Lowering Pulmonary Wedge Pressure after Heart Transplant: Pulmonary Compliance and Resistance Effect

Abstract

BackgroundRight ventricular (RV) afterload is an important risk factor for post-heart transplantation (HTx) mortality, and it results from the interaction between pulmonary vascular resistance (PVR) and pulmonary compliance (CPA). Their product, the RC time, is believed to be constant. An exception is observed in pulmonary hypertension because of elevated left ventricular (LV) filling pressures.ObjectiveUsing HTx as a model for chronic lowering of LV filling pressures, our aim was to assess the variations in RV afterload components after transplantation.MethodsWe retrospectively studied 159 patients with right heart catheterization before and after HTx. The effect of Htx on hemodynamic variables was assessed.ResultsMost of the patients were male (76%), and the mean age was 53 ± 12 years. HTx had a significant effect on the hemodynamics, with normalization of the LV and RV filling pressures and a significant increase in cardiac output and heart rate (HR). The PVR decreased by 56% and CPA increased by 86%. The RC time did not change significantly, instead of increasing secondary to pulmonary wedge pressure (PWP) normalization after HTx as expected. The expected increase in RC time with PWP lowering was offset by the increase in HR (because of autonomic denervation of the heart). This effect was independent from the decrease of PWP.ConclusionsThe RC time remained unchanged after HTx, notwithstanding the fact that pulmonary capillary wedge pressure significantly decreased. An increased HR may have an important effect on RC time and RV afterload. Studying these interactions may be of value to the assessment of HTx candidates and explaining early RV failure after HTx.

Pulmonary Artery Hypertension as A Risk Factor for Long-Term Survival after Heart Transplantation

“…They have shown that PVR and TPG are independent predictors of worse long-term outcome. The decrease of PVR values after HTx was identified as positive predictor of better survival [Moreira 2015]. Rivinius et al showed that PVR >300 dyn•s•cm -5a and PVRI also are independent predictors of survival after HTx 1.001-1.012; P = .018), while TPG had a hazard ratio of 1.172 (95% [CI]: 1.032-1.033; P = .015).…”

Comprehensive assessments of pulmonary circulation in children with pulmonary hypertension associated with congenital heart disease

“…Wright et al reported that exercise was associated with a decrease in Cp and a resulting decline in RC time in healthy individuals (12). Moreira et al reported that RC time was inversely correlated with heart rate in patients who underwent heart transplantation (39). These findings indicate that an increase in heart rate leads to a decline in RC time.…”

Resultados Clínicos e Hemodinâmicos de Longo Prazo após o Transplante de Coração em Pacientes Pré-Tratados com Sildenafil

“…Portanto, a pressão arterial pulmonar diastólica (PAPd) está firmemente correlacionada com a pressão capilar pulmonar (PCP). 6 , 7 Por outro lado, o componente vasorreativo da HP se desenvolve com a HP duradoura. Ele é caracterizado por vasoespasmo, vasoconstrição e alterações morfológicas dos vasos.…”

“…Therefore, diastolic pulmonary artery pressure (dPAP) correlates closely with pulmonary capillary wedge pressure (PCWP). 6 , 7 On the other hand, the vasoreactive component of PH develops with long-standing PH. It is characterized by vasospasm, vasoconstriction, and morphologic changes of the pulmonary vasculature.…”