(P130) MANAGEMENT AND OUTCOMES OF MITRAL ANNULAR CALCIFICATION THROMBUS: A SYSTEMATIC REVIEW

Background: Mitral annular calcification (MAC) is a common chronic degenerative process of the mitral valve that is increasing in frequency due to an aging population. Thrombus formation on MAC is a rare complication that likely contributes to the increased risk of thromboembolic events in this population (Figure 1). The management and outcomes of patients with thrombus on MAC are unknown. To address this knowledge gap, we performed a systematic review on patients with thrombus formation in the setting of MAC.

METHODS AND RESULTS: Medline, Embase, and Cochrane databases were searched from inception to December 2021 to identify studies with thrombus attached to MAC. Patients with prior mitral valve intervention or prosthesis were excluded. The primary outcomes of interest were treatment/intervention, mortality, and thromboembolic events. Secondary outcomes of interest included MAC thrombus recurrence. Fifteen studies with 22 cases of MAC thrombus were included in the systematic review (Table 1). The average age at diagnosis was 69.1±14.8 years and 82% were female. Most patients presented with stroke or transient ischemic event (68%, n=15) or myocardial infarction (18%, n=4). All patients were diagnosed with either transthoracic (82%, n=18) or transesophageal (18%, n=4) echocardiography. Seventy-seven percent (n=17) of patients were treated with anticoagulation alone and 23% (n=5) required surgery. Reasons for surgical treatment included prevention of recurrent embolization of MAC thrombus (14%, n=3), severe mitral stenosis (5%, n=1), and severe coronary artery disease (5%, n=1). No mortality was reported at presentation or during follow-up. Thromboembolic events after diagnosis were common, affecting 27% (n=6), including 3 anticoagulated patients. For those treated with anticoagulation alone, 23% (n=5) had persistent thrombus with or without embolization.

Conclusion: This is the first systematic review examining the management and outcomes of patients with MAC thrombus. Careful echocardiographic interrogation of MAC to exclude the presence of thrombus should be performed in patients with MAC who present with a thromboembolic event. Most patients can be managed with anticoagulation alone, although a significant number will require surgery for recurrent embolization. Persistent thrombus despite anticoagulation and recurrent embolization are common in this population. Thus, larger studies on MAC thrombus management are needed to elucidate the optimal long-term care for these patients.