Intracardiac thrombus in a patient with mitral bioprosthesis and atrial fibrillation treated with direct oral anticoaugulant: A case report.

Rationale: Atrial fibrillation (AF) is the most common cardiac arrhythmia and is associated with increased morbidity, especially stroke and heart failure. There is also increasing awareness that atrial fibrillation is a major cause of embolic events which in 75% of cases are complicated by cerebrovascular accidents.

Patient Concerns: A 50-year-old woman with mitral bioprosthesis under warfarin for nonvalvular atrial fibrillation was referred to our Coronary Intensive Care Unit due to acute myocardial infarction without evidence of significant coronary artery stenosis.

Diagnoses: Cardiovascular examination showed an irregular pulse and a grade II diastolic murmur was audible at the apical area. The patient underwent coronary angiography showing absence of obstructive coronary artery disease. We decided to replace Warfarin with direct oral anticoagulants as anticoagulant therapy.

Interventions: Transoesophageal echocardiography revealed a thrombus in left atrial appendage that was treated by replacing warfarin with an oral direct thrombin inhibitor.

Outcomes: At 2-month follow-up, the therapy showed to be effective for thrombus resolution.

Lessons: Our case demonstrated how AF has high risk of thromboembolic complications, not only in terms of stroke but also of myocardial infarction and death.The use of direct oral anticoagulants in AF patients with bioprosthetic heart valves is still debated due to an unclear definition of "nonvalvular" AF.