Defining short-term outcomes of minor ischemic stroke due to small artery occlusion in the era of dual antiplatelet treatment: A READAPT study sub-analysis

Background The outcomes of minor ischemic stroke resulting from small artery occlusion (SAO-MIS) have not yet been characterized after dual antiplatelet treatment (DAPT) has become the standard of care. We provided updated figures on the short-term prognosis of SAO-MIS treated with early short-term DAPT and compared the outcomes of SAO-MIS versus non-SAO-MIS patients. Methods This is a prespecified sub-analysis from a prospective multicentric real-world study (READAPT, NCT05476081) including patients with minor (NIHSS≤5) non-cardioembolic ischemic stroke treated with DAPT. The primary outcome was a composite of 90-day symptomatic ischemic stroke or major cardiovascular events. Secondary outcomes were the 90-day ordinal distribution of modified Rankin Scale (mRS) scores, 90-day excellent functional outcome (mRS of 0 to 1), and 24-h early neurological deterioration (END). Safety outcomes were 90-day intracerebral hemorrhage, moderate-to-severe and any bleedings. All outcomes were compared between SAO-MIS and non-SAO-MIS patients. Results We included 678 MIS, of whom 253 (37.3 %) were SAO-related. At 90 days, 3 patients with SAO-MIS had primary outcome (1.2 % [95 % CI 0.2 %–3.5 %]), which were all SAO-related ischemic strokes. For the secondary outcomes, most SAO-MIS patients (n = 191, 75.5 %) had 90-day excellent functional outcome and 12 had 24-h END (4.7 % [95 % CI 2.5 %–8.3 %]). Referring to safety outcomes, 90-day intracerebral hemorrhage occurred only in one patient with SAO-MIS (0.4 % [95 % CI 0.0 %- 2.2 %]). Compared to non-SAO-MIS, the 90-day risk of recurrent vascular events was significantly lower among SAO-MIS (aHR 0.24 [95 % CI 0.08–0.68]; p = 0.007), while there were not significant differences in other secondary outcomes, nor in the risk of safety events. Conclusions Our findings show overall favorable short-term prognosis after SAO-MIS treated with DAPT. Future studies should investigate factors associated with residual stroke risk and long-term outcomes of SAO-MIS.