Abstract
Background and Aims
Pulmonary hypertension (PH) is prevalent in patients with functioning high-flow arterio-venous fistula (HFAVF) and associated with congestive heart failure (CHF). The real incidence and possible causes of this phenomenon is a matter of debate. Hemodynamic effects of HFAVF is considering as one of the reasons for PH formation. The subject of study was the impact of HFAVF on selected parameters of central hemodynamics. In particular, the diagnostic relevance of test of temporary HFAVF occlusion (TTO) was evaluated during right heart catheterization (RHC).
Method
A total of 13 patients were enrolled: 8 - after kidney transplantation (KT) with preserved allograft function and 5 - on maintenance hemodialysis (HD). All of them demonstrated clinical presentation of CHF III-IV class (NYHA). Severe PH and diastolic disfunction (DD) were observed at a baseline: echocardiographic systolic pulmonary arterial pressure sPAP (mmHg): M=59 (SD 13), ratio of mitral early diastolic inflow velocity (E) (pulsed wave Doppler) to average of septal and lateral mitral annular early-diastolic peak velocity (e′) (tissue Doppler imaging) E/e′ M=18 (SD 5). The ones who have comorbid conditions that cause PH were excluded. All patients bore an upper arm HFAVF, flow of the AVF (Qa) measured by Doppler ultrasonography was markedly high (Qa): M = 3,8 l/min (SD 1,2), the cardio-pulmonary recirculation (Qa/CO): M = 51% (SD 13). All patients underwent RHC and TTO AVF. Echocardiography (Echo) was performed initially and on the follow up (8 weeks after AVF closure/flow reduction). Statistical analysis was performed using the STATISTICA 13 software (Wilcoxon, T-test).
Results
The results of RHC and Echo data are presented in tables 1, 2.
As can be seen from the table data, all cases demonstrated instrumental features of high output CHF (HO CHF) in accordance with patient’s clinical status. TTO of HFAVF resulted in statistically significant decrease in CO and CI values, but no changes in PAP parameters were observed. Taking into account clinical and instrumental features of advanced CHF, HF AVF was closed in 8 patients after KT and in 2 patients on HD. 3 patients on HD underwent AVF flow reduction up to Qa not exceeding 1,1 l/min. Follow-up demonstrated complete resolution of CHF and dramatic improvement of DD, reduction in CO, CI, sPAP, volume parameters.
CO, cardiac output; CI, cardiac index; sPAP, systolic pulmonary arterial pressure; meanPAP, mean pulmonary arterial pressure; RAP, mean right atrial pressure; PCWP, pulmonary capillary wedge pressure; LV EDVi, left ventricular end-diastolic volume index; LAVi, left atrial volume index; RAVi, right atrial volume index;
Conclusion
PH is a component of AVF-induced HO CHF and could be classified as postcapillary one. TTO confirms significant HFAVF contribution to specific changes of parameters of central hemodynamics due to HO CHF. TTO does not impact on PAP values and therefore is not valid to clarify PH genesis per se.
175 Changes in Systolic Pulmonary Arterial Pressure during Exercise are Related to Changes in Mitral Regurgitation
