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.

Effect of Obesity on Left Atrial Strain in Persons Aged 35-55 Years (The Asklepios Study).

Obesity increases the risk of heart failure and atrial fibrillation. Left atrial (LA) dysfunction is increasingly recognized as a mediator of cardiovascular disease. Early effects of obesity on LA function have not been examined in large population samples. We quantified LA strain and strain rate (SR) through speckle tracking echocardiography in 1,531 middle-aged community-based participants enrolled in the Asklepios study. We compared LA function between individuals with body mass index (BMI) < 25 kg/m2 (n = 779), 25 to 29.9 kg/m2 (n = 618) and ≥ 30 kg/m2 (n = 134). Significant differences in reservoir longitudinal LA strain (BMI < 25 kg/m2 = 35.3%, BMI 25-29.9 kg/m2 = 33.1%, and BMI ≥ 30 kg/m2 = 30.9%; p < 0.00001) strain rate ([SR] BMI < 25 kg/m2 = 151; BMI 25 to 29.9 kg/m2 = 141; and BMI ≥ 30 kg/m2 = 135 %/s; p <0.00001) and expansion index (BMI < 25 kg/m2 = 1.6, BMI 25 to 29.9 kg/m2 = 1.4, and BMI ≥ 30 kg/m2 = 1.4; p <0.00001) were seen, indicating reduced reservoir function with increasing BMI. Obesity was also associated with impaired LA conduit function, including conduit longitudinal LA strain (BMI < 25 kg/m2 = 21.6%, BMI 25 to 29.9 kg/m2 = 18.9%, and BMI ≥ 30 kg/m2 = 16.7%; p <0.00001), SR (BMI < 25 kg/m2 = -189, BMI 25 to 29.9 kg/m2 = 166, and BMI ≥ 30 kg/m2 = 150 %/s; p <0.0001) and passive LA emptying fraction (BMI < 25 kg/m2 = 40.5, BMI 25 to 29.9 kg/m2 = 36.5, and BMI ≥ 30 kg/m2 = 36%, p <0.00001). These differences persisted after adjustment for age, gender and other potential confounders. In contrast to reservoir and conduit function, obesity was associated with increased booster pump function (active LA emptying fraction: BMI < 25 kg/m2 = 19.4%, BMI 25 to 29.9 kg/m2 = 20.5%, and BMI ≥ 30 kg/m2 = 21.5%; p <0.00001). In middle-aged adults, obesity is associated with impaired reservoir and conduit LA function and higher booster function, which may be compensatory. Loss of booster LA function, either because of more advanced LA dysfunction or atrial fibrillation, may play an important role in precipitating heart failure in obese individuals.

Incremental Value of Live/Real Time Three-Dimensional over Two-Dimensional Transesophageal Echocardiography in the Assessment of Atrial Septal Pouch.

An atrial septal pouch (ASP) results from partial fusion of the septum primum and the septum secundum, and depending on the site of fusion, the pouch can be left-sided (LASP) or right-sided (RASP). LASPs have been described in association with thrombi found in patients admitted with acute strokes, raising awareness of its potential cardioembolic role, especially in those with no other clearly identifiable embolic source. We retrospectively studied 39 patients in whom the presence of an ASP had been identified by three-dimensional transesophageal echocardiography (3DTEE) and who had a two-dimensional transesophageal echocardiogram (2DTEE) performed during the same clinical encounter. The incremental value provided by 3DTEE over 2DTEE included the detection of six ASPs not found by 2DTEE; the detection of two ASPs in the same subject (in four patients) not identified by 2DTEE; larger ASP measurements of length and height in over 80% of the cases; and measurement of the ASP width (elevational axis) for the calculation of the area of the ASP opening, because of its unique capability to view the pouch en face. In addition, the volume of ASP and of the echogenic masses contained in the ASP (four of 39 patients) could be calculated by 3DTEE, which is a superior parameter of size characterization when compared to individual dimensions. One of these patients who presented with ischemic stroke diagnosed by magnetic resonance imaging had a large (>2 cm) mass in a LASP, with echolucencies similar to those seen in thrombi and associated with clot lysis and resolution. This mass completely disappeared on anticoagulant therapy lending credence that it was most likely a thrombus. There was no history of stroke or any other type of embolic event in the other three patients with masses in ASP. In conclusion, this retrospective study highlights the incremental value of 3DTEE over 2DTEE in the comprehensive assessment and characterization of ASPs, which can aid in the clarification of their role in cryptogenic stroke patients.

Incremental value of live/real time three-dimensional transesophageal echocardiography over the two-dimensional technique in the assessment of primary cardiac malignant fibrous histiocytoma.

We describe a case of primary cardiac malignant fibrous histiocytoma where live/real time three-dimensional transesophageal echocardiography added incremental value to the two-dimensional modalities. Specifically, the three-dimensional technique allowed us to delineate the true extent and infiltration of the tumor, to identify characteristics of the tumor mass suggestive of its malignant nature, and to quantitatively assess the total tumor burden.