Comparison of the capability of risk stratification evaluation between two- and three-dimensional speckle-tracking strain in pre-capillary pulmonary hypertension

Regular Risk Assessment in Pulmonary Arterial Hypertension - A Whistleblower for Hidden Disease Progression

Despite developments in the treatment of pulmonary arterial hypertension, timely treatment is seldom achieved, and hidden progression is not uncommonly disguised as a seemingly "stable" condition. Appropriate risk assessment tools facilitate goal-oriented treatment strategies. This article aimed to review the development of these risk assessment tools including early assessment equations/scores, European guidelines-based risk assessment scores, and tools derived from the United States nationwide registry. A stepwise and regular approach with these assessment tools in clinical practice is highly recommended for timely treatment escalation to stop disease progression early. In this review, a practical and recommended algorithm of these assessment tools is also provided.

Ventilation/perfusion imaging predicts response to balloon pulmonary angioplasty in patients with chronic thromboembolic pulmonary hypertension

OBJECTS

Although balloon pulmonary angioplasty (BPA) has emerged as an alternative treatment option for chronic thromboembolic pulmonary hypertension (CTEPH), it is followed in some patients by residual PH. We studied the efficacy of BPA on pulmonary blood flow and the predictive value of ventilation/perfusion (V/Q) scanning.

METHODS

We retrospectively reviewed the clinical database, which included patients diagnosed with CTEPH who had received BPA. All patients undergone V/Q scanning to quantify the extent of pulmonary perfusion abnormality before and after BPA. Pulmonary hemodynamics were assessed by right heart catheterization, and cardiac function and exercise capacity were evaluated at baseline and post-BPA. A total of 120 CTEPH patients were included for analysis.

RESULTS

BPA significantly alleviated mean pulmonary arterial pressure (mPAP: 48.0 ± 12.9 mmHg vs 34.7 ± 10.3 mmHg, P < 0.001) and pulmonary vascular resistance (PVR: 8.8 ± 4.1 Wood units vs 5.2 ± 3.0 Wood units, P < 0.001), and improved cardiac function (N-terminal pro B-type natriuretic peptide: 1628.7 ± 2887.2 pg/mL vs 400.4 ± 669.3 pg/mL, P < 0.001) and exercise capacity (6-minute walking distance: 386 ± 122 m vs 461 ± 86 m, P < 0.001). The extent of pulmonary perfusion abnormality represented by the percentage of perfusion defects (PPDs%) was improved after BPA (50.1 ± 13.6 vs 35.6 ± 14.2, P < 0.001), with the right and inferior lung lobes benefitting the most. PPDs% < 35.5 at baseline and greater restoration of PPDs% after BPA (∆PPDs% > 20.6) were associated with a better response to BPA (PPDs% < 35.5: odds ratio [OR] 10.857, 95% confidence interval [95%CI] 1.393-84.635, P = 0.023; ∆PPDs% > 20.6: OR 1.035, 95% CI 1.002-1.068, P = 0.036).

CONCLUSION

BPA significantly restored pulmonary blood flow, predominantly in the right and inferior lobes. V/Q scanning has the potential to predict the therapeutic response to BPA for CTEPH.

Evaluation of Left Ventricular Diastolic Function by 2-D Speckle Tracking Echocardiography in Patients with Connective Tissue Disease-Associated Pulmonary Artery Hypertension

The purpose of this study was to evaluate the role of 2-D speckle tracking imaging in assessing left ventricular diastolic function in patients with connective tissue disease (CTD). A total of 98 CTD patients and 32 healthy controls were prospectively recruited. Early (E) and late (A) diastolic velocities of the transmitral flow were measured by pulsed Doppler echocardiography. Peak early diastolic myocardial velocity (E') was calculated on tissue Doppler echocardiography. The longitudinal strain rate (SR) was calculated as the average of three apical views, while circumferential and radial SRs were measured in three short-axis views. Pulmonary arterial hypertension (PAH) was defined as systolic pulmonary arterial pressure (sPAP) >36 mm Hg. Compared with the control group, CTD patients exhibited significant impairment of left ventricular diastolic function, manifested as lower global SR during early diastole (SRe) in the longitudinal deformation and higher E/SRe in both longitudinal and radial deformation. CTD-PAH patients had significantly lower SRe and higher E/SRe values in both the longitudinal and radial deformation compared with the patients with CTD without PAH. Pearson's correlation analysis revealed that sPAP levels correlated positively with E/E', longitudinal E/SRe, circumferential E/SRe and radial SRe, and it correlated negatively with septal E' and radial E/SRe. Receiver operating characteristic curve analysis suggested that E/E', longitudinal E/SRe and radial SRe could be used to predict PAH. The present study indicates that 2-D speckle tracking imaging is a useful method for evaluation of left ventricular diastolic function, and these derived parameters can serve as good predictors of PAH, but it may not be superior to the commonly used E/E' in CTD patients.

Parameter subset reduction for patient-specific modelling of arrhythmogenic cardiomyopathy-related mutation carriers in the CircAdapt model

Arrhythmogenic cardiomyopathy (AC) is an inherited cardiac disease, clinically characterized by life-threatening ventricular arrhythmias and progressive cardiac dysfunction. Patient-specific computational models could help understand the disease progression and may help in clinical decision-making. We propose an inverse modelling approach using the CircAdapt model to estimate patient-specific regional abnormalities in tissue properties in AC subjects. However, the number of parameters (n = 110) and their complex interactions make personalized parameter estimation challenging. The goal of this study is to develop a framework for parameter reduction and estimation combining Morris screening, quasi-Monte Carlo (qMC) simulations and particle swarm optimization (PSO). This framework identifies the best subset of tissue properties based on clinical measurements allowing patient-specific identification of right ventricular tissue abnormalities. We applied this framework on 15 AC genotype-positive subjects with varying degrees of myocardial disease. Cohort studies have shown that atypical regional right ventricular (RV) deformation patterns reveal an early-stage AC disease. The CircAdapt model of cardiovascular mechanics and haemodynamics has already demonstrated its ability to capture typical deformation patterns of AC subjects. We, therefore, use clinically measured cardiac deformation patterns to estimate model parameters describing myocardial disease substrates underlying these AC-related RV deformation abnormalities. Morris screening reduced the subset to 48 parameters. qMC and PSO further reduced the subset to a final selection of 16 parameters, including regional tissue contractility, passive stiffness, activation delay and wall reference area. This article is part of the theme issue 'Uncertainty quantification in cardiac and cardiovascular modelling and simulation'.