Low-Dose Aspirin after an Episode of Haemorrhagic Stroke Is Associated with Improved Survival

Abstract

We aimed at investigating how antiplatelet drug use affected mortality in patients with a history of haemorrhagic stroke (HS). Thus, starting 30 days after an HS episode, we followed 1,004 patients with intracerebral haemorrhage (ICH) and 929 patients with subarachnoid haemorrhage (SAH) for a median of 6.4 years. We estimated the effect of time-dependent exposure to antiplatelets after HS on all-cause mortality. Cox proportional hazard models were used to compute adjusted hazard ratios (aHRs) and 95% confidence intervals (CI). We found that current use of low-dose aspirin was associated with a 32% improved survival (aHR = 0.68; 95% CI: 0.53–0.88), with a similar association among ICH (aHR = 0.66; 95% CI: 0.49–0.89) and SAH (aHR = 0.61; 95% CI: 0.36–1.04) patients. A statistically significant improved survival associated with current use of low-dose aspirin during follow-up was only observed among individuals who used antithrombotic drugs in the year before the HS (prior use: aHR = 0.56; 95% CI: 0.39–0.80; non-prior use: aHR = 0.87; 95% CI: 0.61–1.24). Current use of clopidogrel was not associated with survival (aHR = 1.35; 95% CI: 0.88–2.08). Statin use was associated with improved survival (aHR = 0.38; 95% CI: 0.31–0.47). On the other hand, discontinuation of statins (aHR = 1.31; 95% CI: 1.02–1.68) or low-dose aspirin (aHR = 1.54; 95% CI: 1.21–1.97) was associated with decreased survival. In our study, use of low-dose aspirin after an episode of HS to reduce vascular risks is safe, particularly in patients who were on antithrombotic therapy before the episode. Our results suggest an improved survival associated with low-dose aspirin. This finding must be interpreted with care due to the observational nature of the study, and warrants further studies.