Prevalence of Moderate or Severe Left Ventricular Diastolic Dysfunction in Obese Persons with Obstructive Sleep Apnea

Positive Airway Pressure Therapy Adherence and Health Care Resource Use in Patients With Obstructive Sleep Apnea and Heart Failure With Preserved Ejection Fraction

Background Obstructive sleep apnea (OSA) is common in heart failure with preserved ejection fraction (HFpEF). However, current evidence is equivocal regarding the potential benefits of treating OSA with positive airway pressure (PAP) therapy in HFpEF. This study assessed the association between adherence to PAP therapy and health care resource use in patients with OSA and HFpEF. Methods and Results Administrative insurance claims data linked with objective PAP therapy usage data from patients with OSA and HFpEF were used to determine associations between PAP adherence and a composite outcome including hospitalizations and emergency room visits. One-year PAP adherence was based on an adapted US Medicare definition. Propensity score methods were used to create groups with similar characteristics across PAP adherence levels. The study cohort included 4237 patients (54.0% female, mean age 64.1 years); 40% were considered adherent to PAP therapy (30% intermediate adherent, 30% nonadherent). In the matched cohort, PAP-adherent patients had fewer health care resource use visits than nonadherent patients, a 57% decrease in hospitalizations, and a 36% decrease in emergency room visits versus the year before PAP initiation. Total health care costs were lower in adherent patients than nonadherent patients ($12 732 versus $15 610, P<0.001). Outcomes for intermediately adherent patients were most similar to those for nonadherent patients. Conclusions Treating OSA with PAP therapy in patients with HFpEF was associated with a reduction in health care resource use. These data highlight the importance of managing concomitant OSA in patients with HFpEF, and the need for strategies to enhance PAP adherence in this population.

Obstructive Sleep Apnea in Heart Failure: Review of Prevalence, Treatment with Continuous Positive Airway Pressure, and Prognosis

Obstructive sleep apnea is a sleep-related breathing disorder that has a major impact on cardiovascular function. It has been associated with hypertension, coronary artery disease, cardiac arrhythmias, sudden cardiac death, and heart failure. This review focuses on the relationship between obstructive sleep apnea and heart failure with either reduced or preserved ejection fraction. We discuss the pathophysiology of obstructive sleep apnea, as well as its prevalence, treatment outcomes with continuous positive airway pressure, and prognosis in these 2 distinct types of heart failure. We also identify areas in which further work is needed to improve our understanding of this association in heart failure patients.

Thoracic Surgery Considerations in Obese Patients

The obesity epidemic in the United States has increased greatly over the past several decades, and thoracic surgeons are likely to see obese patients routinely in their practices. Obesity has direct deleterious health effects such as metabolic disorder and cardiovascular disease, and is associated with many cancers. Obese patients who need thoracic surgery pose practical challenges to many of the routine elements in perioperative management. Preoperative assessment of obesity-related comorbid conditions and risk stratification for surgery, thorough intraoperative planning for anesthesia and surgery, and postoperative strategies to optimize pulmonary hygiene and mobility minimize the risk of adverse outcomes.

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.

Obstructive sleep apnea is independently associated with worse diastolic function in coronary artery disease

BACKGROUND

Diastolic dysfunction is common in patients with coronary artery disease (CAD). We hypothesize that patients with CAD and preserved left ventricular ejection fraction (LVEF) and obstructive sleep apnea (OSA) will have worse diastolic function than similar patients without OSA.

MATERIAL AND METHODS

We analyzed sleep-study recordings and echocardiographic measurements obtained at baseline in a randomized controlled trial (RICCADSA) of revascularized patients with CAD who had LVEF of at least 50%. OSA was defined as an apnea-hypopnea-index (AHI) ≥15 events/h, and, no OSA, as an AHI <5. Worse diastolic function was defined as assumed elevated left ventricular filling pressure based on peak flow velocity in early diastole/Tissue Doppler of early diastolic ventricular filling (E/é) of >13 (or >9 in patients with an enlarged left atrial diameter [≥39 mm for women and ≥40 mm for men]).

