Postoperative Heparin-induced Thrombocytopenia Research Articles

A Modified 4Ts Score for Heparin-Induced Thrombocytopenia in the Mechanical Circulatory Support Population

To identify risk factors and develop a pretest scoring system to differentiate patients with heparin-induced thrombocytopenia (HIT) in the mechanical circulatory support (MCS) population. The authors present a modified "4TMCS" scoring system, which considers the "type of mechanical circulatory support" that may help identify patients at risk for developing postoperative HIT. A retrospective cohort study. Patients who underwent cardiac surgery were categorized into 3 groups: (1) normal platelet count, (2) thrombocytopenia with a negative HIT test, and (3) thrombocytopenia with a positive HIT test. A comparison of diagnostic accuracy between the 4Ts and 4TMCS probability scores was performed. At a single adult tertiary-care center. A total of 5,314 patients who underwent cardiac surgery between May 1, 2008 and December 31, 2016. None. In total, 125 out of 5,314 patients (2.4%) were diagnosed with HIT, of whom 75 out of 5,314 (1.4%) had clinical evidence of thrombosis. Overall, in-hospital mortality was 25.6%, 11.7%, and 1.5% in the HIT(+), HIT(-), and control groups, respectively (p < 0.001). Mechanical circulatory support was associated with a significantly increased risk for HIT, with an incidence of 5.9% in patients receiving MCS versus 1.9% in those without (p < 0.001). Area under the receiver operator curve (AUC) analysis demonstrated improved diagnostic accuracy of the 4TMCS score compared with the 4Ts (AUC=0.83 v 0.77, p < 0.044). The 4TMCS score had higher sensitivity than the 4Ts, using the guideline-recommended score cutoff of ≥4 (95.2% v 85.7%). Heparin-induced thrombocytopenia is associated with worse outcomes and increased morbidity and mortality in the MCS population. Awareness of patient risk factors and the application of a modified 4TMCS probability score may allow for more accurate screening and treatment of HIT in the MCS population.

Heparin-Induced Thrombocytopenia After Cardiac Surgery—A Statewide Review of Health Care Utilization

BackgroundDespite its severe consequences, clinical and economic impacts of heparin-induced thrombocytopenia (HIT) after cardiac operations have not been well characterized. This study assessed statewide incidence, outcomes, and resource consumption associated with HIT after cardiac operations. MethodsThis was a retrospective investigation of cardiac surgery patients using the Maryland Health Services Cost Review Commission’s database from 2012 to 2020. Health care costs, utilization, and outcomes for those who experienced postoperative HIT were compared with propensity score–matched controls. ResultsOf 33 583 cardiac surgery patients, 184 (0.55%) were diagnosed with postoperative HIT. Compared with non-HIT patients, HIT patients were significantly more likely to be in the oldest age group (>80 years; P < .001) and to have greater severity of illness at admission (P < .001). HIT was associated with a longer hospitalization (21 vs 7 days; P < .001), greater mortality (13.6% vs 2.3%; P < .001), and greater hospital charges ($123 160 vs $45 303; P < .001), even after propensity score matching. Readmission rates were not significantly different, however, and readmission hospital charges did not significantly differ between HIT and non-HIT patients. ConclusionsIn addition to worse outcomes, HIT was associated with higher costs during index admissions but not during readmissions of cardiac surgery patients. Strategies to minimize HIT could yield better outcomes and reduced costs, particularly relevant for health care systems seeking improved value-based care while reducing unnecessary hospitalizations.

