Cryptogenic stroke in women: impact of insertable cardiac monitoring in the STROKEWISE cohort study

The clinical value of insertable cardiac monitoring (ICM) for detecting asymptomatic atrial fibrillation (AF) and guiding anticoagulation in patients with cryptogenic stroke remains uncertain. This study aimed to evaluate the association between ICM-detected AF and recurrent stroke, mortality, and major bleeding in women.

We consecutively compared women with cryptogenic stroke who received an ICM at Akershus University Hospital (2016–23), with a control group from Haukeland University Hospital with standard non-invasive follow-up. Participants from both hospitals had complete data in the Norwegian Stroke Registry. Primary outcomes were AF detection and recurrent stroke at 1 and 2 years; secondary outcomes included mortality, composite stroke and mortality, ischaemic cardiovascular events, oral anticoagulation initiation, and major bleeding. Multivariable logistic regression analysis was used for binary outcomes and Cox proportional hazards models for time-to-event outcomes, both adjusted for prespecified vascular risk factors. Among 475 women (mean age 73 ± 12 years; ICM n = 262), AF was detected in 36% in the ICM group vs. 9% in in the control group (OR 6.9, 95% CI 3.7–13.5; P < 0.001). No significant differences were observed in recurrent stroke (HR 1.8, 95% CI 0.78–4.36; P = 0.17), mortality (HR 0.88, 95% CI 0.58–1.58; P = 0.88), or the composite outcome (HR 0.96, 95% CI 0.6–1.5; P = 0.85) with a median follow-up of 42 months (IQR 15–66). However, fixed-time analyses showed significantly lower 2-year mortality with ICM (OR 0.40, 95% CI 0.16–0.94; P = 0.036) and fewer bleeding events (OR 0.19, 95% CI 0.06–0.52; P = 0.002). Age and troponin T were consistent independent predictors of adverse outcomes.

ICM increased AF detection and enabled safe anticoagulation in women with acute cryptogenic stroke. Although stroke recurrence did not differ significantly, signals of lower mortality and major bleeding support prolonged monitoring to optimize secondary prevention.

NCT07194811, https://clinicaltrials.gov/study/NCT07194811