Page 189 - Assessing right ventricular function and the pulmonary circulation in pulmonary hypertension Onno Anthonius Spruijt

therapy in terms of hemodynamics, cardiac function and exercise capacity as patients with idiopathic pulmonary arterial hypertension and a preserved DLCO.
Emerging modalities in pulmonary hypertension
Chapter 7 summarizes emerging imaging techniques in the setting of pulmonary hypertension. A well-known technique to characterize the myocardium with CMRI is the assessment of late gadolinium enhancement.
Currently, there is no possibility to clinically assess the primary disease process in the pulmonary arteries of patients with pulmonary arterial hypertension. 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 patients with idiopathic pulmonary arterial hypertension. Subsequently, we assessed whether [18F]-FLT could track the pulmonary vascular remodeling in a monocrotaline ratmodel (animal model of pulmonary hypertension) and the reverse remodeling after treating the animals with targeted therapies. We found that the uptake of [18F]-FLT in the lungs of patients with idiopathic pulmonary arterial hypertension was significantly increased compared to control subjects and was related to markers of disease severity. The uptake of [18F]-FLT was heterogeneous among IPAH patients. Furthermore, [18F]-FLT was able to track the pulmonary vascular remodeling in the monocrotaline ratmodel and the reverse remodeling after treating the animals with dichloroacetate and imatinib. Our results suggest that [18F]-FLT PET/CT can be developed as a tool to select IPAH patients with a hyperproliferative stat that may benefit from anti-proliferative therapy. In addition, [18F]-FLT PET/CT might be used to assess treatment response.
An emerging technique to characterize the myocardium by CMRI is native T1-mapping. To quantify native T1-values, there is no need for a reference area of myocardium, making it possible to directly quantify the total myocardium. Furthermore, native T1-mapping has the advantage of not requiring the usage of contrast agents. In chapter 9 we investigated this technique in precapillary pulmonary hypertension patients. Native T1-values were increased at the interventricular insertion regions compared to the RV free wall, LV free wall and interventricular septum. Native T1-values at the interventricular insertion regions were significantly related to markers of disease severity. No differences in native T1-values were found between patients with idiopathic pulmonary arterial hypertension, systemic scleroderma related pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension. Our results suggests that native T1-mapping can be
Chapter 11
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