Impact of plasma volume redistribution on outcomes in patients with heart failure with reduced ejection fraction

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Abstract Funding Acknowledgements Type of funding sources: None. Background The impact of capacitance and blood volume redistribution on outcomes of patients with chronic heart failure is incompletely understood. Quantitative plasma volume (PV) measurements together with echocardiographic evaluation allow a comprehensive assessment of the interplay between volumetric overload, cardiac chamber remodelling and myocardial function. Purpose We hypothesize that PV expansion is associated with myocardial and renal dysfunction, right ventricular-pulmonary arterial uncoupling and unfavorable outcomes in HF patients with reduced ejection fraction (HFrEF). Methods Patients hospitalized at Mayo Clinic with decompensated HF and who had PV by the indicator-dilution nuclear methodology (Daxor BVA100) were included. Patients were considered hypervolemic if BV was ≥25% over expected. The primary endpoint was the composite of all-cause mortality or heart transplantation. The closest TTE to the time of PV was used to measure various indexes of myocardial performance (standard echo parameters and global chamber-specific strain parameters). Event-free survival was estimated using the Kaplan-Meier method. The relationship between PV and various parameters was evaluated with correlation coefficient (r²). Results A total of 65 patients were enrolled in the study. Reduced LVEF was present in 53 (81.6%) patients. There were 44 events (32 deaths, 12 heart transplants) after a median follow-up of 43 months (IQR 14–65). Results in patients with HFrEF are presented in the Table. Our main findings were: 1) PV expansion was associated with an increased risk of adverse events (Figure 1); 2) Volume redistribution correlated with various indexes of cardiac chamber function, suggesting that volume overload and associated cardiac remodeling may be responsible for altered myocardial mechanics in patients with HFrEF (Figure 2); 3) right ventricular-pulmonary arterial uncoupling was triggered by the plasma volume expansion, that causes postcapillary pulmonary hypertension; 4) PV redistribution was also associated with renal dysfunction and increasing the level of the protein catabolism (Table 1). Conclusion Expansion of plasma volume in HFrEF patients is associated with left atrium dilatation, abnormal filling of both atria and right ventricular dilatation / dysfunction. Plasma volume redistributions apparently became a trigger of right ventricular-pulmonary arterial uncoupling and stimulated postcapillary pulmonary hypertension, renal dysfunction with increasing the level of protein catabolism and unfavorable outcomes.