Thromboembolism in Heart Transplantation: Role of Prothrombin G20210A and Factor V Leiden

Deep vein thrombosis and pulmonary embolism after heart transplantation

INTRODUCTION

Venous thromboembolism (VTE), such as deep vein thrombosis (DVT) and pulmonary embolism (PE), is an important and serious postoperative complication after heart transplantation. We sought to characterize in-hospital VTE after heart transplantation and its association with clinical outcomes.

METHOD

Adult (≧18 years) patients undergoing heart transplantation from 2015 to 2019 at our center were retrospectively reviewed. Post-transplant VTE was defined as newly diagnosed venous system thrombus by imaging studies.

RESULTS

There were 254 patients. The cohort's median age was 55 years. A total of 61 patients were diagnosed with VTE, including 1 with right atrial thrombus, 54 with upper extremity DVT in which one patient subsequently developed PE, 4 with lower extremity DVT, and 2 with upper and lower extremity DVT. The cumulative incidence of VTE was 42% at 60-days of post heart transplant. Patients with VTE had longer hospital stay (p<0.001), higher in-hospital mortality (p = 0.010), and worse 5-year survival (p = 0.009). On the multivariable Cox analysis, history of DVT/PE and intubation for more than 3 days were associated with an increased risk of in hospital VTE.

CONCLUSION

The incidence of VTE in heart transplant recipients is high. Post-transplant surveillance, and appropriate preventive measures and treatment strategies after diagnosis are warranted. This article is protected by copyright. All rights reserved.

Evaluation of Direct Oral Anticoagulation Therapy in Heart and Lung Transplant Recipients

CONTEXT

Anticoagulation therapy is common in thoracic transplant recipients. Direct oral anticoagulants (DOACs) are alternatives to warfarin therapy, but characterization of their use in solid organ transplant is absent.

OBJECTIVE

The primary objective of this study was to describe a thoracic transplant patient population initiated on DOAC therapy. Secondary objectives were to assess adverse reactions, venous thromboembolism (VTE) recurrence, and drug-drug interactions during DOAC therapy.

STUDY DESIGN

Single-center retrospective cohort study.

SETTING

A tertiary care medical center including inpatient hospitalization and outpatient transplant clinic visits.

PATIENTS

Thoracic transplant recipients who were initiated on DOACs between May 1, 2011, and March 1, 2015, at the University of Pittsburgh Medical Center were included.

RESULTS

A total of 37 patients were included in the analysis. A majority of the patients were lung transplant recipients (86.4%) with a median age of 60.7 years. Twenty-eight patients had a history of VTE. The primary indication for DOAC initiation was VTE (86.5%). Rivaroxaban (78.4%) was the most commonly utilized agent. Dose reductions for major drug interactions (37.8%), renal insufficiency (10.8%), or both (8.1%) occurred within the study. Two patients had breakthrough VTE during DOAC therapy. Eight bleeding events were reported in the cohort, one of which was considered a major bleed. There was no difference in the incidence of bleeding in patients with drug-drug interactions and without drug-drug interactions during DOAC therapy (26.0% vs 7.1%, P = .154).

CONCLUSION

Direct oral anticoagulant therapy was well tolerated by thoracic transplant recipients. Drug interactions and renal dose adjustments were common.

Ischemic Stroke after Heart Transplantation

Cerebrovascular complications after orthotopic heart transplantation (OHT) are more common in comparison with neurological sequelae subsequent to routine cardiac surgery. Ischemic stroke and transient ischemic attack (TIA) are more common (with an incidence of up to 13%) than intracranial hemorrhage (2.5%). Clinically, ischemic stroke is manifested by the appearance of focal neurologic deficits, although sometimes a stroke may be silent or manifests itself by the appearance of encephalopathy, reflecting a diffuse brain disorder. Ischemic stroke subtypes distribution in perioperative and postoperative period after OHT is very different from classical distribution, with different pathogenic mechanisms. Infact, ischemic stroke may be caused by less common and unusual mechanisms, linked to surgical procedures and to postoperative inflammation, peculiar to this group of patients. However, many strokes (40%) occur without a well-defined etiology (cryptogenic strokes). A silent atrial fibrillation (AF) may play a role in pathogenesis of these strokes and P wave dispersion may represent a predictor of AF. In OHT patients, P wave dispersion correlates with homocysteine plasma levels and hyperhomocysteinemia could play a role in the pathogenesis of these strokes with multiple mechanisms increasing the risk of AF. In conclusion, stroke after heart transplantation represents a complication with considerable impact not only on mortality but also on subsequent poor functional outcome.