RESULTS

Data from 431 patients were evaluated (mean age: 63.7 ± 8.8 y; men: 82.5%; OSA: n = 331). Worse diastolic function was more common among the patients with OSA than those without (54.4% vs 41.0%, p = 0.019). In multivariate analysis, OSA was associated with worse diastolic function (odds ratio [OR] 1.90, 95% confidence interval [CI] 1.13; 3.18) adjusted for female sex (OR 2.28, 95% CI 1.28; 4.07), hypertension (OR 1.84, 95% CI 1.20; 2.82), and diabetes mellitus (OR 2.45, 95% CI 1.42; 4.23). Age ≥60 years, obesity, and current smoking were nonsignificant.

CONCLUSIONS

In this cohort with CAD and preserved LVEF, OSA was associated with worse diastolic function independent of the traditionally recognized risk indicators.

Postoperative complications after thoracic surgery in the morbidly obese patient

Little has been recently published about specific postoperative complications following thoracic surgery in the morbidly obese patient. Greater numbers of patients who are obese, morbidly obese, or supermorbidly obese are undergoing surgical procedures. Postoperative complications after thoracic surgery in these patients that can lead to increased morbidity and mortality, prolonged hospital stay, and increased cost of care are considered. Complications include difficulties with mask ventilation and securing the airway, obstructive sleep apnea with risk of oversedation, pulmonary complications related to reduced total lung capacity, reduced functional residual capacity, and reduced vital capacity, risks of aspiration pneumonitis and ventilator-associated pneumonia, cardiomyopathies, and atrial fibrillation, inadequate diabetes management, positioning injuries, increased risk of venous thrombosis, and pulmonary embolism. The type of thoracic surgical procedure may also pose other problems to consider during the postoperative period. Obese patients undergoing thoracic surgery pose a challenge to those caring for them. Those working with these patients must understand how to recognize, prevent, and manage these postoperative complications.

Obstructive Sleep Apnoea and Its Association with Left Ventricular Function and Aortic Root Parameters in Newly Diagnosed, Untreated Patients: A Prospective Study

This prospective study investigated whether untreated obstructive sleep apnoea-hypopnoea syndrome (OSAHS), which is strongly associated with cardiovascular disease, is a risk factor for left ventricular (LV) systolic and diastolic dysfunction and aortic root dilatation. Ninety consecutive patients with breathing and snoring problems, including 64 with newly diagnosed, untreated OSAHS, were classified into four groups based on their apnoea-hypopnoea index (AHI). All participants underwent overnight polysomnographic and complete echocardiographic examinations, and LV systolic, diastolic and aortic measurements were compared. Body mass index was the only demographic characteristic that significantly increased as the severity of OSAHS (AHI) increased and it significantly correlated with AHI. Patients with a higher AHI had a significantly higher aortic root diameter and aortic stiffness index, and significantly lower aortic strain. The LV diastolic parameters were least favourable in patients with more severe OSAHS. The LV ejection fraction did not differ significantly between groups. It was concluded that LV diastolic function and aortic elastic parameters deteriorate with OSAHS.

The incremental effect of obstructive sleep apnea syndrome on right and left ventricular myocardial performance in newly diagnosed essential hypertensive subjects

Obstructive sleep apnea syndrome (OSAS) may predispose patients to congestive heart failure, suggesting a deleterious effect of OSAS on myocardial contractility. We investigated whether essential hypertensive individuals with OSAS are characterized by decreased right and left ventricular myocardial performance. Our study population consisted of 45 consecutive patients with newly diagnosed untreated stage I-II essential hypertension suffering from OSAS (35 men, aged 49+/-8 years) and 48 hypertensives without OSAS, matched for age, sex, level of blood pressure, heart rate, body mass index and smoking status. All subjects underwent polysomnography and echocardiography. Right and left ventricular functions were evaluated using the myocardial performance index (MPI). Right and left ventricular functions were altered in hypertensives with OSAS. The mean right MPI was 0.26+/-0.11 in hypertensives without OSAS and 0.51+/-0.16 in hypertensives with OSAS (P<0.01). The mean left MPI values were 0.29+/-0.07 and 0.44+/-0.13, respectively (P<0.01). Right and left MPI correlated positively and significantly with apnea-hypopnea index (rho=0.40, P=0.002).OSAS is associated with impaired right and left ventricular function. These phenomena were independent of hypertension.

