Page 18 - Assessing right ventricular function and the pulmonary circulation in pulmonary hypertension Onno Anthonius Spruijt

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Emerging modalities in pulmonary hypertension
Chapter 7 summarizes emerging imaging techniques in the setting of pulmonary hypertension. As depicted in the introduction the diagnosis of PH is made during RHC. Subsequently, assessing disease severity and monitoring of patients is done by assessing hemodynamics, indices of right ventricular function as well as exercise tests. However, currently there is no possibility to clinically assess the primary disease process in the pulmonary arteries of patients with precapillary pulmonary hypertension. Since preclinical studies are increasingly focusing on therapies directly targeting the pulmonary vascular remodeling, there is an urgent need for an imaging method that allows quantification of this remodeling. Such a technique would not only provide insight into the underlying disease process, but would also enable assessment of responses to targeted therapies. Therefore, in chapter 8, we investigated whether 3’-[18F]fluoro-3’-deoxythymidine ([18F]-FLT) positron emission tomography (PET/CT) could be used to quantitatively assess proliferation in the pulmonary vasculature of PAH patients. Furthermore, we tested whether [18F]-FLT was able to track the pulmonary vascular remodeling and reverse remodeling after administration of targeted therapies in a monocrotaline PH rat model.
An emerging technique to characterize the myocardium by cardiac magnetic resonance imaging is native T1-mapping. In chapter 9 we investigated this technique in precapillary pulmonary hypertension patients.
As summarized in the general introduction, patients with pulmonary hypertension have a decreased exercise tolerance and this exercise intolerance in mainly determined by circulatory limitations. Whether this exercise intolerance coincides with an inability to increase right ventricular contractility was investigated in chapter 10 during an invasive cardiopulmonary exercise test.