Clinical characteristics of pulmonary hypertension depending on the lung microvascular hemodynamic type and histology in patients after mitral valve disease treatment

Aim . To identify the main differences in patients undergoing surgical treatment of acquired mitral valve (MV) disease depending on the preoperative type of pulmonary hypertension (PH), as well as to identify factors associated with PH persistence and its type one year after surgical treatment of MV disease. Material and methods . This open-label, single-­center prospective study included 40 patients with valvular heart disease (VHD) undergoing MV surgery. These patients had verified PH according to the right heart catheterization (RHC) as follows: 15 patients with isolated post-capillary PH and 25 patients with a combined post-/precapillary PH. Intraoperatively, 26 patients with PH underwent a right lung tissue biopsy with subsequent histological examination. One year after surgery, RHC was performed to assess PH dynamics. The significance ranks of the predictors were used to assess the contribution of factors to PH dynamics after surgery. Results . Patients with VHD and combined post/precapillary PH were characte­rized by more impaired right ventricle-­pulmonary artery coupling, increased le­vels of myocardial strain markers, severe changes in pulmonary circulation hemodynamics, arteriolization of venules, and a higher frequency of pandemic arterial thrombosis (53,3%) compared to patients with isolated postcapillary PH (9%). According to RHC data one year after surgery (n=21), PH regression was observed in 28,5%, while isolated postcapillary PH persisted in 42,85%, and combined post/precapillary PH — in 28,5%. The factors, that made the most significant contribution to PH regression one year after surgery included mitral valve stenosis (100 units), atrial fibrillation (73 units), type 2 diabetes (72 units), combined intervention on the mitral valve and aortic valve (61 units), obesity class (56 units), male sex (48 units). The character of morphological lung changes did not significantly contribute to perioperative dynamics of PH. Conclusion . Patients with VHD and combined post/precapillary PH are characterized by more impaired right ventricle-­pulmonary artery coupling, elevated levels of myocardial strain markers, severe changes in pulmonary circulation hemodynamics with arteriolization of venules and a higher prevalence of pandemic arterial thrombosis. For the first time, potentially modifiable factors have been identified as making the greatest impact on the PH dynamics one year after surgery.