Supplementary Material for: Age-related Variations in Patterns of Patent Foramen Ovale-Stroke versus Other Cryptogenic Stroke

Introduction: Patent Foramen Ovale (PFO)-stroke, a form of cryptogenic stroke, has certain identifying clinical and imaging features. However, data describing this stroke type remains inconsistent. This study examined the potential variations in PFO-stroke features, depending on age.

Methods: From a hospital registry, cryptogenic stroke patients were retrospectively selected, and PFO-strokes identified by the presence of >10 microembolic signals (MES) on transcranial doppler (TCD) saline agitation test. Cryptogenic strokes were grouped according to age (<70 as young, >70 as elderly). Clinical and imaging variables of PFO-strokes and non-PFO strokes were compared, with and without age considered.

Results: Of the 462 cryptogenic patients, 30.5% (141/462) were PFO-strokes, while majority (321/462) had no PFO. When cryptogenic strokes were analyzed by age, the significant difference was noted in the lesion number, pattern, and side. A single (72.8% vs 57.9%, p=0.020) and a small single lesion (51.1% vs 35.5%, p=0.039) were frequently seen in the younger PFO-strokes than the non-PFO counterpart, while mixed territory lesions identified the elderly PFO-strokes (30.6% vs 8.9%, p=0.001). A multivariate logistic regression analysis of PFO-strokes further showed that age was independently associated with lesion side (OR 1.12 (1.05-1.20), p<0.001) and lesion number (OR 1.06 (1.02-1.10), p=0.005).

Conclusions: Incorporating age-specific imaging criteria in the identification of PFO-strokes may be of additional value. Further, PFO may remain contributory to the stroke risk in the elderly, in association with vascular risk factors.