Impact of obstructive sleep apnea on left ventricular diastolic function

The aim of this study was to investigate the impact of obstructive sleep apnea (OSA) on left ventricular (LV) functional changes by using tissue Doppler imaging-derived indexes in patients with OSA. We studied 62 patients classified into 3 groups, namely 18 with mild to moderate OSA, 24 with severe OSA, and 20 control subjects without OSA according to the apnea-hypopnea index (AHI) on complete overnight polysomnogram. All underwent conventional and tissue Doppler echocardiographies. Only early diastolic velocity (Ea; -6.2 +/- 0.3 vs -7.1 +/- 0.3 vs -7.3 +/- 0.3 cm/s, respectively, for the 3 groups, p = 0.023) was significantly decreased in the severe OSA group. Other echocardiographic parameters of diastolic function such as isovolumic relaxation time, deceleration time, mitral inflow early/late wave velocity ratio, and pulmonary vein systolic/diastolic pulmonary vein velocity ratio were comparable among the 3 groups. AHI was correlated only with tissue Doppler imaging-derived indexes of LV diastolic function (Ea r = -0.382, p = 0.002; Ea/late diastolic velocity r = -0.329, p = 0.009), but not with conventional Doppler indexes. AHI remained a significant predictor of Ea after adjusting for age, heart rate, fasting glucose level, blood pressure, body mass index, and LV mass index in a multiple stepwise linear regression model (p = 0.007). In conclusion, only patients with severe OSA showed a greater impairment of LV diastolic function. Of all echocardiographic parameters of diastolic dysfunction investigated, only Ea was identified as the best index to demonstrate an association between LV diastolic dysfunction and severity of OSA independently of body mass index, diabetes mellitus, and hypertension.

Major weight loss prevents long-term left atrial enlargement in patients with morbid and extreme obesity

AIMS

To assess long-term changes in left atrial (LA) volume in patients with morbid obesity [body mass index (BMI) >or=35 kg/m(2) with co-morbidities] and extreme obesity (BMI >or=40 kg/m(2)), after surgically-induced weight loss (WL) after gastric bypass surgery.

METHODS AND RESULTS

We reviewed 57 patients who underwent gastric bypass surgery and had echocardiograms both before and after the operation. A control group was frequency-matched for BMI, sex, age, and for duration of follow-up. After a mean follow-up of 3.6 years, LA volume did not change significantly in patients who underwent bariatric surgery, but increased in the control group by 15 +/- 28 ml (P < 0.0001), and 0.1 +/- 0.2 ml (P < 0.0001) for height-indexed LA volume, with a difference between cases and controls that remained significant after adjusting for potential confounders (P = 0.01). In the study population as a whole, there was a positive correlation between change in body weight and change in LA volume (r = 0.22, P = 0.006) independent of clinical conditions associated with LA enlargement.

CONCLUSION

Change in body weight is associated with change in LA size independent of obesity-associated co-morbidities. Successful WL induced by bariatric surgery prevents the progressive increase in LA volume.

Resolution of obstructive sleep apnea after laparoscopic gastric bypass

BACKGROUND

Obstructive sleep apnea is a common condition in patients undergoing bariatric surgery. The aim of this study was to determine the clinical outcome of a cohort of morbidly obese patients with documented sleep apnea who underwent laparoscopic Roux-en-Y gastric bypass (LRYGBP).

METHODS

56 morbidly obese patients with documented sleep apnea by polysomnography underwent LRYGBP. There were 36 females with mean age 46 years and mean BMI 49 kg/m2. The Epworth sleepiness scale (ESS) scores and the number of patients requiring the use of continuous positive airway pressure (CPAP) therapy were recorded preoperatively and at 3-month intervals.

RESULTS

The mean length of sleep apnea condition was 44 +/- 55 months. Preoperative polysomnography scores were classified as severe in 50% of patients, moderate in 30%, and mild in 20%. 29 of 56 (52%) patients required CPAP therapy preoperatively. The mean excess body weight loss was 73 +/- 3% at 12 months. The mean ESS score decreased from 13.7 preoperatively to 5.3 at 1 month postoperatively (P<0.05) and maintained below the threshold level (<7) for the entire 12 months of follow-up. Of the 29 patients requiring preoperative CPAP, only 4 (14%) patients required CPAP at 3 months postoperatively and none required CPAP at 9 months.

CONCLUSIONS

Weight loss associated with LRYGBP significantly improves the symptoms of sleep apnea and is effective in discontinuation in the clinical use of CPAP therapy. Improvement of obstructive sleep apnea symptoms occur as early as 1 month postoperatively.

