliance: 65%). After completion of CPAP therapy, STE was repeated to evaluate LV torsion.

RESULTS

LV torsion was decreased in the severe OSA group compared to mild and moderate OSA but was similar to controls as a result of predominant decrease in apical rotation. AHI had no correlation with LV torsion in moderate OSA but a significant and mild negative correlation with LV torsion in severe OSA. When adjusted for potential confounding variables such as left ventricular mass index, diastolic dysfunction and the presence of hypertension, AHI and E/E' remained significant predictors of LV torsion in OSA patients. LV apical rotation tended to increase after effective CPAP therapy. On the other hand, LV basal rotation decreased significantly.

CONCLUSIONS

LV torsion was altered in OSA patients with varying degrees according to the disease severity. Furthermore, there was no significant change of torsion after 24 weeks of CPAP therapy.

Echocardiographic changes with non-invasive ventilation and CPAP in obesity hypoventilation syndrome

Rationale

Despite a significant association between obesity hypoventilation syndrome (OHS) and cardiac dysfunction, no randomised trials have assessed the impact of non-invasive ventilation (NIV) or CPAP on cardiac structure and function assessed by echocardiography.

Objectives

We performed a secondary analysis of the data from the largest multicentre randomised controlled trial of OHS (Pickwick project, n=221) to determine the comparative efficacy of 2 months of NIV (n=71), CPAP (n=80) and lifestyle modification (control group, n=70) on structural and functional echocardiographic changes.

Methods

Conventional transthoracic two-dimensional and Doppler echocardiograms were obtained at baseline and after 2 months. Echocardiographers at each site were blinded to the treatment arms. Statistical analysis was performed using intention-to-treat analysis.

Results

At baseline, 55% of patients had pulmonary hypertension and 51% had evidence of left ventricular hypertrophy. Treatment with NIV, but not CPAP, lowered systolic pulmonary artery pressure (−3.4 mm Hg, 95% CI −5.3 to –1.5; adjusted P=0.025 vs control and P=0.033 vs CPAP). The degree of improvement in systolic pulmonary artery pressure was greater in patients treated with NIV who had pulmonary hypertension at baseline (−6.4 mm Hg, 95% CI −9 to –3.8). Only NIV therapy decreased left ventricular hypertrophy with a significant reduction in left ventricular mass index (−5.7 g/m2; 95% CI −11.0 to –4.4). After adjusted analysis, NIV was superior to control group in improving left ventricular mass index (P=0.015). Only treatment with NIV led to a significant improvement in 6 min walk distance (32 m; 95% CI 19 to 46).

Conclusion

In patients with OHS, medium-term treatment with NIV is more effective than CPAP and lifestyle modification in improving pulmonary hypertension, left ventricular hypertrophy and functional outcomes. Long-term studies are needed to confirm these results.

Trial registration number

Pre-results, NCT01405976 (https://clinicaltrials.gov/).

The effects of adenotonsillar hypertrophy corrective surgery on left ventricular functions and pulmonary artery pressure in children

OBJECTIVE

Comparison of left ventricular functions in preoperative and postoperative periods of children with adenotonsillar hypertrophy (ATH) who have findings of upper airway obstruction (UAO), using echocardiographic parameters.

METHODS

Thirty children who were diagnosed with UAO due to ATH, and who have undergone adenoidectomy/adenotonsillectomy and 30 healthy children, between 2 and 11 years of age, were included in the study. Patient group was evaluated by the pulsed wave tissue Doppler echocardiography, as well as with conventional echocardiography, before and 6 months after the operation.

RESULTS

Of 30 children in study group, 18 (60%) had adenotonsillectomy and 12 (40%) had adenoidectomy. The differences between groups regarding myocardial performance index (MPI) was not statistically significant (p = 0.847). There was not any statistically significant difference between groups in terms of mitral isovolemic acceleration (MIVA) (2.28 ± 0.67, 2.24 ± 0.55, 2.23 ± 0.49; p = 0.943, respectively). Interventricular septum diameter (IVSD) was significantly higher in preoperative group than postoperative and control groups (3.68 ± 0.52, 3.50 ± 0.40, 3.38 ± 0.60; p = 0.028, respectively). Pulmonary acceleration time (PAcT) was found to be significantly lower in preoperative group compared to postoperative and control groups (107.64 ± 16.60, 119.52 ± 15.95, 120.47 ± 16.19; p = 0.004, respectively). Mean pulmonary arterial pressure (mPAP) was significantly higher in preoperative group than postoperative and control groups (30.58 ± 8.11, 25.23 ± 9.07, 25.00 ± 6.52; p = 0.002, respectively). In postoperative group mPAP was found to be similar to the control group.

