Background: Intra-aortic balloon pumps (IABP) frequently are used to provide hemodynamic support during high risk percutaneous coronary intervention (PCI), but clinical evidence to support their use is mixed. We examined hospital variation in IABP use among high risk PCI patients, and determined the association of IABP use on mortality in this population.
Methods and results: We analyzed data submitted to the CathPCI Registry between January 2005 and December 2007. High risk PCI was defined as having at least 1 of the following features: unprotected left main artery as the target vessel, cardiogenic shock, severely depressed left ventricular function, or ST segment elevation myocardial infarction. Hospitals were categorized into quartiles by their proportional use of IABP. We examined differences in in-hospital mortality across hospital quartiles using a hierarchical logistic regression model to adjust for differences in patient and hospital characteristics across hospital quartiles of IABP use. IABPs were used in 18,990 (10.5%) of 181,599 high risk PCIs. Proportional use of IABP varied significantly across hospital quartiles: Q1, 0.0 to 6.5%; Q2, 6.6 to 9.2%; Q3, 9.3 to 14.1%; Q4, 14.2 to 40.0%. In multivariable analysis, after adjustment for differences in patient and hospital characteristics, in-hospital mortality was comparable across quartiles of hospital IABP usage (Q1, Ref; Q2, odds ratio 1.11, 95% CI 0.99-1.24; Q3, OR 1.03, 95% CI 0.92-1.15; Q4, OR 1.06, 95% CI 0.94-1.18).
Conclusions: IABP use varied significantly across hospitals for high risk PCI. However, this variation in IABP use was not associated with differences in in-hospital mortality.