PURPOSE: The purpose of our study was to evaluate the effect of CPAP on right heart function parameters of TAPSE ( Tricuspid Annular Plane Systolic Excursion ) and right ventricular contraction velocity by color tissue doppler ECHO.
METHODS: Subjects were enrolled after demonstrating OSA on an observed polysomnography. Those with clinically significant heart failure, recent MI, EF < 45%, valvular or structural heart disease and those with change in their medications which would alter cardiac hemodynamics were excluded. Subjects with AHI > 20 had baseline ECHO and repeat ECHO at 3 months of CPAP. Based on the recently established consensus guidelines of ECHO assessment for the right heart by the American Society of Echocardiography in 2010, TAPSE was measured as the distance of systolic excursion of the RV annular segment along its longitudinal plane in the apical four chamber window. Systolic Contraction velocity was determined by color-coded tissue doppler acquired at high frame rates and analyzed offline. CPAP adherence was defined as > 4 hrs per day CPAP use for > 70% of days.
RESULTS: Twenty one subjects met criteria for echo comparison before and after intervention with CPAP. Average AHI was 61.1 ( SD 32.1 ). At three months of CPAP use TAPSE improved by 2.5 mm (95% CI 0.16-0.34 p=0.0001) and right ventricular systolic velocity improved by 1.44 cm/s (95% CI 0.89-2.00 p=0.0002).
CONCLUSIONS: Treatment of OSA with CPAP results in improvement of right heart systolic function as early as three months.
CLINICAL IMPLICATIONS: ECHO measurement of TAPSE and right ventricular systolic velocity may provide a non-invasive method for objectively assessing the efficacy of CPAP treatment on right ventricular function. TAPSE has been well validated with little interobserver variability. Since cor-pulmonale is a major morbidity of OSA, the ability to quantify therapeutic improvement directly and objectively is valuable in guiding therapy. To our knowledge this is the only study which has shown this therapeutic improvement in TAPSE in a cohort of patients confirmed to have OSA by polysomnography.
DISCLOSURE: The following authors have nothing to disclose: Muhammad Akbar, Timothy Woods, Aniko Szabo, Rose Franco
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