Thrombocytopenia After Transcatheter Valve-in-Valve Implantation: Prognostic Marker or Mere Finding?

Positive Heparin/PF4 Antibodies and High Mortality Rate: a Retrospective Case-Series Analysis

Introduction

Heparin-induced thrombocytopenia (HIT) is a potentially lethal complication of unfractionated or low-molecular weight heparin therapy. We aimed to determine the incidence and mortality rate of patients with positive heparin/platelet factor 4 (PF4) antibodies, which is a rapid detection test of HIT.

Methods

Coronary artery bypass grafting and mitral and aortic valve surgeries were evaluated. Cardiopulmonary bypass was employed in all patients. The diagnosis of HIT was based on immunological assays. Postoperative complications, mortality rates, and the causes of death were specified in patients with positive heparin/PF4 antibodies.

Results

Postoperative thrombocytopenia was detected in 257 patients. Twenty of these patients undergoing open heart surgery were included in the final analysis. Antibodies against heparin/PF4 complex were positive in 20 patients. The mean body mass index was 28.8±2.3 kg/m², mean value of left ventricular ejection fraction was 48.3±6.7%, cardiopulmonary bypass time was 113.0±35.0 min, aortic cross-clamping time was 88.0±32.7 min, mean intensive care unit length of stay was 10.9±4.9 days, mean preoperative platelet count was 307.250±88528 platelets/microliter, and mean postoperative platelet count was 243.050±89.354 platelets/microliter. The mean duration of heparin exposure was 6.9±2.9 days. The mortality rate was 45% (nine patients) and 1.2% (three patients) in heparin/PF4 complex positive and negative patients, respectively.

Conclusion

Although the incidence of HIT was low in patients undergoing open heart surgery, an increased rate of early mortality was observed in patients with positive heparin/PF4 antibodies.

Impact of chronic thrombocytopenia on in-hospital outcomes and healthcare resource utilization after transcatheter aortic valve replacement

BACKGROUND

There is little data on the impact of chronic thrombocytopenia (CTP) on outcomes after transcatheter aortic valve repair (TAVR). Most studies are from single centers and mostly focused on postprocedure thrombocytopenia.

OBJECTIVES

This study sought to report on the impact of CTP (>1 year) on in-hospital outcomes and healthcare resource utilization after TAVR.

METHODS

From the National Inpatient Sample (NIS) between 2012 and 2015, we identified patients with CTP who underwent TAVR. A 1:1 propensity-matched cohort was created to examine in-hospital outcomes in patients with and without CTP. The primary outcome was in-hospital mortality. Secondary outcomes included postprocedure complications, length of stay, total cost, and discharge disposition.

RESULTS

A matched pair of 4,300 patients with and without CTP were identified. Patients with CTP had higher in-hospital mortality as compared to no CTP patients (6.0 vs. 3.3%, p-value .007), increased postprocedure hemorrhage, platelet and blood transfusion, vascular complications, postop sepsis, and acute kidney injury. With regards to resource utilization, CTP patients had a longer length of stay, higher total cost and were more likely to be discharged to a facility (34.1 vs. 27.6%) other than home (All, p-value <.001). Subanalysis, however, revealed this difference in resource utilization was seen when patients developed postprocedure complications.

CONCLUSION

This study demonstrated higher risk of in-hospital mortality, perioperative complications, and healthcare resource utilization in patients with baseline CTP undergoing TAVR. Further studies are required to investigate ways to improve the management of these patients.