For a study, researchers sought to evaluate dabigatran’s effectiveness and safety compared to standard care for atrial fibrillation (AF) caused by left-sided valvular heart disease (VHD), including mitral stenosis (MS). Dabigatran or standard care was randomly assigned to patients with AF and left-sided VHD. On 1-year follow-up brain magnetic resonance imaging, the primary endpoint was the incidence of clinical stroke or a new brain lesion (silent brain infarct and microbleed). Patients were shifted from warfarin (n=52), antiplatelets alone (n=5), or no treatment (n=2) to dabigatran in the dabigatran group. About 53 people in the usual group—including 42 MS patients—used warfarin, while 7 took antiplatelets. Neither group experienced mortality nor a clinical stroke occurrence during the follow-up period. In the dabigatran group, there were 20 silent brain infarction and microbleed cases, while in the usual treatment group, there were 20 cases and 4, respectively. About 34% vs. 40%, relative risk 0.87, 95% CI 0.59 to 1.29, P=0.491, show no appreciable differences in the primary endpoint incidence rate between groups. In 82 patients with MS (40 in the dabigatran group and 42 in the control group), the primary endpoint rate was comparable between groups (32% vs. 34%; relative risk 0.93; 95% CI: 0.57 to 1.50; P=0.759). In patients with severe VHD and AF, primary endpoint rates following dabigatran treatment were comparable to those following conventional treatment. In individuals with AF and VHD, new oral anticoagulants might be a viable substitute for warfarin; this should be validated in future investigations.