Heparin-Induced Thrombocytopenia in Patients Undergoing Valvular and Aortic Surgery: A Modern Assessment of Risk

Objective: The incidence and outcomes of patients with heparin-induced thrombocytopenia (HIT) are well defined for general cardiac surgical populations. The purpose of this study was to define the outcomes of patients with HIT in a population excluding patients who underwent coronary artery bypass grafting (CABG). Methods: The local Society of Thoracic Surgeons cardiac surgical database was queried between January 2008 and May 2017 for patients who underwent either open valvular surgery or aortic surgery. Patients who underwent either isolated or combined CABG procedures were excluded. Cohorts were formed based on the presence or absence of postoperative HIT. Logistic regression models were built to determine the association between postoperative HIT and outcomes, adjusted for both preoperative and intraoperative variables. Results: Of the total cohort (8,107 patients), 176 patients (2.2%) developed HIT after surgery. HIT patients experienced an increased incidence of morbidities postoperatively, including reoperation for bleeding, reoperation for cardiac and noncardiac etiologies, postoperative stroke, perioperative myocardial infarction, postoperative sternal infection, postoperative arrhythmia, new-onset renal failure, and dialysis (all with P < 0.01). The unadjusted 30-day mortality was 14.8% in HIT patients vs 4.9% in those without HIT (P < 0.01). After risk adjustment, reoperation for noncardiac events, renal failure, new dialysis, postoperative stroke, arrhythmia, and sternal wound infection remained significantly elevated in patients who developed postoperative HIT. Conclusions: Patients who developed HIT after non-CABG cardiac surgery experienced increased postoperative rates of morbidity and mortality. Early diagnosis and treatment remained mainstays of therapy. Early identification of patients at highest risk should prompt careful risk stratification when possible.