CONCLUSIONS

Clinical or subclinical left ventricle (LV) dysfunction in children with ATH who have findings of UAO was not determined while mean pulmonary arterial pressure was significantly higher compared with the control cases. Besides early adenotonsillectomy is a beneficial treatment option for these patients.

Effect of CPAP on diastolic function in coronary artery disease patients with nonsleepy obstructive sleep apnea: A randomized controlled trial

BACKGROUND

Obstructive sleep apnea (OSA) has been associated with worse diastolic function in patients with coronary artery disease (CAD). This analysis determined whether continuous positive airway pressure (CPAP) treatment would improve diastolic function in CAD patients with nonsleepy OSA.

METHODS

Between December 2005 and November 2010, 244 revascularized CAD patients with nonsleepy OSA (apnea-hypopnea index (AHI) ≥15/h, Epworth Sleepiness Scale [ESS] score<10) were randomly assigned to CPAP or no-CPAP. Echocardiographic measurements were obtained at baseline, and after 3 and 12months.

RESULTS

A total of 171 patients with preserved left ventricular ejection fraction (≥50%), no atrial fibrillation or severe valve abnormalities, and technically adequate echocardiograms at baseline and follow-up visits were included (CPAP, n=87; no-CPAP, n=84). In the intention-to-treat analysis, CPAP had no significant effect on echocardiographic parameters of mild (enlarged left atrium or decreased diastolic relaxation velocity) or worse (increased E/é filling index [presumed elevated left ventricular filling pressure]) diastolic function. Post-hoc analysis revealed a significant association between CPAP usage for ≥4h/night and an increase in diastolic relaxation velocity at 12months' follow-up (odds ratio 2.3, 95% confidence interval 1.0-4.9; p=0.039) after adjustment for age, sex, body mass index, and left atrium diameter at baseline.

CONCLUSIONS

CPAP did not improve diastolic dysfunction in CAD patients with nonsleepy OSA. However, good CPAP adherence was significantly associated with an increase in diastolic relaxation velocity after one year.

Effects of Obstructive Sleep Apnea and Obesity on Cardiac Remodeling: The Wisconsin Sleep Cohort Study

STUDY OBJECTIVES

To characterize the prospective associations of obstructive sleep apnea (OSA) with future echocardiographic measures of adverse cardiac remodeling.

METHODS

This was a prospective long-term observational study. Participants had overnight polysomnography followed by transthoracic echocardiography a mean (standard deviation) of 18.0 (3.7) y later. OSA was characterized by the apnea-hypopnea index (AHI, events/hour). Echocardiography was used to assess left ventricular (LV) systolic and diastolic function and mass, left atrial volume and pressure, cardiac output, systemic vascular resistance, and right ventricular (RV) systolic function, size, and hemodynamics. Multivariate regression models estimated associations between log10(AHI+1) and future echocardiographic findings. A secondary analysis looked at oxygen desaturation indices and future echocardiographic findings.

RESULTS

At entry, the 601 participants were mean (standard deviation) 47 (8) y old (47% female). After adjustment for age, sex, and body mass index, baseline log10(AHI+1) was associated significantly with future reduced LV ejection fraction and tricuspid annular plane systolic excursion (TAPSE) ≤ 15 mm. After further adjustment for cardiovascular risk factors, participants with higher baseline log10(AHI+1) had lower future LV ejection fraction (β = -1.35 [standard error = 0.6]/log10(AHI+1), P = 0.03) and higher odds of TAPSE ≤ 15 mm (odds ratio = 6.3/log10(AHI+1), 95% confidence interval = 1.3-30.5, P = 0.02). SaO2 desaturation indices were associated independently with LV mass, LV wall thickness, and RV area (all P < 0.03).

CONCLUSIONS

OSA is associated independently with decreasing LV systolic function and with reduced RV function. Echocardiographic measures of adverse cardiac remodeling are strongly associated with OSA but are confounded by obesity. Hypoxia may be a stimulus for hypertrophy in individuals with OSA.

