Background: Congestion is a major determinant of clinical outcomes in heart failure (HF). Diuretics, ultrafiltration, inotropes or vasodilators have not improved clinical outcomes. We recently reported that short-term superior vena cava (SVC) occlusion rapidly reduces cardiac filling pressures and maintains cardiac output and systemic pressure in patients with HF. The preCARDIA system is a catheter-mounted SVC occlusion balloon and controller capable of intermittently occluding the SVC over prolonged periods of time. We tested the haemodynamic effects of the preCARDIA system in a swine model of congestive HF.
Methods: We employed a model of post-acute MI HF. The preCARDIA device was introduced and activated to occlude the SVC for 5 minutes, followed by 30 seconds of balloon collapse for 18 hours total.
Results: Device insertion and activation was successful in all three pigs. At 6, 12 and 18 hours after initiation of SVC therapy, right internal jugular venous pressure increased; right atrial, pulmonary capillary wedge and mean pulmonary artery pressures decreased, while cardiac output remained unchanged. The mean arterial pressure remained above 60 mmHg during SVC therapy. Gross and histologic pathology showed no evidence of increased cerebral or ocular oedema, no pulmonary emboli or cardiac damage and no evidence of SVC damage or thrombosis due to the preCARDIA device.
Conclusion: Intermittent SVC occlusion with the preCARDIA system is a novel approach to mechanically reduce biventricular pressures while maintaining cardiac output in the setting of HF. The SVC Occlusion in Subjects With Acute Decompensated Heart Failure (VENUS-HF) trial will test the safety and feasibility of the preCARDIA device in patients with HF.