Association of thrombocytopenia with the use of intra-aortic balloon pumps

Abstract

Purpose: The intra-aortic balloon pump has become an important tool in the management of patients with severe coronary artery disease. Although pump-induced thrombocytopenia was described more than 20 years ago, there has been no prospective study of this condition. Patients and Methods: In a prospective study of consecutive adult intensive care patients admitted with acute coronary syndromes, we compared serial platelet counts in 58 patients treated with an intra-aortic balloon pump with 51 patients who were not. All patients received intravenous heparin. Results: Clinical characteristics of the two groups were similar, except that unstable angina was more frequent among balloon pump patients. On each of 6 consecutive days, the mean platelet counts of patients treated with a balloon pump were significantly lower than those of non-pump patients. Platelet counts (mean ± SD) of balloon pump patients decreased to a nadir of 63% ± 4% of the initial count on day 4, but subsequently stabilized. There was only a slight, transient decrease in the platelet counts of non-pump patients. Overall, 47% of balloon pump patients developed thrombocytopenia (platelet count <150,000/mm 3) compared with 12% of non-pump patients ( P <0.01). Platelet counts dropped by at least half of initial counts in 26% of balloon pump patients compared with 4% of non-pump patients ( P <0.01). Multivariate analysis demonstrated that the use of an intra-aortic balloon pump was independently associated with a substantial (≥50%) decline in platelet count (odds ratio 7.2, 95% confidence interval 1.4 to 40, P = 0.03). Removal of the balloon pump was associated with a rapid increase in platelet count. Conclusions: The use of an intra-aortic balloon pump led to a steady and predictable decrease in platelet count, which recovered rapidly if the balloon pump was removed or slowly if the device remained in place.