Left Ventricular Unloading Using Intra-Aortic Entrainment Pumping Before Reperfusion Reduces Post-AMI Infarct Size.

BACKGROUND: Anterior myocardial infarction standard of care prioritizes swift coronary reperfusion. Recent studies show left ventricular (LV) unloading with transvalvular axial-flow pumps for 30 minutes before reperfusion (versus immediate reperfusion) reduces 28-day infarct size. Intra-aortic entrainment pumping, using hardware located away from the heart to provide support throughout the cardiac cycle, reduce effective systemic vascular resistance, and augment visceral blood flow and pressure, may reproduce this benefit with reduced risk. This study characterized hemodynamic effects of unloading before and during reperfusion using intra-aortic entrainment pumping and investigated whether unloading reduced anterior myocardial infarction (AMI) scar size. METHODS AND RESULTS: Yorkshire swine were subjected to 90 minutes of left anterior descending artery balloon occlusion and randomly assigned to immediate reperfusion (n=6) versus 30 minutes unloading before reperfusion followed by 120 minutes further unloading (n=7). Unloading was achieved using percutaneous entrainment pumping in the descending aorta. The AMI model matches that used in recent transvalvular pumping studies. Mortality before randomization was 22%. After randomization, mortality was 36% for immediate reperfusion and 0% for unloading. Unloading showed immediate hemodynamic benefit that increased through reperfusion and continued support, leading to distinct differences in cardiac function between groups after 30 minutes of reperfusion. Unloading increased stroke volume and cardiac efficiency at this timepoint relative to pre-occlusion baseline and reduced 28-day LV scar size by 37-45%. CONCLUSIONS: We present the first preclinical data showing extra-cardiac LV unloading before coronary reperfusion using intra-aortic entrainment pumping decreases 28-day infarct size. Extra-cardiac unloading to reduce LV scar size may provide an alternative to transvalvular pumping with potential advantages including reduced risk.

Safety and Performance of the Aortix Device in Acute Decompensated Heart Failure and Cardiorenal Syndrome.

BACKGROUND: Cardiorenal syndrome (CRS) complicates 33% of acute decompensated heart failure (ADHF) admissions, and patients with persistent congestion at discharge have high 30-day event rates. OBJECTIVES: The purpose of this study was to evaluate a novel catheter-deployed intra-aortic entrainment pump (IAEP) in patients with ADHF with CRS and persistent congestion. METHODS: A multicenter (n = 14), nonrandomized, single-arm, safety and feasibility study of IAEP therapy was conducted. Within patient changes (post-pre IAEP therapy) in fluid loss, hemodynamics, patient-reported dyspnea, and serum biomarkers were assessed using Wilcoxon signed-rank testing. RESULTS: Of 21 enrolled patients, 18 received Aortix therapy. Mean ± SD patient age was 60.3 ± 7.9 years. The median left ventricular ejection fraction was 22.5% (25th-75th percentile: 10.0%-53.5%); 27.8% had a left ventricular ejection fraction ≥50%. Pre-therapy, patients received 8.7 ± 4.1 days of loop diuretic agents and 44% were on inotropes. Pump therapy averaged 4.6 ± 1.6 days, yielding net fluid losses of 10.7 ± 6.5 L (P < 0.001) and significant (P < 0.01) reductions in central venous pressure (change from baseline: -8.5 mm Hg [25th-75th percentile: -3.5 to -10.0 mm Hg]), pulmonary capillary wedge pressure (-11.0 mm Hg [25th-75th percentile: -5.0 to -14.0 mm Hg]), and serum creatinine (-0.2 mg/dL [25th-75th percentile: -0.1 to -0.5 mg/dL]) with improved estimated glomerular filtration rate (+5.0 mL/min/1.73 m2 [25th-75th percentile: 2.0-9.0 mL/min/1.73 m2]) and patient-reported dyspnea score (+16 [25th-75th percentile: 3-37]). Dyspnea scores, natriuretic peptides, and renal function improvements persisted through 30 days. CONCLUSIONS: This pilot study of patients with ADHF, persistent congestion, and worsening renal function due to CRS supports the potential for safely achieving decongestion using IAEP therapy. These initial promising results provide the basis for future randomized clinical trials of this novel pump. (An Evaluation of the Safety and Performance of the Aortix System for Intra-Aortic Mechanical Circulatory Support in Patients with Cardiorenal Syndrome [The Aortix CRS Pilot Study]; NCT04145635).

Improved hemodynamics with a novel miniaturized intra-aortic axial flow pump in a porcine model of acute left ventricular dysfunction.

Currently, long-term mechanical circulatory support (MCS) is limited to large, complex devices that require invasive, high-risk surgical implantation. These devices are mainly used in patients with late stage heart failure (HF). We are developing a novel percutaneous intra-aortic micro-axial fluid entrainment pump intended for long-term MCS in patients with earlier stage HF. This study examined the pump's hemodynamic effects in a porcine model of acute HF. In three porcine experiments, the pump was deployed in the thoracic aorta by standard cardiac catheterization techniques and was anchored with self-expanding struts. Acute cardiac dysfunction was induced by infusing esmolol continuously. Pump support increased cardiac output (+10.4%), stroke volume (+8.9%), and ejection fraction (+10.8%) while decreasing cardiac stroke work (-10.8%) and afterload (-22.7%). Furthermore, pump support significantly enhanced renal perfusion through sustained increases in both renal artery flow (+36.4%) and pressure (+73.6%). In a porcine model of acute HF, the catheter-based intra-aortic fluid entrainment pump improved hemodynamics and renal perfusion. These results suggest that the pump could improve HF outcomes and patients' quality of life by resting the heart, promoting reverse remodeling, and augmenting end-organ perfusion. Furthermore, the enhanced renal perfusion may help disrupt the cardiorenal syndrome cycle and improve HF treatment.