Atrial Fibrillation Detected before or after Stroke: Role of Anticoagulation

BACKGROUND

Atrial fibrillation (AF) known before ischemic stroke (KAF) has been postulated to be an independent category with a recurrence risk higher than that of AF detected after stroke (AFDAS). However, it is unknown whether this risk difference is confounded by pre-existing anticoagulation, which is most common in KAF and also indicates a high ischemic stroke recurrence risk.

METHODS

Individual patient data analysis from 5 prospective cohorts of anticoagulated patients following AF-associated ischemic stroke. We compared the primary (ischemic stroke recurrence) and secondary outcome (all-cause death) among patients with AFDAS versus KAF and among anticoagulation-naïve versus previously anticoagulated patients using multivariable Cox, Fine-Gray models, and goodness-of-fit statistics to investigate the relative independent prognostic importance of AF-category and pre-existing anticoagulation.

RESULTS

Of 4,357 patients, 1,889 (43%) had AFDAS and 2,468 (57%) had KAF, while 3,105 (71%) were anticoagulation-naïve before stroke and 1,252 (29%) were previously anticoagulated. During 6,071 patient-years of follow-up, we observed 244 recurrent strokes and 661 deaths. Only pre-existing anticoagulation (but not KAF) was independently associated with a higher hazard for stroke recurrence in both Cox and Fine-Gray models. Models incorporating pre-existing anticoagulation showed better fit than those with AF category; adding AF-category did not result in better model fit. Neither pre-existing anticoagulation nor KAF were independently associated with death.

CONCLUSION

Our findings challenge the notion that KAF and AFDAS are clinically relevant and distinct prognostic entities. Instead of attributing an independently high stroke recurrence risk to KAF, future research should focus on the causes of stroke despite anticoagulation to develop improved preventive treatments. ANN NEUROL 2023;94:43-54.

White matter perivascular spaces are related to cortical superficial siderosis in cerebral amyloid angiopathy

BACKGROUND AND PURPOSE

We set out to investigate whether MRI-visible centrum semiovale perivascular spaces (CSO-PVS), a potential biomarker of impaired interstitial fluid drainage in sporadic cerebral amyloid angiopathy, is associated with cortical superficial siderosis (cSS), reflecting recurrent hemorrhage from severe leptomeningeal and superficial cortical vascular amyloid.

METHODS

Retrospective multicenter cohort study of possible/probable cerebral amyloid angiopathy according to the Boston criteria. PVS were rated in basal ganglia and CSO (CSO-PVS) on axial T2-weighted sequences, using a validated 4-point visual rating scale and were classified as high (score>2) or low degree (score≤2) for prespecified analyses. Independent risk factors for high CSO-PVS degree were investigated in logistic regression.

RESULTS

The final cohort consisted of 138 cerebral amyloid angiopathy patients (mean age, 71.8 years; 95% confidence interval, 70.2-73.4 years; 52.2% men). High CSO-PVS degree was present in 61.2% of cases. The prevalence of any cSS, and disseminated cSS (involving >3 sulci), was higher in patients with high versus low CSO-PVS degree (for any cSS 45.9% versus 13.5%; P<0.00005; for disseminated cSS 31.8% versus 0%; P<0.00005). In multivariable logistic regression analysis, cSS presence (odds ratio, 4.78; 95% confidence interval, 1.64-13.87; P=0.004) was an independent predictors of high CSO-PVS degree. We found no associations between basal ganglia PVS and cSS.

CONCLUSIONS

High degree of CSO-PVS is highly prevalent in sporadic cerebral amyloid angiopathy and is related to cSS. Our findings suggest that severe leptomeningeal and cortical vascular amyloid (causing cSS) is related to impaired interstitial fluid drainage from cerebral white matter, although determining the causal direction of this relationship requires prospective studies.