A clinical approach to obstructive sleep apnea as a risk factor for cardiovascular disease

Obstructive sleep apnea (OSA) is associated with cardiovascular risk factors, cardiovascular diseases, and increased mortality. Epidemiological studies have established these associations, and there are now numerous experimental and clinical studies which have provided information on the possible underlying mechanisms. Mechanistic proof-of-concept studies with surrogate endpoints have been performed to demonstrate that treatment of OSA by continuous positive airway pressure (CPAP) has the potential to reverse or at least to attenuate not only OSA but also the adverse cardiovascular effects associated with OSA. However, no randomized studies have been performed to demonstrate that treatment of OSA by CPAP improves clinical outcomes in patients with cardiovascular risk factors and/or established cardiovascular disease and concomitant OSA. In the present review, we summarize the current knowledge on the role of OSA as a potential cardiovascular risk factor, the impact of OSA on cardiac function, the role of OSA as a modifier of the course of cardiovascular diseases such as coronary artery disease, atrial fibrillation, and heart failure, and the insights from studies evaluating the impact of CPAP therapy on the cardiovascular features associated with OSA.

Cost of stroke: a controlled national study evaluating societal effects on patients and their partners

Background

To estimate the direct and indirect costs of stroke in patients and their partners.

Description

Direct and indirect costs were calculated using records from the Danish National Patient Registry from 93,047 ischemic, 26,012 hemorrhagic and 128,824 unspecified stroke patients and compared with 364,433, 103,741 and 500,490 matched controls, respectively.

Results

Independent of age and gender, stroke patients had significantly higher rates of mortality, health-related contacts, medication use and lower employment, lower income and higher social-transfer payments than controls. The attributable cost of direct net health care costs after the stroke (general practitioner services, hospital services, and medication) and indirect costs (loss of labor market income) were €10,720, €8,205 and €7,377 for patients, and €989, €1,544 and €1.645 for their partners, over and above that of controls for hemorrhagic, ischemic and unspecified stroke, respectively. The negative social- and health-related status could be identified up to eleven years before the first diagnosis.

Conclusion

Stroke has significant mortality, morbidity and socioeconomic consequences for patients, their partners and society.

Effect of CPAP on Cardiac Function in Minimally Symptomatic Patients with OSA: Results from a Subset of the MOSAIC Randomized Trial

STUDY OBJECTIVES

Minimally symptomatic obstructive sleep apnea (OSA) is highly prevalent, and the effects of continuous positive airway pressure (CPAP) on myocardial function in these patients are unknown. The MOSAIC randomized, controlled trial of CPAP for minimally symptomatic OSA assessed the effect of CPAP on myocardial function in a subset of patients.

METHODS

Two centers taking part in the MOSAIC trial randomized 238 patients in parallel to 6 months of CPAP (120) or standard care (118). Of these, 168 patients had echocardiograms, and 68 patients had a cardiac magnetic resonance scan (CMR). A larger group (314) from 4 centers had brain natriuretic peptide (BNP) measured.

RESULTS

Mean (SD) baseline oxygen desaturation index (ODI) and Epworth sleepiness score (ESS) were 13.5 (13.2), and 8.4 (4.0), respectively. CPAP significantly reduced ESS and ODI. Baseline LV ejection fraction (LVEF) was well preserved (60.4%). CPAP had no significant effect on echo-derived left atrial (LA) area (-1.0 cm2, 95% CI -2.6 to +0.6, p = 0.23) or early to late left ventricular filling velocity (E/A) ratio (-0.01, 95% CI -0.07 to +0.05, p = 0.79). There was a small change in echo-derived LV end diastolic volume (EDV) with CPAP (-5.9 mL, 95% CI -10.6 to -1.2, p = 0.015). No significant changes were detected by CMR on LV mass index (+1.1 g/m(2), 95% CI -5.9 to +8.0, p = 0.76) or LVEF (+0.8%, 95% CI -1.2 to +2.8, p = 0.41). CPAP did not affect BNP levels (p = 0.16).

CONCLUSIONS

Six months of CPAP therapy does not change cardiac functional or structural parameters measured by echocardiogram or CMR in patients with minimally symptomatic mild-to-moderate OSA.

CLINICAL TRIAL REGISTRATION

ISRCTN 34164388 (http://isrctn.org).

Decreased exercise capacity and sleep-disordered breathing in patients with hypertrophic cardiomyopathy

BACKGROUND

Mechanisms of decreased exercise capacity in patients with hypertrophic cardiomyopathy (HCM) are not well understood. Sleep-disordered breathing (SDB) is a highly prevalent but treatable disorder in patients with HCM. The role of comorbid SDB in the attenuated exercise capacity in HCM has not been studied previously.

METHODS

Overnight oximetry, cardiopulmonary exercise testing, and echocardiographic studies were performed in consecutive patients with HCM seen at the Mayo Clinic. SDB was considered present if the oxygen desaturation index (number of ≥ 4% desaturations/h) was ≥ 10. Peak oxygen consumption (VO2 peak) (the most reproducible and prognostic measure of cardiovascular fitness) was then correlated with the presence and severity of SDB.

