Pulmonary hypertension

Pulmonary hypertension (PH) is a haemodynamic condition that leads to a progressive increase in pulmonary vascular resistance and mean pulmonary artery pressure. Irrespective of its aetiology, the main cause of death in PH patients is right ventricular (RV) failure. Noninvasive imaging techniques play an essential role in diagnosing PH and monitoring disease progression. This chapter provides an overview of the most important noninvasive imaging tools for assessing pulmonary pressures, RV function and monitoring

Increased native T1-values at the interventricular insertion regions in precapillary pulmonary hypertension

Cardiac magnetic resonance imaging of the pressure overloaded right ventricle (RV) of precapillary pulmonary hypertension (PH) patients, exhibits late gadolinium enhancement at the interventricular insertion regions, a phenomenon which has been linked to focal fibrosis. Native T1-mapping is an alternative technique to characterize myocardium and has the advantage of not requiring the use of contrast agents. The aim of this study was to characterize the myocardium of idiopathic pulmonary arterial hypertension (IPAH), systemic scleroderma related PH (PAH-Ssc) and chronic thromboembolic PH (CTEPH) patients using native T1-mapping and to see whether native T1-values were related to disease severity. Furthermore, we compared native T1-values between the different precapillary PH categories. Native T1-mapping was performed in 46 IPAH, 14 PAH-SSc and 10 CTEPH patients and 10 control subjects. Native T1-values were assessed using regions of interest at the RV and LV free wall, interventricular septum and interventricular insertion regions. In PH patients, native T1-values of the interventricular insertion regions were significantly higher than the native T1-values of the RV free wall, LV free wall and interventricular septum. Native T1-values at the insertion regions were significantly related to disease severity. Native T1-values were not different between IPAH, PAH-Ssc and CTEPH patients. Native T1-values of the interventricular insertion regions are significantly increased in precapillary PH and are related to disease severity. Native T1-mapping can be developed as an alternative technique for the characterization of the interventricular insertion regions and has the advantage of not requiring the use of contrast agents

Serial assessment of right ventricular systolic function in patients with precapillary pulmonary hypertension using simple echocardiographic parameters: A comparison with cardiac magnetic resonance imaging

BACKGROUND: Although cardiac magnetic resonance imaging (CMRI) is the gold standard for the (serial) assessment of right ventricular (RV) function, the technique has several drawbacks: CMRI is relatively expensive, has a limited availability, and the analyses are time consuming. Echocardiography (echo) can overcome several of these issues. The aim of this study was to compare simple echo-derived parameters of RV systolic function with CMRI-derived RV ejection fraction (RVEF) in patients with precapillary pulmonary hypertension (PH) and to determine which echo parameters best followed the change in CMRI-derived-RVEF during follow-up. METHODS: CMRI and echo were performed in 96 precapillary PH patients. In 38 patients a second set of a CMRI and echo were available. Retrospectively, echo-derived right ventricular fractional area change (RVFAC), tricuspid annulus plane systolic excursion (TAPSE), fractional transversal (FTWM), and longitudinal wall motion (FLWM) were assessed and compared with CMRI-derived-RVEF. Furthermore, the changes in RVFAC, TAPSE, FTWM, and FLWM during follow-up were compared with the change in CMRI-derived-RVEF. RESULTS: All four echo parameters were significantly correlated to CMRI-derived-RVEF. The strongest relationship was seen between CMRI-derived-RVEF and RVFAC (r(2)=0.567). However, sensitivity for predicting a deterioration in CMRI-derived RVEF was poor for all four echo-derived parameters (ranging from 33% to 56%). CONCLUSIONS: Although RVFAC, TAPSE, FTWM, and FLWM were significantly correlated to CMRI-derived-RVEF, all four echo parameters showed a low sensitivity for predicting a deterioration in CMRI-derived RVEF during follow-up. Therefore, RVFAC, TAPSE, FTWM, and FLWM are not suitable parameters for the serial assessment of RV systolic function in patients with precapillary PH

Application of [18F]FLT-PET in pulmonary arterial hypertension: a clinical study in pulmonary arterial hypertension patients and unaffected bone morphogenetic protein receptor type 2 mutation carriers

Pulmonary arterial hypertension is a heterogeneous group of diseases characterized by vascular cell proliferation leading to pulmonary vascular remodelling and ultimately right heart failure. Previous data indicated that 3′-deoxy-3′-[18F]-fluorothymidine (18FLT) positron emission tomography (PET) scanning was increased in pulmonary arterial hypertension patients, hence providing a possible biomarker for pulmonary arterial hypertension as it reflects vascular cell hyperproliferation in the lung. This study sought to validate 18FLT-PET in an expanded cohort of pulmonary arterial hypertension patients in comparison to matched healthy controls and unaffected bone morphogenetic protein receptor type 2 mutation carriers. 18FLT-PET scanning was performed in 21 pulmonary arterial hypertension patients (15 hereditary pulmonary arterial hypertension and 6 idiopathic pulmonary arterial hypertension), 11 unaffected mutation carriers and 9 healthy control subjects. In-depth kinetic analysis indicated that there were no differences in lung 18FLT k3 phosphorylation among pulmonary arterial hypertension patients, unaffected bone morphogenetic protein receptor type 2 mutation carriers and healthy controls. Lung 18FLT uptake did not correlate with haemodynamic or clinical parameters in pulmonary arterial hypertension patients. Sequential 18FLT-PET scanning in three patients demonstrated uneven regional distribution in 18FLT uptake by 3D parametric mapping of the lung, although this did not follow the clinical course of the patient. We did not detect significantly increased lung 18FLT uptake in pulmonary arterial hypertension patients, nor in the unaffected bone morphogenetic protein receptor type 2 mutation carriers, as compared to healthy subjects. The conflicting results with our preliminary human 18FLT report may be explained by a small sample size previously and we observed large variation of lung 18FLT signals between patients, challenging the application of 18FLT-PET as a biomarker in the pulmonary arterial hypertension clinic