Hemodynamic effects of standard versus larger-capacity intraaortic balloon counterpulsation pumps

Several recent trials have examined the clinical utility of intraaortic balloon counterpulsation pumps (IABPs) in cardiogenic shock and acute coronary syndromes. More recently, a larger-capacity 50 cc IABP was introduced into practice. No data comparing the hemodynamic effects of the 40 cc vs 50 cc IABP exist. Our aim was to explore the hemodynamic effects of the 50 cc IABP in real-world clinical practice.

Demographic, hemodynamic, and laboratory data were retrospectively examined in 26 consecutive subjects treated with a 50 cc IABP and compared with 26 patients receiving a 40 cc IABP between 2012 and 2013. IABP tracings were analyzed within 24 hours of implantation in all patients. Pulmonary artery catheter data were available before and after IABP implantation in 20 subjects.

Baseline demographics, including body surface area, were similar between groups. Compared with the 40 cc IABP group, 50 cc IABP recipients showed higher augmented diastolic blood pressure, greater systolic unloading, and a larger reduction in pulmonary capillary occlusion pressure (PCOP). Percent diastolic augmentation was higher among 50 cc IABP recipients. Only 58% of subjects achieved <10 mm Hg of systolic unloading in the 40 cc group compared with 27% in the 50 cc group. For both the 40 cc and 50 cc IABPs, the magnitude of systolic unloading correlated inversely with PCOP and directly with the magnitude of diastolic augmentation.

In real-world practice, greater systolic unloading and diastolic augmentation were observed among 50 cc vs 40 cc IABP recipients. Future trials evaluating the clinical utility of the 50 cc IABP are required.