DEFENSE-PFO Model (Cryptogenic Stroke Benefit) Calculator

Patient age (years) Atrial Septal Aneurysm (ASA) present? Septal hypermobility (phasic excursion, mm) High-risk threshold in DEFENSE-PFO: ≥10 mm. PFO separation/height (maximum septum primum–secundum separation, mm) High-risk threshold in DEFENSE-PFO: ≥2 mm.

DEFENSE-PFO Model (Cryptogenic Stroke Benefit): Explanation and Clinical Context The DEFENSE-PFO trial evaluated patients with cryptogenic stroke and high-risk patent foramen ovale (PFO) on transesophageal echocardiography—defined by at least one of the following: atrial septal aneurysm (ASA), marked septal hypermobility (≥10 mm excursion), or a large PFO (≥2 mm separation). In this group, percutaneous closure significantly reduced recurrent events compared to medical therapy alone. At 2 years, ischemic stroke occurred in 10.5% of the medical group versus 0% in the closure group (ARR ≈10%, NNT ≈10).

The composite endpoint (stroke, vascular death, or TIMI major bleeding) also favored closure (12.9% vs 0%). Because the study exclusively enrolled high-risk PFO, these effect sizes apply only in that subset. Post-hoc analyses suggest that older adults (≥60 years) with high-risk PFO may derive greater absolute benefit, but this requires cautious interpretation.

Outside this setting, clinicians should integrate clinical context, imaging findings, and causal probability estimates (e.g., RoPE and PASCAL models) before deciding on closure.