Decreased Right and Left Ventricular Myocardial Performance in Obstructive Sleep Apnea

BACKGROUND

Obstructive sleep apnea (OSA) may predispose patients to congestive heart failure (CHF), suggesting a deleterious effect of OSA on myocardial contractility.

METHODS

A cross-sectional study of 85 subjects with suspected OSA who had undergone their first overnight polysomnogram, accompanied by an echocardiographic study. Patients were divided according to the apnea-hypopnea index as follows: < 5 (control subjects); 5 to 14 (mild OSA); and >or= 15 (moderate-to-severe OSA). Right and left ventricular function was evaluated using the myocardial performance index (MPI) and other echocardiographic parameters. For the right ventricle analyses, we excluded patients with a Doppler pulmonary systolic pressure of >or= 45 mm Hg, while for the left ventricle we excluded patients with an ejection fraction of <or= 45%.

RESULTS

The mean (+/- SD) age was 60 +/- 15 years, and 83% were men. Right and left ventricular function were altered in patients with OSA, especially in those with the moderate-to-severe OSA, even after adjustment for potential confounders. The mean right MPI was 0.23 +/- 0.10 in control subjects, 0.26 +/- 0.16 in patients with mild OSA, and 0.37 +/- 0.11 in patients with moderate-to-severe OSA (p value for trend, < 0.01). The mean left MPI values were 0.28 +/- 0.05, 0.27 +/- 0.07, and 0.41 +/- 0.14, respectively (p value for trend, 0.04). Right and left MPI correlated positively and significantly with the apnea-hypopnea index (rho = 0.40, p = 0.002; and rho = 0.27, p = 0.02, respectively). Mean left atrial volume index was increased in patients with OSA (control subjects, 26.8 +/- 11; patients with mild OSA, 32.5 +/- 15; and patients with moderate-to-severe OSA, 30.4 +/- 11; p value for trend, 0.04).

CONCLUSIONS

OSA, particularly when moderate to severe, is associated with impaired right and left ventricular function and increased left atrial volume. These findings support the notion that OSA may contribute to the development of atrial fibrillation and CHF.

Anesthesia for thoracic surgery in morbidly obese patients

PURPOSE OF REVIEW

This review considers the anesthetic management of obese patients undergoing thoracic surgery. Extremely or morbidly obese patients differ from patients of normal weight in several ways. Obese patients have altered anatomy and physiology, and usually have associated comorbid medical conditions that may complicate their operative course and increase their risks for postoperative complications.

RECENT FINDINGS

During anesthetic induction and laryngoscopy for tracheal intubation the morbidly obese patient should be in the reverse Trendelenburg position with the head and neck elevated above the table. Placement of a double-lumen tube should be no more difficult in an obese patient than in a normal-weight patient. There are no clear advantages for any of the commonly available inhalational anesthetic agents and each can be used for general anesthesia.

SUMMARY

With proper attention to their special needs, the morbidly obese patient can safely undergo thoracic surgery and one-lung ventilation.

Comparison of intracardiac cell transplantation: autologous skeletal myoblasts versus bone marrow cells

An increasing number of patients living with cardiovascular disease (CVD) and still unacceptably high mortality created an urgent need to effectively treat and prevent disease-related events. Within the past 5 years, skeletal myoblasts (SKMBs) and bone marrow (or blood)-derived mononuclear cells (BMNCs) have demonstrated preclinical efficacy in reducing ischemia and salvaging already injured myocardium, and in preventing left ventricular (LV) remodeling, respectively. These findings have been translated into clinical trials, so far totaling over 200 patients for SKMBs and over 800 patients for BMNCs. These safety/feasibility and early phase II studies showed promising but somewhat conflicting symptomatic and functional improvements, and some safety concerns have arisen. However, the patient population, cell type, dose, time and mode of delivery, and outcome measures differed, making comparisons problematic. In addition, the mechanisms through which cells engraft and deliver their beneficial effects remain to be fully elucidated. It is now time to critically evaluate progress made and challenges encountered in order to select not only the most suitable cells for cardiac repair but also to define appropriate patient populations and outcome measures. Reiterations between bench and bedside will increase the likelihood of cell therapy success, reduce the time to development of combined of drug- and cell-based disease management algorithms, and offer these therapies to patients to achieve a greater reduction of symptoms and allow for a sustained improvement of quality of life.