Abstract Body (Do not enter title and authors here): Background: Optimal hemodynamics for right ventricular dysfunction (RVD) differs from those for left ventricular dysfunction. However, evidence regarding optimal hemodynamics and prognostic predictors of RVD remains limited, highlighting the need for further investigation.
Research Questions: What is the optimal hemodynamic status to increase cardiac output and what are the prognostic predictors in patients with right ventricular dysfunction?
Methods: This retrospective, single-center cohort study was conducted between 2014 and 2024. We analyzed data from patients diagnosed with RVD, defined as pulmonary artery pulse index ([sPAP–dPAP]/RAP) <1.85 and RAP/PAWP >0.63 based on right heart catheterization (RHC). Patients with left ventricular ejection fraction <50% were excluded. Two sub-studies were conducted: Study A assessed the relationship between cardiac index and hemodynamic parameters derived from RHC, and Study B investigated the prognostic value of hemodynamic parameters associated with RVD. The primary outcome in Study B was a composite of all-cause death and heart failure hospitalization.
Results: A total of 210 RHC examinations from 162 patients (median age 69 years) were analyzed. In Study A, a higher RAP was associated with increased cardiac output up to approximately 12 mmHg, beyond which further increases in RAP were associated with a decline in output, although the nonlinearity was not statistically significant. A higher heart rate was significantly associated with an increased cardiac output in patients with sinus rhythm, with a peak effect of approximately 80 bpm. In patients with atrial fibrillation, cardiac output increased steadily with rising heart rate. In Study B, 34 patients experienced the primary outcome during a median follow-up period of 505 days. Patients who experienced the primary outcome had higher heart rate, PAWP, and RAP, as well as a lower pulmonary artery compliance (PAC: stroke volume/[sPAP–dPAP]). Kaplan–Meier analysis demonstrated that PAC ≤ 4.5 mL/mmHg (median, p=0.02) and RAP > 10 mmHg (median, p=0.01) were associated with worse outcomes. In Cox proportional hazards analysis, PAC ≤ 4.5 mL/mmHg (HR 2.37; p=0.02) and RAP > 10 mmHg (HR 2.43; p=0.02) independently predicted the primary outcome after adjusting for age and sex.
Conclusions: In patients with RVD, optimal preload and heart rate contributed to increased cardiac output. Low PAC and high RAP were independent predictors of cardiac events in this population.