Initial experience with the Impella Recover LP 2.5 micro-axial pump in patients undergoing high-risk coronary angioplasty.

INTRODUCTION: The Impella LP 2.5 device is a new percutaneous left ventricular assist device, an intravascular micro-axial blood pump designed for short term circulatory support in conditions characterized by profoundly reduced ventricular function. Percutaneous coronary intervention (PCI) is increasingly being used in patients who have severely compromised left ventricular contractility and complex coronary lesions, including multivessel disease.

METHODS: Three patients (pts) underwent elective PCI with the use of the Impella system. All were very poor candidates for surgery because of severe comorbidities, with mean logistic EuroSCORE 39.3%. Echocardiography was used to rule out anatomical contraindications before implantation of the device. All pts had previous myocardial infarctions and impaired left ventricular (LV) function with LV ejection fraction <25-30%. We evaluated the effects of the pump on cardiac output, mean pulmonary wedge pressure and mean blood pressure, using right heart catheterization. We also assessed hemoglobin, cardiac enzymes (CK, CKMB and troponin), creatinine and NT-proBNP levels before and the day after the intervention.

RESULTS: The procedure was uncomplicated, without any acute, device-related adverse events during LV support. The Impella was used for a mean time of 9.3 hours (range 2 to 24 hours) and was removed immediately after the intervention in all but one patient. The device did not induce or increase aortic valve regurgitation. Two pts needed pharmacologic inotropic support during the procedure. Mean blood pressure increased in all 3 pts without pulmonary wedge pressure reduction, presumably due to a combination of pump function and PCI-induced ischemia. The mean drop in hemoglobin levels was 1.7 g/dl. The mean increase in creatinine levels due to contrast was 1 mg/dl. NT-proBNP showed a variable response. Two pts remained stable at follow up and one expired one month later due to worsening heart failure.

CONCLUSIONS: The growing heart failure population and the benefit of revascularization in patients with severe LV dysfunction have led to an increase in the number of mechanically assisted percutaneous coronary interventions. Circulatory support with the Impella LP 2.5 pump during high risk PCI is feasible, but larger studies are required to demonstrate its efficacy in these severely compromised and vulnerable patients.