A Modified 4Ts Score for Heparin-Induced Thrombocytopenia in the Mechanical Circulatory Support Population

Purpose Patients undergoing cardiac surgery are at increased risk for heparin-induced thrombocytopenia (HIT). The aim of this study was to identify risk factors and assess the morbidity and mortality associated with HIT in the mechanical circulatory support population. We present a modified “4TMCS” scoring system for this population of patients. MCS represents a “definite” cause of thrombocytopenia and the proposed 4TMCS score replaces the other causes category with “Type of mechanical circulatory support”. Methods We performed analysis of patients who underwent cardiac surgery at Stanford University Medical Center between May 1, 2008 and December 31, 2016. Patients were categorized into three groups: 1) Control, patients with normal post-operative platelet count; 2) HIT(-), patients who developed thrombocytopenia and tested negative for HIT; and 3) HIT(+), patients who developed thrombocytopenia and tested positive for HIT. Independent predictors of post-operative HIT were evaluated, and a comparison of diagnostic accuracy between the 4Ts and 4TMCS probability scores was performed. Results We identified 5,314 patients eligible for analysis between 2008 and 2016. In total, 125/5314 (2.4%) patients were diagnosed with HIT, of which 75/5314 (1.4%) had clinical evidence of thrombosis. Overall, in-hospital mortality was 25.6%, 11.7%, and 1.5% in the HIT(+), HIT(-), and control groups, respectively (P Conclusion Heparin-induced thrombocytopenia is associated with worse outcomes and increased morbidity and mortality in patients undergoing cardiac surgery. Patients receiving MCS may be at increased risk for development of post-operative HIT. Awareness of pre-operative patient risk factors and application of a modified 4TMCS probability score may allow for more accurate screening and treatment of HIT in the MCS population.

Incidence, Outcomes and Risk Factors of Heparin-Induced Thrombocytopenia After Total Joint Arthroplasty: A National Inpatient Sample Database Study

Backgrounds: Heparin-induced thrombocytopenia (HIT) is a severe immune-mediated complication of heparin exposure, leading to negative consequences after total hip (THA) and knee arthroplasty (TKA). Materials and Methods: A retrospective study was conducted using the National Inpatient Sample (NIS) database from 2005 to 2014. The incidence and outcomes of HIT after THA or TKA were documented. Logistic regression analysis was performed to identify the postoperative HIT risk factors. Results: A total of 59 3045 patients who underwent THA and 1228 707 patients who underwent TKA were identified. The cumulative incidences were 0.02% and 0.01%, respectively. The HIT group presented significantly higher Charlson Comorbidity Index and Elixhauser Comorbidity Index scores, longer hospital stays (LOS), and higher medical costs. HIT led to a significantly higher mortality rate after THA (2.17% vs 0.16%, P = .0091). In THA, the HIT risk factors were racial minority, AIDS, pulmonary circulation disorders (PCD), psychoses, and hypertension. In TKA, the HIT risk factors were racial minority, PCD, and weight loss. Conclusion: The incidence of HIT after THA and TKA is relatively low; however, HIT significantly increases inpatient mortality, LOS, and medical cost.

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

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). 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. 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. 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.

A Case Of Bilateral Adrenal Hemorrhage and Subsequent Adrenal Crisis due to Heparin-Induced Thrombocytopenia

ABSTRACT Objective: To discuss a case of adrenal insufficiency (AI) caused by heparin-induced thrombocytopenia (HIT) and subsequent adrenal hemorrhage. Methods: We describe the case of a patient who developed postoperative HIT, which went undetected until the patient presented with fulminant adrenal crisis. We provide here an overview of the work-up, diagnosis, and treatment of HIT-associated AI. Results: HIT is a rare cause of bilateral adrenal hemorrhage, and subsequent AI secondary to HIT is often clinically unsuspected until overt hemodynamic collapse occurs. Conclusions: Lack of early detection and appropriate treatment of HIT-induced AI can lead to significant patient morbidity and mortality. Awareness of this clinical condition is key to early recognition and treatment.

