Abstract 19697: Left Ventricular Unloading by Impella® Microaxial Flow Pump for Treatment of Left Ventricular Overload in Venoarterial Ecmo Supported Cardiogenic Shock Patients

Abstract

Background Venoarterial (VA)-ECMO is an established support for refractory cardiogenic shock (CS), but may be complicated by an increase of cardiac afterload leading to left ventricular (LV) distension with consecutive pulmonary edema and deterioration of left ventricular function. Methods VA-ECMO was instituted in patients with refractory CS of different etiology. Progressive LV overload was detected by clinical signs of pulmonary edema and critical elevated LV end diastolic pressure (LVEDP). LV unloading by Impella ® 2.5 via femoral access was established. Patients were followed up for heart rate, catecholamine demand, white blood cell count (WBC) and serum lactate levels before and after 24 hours (h). Fatal bleeding complications, signs of limb ischemia and 28-day mortality were assessed. Data are presented as mean±SD. Results Six patients, SAPS II-Score on admission 56±15, age 61±18 yrs are presented. Three MI patients complicated with refractory CS. One patient with myocarditis, one due to acute heart failure complicated by septic shock and one due to acute heart transplant rejection. Five/6 patients were on mechanical ventilation and all showed clinical and radiologic signs of pulmonary edema (LVEDP before LV unloading 35±15 mmHg). Under Impella ® support (5±2 days) heart rate decreased after 24 h from 120±15 to 104±20/min. After 24h catecholamine demand decreased (dobutamine and epinephrine p=n.s.; norepinephrine 0.44±0.38 to 0.20±0.19 µg/kg/min, p=0.04). Serum lactate levels declined from 5.5±4.8 to 2.5±1 mmol/l at 24 h and 1.3±0.3 mmol/l at 72 h. WBC declined from 22±6 to 18±6 thd/µl (p=0.004) after 24 h. No fatal bleeding complications or limb ischemia occurred. 28-day mortality was 17 %. One patient with myocarditis died in multiorgan failure. Conclusion VA-ECMO treatment of CS complicated by LV overload can safely and efficiently be treated by LV unloading using microaxial flow pump Impella ® 2.5. This biventricular decompression rapidly reduces catecholamine demand and lactate levels indicating an improved organ function followed by a resolution of SIRS due to cardiac shock (reduced WBC).