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Background: The interplay between the right ventricle and the pulmonary artery, known as right ventricular to pulmonary artery (RV-PA) coupling, is crucial for assessing right ventricular systolic function against the afterload from the pulmonary circulation. Pulmonary artery pressure levels are ideally measured by right heart catheterization. Yet, echocardiography represents the most utilized method for evaluating pulmonary artery pressure levels, albeit with limitations in accuracy. This study therefore aims to evaluate the prognostic significance of right ventricular to pulmonary artery (RV-PA) coupling expressed as tricuspid annular plane systolic excursion (TAPSE) related to systolic pulmonary artery pressure (sPAP) levels measured by right heart catheterization (TAPSE/sPAPinvasive) or estimated by transthoracic echocardiography (TAPSE/sPAPechocardiography) in patients with severe aortic stenosis undergoing transcatheter aortic valve replacement (TAVR). Methods: Using data from a bicentric registry, this study compares TAPSE/sPAPinvasive vs. TAPSE/sPAPechocardiography in predicting 1-year all-cause mortality after TAVR. Results: Among 333 patients with complete echocardiography and right heart catheterization data obtained before TAVR, their mean age was 79.8 ± 6.74 years, 39.6% were female, and general 1-year survival was 89.8%. sPAPinvasive and sPAPechocardiography showed only moderate correlation (Pearson correlation coefficient R: 0.53, p value: <0.0001). TAPSE/sPAPinvasive was superior to TAPSE/sPAPechocardiography in predicting 1-year all-cause mortality after TAVR (area under the curve: 0.662 vs. 0.569, p value: 0.025). Patients with reduced TAPSE/sPAPinvasive levels (< 0.365 mm/mmHg) evidenced significantly lower 1-year survival rates than patients with preserved TAPSE/sPAPinvasive levels (81.8 vs. 93.6%, p value: 0.001; hazard ratio for 1-year mortality: 3.09 [95% confidence interval: 1.55-6.17]). Echocardiographic follow-up data revealed that patients with reduced RV-PA coupling suffer from persistent right ventricular dysfunction (TAPSE: 16.6 ± 4.05 mm vs. 21.6 ± 4.81 mm in patients with preserved RV-PA coupling) and severe tricuspid regurgitation (diagnosed in 19.7 vs. 6.58% in patients with preserved RV-PA coupling). Conclusions: RV-PA coupling expressed as TAPSE/sPAPinvasive can refine stratification of severe aortic stenosis patients into low-risk and high-risk cohorts for mortality after TAVR. Moreover, it can help to anticipate persistent extra-aortic valve cardiac damage, which will demand further treatment.
RESUMO
PURPOSE: The purpose of this study was to determine whether automated quantification of pulmonary perfused blood volume (PBV) in dual-energy computed tomography pulmonary angiography is of diagnostic value in assessing the severity of acute pulmonary embolism (PE). MATERIALS AND METHODS: Ethical approval and informed consent were waived by the responsible institutional review board for this retrospective study. Of 224 consecutive patients with dual-energy computed tomography pulmonary angiographic findings positive for acute PE, we excluded 153 patients because of thoracic comorbidities (n = 130), missing data (n = 11), severe artifacts (n = 11), or inadequate enhancement (n = 1). Automated quantification of PBV was performed in the remaining 71 patients (mean [SD] age, 62 [16] years) with acute PE and no cardiopulmonary comorbidities. Perfused blood volume values adjusted for age and sex were correlated with the Qanadli obstruction score, morphological computed tomographic signs of right heart dysfunction, serum levels of troponin, and the necessity for intensive care unit (ICU) admission. RESULTS: Dual-energy computed tomography pulmonary angiography-derived PBV values inversely correlated with the Qanadli score (r = -0.46; P < 0.001), the right and left ventricle (RV/LV) ratio (r = -0.52; P < 0.001), and troponin I (r = -0.45; P = 0.001). The patients with global PBV values lower than 60% were significantly more likely to require admission to an ICU than did the patients with global pulmonary PBV of 60% or higher (47% vs 11%; P = 0.003; positive predictive value, 47%; negative predictive value, 89%). On the univariate analysis, a significant negative correlation was found between the global PBV values and the Qanadli obstruction score (r = -0.46; P < 0.001), the RV/LV diameter ratio (r = -0.52; P < 0.001), and the necessity for ICU admission (r = -0.39; P = 0.001). On the retrospective multivariate regression analysis, the areas under the receiver operating characteristic curve for the prediction of ICU admission were 0.75 for the pulmonary PBV, 0.83 for the Qanadli obstruction score, 0.68 for the computed tomographic signs of right heart dysfunction (interventricular septal bowing and/or contrast reflux), and 0.76 for the RV/LV diameter ratio. CONCLUSIONS: Dual-energy computed tomography pulmonary angiography can be used for an immediate, reader-independent estimation of global pulmonary PBV in acute PE, which inversely correlates with thrombus load, laboratory parameters of PE severity, and the necessity for ICU admission.