Recurrent lower limb arterial thrombosis in a patient with heparin-induced thrombocytopenia – Case report

Background: Heparin-induced thrombocytopenia (HIT) is an immune-mediated disorder following heparin therapy presenting with thrombocytopenia and associated arterial or/and venous thrombosis (heparin induced thrombocytopenia with thrombosis–HITT). Unrecognised HIT can lead to severe complications like limb amputation and death. Case report: We report a case of a patient who presented with HIT-associated recurrent lower limb arterial thrombotic occlusions and popliteal venous thrombosis 29 days after coronary bypass graf surgery. The patient underwent urgent thrombectomy of superfcial femoral, popliteal and posterior tibial artery. Because of recurrent thrombotic occlusions of lower limb arteries three surgical revisions were performed. Te platelet count decreased from 124 × 109/l to 53 × 109/l on the fifth day after the first intervention. After clinical suspicion of HIT, heparin was discontinued and fondaparinux was started. Arterial thrombosis did not recur and the patient recovered without consequences. Conclusions: HIT occurs in 1–3 % of patients after cardiac surgery. Strict following of international guidelines regarding the frequency of platelet count monitoring, assessing probability for HIT and laboratory testing is mandatory in order not to miss the diagnosis of HIT. HIT can manifest clinically several days after the first exposure to heparin. If a patient presents with acute thrombosis and thrombocytopenia, HITT should be suspected. Postoperative HIT is associated with higher morbidity and mortality. Early recognition is crucial to prevent severe complications and death.

Recidivne tromboze arterij spodnjega uda pri bolniku s trombocitopenijo, povzročeno s heparinom – Prikaz primera

Background: Heparin-induced thrombocytopenia (HIT) is an immune-mediated disorder following heparin therapy presenting with thrombocytopenia and associated arterial or/and venous thrombosis (heparin induced thrombocytopenia with thrombosis–HITT). Unrecognised HIT can lead to severe complications like limb amputation and death.Case report: We report a case of a patient who presented with HIT-associated recurrent lower limb arterial thrombotic occlusions and popliteal venous thrombosis 29 days after coronary bypass graf surgery. The patient underwent urgent thrombectomy of superfcial femoral, popliteal and posterior tibial artery. Because of recurrent thrombotic occlusions of lower limb arteries three surgical revisions were performed. Te platelet count decreased from 124 × 109/l to 53 × 109/l on the fifth day after the first intervention. After clinical suspicion of HIT, heparin was discontinued and fondaparinux was started. Arterial thrombosis did not recur and the patient recovered without consequences.Conclusions: HIT occurs in 1–3 % of patients after cardiac surgery. Strict following of international guidelines regarding the frequency of platelet count monitoring, assessing probability for HIT and laboratory testing is mandatory in order not to miss the diagnosis of HIT. HIT can manifest clinically several days after the first exposure to heparin. If a patient presents with acute thrombosis and thrombocytopenia, HITT should be suspected. Postoperative HIT is associated with higher morbidity and mortality. Early recognition is crucial to prevent severe complications and death.

Early Stenosis of Stentless Aortic Valve Prosthesis: A Word of Caution

Early stenosis of stentless bioprosthetic valves is rarely reported. In this report, we discuss a 75-year-old woman who presented with signs of congestive heart failure 5 months after a stentless aortic valve replacement, complicated by postoperative heparin-induced thrombocytopenia. Intraoperative findings were highly unusual, consisting of a fibrous band in the subvalvular apparatus linking the interventricular septum to the free wall of the left ventricle, resulting in significant left ventricular outflow tract obstruction. The possible causes of the fibrous band are discussed.

Heparin-induced Thrombocytopenia Type II after Cardiac Surgery: Predictors and Outcome

Heparin-induced thrombocytopenia (HIT) is a serious complication after cardiac surgery. The aim of the present study was to identify pre- and intraoperative predictors for the postoperative occurrence of HIT. The study additionally focused on the impact of HIT on postoperative outcome. Retrospective analysis was performed for 5073 patients who had required extracorporeal circulation during cardiac surgery. Patients were divided into 3 groups: 1) patients who had postoperative HIT (HIT+); 2) patients with postoperative thrombocytopenia but without HIT (HIT-); and 3) patients with normal platelet count (C). The groups were statistically compared with regard to pre-, intra- and postoperative parameters. Statistically significant predictors were renal insufficiency, intravenous application of heparin for more than 3 days, previous percutaneous coronary intervention within the last 4 weeks, urgency/emergency operation, combined surgery, prolonged extracorporeal circulation or cross-clamping time, and low cardiac output syndrome. Postoperative HIT was associated with an enhanced risk of renal failure, infectious and thromboembolic complications and in-hospital mortality. Postoperative HIT increases morbidity and mortality. The predictors presented in this study can be used to identify patients at risk of developing HIT.

