Right ventricular-pulmonary artery coupling ratio derived from 3D echocardiography - better predictor of outcome in patients with precapillary pulmonary hypertension

Abstract

Abstract Funding Acknowledgements Type of funding sources: None. Background In patients with pulmonary hypertension (PH), right ventricular (RV) function has a well-known prognostic value. Recent data suggest that right ventricular-pulmonary artery (RV-PA) coupling is an independent predictor of outcome in this setting. RV-PA coupling can be assessed invasively as the endsystolic/arterial elastance ratio or noninvasively using surrogates such as CMR-derived RV stroke-volume (SV) to endsystolic volume (ESV) ratio or 2D echocardiography-derived TAPSE/PASP ratio. Data regarding the 3D echocardiography-derived RV SV/ESV as parameter of RV-PA coupling in PH patients are scarce. Purpose To assess the RV-PA coupling as 3DE-RV SV/ESV ratio and its impact on clinical outcome in patients with precapillary PH compared with the validated 2DE-TAPSE/PASP. Methods Thirty-two patients (40±13 years, 27 women) with precapillary PH receiving vasodilator therapy and 25 controls of similar age and gender (37±9 years, 18 women) were studied. Clinical data, BNP levels and RV function parameters (TAPSE, free-RV wall S- and e’-wave, RV FAC, Tei index, RV-IVA, RVEF by 3DE) were assessed. RV global longitudinal strain (RV-GLS) was measured as the average of 6 segments and RV free wall strain as the average of 3 segments by speckle-tracking 2DE. RV-PA coupling was assessed as TAPSE/PASP and 3DE-RV SV/ESV ratios. PH patients were followed for 41 months (2–77). Cardiac death was the endpoint. Results PH patients had impaired 2DE and 3DE RV function parameters and RV-PA coupling compared to controls (p<0.001). At baseline, 3DE-RV SV/ESV and TAPSE/PAPS correlated with each other (r=0.51, p = 0.003) and both correlated with RV function parameters, but only SV/ESV correlated with BNP levels (Table) and WHO functional class (0.71±0.16 in class II, 0.66±0.21 in class III, 0.34±0.14 in class IV, p = 0.01). During follow-up, 5 patients died and these patients had at baseline higher BNP levels (LnBNP 5.91±1.62 vs 4.32±1.29, p = 0.02) and lower values of TAPSE (15±4 vs 18±3 mm, p = 0.03), S-RV (9.2±2.3 vs 11.1±1.8 cm/s, p = 0.04), RV free wall strain (−11.6±6.6 vs −18.1±5.3%, p = 0.02), RVEF (32±11 vs 40±7%, p = 0.04), and SV/ESV (0.49±0.22 vs 0.68±0.19, p = 0.05), but similar values for TAPSE/PASP (0.18±0.10 vs 0.20±0.05 mm/mmHg, p = 0.75). Conclusion In PH patients, 3DE-RV SV/ESV ratio as parameter of RV-PA coupling is altered and correlates with clinical status and RV function parameters. Besides parameters of RV function and BNP levels, 3DE-RV SV/ESV ratio seems a better predictor than TAPSE/PASP in this setting.