RESULTS

A total of 198 patients with HCM were studied (age, 53 ± 16 years; 122 men), of whom 32% met the criteria for the SDB diagnosis. Patients with SDB had decreased VO2 peak compared with those without SDB (16 mL O2/kg/min vs 21 mL O2/kg/min, P < .001). SDB remained significantly associated with VO2 peak after accounting for confounding clinical variables (P < .001) including age, sex, BMI, atrial fibrillation, and coronary artery disease.

CONCLUSIONS

In patients with HCM, the presence of SDB is associated with decreased VO2 peak. SDB may represent an important and potentially modifiable contributor to impaired exercise tolerance in this unique population.

Relationship between diastolic ventricular dysfunction and subclinical sleep-disordered breathing in atrial fibrillation ablation candidates

Sleep-disordered breathing (SDB) is recognized as a primary factor or mediator of atrial fibrillation (AF). We hypothesized that the severity of SDB among AF ablation candidates would be associated with left ventricular diastolic dysfunction (LVDD) even for subclinical SDB. A total of 246 patients hospitalized for initial pulmonary vein isolation (PVI) were analyzed. Known SDB cases were excluded. We measured the oxygen desaturation index (ODI) by pulse oximetry overnight as an indicator of SDB, and classified SDB severity by 3 % ODI as normal (ODI < 5 events/h), mild (ODI ≤ 5 to <15 events/h), or moderate-to-severe (ODI ≥15 events/h). The LVDD was assessed by echocardiography using combined categories with tissue Doppler imaging and left atrial (LA) volume measurement. Among the participants, 42 patients (17.1 %) had LVDD. The prevalence of LVDD increased with the SDB severity from 8.6 % (normal) to 12.7 % (mild) to 40.0 % (moderate-to-severe SDB) (p < 0.0001). In the multivariate logistic regression analysis, the odds ratio of having LVDD in the moderate-to-severe SDB group (ODI ≥ 15) vs. normal group (ODI < 5) was 5.96 (95 % CI, 2.10-19.00, P = 0.006). The presence of moderate-to-severe SDB in AF ablation candidates adversely affected LV diastolic function even during a subclinical state of SDB.

Beneficial Effects of Positive Airway Pressure Therapy for Sleep-Disordered Breathing in Heart Failure Patients With Preserved Left Ventricular Ejection Fraction

BACKGROUND

Right-heart dysfunction is associated with poor prognosis in heart failure with preserved left ventricular ejection fraction (HFpEF). It remains unclear whether sleep-disordered breathing (SDB) treatment using positive airway pressure (PAP) improves right-heart and pulmonary function and exercise capacity and reduces mortality rates of HFpEF patients.

HYPOTHESIS

PAP may improve right-heart and pulmonary function, exercise capacity and prognosis in HFpEF patients with SDB.

METHODS

One hundred nine consecutive patients with HFpEF (left ventricular ejection fraction >50%) and moderate to severe SDB (apnea-hypopnea index ≥15/h) treated with medications were divided into 2 groups: 31 patients with PAP (PAP group) and 78 patients without PAP (non-PAP group). Right ventricular fractional area change (RV-FAC), tricuspid valve regurgitation pressure gradient (TR-PG), tricuspid valve E/E', forced expiratory volume in 1 second/forced vital capacity (FEV1 /FVC), percentage of vital capacity, and peak VO2 were determined before and 6 months later, and all-cause mortality was followed up for 916 days.

RESULTS

All parameters improved in the PAP group (RV-FAC, 36.0% -46.5%; TR-PG, 31.1 mm Hg-22.4 mm Hg; tricuspid valve E/E', 7.8-5.1; FEV1 /FVC, 83.9%-89.8%; percentage of vital capacity, 83.5%-89.9%; and peak VO2 , 16.6 mL/kg/min-19.6 mL/kg/min; P <0.05, respectively) but not in the non-PAP group. Importantly, all-cause mortality was significantly lower in the PAP group than in the non-PAP group (0% vs 12.8%; log-rank P = 0.014).

CONCLUSIONS

Positive airway pressure improves right-heart and pulmonary function and exercise capacity and may reduce all-cause mortality in patients with HFpEF and SDB.

