Deep Dive into the Cardio-Pulmonary-Renal Interactions in Patients with Pulmonary Hypertension: Serum Creatinine Levels Even Within the Normal Range Related to Long-Term Survival.

Background: Renal function in patients with pulmonary hypertension (PH) can be disrupted due to hypotension, low cardiac output, and venous pressure overload because of the its dependency on the pressure gradient between systemic arterial and venous circulations. The aim was to investigate whether measures of venous and pulmonary circulations determine renal function in patients with PH.

Methods: The single-center study group comprised 1071 patients with a hemodynamically confirmed PH diagnosis. Serum creatinine level was used for surrogate of renal perfusion status. Echocardiographic measures included left ventricle ejection fraction (LVEF), tricuspid annular plane excursion (TAPSE), and right atrial area (RAA). Hemodynamic parameters included mean aortic and pulmonary pressures (MAP and PAMP), pulmonary capillary wedge (PCWP) and right atrial pressure (RAP), transsystemic and transpulmonary pressure gradients (TSG and TPG), and pulmonary and systemic vascular resistances (PVR and SVR), respectively.

Results: Serum creatinine was significantly associated with TSG, RAP, TPG, PAMP, PVR, PVR/SVR ratio, cardiac index, stroke volume index, mixed venous O2 Sat %, TAPSE, RAA, LVEF%, pericardial effusion and BNP/NT-ProBNP levels (P < .05 for all), but not with MAP, PCWP, and SVR. According to the creatinine tertiles, survival rates were significantly different between groups 1 vs. 3, and 2 vs. 3 (P = .001 for both).

Conclusion: An integrative approach regarding cardio-pulmonary-renal interactions seems to provide a comprehensive perspective for circulatory status and renal function in patients with PH and congestive heart failure. More importantly, even small increases of serum creatinine levels within the normal range seems to be associated long-term survival differences.