The impact of the initial treatment of venous thromboembolism on the severity of chronic thromboembolic pulmonary hypertension

<bold>Introduction:</bold> Chronic thromboembolic pulmonary hypertension (CTEPH) arises from organized thromboembolism and altered vascular remodeling. The pathogenesis of CTEPH is not fully understood, with acute venous thromboembolism (VTE) being an assumed classic risk factor, but only accounting for 1-5% of CTEPH cases in survivors of acute pulmonary embolism (PE). <bold>Aim:</bold> The aim of the study was to investigate the impact of the initial treatment of VTE on the severity of pulmonary hypertension (PH). <bold>Methods:</bold> The study was designed as a retrospective cohort monocentric study that involved patients with newly diagnosed CTEPH during a four-year period. The analysis focused on demographic data, previous medical history and the right heart catheterization results. <bold>Results:</bold> The study included 80 patients, mean age 71.47±10.97 years, 47 female (58.8%), whereby 62 patients had confirmation of previous VTE (77.5%). There was no statistically significant difference between hemodynamic parameters derived from right heart catheterization in relation to the history of VTE (mPAP 39.42±9.33 mmHg vs. 39.89±9.22 mmHg, p=0.85; PVR 10.58±4.14 WU vs. 11.86±6.54 WU, p=0.44). There was no statistically significant difference in frequency of different severity group of PH in patients with and without history of VTE (χ2=1.12; p=0.62; Cramer’s V=0.12; p=0.62). <bold>Conclusions:</bold> The severity of CTEPH does not significantly differ between patients initially diagnosed and adequately treated for VTE compared to those in whom VTE had not been previously recognized. The initial treatment of VTE in our study was not identified as a risk factor for the severity of CTEPH.