Right Ventricular End-Diastolic Pressure Is a Key to the Changes in Cardiac Output During Adaptive Servo-Ventilation Support in Patients With Heart Failure

Adaptive servo-ventilation (ASV) is a recently-developed non-invasive therapy that improves the clinical course of heart failure (HF) patients. However, the precise hemodynamic response and predictors of ASV therapy remain uncertain. Overall, 69 patients with New York Heart Association HF class II-IV underwent 10-minute ASV testing along with hemodynamic studies. Among them, 21 (30%) achieved an acute response, which was defined as an increase in the cardiac index (CI) during ASV. ΔLeft ventricular end-diastolic pressure (LVEDP) did not correlate with ΔCI, whereas Δtransmural LVEDP, which was calculated by subtracting right ventricular end-diastolic pressure (RVEDP) from LVEDP, and ΔCI were positively correlated, similar to the ascending limb of Frank-Starling's law (P = 0.009, r = 0.311). Among baseline data, higher RVEDP and higher LVEDP were significant predictors of an acute response by logistic regression analyses (P < 0.05 for both). RVEDP had a significantly higher area under the curve than LVEDP in the receiver operating characteristic analyses (0.846 versus 0.673, P = 0.028). Higher baseline RVEDP was significantly associated with a greater decrease in RVEDP during ASV (P < 0.001, r = -0.604). In conclusion, in HF patients with elevated RVEDP, ASV increased cardiac output through a decrease in RVEDP and an increase in transmural LVEDP, according to the ascending limb of Frank-Starling's law.