Changes in Pulmonary Hemodynamics Resulted From Long-Term Mechanical Heart Support

Abstract

Aim      To study the dynamics of right ventricular function and pulmonary hemodynamics in patients with pulmonary hypertension during mechanical circulatory support of the heart.Material and methods  A retrospective analysis was performed for 25 implantations of left ventricular assist device performed in the Meshalkin National Medical Research Center from 2006 through 2021. Mechanical assist devices were implanted in 21 men and 4 women (median age, 37.5 [29; 48] years). All patients had severe, NYHA functional class III-IV chronic heart failure refractory to the optimal drug therapy. Invasive measurements showed that mean pulmonary arterial pressure (MPAP) was 50 [44.5; 60] mm Hg, transpulmonary pressure gradient (TPG) was 16 [14; 19] mm Hg, and calculated pulmonary vascular resistance was 5.4 [4.9; 9] Wood units, which is an absolute contraindication (TPG >15 mm Hg or pulmonary vascular resistance >5 Wood units) for heart transplantation (HT).Results Duration of left ventricular support was from 17 to 948 days. For 12 (48 %) patients, the HT was performed at 180-948 days following the implantation of left ventricular assist device; 3 patients are presently waiting for HT; 10 patients died from various complications, 6 of them died during the hospital stage. Already during the early stage after the implantation of the mechanical assist device, pulmonary hemodynamics significantly improved. Thus, in one week, MPAP decreased from 50 [44.5; 60] mm Hg to 36 [33; 38] mm Hg (р=0.012) whereas pulmonary vascular resistance decreased from 5.4 [4.9; 9] to 2.9 [2.4; 3.6] Wood units (р=0.008). Follow-up showed further improvement of pulmonary hemodynamics; at 1 month, MPAP was 29 [27; 30] mm Hg and by the time of HT, MPAP was 2.0 [24.8; 26.3] mm Hg (р=0.01), i.e., reached a normal level, which made it possible to perform HT. Similar dynamics was observed for other variables that reflected pulmonary hemodynamics.Conclusion      Mechanical support of the heart is able to alleviate manifestations of pulmonary hypertension in most patients with end-stage heart failure. It is necessary to develop an algorithm for identifying the category of patients with a high risk of progression of right ventricular failure.