Clinical relevance of heparin-PF4 complex antibody in DVT after total joint replacement

BackgroundAntibodies to the heparin-platelet factor-4 (HPF-4) complex (HIT antibodies) have been observed in patients with heparin-induced thrombocytopenia (HIT). These antibodies are thought to be involved in thrombosis through activation of platelet/endothelial cells. This prospective study was conducted to determine the incidence of post-operative HIT antibodies to assess the associated risk of deep vein thrombosis (DVT) in patients undergoing total knee arthroplasty (TKA) or total hip arthroplasty (THA).MethodsWe studied 104 patients who underwent unilateral primary TKA (n = 44) and primary THA (n = 60) with short-duration prophylaxis (1–2 days of a fixed dose of unfractionated heparin). HIT antibodies were assayed using a sandwich-type ELISA before the operation and after heparin treatment (post-operative day 7).ResultsIn the clinical outcome, the incidence of symptomatic DVT was 15.4% (16/104, TKA; 10, THA 6) and pulmonary embolism (PE) was not observed. The total seroconversion rate of HIT antibodies at post-operative day 7 was 34.6% (36/104). Among 36 seroconverted patients, 11 (30.6%) developed symptomatic DVT and 5 out of 68 of the non-seroconverted patients (7.4%) developed symptomatic DVT. The incidence for DVT was significantly higher in the seroconverted patients compared with that of the non-seroconverted patients (odds ratio 5.5, 95%CI: 1.7–17.6 p = 0.0028). Furthermore, in the patients with symptomatic DVT, the titer of HIT antibodies at post-operative day 7 was significantly higher compared with those without symptomatic DVT.ConclusionOur data therefore suggest that seroconversion for HIT antibodies generated by heparin is associated with a risk of DVT in patients undergoing total joint replacement.

Impact of Heparin-Induced Thrombocytopenia on Postoperative Outcomes After Cardiac Surgery

The objectives of this study are to determine the effect of heparin-induced thrombocytopenia (HIT) on postoperative morbidity and mortality after cardiac surgery and to identify preoperative risk factors for HIT. From 2002 to 2005, 487 cardiac surgery patients with postoperative thrombocytopenia (50% drop in platelet count or absolute count < 100,000/muL) underwent at least one enzyme-linked immunosorbent assay for HIT platelet factor 4 antibodies. Risk factors and outcomes of patients with a positive HIT assay (HIT+) were compared with patients with thrombocytopenia, but without HIT antibodies (HIT-). 23.2% of patients (113 of 487) were HIT+. Multivariable predictors of HIT included previous percutaneous coronary interventions (odds ratio [OR] = 1.76, p = 0.03), class IV New York Heart Association heart failure (OR = 1.80, p = 0.012), and infectious endocarditis (OR = 3.66, p = 0.0123). Postoperative infections occurred more frequently in HIT+ patients, including sepsis (16.8% versus 9.9%, p = 0.0433) and pneumonia (46.9% versus 23.3 %, p < 0.001). The HIT+ patients also had a higher rate of renal failure requiring hemodialysis (23.0% versus 9.1%, p < 0.001) and acute limb ischemia (15.9% versus 4.3%, p < 0.001). Thirty-day mortality was significantly higher in the HIT+ group (24.8% versus 15.2%, p = 0.019). Postoperative HIT emerged as an independent predictor of renal failure (OR = 1.73, p < 0.001) and thromboembolic complications (OR = 2.39, p = 0.02). Heparin-induced thrombocytopenia patients are at significantly greater risk of thrombosis, renal failure, and mortality in the postoperative setting. Greater awareness of this devastating problem may allow earlier detection of HIT, with prompt institution of appropriate anticoagulation therapy, which could potentially limit the associated morbidity and mortality.