P339 Gradient adjusted cardiac power index does not improve prediction of survival post transcatheter aortic valve replacement compared to cardiac power index alone
Abstract Funding Acknowledgements None Background Cardiac Power Index (CPI) is an integrative hemodynamic measure of cardiac pumping capability and is the product of the simultaneously measured mean arterial pressure (MAP) and cardiac output (CO). In patients with aortic stenosis (AS), MAP is not reflective of mean systolic left ventricular (LV) pressure due to the transvalvular gradient. Non-invasive assessment of mean systolic LV pressure is challenging in severe aortic stenosis. CPI assessed using systemic MAP was previously shown to predict survival post transcatheter aortic valve replacement (TAVR). Purpose We evaluated the utility of a gradient adjusted CPI in predicting survival post TAVR compared to CPI alone Methods A retrospective study was performed including patients undergoing TAVR with 1 year follow-up. Baseline demographics, clinical, and echocardiographic data were abstracted from a cohort of 1,011 patients. CPI was calculated, (CO x MAP)/ (451 x BSA) Watts/m2. Gradient adjusted CPI was calculated using an augmented MAP i) adding aortic valve mean gradient(AVMG) to systolic blood pressure (CPI1); ii) adding aortic valve maximal instantaneous gradient to systolic blood pressure (CPI2) and iii) adding AVMG to MAP (CPI3). Patient survival score was calculated using a step up technique to identify the cut off value for CPI and gradient adjusted CPI to identify, where the maximum difference in mortality occurred. Multivariate cox-regression analysis was performed to adjust for baseline covariates. Receiver operator curves(ROC) for CPI and gradient adjusted CPI were calculated to predict survival post TAVR. Results The mortality rate at 1 yr was 16%. Mean age and AVMG of survivors was 81 +/- 9 yrs and 43 +/-14 mmHg vs 80 +/-9 yrs and 42 +/- 13 mmHg in the deceased group. Proportion of female patients was similar in both groups (p = 0.7). Patients in the deceased group at baseline had a higher prevalence of chronic lung disease, atrial fibrillation, heart failure within 2-weeks of procedure, higher STS-PROM score, lower serum albumin level, higher prevalence of moderate to severe tricuspid regurgitation, higher right ventricular systolic pressure and higher prevalence of dialysis. Both CPI and gradient adjusted CPI were independently associated with survival at 1 year. The area under ROC for CP, CP1, CP2 and CP3 were 0.67 (95% confidence interval [CI] 0.62 - 0.72), 0.65 (95% CI 0.60 – 0.70), 0.66 (95% CI 0.61 – 0.71) and 0.63 (95% CI 0.58 – 0.68) respectively. Conclusion Gradient adjusted CPI did not improve accuracy of predicting post TAVR survival at 1 year compared to CPI alone. Abstract P339 Figure. Area under ROC
P614Comparison of echo parameters with cardiac MRI in the assessment of right ventricular function
Abstract Introduction Systolic right ventricular (RV) function has prognostic significance both in acquired and congenital heart diseases. However accurate assessment of RV ejection fraction (EF) with transthoracic echocardiography (TTE) remains challenging due to the complex geometric shape of the RV. Magnetic resonance imaging (MRI) remains the gold standard modality for assessment of RV function; however the cost and availability limits the regular use of MRI in clinical practice. The RV strain measured by speckle tracking (RVS) is a novel method of assessing RV EF. Purpose The purpose of the study was to assess the accuracy of RVS compared RV fractional area change (FAC%), tricuspid annular peak systolic excursion (TAPSE) and Doppler tissue imaging-derived isovolumic acceleration and peak systolic velocity (S') at the lateral tricuspid annulus in the assessment of impaired RV EF. Methods We retrospectively identified patients who had a cardiac MRI between 2012- 2017 and only included patients with a TTE within 1 month of the MRI for our final analysis. Baseline characteristics, TTE and MRI parameters were extracted from chart review. RV strain was measured retrospectively using ECHOINSIGHT software. Four TTE parameters including RVS, TAPSE, S' and FAC% were tested for accuracy to identify impaired RV EF (defined as EF<45%) using receiver operator curves. Results The study cohort included 500 patients with mean age 55 yr ± 18 and right ventricular systolic pressure 33.7±13.6 mmHg. The proportion of female gender, diabetes, hypertension and obstructive sleep apnea were 38%, 15.6%, 43% & 19.8% respectively. The area under ROC for TAPSE, S', FAC% and RVS were 0.58 (95% confidence interval [CI] 0.51–0.65, p=0.03), 0.59 (95% CI 0.52–0.66, p=0.03), 0.67 (95% CI 0.61–0.73, p=0.03) and 0.70 (0.64–0.76, p=0.03) for assessing RV EF <45%. Conclusion Right ventricular strain most accurately detected impaired right ventricular ejection fraction as obtained by MRI. Acknowledgement/Funding None