[New therapy concepts for heart failure with preserved ejection fraction]

The management of patients with heart failure and preserved ejection fraction (HFpEF) remains challenging and requires an accurate diagnosis. Although currently no convincing therapy that can prolong survival in patients with HFpEF has been established, treatment of fluid retention, heart rate and control of comorbidities are important cornerstones to improve the quality of life and symptoms. In recent years many new therapy targets have been tested for development of successful interventional strategies for HFpEF. Insights into new mechanisms of HFpEF have shown that heart failure is associated with dysregulation of the nitric oxide-cyclic guanosine monophosphate-protein kinase (NO-cGMP-PK) pathway. Two new drugs are currently under investigation to test whether this pathway can be significantly improved by either the neprilysin inhibitor LCZ 696 due to an increase in natriuretic peptides or by the soluble guanylate cyclase stimulator vericiguat, which is also able to increase cGMP. In addition, several preclinical or early phase studies which are currently investigating new mechanisms for matrix, intracellular calcium and energy regulation including the role of microRNAs and new devices are presented and discussed.

Diastolic dysfunction in controlled hypertensive patients with mild-moderate obstructive sleep apnea

BACKGROUND

Hypertension and severe obstructive sleep apnea (OSA) may independently contribute to left ventricular diastolic dysfunction. However, scanty data is available on this issue in hypertensives with mild-moderate OSA.

METHODS AND RESULTS

We performed polysomnography, echocardiography and 24h ambulatory blood pressure monitoring in 115 treated essential hypertensives with suspicion of OSA. After exclusion of severe/treated OSA and/or cardiovascular disease patients, mild-moderate OSA (5 ≤ apnoea/hypopnoea index<30 events·h(-1)) was diagnosed in 47.3% of the remaining 91 patients, while 52.7% were free of OSA. Transmitral early (E) and late (A) peak flow velocities were assessed in 69 patients, and mitral annular velocity (E') in 53. Compared to non-OSA, mild-moderate OSA heart rate was higher (p=0.031) while E/A was lower (p<0.001) without differences in 24h mean systolic and diastolic blood pressures (125.36 ± 12.46/76.46 ± 6.97 vs 128.63 ± 11.50/77.70 ± 7.72 mmHg, respectively, NS). Patients with E'< 10 cm/s and E/A<0.8 showed a lower mean SpO2 than subjects with normal diastolic function (p=0.004; p<0.001). In a logistic regression model age, mean SpO2, daytime heart rate and nocturnal diastolic blood pressure fall were associated with altered relaxation pattern, independently from BMI and gender.

CONCLUSIONS

In controlled hypertensives mild-moderate OSA may be associated with early diastolic dysfunction, independently from age, gender and mean blood pressure and in the absence of concentric left ventricular hypertrophy. Moreover nocturnal hypoxia may be a key factor in determining early diastolic dysfunction, under the synergic effects of hypertension and mild-moderate OSA.

Report of the American Heart Association (AHA) Scientific Sessions 2014, Chicago

The American Heart Association (AHA) Scientific Sessions were held in Chicago on November 15-19, 2014. The meeting attracted more than 17,000 participants, including physicians, research scientists, students, and paramedical personnel, from more than 100 countries. Sessions over the 5 days included comprehensive and unparalleled education delivered via more than 5,000 presentations, with 1,000 invited faculty members and 4,000 abstract presentations from world leaders in cardiovascular (CV) disease. There were 16 trials scheduled in 4 late-breaking clinical trial sessions. The Dual Antiplatelet Therapy study revealed that aspirin plus a thienopyridine beyond 1 year subsequent to placement of a drug-eluting stent, as compared with aspirin therapy alone, significantly reduced stent thrombosis and major CV and cerebrovascular events but was associated with increased risk of bleeding. The IMPROVE-IT research showed that, relative to simvastatin with placebo, simvastatin with 10 mg of ezetimibe daily led to a significantly lower primary combined endpoint in moderate- to high-risk patients, who stabilized following acute coronary syndrome. This was the first trial to demonstrate incremental clinical benefit by adding a nonstatin agent to statin therapy and reaffirmed the low-density lipoprotein (LDL) hypothesis stating that reducing LDL-cholesterol prevents CV events. Summaries and overviews of both the late-breaking trials and the sessions to which members of the Japanese Circulation Society contributed are presented.

New therapeutic options in heart failure. What's on the horizon? An overview

Heart failure is a complex clinical syndrome responsible for high morbidity and mortality in the world. Despite advances in the management of heart failure, the prognosis of these patients remains poor and there is a critical need for new treatment strategies improving the clinical outcomes. New approaches in heart failure therapies target cellular mechanisms, as well as mechanical and structural aspects of heart failure that are not addressed by recent therapies. These include abnormalities in molecular mechanisms, electrical conduction and ventricular remodeling. This review presents the pathophysiological basis, mechanisms of action and available clinical efficacy and safety data of drugs and mechanical therapies that are currently under development.