Usefulness of the Continuous-Wave Doppler-Derived Pulmonary Arterial-Right Ventricular Pressure Gradient Just before Atrial Contraction for the Estimation of Pulmonary Arterial Diastolic and Wedge Pressures

Echocardiographic estimation of right ventricular diastolic stiffness based on pulmonary regurgitant velocity waveform analysis in precapillary pulmonary hypertension

Right ventricular (RV) diastolic stiffness is an independent predictor of survival and is strongly associated with disease severity in patients with precapillary pulmonary hypertension (PH). Therefore, a fully validated echocardiographic method for assessing RV diastolic stiffness needs to be established. This study aimed to compare echocardiography-derived RV diastolic stiffness and invasively measured pressure-volume loop-derived RV diastolic stiffness in patients with precapillary PH. We studied 50 consecutive patients with suspected or confirmed precapillary PH who underwent cardiac catheterization, magnetic resonance imaging, and echocardiography within a 1-week interval. Single-beat RV pressure-volume analysis was performed to determine the gold standard for RV diastolic stiffness. Elevated RV end-diastolic pressure (RVEDP) was defined as RVEDP ≥ 8 mmHg. Using continuous-wave Doppler and M-mode echocardiography, an echocardiographic index of RV diastolic stiffness was calculated as the ratio of the atrial-systolic descent of the pulmonary artery-RV pressure gradient derived from pulmonary regurgitant velocity (PRPGDAC) to the tricuspid annular plane movement during atrial contraction (TAPMAC). PRPGDAC/TAPMAC showed significant correlation with β (r = 0.54, p < 0.001) and RVEDP (r = 0.61, p < 0.001). A cut-off value of 0.74 mmHg/mm for PRPGDAC/TAPMAC showed 83% sensitivity and 93% specificity for identifying elevated RVEDP. Multivariate analyses indicated that PRPGDAC/TAPMAC was independently associated with disease severity in patients with precapillary PH, including substantial PH symptoms, stroke volume index, right atrial size, and pressure. PRPGDAC/TAPMAC, based on pulmonary regurgitation velocity waveform analysis, is useful for the noninvasive assessment of RV diastolic stiffness and is associated with prognostic risk factors in precapillary PH.

Prognostic value of an echocardiographic index reflecting right ventricular operating stiffness in patients with heart failure

PURPOSE

We recently reported a noninvasive method for the assessment of right ventricular (RV) operating stiffness that is obtained by dividing the atrial-systolic descent of the pulmonary artery-RV pressure gradient (PRPGD_AC) derived from the pulmonary regurgitant velocity by the tricuspid annular plane movement during atrial contraction (TAPM_AC). Here, we investigated whether this parameter of RV operating stiffness, PRPGD_AC/TAPM_AC, is useful for predicting the prognosis of patients with heart failure (HF).

METHODS

We retrospectively included 127 hospitalized patients with HF who underwent an echocardiographic examination immediately pre-discharge. The PRPGD_AC/TAPM_AC was measured in addition to standard echocardiographic parameters. Patients were followed until 2 years post-discharge. The endpoint was the composite of cardiac death, readmission for acute decompensation, and increased diuretic dose due to worsening HF.

RESULTS

58 patients (46%) experienced the endpoint during follow-up. Univariable and multivariable Cox regression analyses demonstrated that the PRPGD_AC/TAPM_AC was associated with the endpoint. In a Kaplan-Meier analysis, the event rate of the greater PRPGD_AC/TAPM_AC group was significantly higher than that of the lesser PRPGD_AC/TAPM_AC group. In a sequential Cox analysis for predicting the endpoint's occurrence, the addition of PRPGD_AC/TAPM_AC to the model including age, sex, NYHA functional classification, brain natriuretic peptide level, and several echocardiographic parameters including tricuspid annular plane systolic excursion significantly improved the predictive power for prognosis.

CONCLUSION

A completely noninvasive index of RV operating stiffness, PRPGD_AC/TAPM_AC, was useful for predicting prognoses in patients with HF, and it showed an incremental prognostic value over RV systolic function.

Simple and noninvasive method to estimate right ventricular operating stiffness based on echocardiographic pulmonary regurgitant velocity and tricuspid annular plane movement measurements during atrial contraction

It was recently shown that invasively determined right ventricular (RV) stiffness was more closely related to the prognosis of patients with pulmonary hypertension than RV systolic function. So far, a completely noninvasive method to access RV stiffness has not been reported. We aimed to clarify the clinical usefulness of our new echocardiographic index of RV operating stiffness using atrial-systolic descent of the pulmonary artery-RV pressure gradient derived from pulmonary regurgitant velocity (PRPGD_AC) and tricuspid annular plane movement during atrial contraction (TAPM_AC). We studied 81 consecutive patients with various cardiac diseases who underwent echocardiography and cardiac catheterization. We measured PRPGD_AC and TAPM_AC using continuous-wave Doppler and M-mode echocardiography, respectively, and calculated PRPGD_AC/TAPM_AC. RV end-diastolic pressure (RVEDP) and RV pressure increase during atrial contraction (ΔRVP_AC) were invasively measured, and RV volume change during atrial contraction (ΔV_AC) was calculated from echocardiographic late-diastolic transtricuspid flow time-velocity integral and tricuspid annular area; thus ΔRVP_AC/ΔV_AC was used as the standard index for RV operating stiffness. PRPGD_AC/TAPM_AC well correlated with ΔRVP_AC/ΔV_AC (r = 0.84, p < 0.001) and RVEDP (r = 0.80, p < 0.001), and the area under the receiver operating characteristic curve to discriminate RVEDP > 12 mmHg was 0.94. Multivariate regression analysis revealed that PRPGD_AC/TAPM_AC was the single independent determinant of ΔRVP_AC/ΔV_AC (β = 0.86, p < 0.001). PRPGD_AC/TAPM_AC is useful to estimate RV operating stiffness and a good practical indicator of RVEDP.