Thromboprophylaxis and adult congenital heart disease: The latest on indications, risk scoring and therapy

Abstract

Advances in medical care have significantly extended the lifespan of patients with congenital heart disease (CHD), allowing most to survive into adulthood. However, they continue to face significant cardiovascular morbidity, particularly atrial arrhythmias (AA), heart failure, and thromboembolic (TE) events. TE events in adult CHD patients arise from various factors, including AA, intracardiac repairs, cyanotic CHD, Fontan palliation, pregnancy, and mechanical heart valves (MHV). As randomized clinical trials are lacking, most current guidelines rely on observational data and expert opinions, leading to inherent variability. While vitamin K antagonists are the only option for patients with MHV and significant mitral stenosis, direct oral anticoagulants appear to be a reasonable choice for other indications. In the presence of AA, complex conditions alone may justify anticoagulation, whereas thromboembolic and haemorrhagic risks should be evaluated individually for simpler lesions. This review summarizes the available evidence and makes relevant recommendations regarding thromboprophylaxis in ACHD patients, focusing on indications, risk scores, and therapies.

Keywords: Adult congenital heart disease; Management; Thromboembolic events; Thromboprophylaxis.

Fig. 1

Thromboembolic risk Continuum in adults with congenital heart disease. ∗ The cumulative risk factors are arranged in increasing order for graphical purposes, which does not imply that they are necessarily more significant than others. ACHD: adult congenital heart disease; CHD: congenital heart disease; PH: pulmonary hypertension; RV: right ventricle; TE: thromboembolic; UVH: univentricular heart.

Fig. 2

Management of Thromboprophylaxis in adult congenital heart disease patientspresenting with Atrial Arrhythmias. AF: atrial fibrillation; AFL: atrial flutter; IART: intra-atrial re-entrant tachycardia; CHA2DS2-VA: Congestive heart failure, hypertension, age ≥75 years (2 points), diabetes mellitus, prior stroke/transient ischaemic attack/arterial thromboembolism (2 points), vascular disease, age 65–74 years (score) CHD: congenital heart disease; HAS-BLED: Hypertension, Abnormal renal/liver function, Stroke, Bleeding history or predisposition, Labile international normalized ratio, Elderly (>65 years), Drugs/alcohol concomitantly (score); RV: right ventricle.

Fig. 3

Thromboprophylaxis in pregnant women with congenital heart disease - indications. AA: atrial arrhythmia; ACHD: adult congenital heart disease; CHA2DS2-VA: Congestive heart failure, hypertension, age ≥75 years (2 points), diabetes mellitus, prior stroke/transient ischaemic attack/arterial thromboembolism (2 points), vascular disease, age 65–74 years (score); MHV: mechanical heart valve; PH: pulmonary hypertension; TE: thromboembolic.

Fig. 4

Thromboprophylaxis in pregnant women with congenital heart disease – management if previous indication for high dose of VKA. aPTT: activated partial thromboplastin time; INR: international normalized ratio; i.v.: intravenous; LMWH: low molecular weight heparin; MHV: mechanical heart valve; Trim.: trimester; UFH: unfractionated heparin; VKA: vitamin K antagonist.a weeks 6–12; bmonitoring LMWH: starting dose for LMWH is 1 mg/kg body weight for enoxaparin and 100 IU/kg for dalteparin, twice daily subcutaneously; -in-hospital daily anti-Xa levels until target, then weekly (I); -target anti- Xa levels: 1.0–1.2 U/ml (mitral and right sided MHV) or 0.8–1.2 U/ml (aortic MHV) 46 h post-dose (I); -pre-dose anti-Xa levels >0.6 U/ml (IIb).

Fig. 5

Thromboprophylaxis in pregnant women with congenital heart disease – management if previous indication for low dose of VKA. aPTT: activated partial thromboplastin time; INR: international normalized ratio; i.v.: intravenous; LMWH: low molecular weight heparin; MHV: mechanical heart valve; Trim.: trimester; UFH: unfractionated heparin; VKA: vitamin K antagonist.a weeks 6–12; bmonitoring LMWH: starting dose for LMWH is 1 mg/kg body weight for enoxaparin and 100 IU/kg for dalteparin, twice daily subcutaneously; -in-hospital daily anti-Xa levels until target, then weekly (I); -target anti- Xa levels: 1.0–1.2 U/ml (mitral and right sided MHV) or 0.8–1.2 U/ml (aortic MHV) 46 h post-dose (I); -pre-dose anti-Xa levels >0.6 U/ml (IIb). † There are concerns on risk of cerebral bleeding even with low dosage (underreported.