Abstract 12589: Quantitative Assessment of Mid-Systolic Deceleration and Notching in the Right Ventricular Ejection Doppler Envelope is Useful in Predicting Hemodynamics and Patient Outcomes in Pulmonary Arterial Hypertension

Abstract

Background: Increased reflective wave from pulmonary artery (PA) causes mid-systolic deceleration (MSD) and notching in Doppler flow velocity envelope of RV ejection flow. Our aim is to test whether profile of MSD and notching provides insight into hemodynamics and patient outcomes in pulmonary artery hypertension (PAH), using quantitative measurements. We hypothesized that the deceleration time of the MSD slope (DTMSD), meaning the steepness of the slope, reflects interaction between RV ejection and reflective wave, and that peak velocity of post-notching flow (Vpost) reflects RV function. Methods: We reviewed RV ejection flow envelope recordings by pulsed wave Doppler for 157 consecutive patients with PAH between 1/2008 and 3/2013 (age 57 ± 14) with an estimated RV systolic pressure of 79 ± 23 mmHg. DTMSD was measured as the time between the first peak acceleration wave and MSD slope extrapolated to zero line. We also reviewed right heart catheterization performed within one month from echocardiography in 78 of the 157 patients. Results: We identified MSD and notching in 148 patients. On multivariate regression analyses, PA capacitance was the key determinant of DTMSD (beta = -0.49, p <0.0001). Vpost was determined by cardiac index (beta = -0.36, p = 0.0014). During a median follow-up period of 30 months, there were 47 deaths from all causes and 7 lung transplantations. On Cox hazard analyses, shorter DTMSD and smaller Vpost are significant predictors of higher mortality independently of each other (HR 0.92 / 10ms, p = 0.045 and HR 0.97, p = 0.028, respectively). Conclusion: Mid-systolic deceleration of RV ejection flow became steeper in the setting of lower PA compliance causing a greater reflectance wave. Reduced peak velocity of post-notching flow reflected impaired RV with reduced cardiac output. Quantitative assessment of profile of mid-systolic deceleration and notching in RV ejection flow envelope is useful in predicting hemodynamics and patient outcomes in PAH.