Effect of intra-aortic balloon pump support on microcirculation during high-risk percutaneous intervention.

Background: Intra-aortic balloon counter-pulsation (IABP) is recommended for hemodynamic support in cardiogenic shock. In addition, it can be applied during high-risk percutaneous interventions (PCI). While IABP support improves microflow in cardiogenic shock, its effect in hemodynamically stable patients is still unclear. We, therefore, sought to evaluate the effect of IABP treatment on microflow in hemodynamically stable patients undergoing elective high-risk PCI.

Methods: In six patients with >50% left main stenosis, microflow was evaluated according to current guidelines, using side-stream dark-field microscopy, visualizing microcirculatory vessels without using fluorescent dyes. Microflow was analyzed separately for each vessel category (diameter: 10-25microm and 26-50microm), using a semiquantitative system (0= no flow; 1= intermittent flow; 2= sluggish flow; 3= continuous flow) by a trained investigator. Steady state recordings and additional recordings twenty seconds after discontinuation of the electively implanted IABP were acquired.

Results: Microflow in vessel categories 10-25microm and 26-50microm increased in this group of hemodynamically stable patients on use of IABP. Microflow decreased from 2.73 + or - 0.39 (p=0.052; 26-50microm: 2.88 + or - 0.20, p=0.008) to 2.22 + or - 0.23 (2.18 + or - 0.45) after stopping the IABP and increased to 2.90 + or - 0.14 (p=0.009; 2.85 + or - 0.28, p=0.009) after restart of the IABP.

Conclusions: Circulatory support with IABP increases microcirculatory flow in the smallest vessels of the sublingual mucosa. Our data support the hypothesis that intra-aortic balloon counter-pulsation increases coronary and microvascular perfusion, thus, improving microcirculation even in hemodynamically stable patients. The use of IABP may increase safety of complex PCI and decrease the risk of deleterious complications.