AUGMENTATION OF CORONARY BLOOD-FLOW BY INTRAAORTIC BALLOON PUMPING IN PATIENTS AFTER CORONARY ANGIOPLASTY

Background. Controversy exists regarding the ability of intra-aortic balloon pumping to increase coronary blood flow in patients with obstructive coronary artery disease. To assess the effects of intra-aortic balloon pumping on coronary hemodynamics, we measured coronary blood flow velocity with a 0.018-in. Doppler-tipped angioplasty guide wire in 15 patients who received an intra-aortic balloon pump for typical clinical indications. Methods and Results. Intra-aortic balloon pumping augmented diastolic pressure 83+/-35%. In nine patients before angioplasty, peak diastolic coronary flow velocity beyond the stenosis (mean diameter narrowing, 95+/-7%) was 5.3+/-9.6 cm/sec and was unaffected by intra-aortic balloon pumping. After angioplasty, the improved coronary luminal diameter narrowing (n=12; mean narrowing, 18+/-12%) was associated with increased distal diastolic flow velocity integral and peak diastolic and mean velocities (13.3+/-8.4 units: 36.4+/-18.3 and 24.0+/-11.4 cm/sec, respectively; all p<0.01 versus before angioplasty), which were further augmented (36+/-37%, 54+/-49%, and 26+/-17%, respectively; all p<0.01) with intra-aortic balloon pumping. Intra-aortic balloon pumping did not significantly increase the distal systolic velocity integral (10+/-59%) or peak systolic velocity (3+/-33%). Similar degrees of balloon pump augmentation of distal coronary flow velocity values were observed in five angiographically normal reference arteries in four patients. Conclusions. These data demonstrate lack of significant flow improvement beyond most critical stenoses with intra-aortic balloon pumping and the unequivocal restoration and intra-aortic balloon pump-mediated augmentation of both proximal and distal coronary blood flow velocities after amelioration of severe coronary obstructions in patients after successful coronary angioplasty.