Right ventricular free wall longitudinal strain and stroke work index for predicting right heart failure after left ventricular assist device therapy

Abstract

Objectives: Right heart failure (RHF) is an important prognostic factor in continuous-flow left ventricular assist device (LVAD) therapy. We aimed to assess the clinical variables associated with RHF after LVAD implantation and to compare their performance against currently available RHF predictive scoring systems. Methods: The study cohort comprised 57 patients who underwent LVAD therapy between January 2012 and May 2018 in our centre. The mean age of the patients was 39.9 ± 18.3 years, and 43 (81.1%) of them were men. Thirty-eight patients (66.6%) were in the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) profile I or II. The study cohort was divided into the patients with RHF postoperatively (n = 20, 35.1%) and without RHF (n = 37, 64.9%). Results: Independent predictors for RHF were preoperative right ventricular ejection fraction <25% [odds ratio (OR) 4.68, 95% confidence interval (CI) 1.41-15.5; P = 0.01], right ventricular stroke work index <400mmHgml-1 (OR 3.73, 95% CI 1.01-13.7; P = 0.04), right ventricular outflow tract systolic excursion <7mm (OR 1.55, 95% CI 0.31-0.84; P = 0.002), right ventricular outflow tract fractional shortening <15% (OR 1.62, 95% CI 0.34-0.78; P = 0.02), right ventricular free wall longitudinal strain <19% (OR 3.13, 95% CI 1.01-2.43; P = 0.003), right ventricular fractional area change <27% (OR 3.71, 95% CI 1.15-11.9; P = 0.02) and prealbumin <14 mg/dl (OR 3.45, 95% CI 1.07-11.03; P = 0.03). Modest diagnostic performance for RHF was detected in 4 of 7 validated scoring systems with resulting area under the curve values of 0.70 (95% CI 0.55-0.84; P = 0.001) for the Seattle Heart Failure Model; 0.68 (95% CI 0.49-0.81, P = 0.03) for the Fitzpatrick's; 0.68 (95% CI 0.53-0.83, P = 0.028) for the acute physiology and chronic health evaluation (APACHE) II; and 0.66 (95% CI 0.50-0.82, P = 0.04) for the model for end-stage liver disease scoring systems. However, we found best discrimination performance of the score with a resulting area under the curve value of 0.94 (95% CI 0.55-0.89, P = 0.03) for right ventricular free wall longitudinal strain >-15.5% and 0.82 for right ventricular stroke work index <400mmHgml-1m-2 in predicting RHF. Conclusions: Right ventricular free wall longitudinal strain >-15.5% and right ventricular stroke work index <400mmHgml-1m-2 were independent predictors of RHF following LVAD implantation. Currently available prediction risk scores had the modest power of accuracy in the low INTERMACS profile Turkish population.