The novel noninvasive method for prediction of long-term specific therapy efficacy in patients with IPAH and inoperable CTEPH

Abstract

Abstract Introduction The main aim of the treatment in patients (pts) with idiopathic pulmonary arterial hypertension (IPAH) is the achivement of low risk of fatal events during the year, that reflecting the complex of nonivasive and invasive parameters presented in the risk stratification scale of ESC and ERS 2015 guidelines. However, in pts with chronic thromboembolic pulmonary hypertension (CTEPH) there is a lack of evidence to use this scale. Also there is some limitation to perform invasive diagnostics in every patient for complex risk assessment. Thus, the searching for the novel noninvasive markers for prediction of treatment efficacy need further investigation. Purpose To develop the novel approach for predicting of long-term specific therapy efficacy using noninvasive methods of diagnostic in IPAH and CTEPH pts. Methods The study included 88 IPAH and 38 inoperable CTEPH pts. At the time of diagnosis verification and after 1 year of treatment the complex assessment, including 6-minute walking test, cardiopulmonary exercise test, 2D and 3D Echo, right heart catheterization, NT-proBNP level assessment were made. The efficacy of treatment was determined as achievement of cardiac index (CI) equal or more than 2,5 l/min/m2 after 1 year of treatment. To create a model, predicting long-term specific therapy efficacy the classification trees with the full enumeration method for one-dimensional branches C&RT were used. The impact of factors in prediction of the long-term specific therapy efficacy was demonstrated in the ranks of significance of predictors in units (U). Results At baseline all pts with IPAH/inoperable CTEPH were out of the low-risk area. Whereas, after 1 year of treatment 27% of IPAH/CTEPH pts achieved a low risk of fatal events. To develop a model for predicting of the long-term specific therapy efficacy (>1 year) in patients with IPAH/ CTEPH the most significant predictors of achievement of CI equal or more, than 2.5 l/min/m2 were: age (73 U), right ventricular end-diastolic/end-systolic volumes (85 U/84 U) at the time of diagnosis verification, and the dynamics of NT-proBNP (100 U.). According to the most valuble factors the model of long-term therapy efficacy was created: the value of dynamic (Δ) of NT-proBNP from >−376,4 to <30,4 pg/ml after 12 months of treatment with combination of right ventricular end-diastolic volume <150,5 ml at the time of diagnosis verification predict the therapy efficacy. Conclusion The implementation of novel noninvasive method, that predict specific therapy efficacy, allows making a timely decision of therapy escalation in IPAH and CTEPH pts by the first and subsequent years of treatment. Funding Acknowledgement Type of funding sources: Public Institution(s). Main funding source(s): National medical research center of Cardiology, Moscow