Background: Previous studies indicate that superimposing incremental continuous flow on pulsatile aortic flow (aortic flow therapy, AFT) yields an increase in cardiac output. This study examined whether improvement in this hemodynamic index is independent of changes in loading conditions and represents an improvement in cardiac performance.
Methods: The Multi-center Trial of Orqis Medical Cancion System for Enhanced Treatment of Heart Failure (HF) Unresponsive to Medical Therapy (MOMENTUM) was a randomized trial comparing AFT plus medical therapy (n = 109) vs medical therapy alone (n = 59) in patients hospitalized with HF inadequately responsive to therapy. Entry required reduced left ventricular ejection fraction (LVEF) and cardiac index, elevated pulmonary capillary wedge pressure (PCWP), and impaired renal function or high diuretic requirement despite intravenous inotrope or vasodilator treatment. AFT was achieved for up to 96 hours using an arterial-to-arterial circuit (flow up to 1.5 liters/min). Changes in cardiac performance were assessed using the relationship between cardiac index (CI) or stroke work (SW = stroke volume x [Mean blood pressure - PCWP] x 0.00133, kg.cm) and PCWP.
Results: In the control group, a decrease in PCWP was accompanied by a decline in SW from 3.2 +/- 1.4 at baseline to 2.7 +/- 0.9 kg.cm at 4 days. AFT increased SW (from 3.0 +/- 1.6 at baseline to 3.3 +/- 1.7 kg.cm at 4 days; p < 0.0001) and decreased PCWP. An upward-leftward shift occurred in the SW vs PCWP relationship in the AFT group.
Conclusions: AFT resulted in a progressive upward-leftward shift in the SW-PCWP relation compared with the control group, demonstrating improvement in cardiac performance independent of load-related effects.
Trial registration: ClinicalTrials.gov NCT00357591.
Copyright (c) 2010 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.