Echocardiographic assessment of right heart function in the presence of TR: Is right heart strain the answer?

Abstract

Abstract Background Right heart function is challenging to assess with echocardiography due to the complex anatomy and load dependence. To complicate the assessment, significant tricuspid regurgitation flatters the right ventricle. These complexities have led to the need for other modalities and invasive measures of RV function to complement clinical decision-making and risk profiling. Speckle tracking can assess subtle anomalies and appears to be promising for right heart assessment. We assessed right heart strain against classic echocardiographic measures of RV function (TAPSE, RVS’ and fractional area change (FAC)) and invasive measures of RV function (right ventricular stroke work index (RVSWI) and Pulmonary Artery Pulsatility index (PAPi)), in patients with severe TR and without, to see strain reclassifies the assessment of RV function from "normal" to impaired and to assess the prognostic value of right heart strain. Methods A single-centre retrospective analysis of data from 262 consecutive patients (age 74 ±11.2 years old; male 53%) with both right heart catheterization (RHC) and TTE. Clinical data was gathered from patient files, and outcomes of heart failure hospitalisation or death were recorded. Echocardiographic evaluation was completed on commercially available GE ultrasounds and data was stored on a dedicated workstation for offline analysis (EchoPAC version 112.99). Statistical analysis was performed using SAS 15.1. Results Over a median follow up of 34 ±15 months 99 events occurred. 53% of patients had severe TR. RV free wall strain reclassified RV function as impaired in 73% of patients with "normal" RV function as determined by FAC (p value 0.005), and in 71% of patients with normal RVS’ (p value 0.03) with severe TR. Using invasive measures, RVSWI reclassified RV function as abnormal when compared to TAPSE in 53% of patients (p value 0.02). PAPi reclassified RV function as impaired compared to TAPSE in 53% of patients (p value of 0.009). In patients with TR 3+, right atrial strain reclassified presence of right heart dysfunction in 91% of patients compared to TAPSE >17 (p value 0.01) and in 95% of patients compared to RVS’ (p value 0.004). In patients with moderate or less TR, RV strain reclassified 66% as having RV dysfunction with normal FAC (p value 0.003) and reclassified 61% of patients with RV dysfunction in patients with a normal RVS (p value 0.03). Invasive measures did not reclassify RV function assessment in patients with moderate or less TR. In patients with and without TR, RV strain and invasive measures were in accordance. Abnormal RV strain (>-23%) was associated with an adverse prognosis HR 3.63 (1.43 – 9.22). Conclusion In the presence of severe TR, right heart strain helps to reclassify RV function, comparable to invasive measures. Abnormal right heart strain is strongly associated with prognosis and its utility should be confirmed in prospective studies.