Left ventricular support by catheter-mounted axial flow pump reduces infarct size.
OBJECTIVE
We sought to investigate the effect of a catheter-mounted microaxial blood pump (Impella, Aachen, Germany) on myocardial infarct size.


BACKGROUND
The small rotary blood pump Impella provides unloading of the left ventricle and is introducible via the femoral artery.


METHODS
Myocardial infarction was induced by occlusion of major branches of the left anterior descending coronary artery for 60 min followed by 120 min of reperfusion in 26 sheep. The animals were allocated to four groups: group 1 had no support; group 2 was fully supported with the pump during ischemia and reperfusion; group 3 was supported during reperfusion only; and group 4 was partially supported during reperfusion. Infarct size, hemodynamics, myocardial oxygen consumption, lactate extraction, and myocardial flow were analyzed.


RESULTS
Infarct size was significantly reduced in the pump-supported animals (percent area at risk in group 1: 67.2 +/- 4.6%; group 2: 18.1 +/- 10%; group 3: 41.6 +/- 5.8%; group 4: 54 +/- 8%; p = 0.00001). The pump produced 4.1 +/- 0.1 l/min at full support and 2.4 +/- 0.1 l/min at partial support. The pump significantly increased the diastolic and mean blood pressures (groups 2, 3, and 4) and significantly decreased the left ventricular end-diastolic pressure (groups 2 and 3). During ischemia, myocardial flow was not influenced by pump support. At reperfusion, the fully supported group had significantly higher myocardial flow. Pump support reduced myocardial oxygen consumption significantly, and this reduction correlates strongly with the reduction in infarct size (r = 0.9).


CONCLUSIONS
Support by a microaxial blood pump reduces myocardial oxygen consumption during ischemia and reperfusion and leads to a reduction of infarct size. This reduction in infarct size correlates with the degree of unloading during reperfusion.
Meyns
Bart
B
Center for Experimental Surgery and Anesthesiology, Cardiovascular Research Unit, Catholic University of Leuven (KUL), Leuven, Belgium. Bart.Meyns@uz.kuleuven.ac.be
Stolinski
Jarek
J
Leunens
Veerle
V
Verbeken
Erik
E
Flameng
Willem
W
D000818:Animals; D001784:Blood Gas Analysis; D001794:Blood Pressure / Q000502:physiology; D002302:Cardiac Output / Q000502:physiology; D006348:Cardiac Surgical Procedures / Q000379:methods; D004195:Disease Models, Animal; D006339:Heart Rate / Q000502:physiology; D006352:Heart Ventricles / Q000503:physiopathology* / Q000601:surgery; D006353:Heart-Assist Devices; D019344:Lactic Acid / Q000097:blood; D009203:Myocardial Infarction / Q000097:blood / Q000503:physiopathology / Q000628:therapy*; D015425:Myocardial Reperfusion / Q000295:instrumentation / Q000379:methods*; D010101:Oxygen Consumption / Q000502:physiology; D012756:Sheep; D016896:Treatment Outcome; D016277:Ventricular Function, Left / Q000502:physiology
D019344:Lactic Acid