Incidence of acute cerebrovascular events in patients with rheumatic or calcific mitral stenosis: A systematic review and meta-analysis

Patients with mitral stenosis (MS) may be predisposed to acute cerebrovascular events (ACE) and peripheral thromboembolic events (TEE). Concomitant atrial fibrillation (AF), mitral annular calcification (MAC) and rheumatic heart disease (RHD) are independent risk factors. Our aim was to evaluate the incidence of ACEs in MS patients and the implications of AF, MAC and RHD on thromboembolic risks. This systematic review was registered on PROSPERO (CRD42021291316). Six databases were searched from inception to 19th December 2021. The clinical outcomes were composite ACE, ischaemic stroke/transient ischaemic attack (TIA) and peripheral TEE. We included 16 and 9 papers, respectively, in our qualitative and quantitative analyses. The MS cohort with AF had the highest incidence of composite ACE (31.55%; 95% CI 3.60–85.03; I2 = 99%), followed by the MAC (14.85%; 95% CI 7.21–28.11; I2 = 98%), overall MS (8.30%; 95% CI 3.45–18.63; I2 = 96%) and rheumatic MS population (4.92%; 95% CI 3.53–6.83; I2 = 38%). Stroke/TIA were reported in 29.62% of the concomitant AF subgroup (95% CI 2.91–85.51; I2 = 99%) and in 7.11% of the overall MS patients (95% CI 1.91–23.16; I2 = 97%). However, the heterogeneity of the pooled incidence of clinical outcomes in all groups, except the rheumatic MS group, was substantial and significant. The logit-transformed proportion of composite ACE increased by 0.0141 (95% CI 0.0111–0.0171; p < 0.01) per year of follow-up. In the MS population, MAC and concomitant AF are risk factors for the development of ACE. The scarcity of data in our systematic review reflects the need for further studies to explore thromboembolic risks in all MS subtypes.