PFO-related Stroke: RoPE score and PASCAL Calculator
A patent foramen ovale (PFO) is a small hole between the heart’s upper chambers that didn’t close after birth. In some individuals, especially younger adults with no clear risk factors, a PFO may be linked to cryptogenic stroke — a type of stroke with no obvious cause. While most people with a PFO never have a stroke, certain features may increase the likelihood that a PFO is contributing to it.
This calculator helps estimate the likelihood that a stroke was related to a PFO. It combines the RoPE score (which reflects the probability that an embolism from a PFO caused a stroke) and the PASCAL classification, which factors in both stroke characteristics and anatomical features of the PFO. It is a guide to support clinical decision-making, not a substitute for professional evaluation.
RoPE Score and PASCAL Classification
Patent foramen ovale (PFO)
PFO is present in approximately 25% of the general population but is found in about 40-50% of patients with cryptogenic stroke – roughly twice the prevalence compared to stroke patients with known causes. This association is particularly strong in younger patients without traditional vascular risk factors, though it remains significant even in older populations. Multiple studies have confirmed that PFO prevalence in cryptogenic stroke patients exceeds that of both the general population and patients with strokes of identified etiology across all age groups.¹⁻³
While many PFOs can be detected on a transthoracic echocardiogram (TTE) with bubble study, the gold standard for detection and comprehensive evaluation is transesophageal echocardiography (TOE/TEE). TOE provides superior visualisation of the atrial septum, allowing for precise assessment of PFO size, shunt magnitude, and associated features such as atrial septal aneurysm that are critical for determining pathogenicity. Determining whether a detected PFO is incidental or pathogenic remains a key clinical challenge.
Cortical Stroke Pattern and PFO Association
The stroke’s radiological pattern provides important clues about a possible PFO-attributable mechanism. Cortical infarcts (involving the cerebral cortex) are significantly more likely to be associated with embolic mechanisms, including paradoxical embolism through a PFO. In contrast, lacunar infarcts (small subcortical infarcts typically <15mm) are usually caused by small vessel disease related to hypertension or diabetes, not embolic phenomena. The RoPE score specifically awards points for cortical infarct location, reflecting this important distinction. When evaluating a cryptogenic stroke with PFO, the presence of a cortical infarct pattern substantially increases the likelihood of PFO pathogenicity, while a lacunar pattern suggests alternative mechanisms regardless of PFO presence.
To aid in determining PFO pathogenicity, two tools are commonly used:
1. RoPE Score (Risk of Paradoxical Embolism)
The RoPE score was developed to estimate the likelihood that a stroke in a patient with a PFO is truly attributable to the PFO. It is based on clinical and imaging features, including age, hypertension, diabetes, smoking status, prior stroke or TIA, and cortical infarct on imaging.
- Score range: 0–10
- Higher scores (≥7) suggest the PFO is more likely pathogenic
- Lower scores suggest the stroke is more likely due to other mechanisms
2. PASCAL Classification
The PASCAL classification (PFO-Associated Stroke Causal Likelihood) integrates:
- RoPE score (clinical stroke phenotype) and,
- PFO anatomical high-risk features, including:
- Large shunt (>20 microbubbles in left atrium on contrast study)
- Atrial septal aneurysm (septal excursion >10mm from midline)
- PFO size (typically >2mm in diameter)
- Presence of Eustachian valve or Chiari network
It classifies PFO-associated strokes as:
| Probable | Strong causal relationship (high RoPE score plus ≥1 high-risk anatomical feature) |
| Possible | Moderate causal relationship (intermediate RoPE score or high RoPE with no high-risk features) |
| Unlikely | Weak causal relationship (low RoPE score, other likely stroke mechanisms present) |
This classification helps guide treatment decisions, including whether PFO closure is appropriate, especially in borderline cases.
How to Use This Calculator This tool combines the RoPE score and PASCAL classification to help clinicians assess whether a patient’s stroke is likely related to their PFO. It is intended to support, not replace, clinical judgment and individualized patient care.
Refrences:
- Koutroulou I et al. “Patent Foramen Ovale in Cryptogenic Ischemic Stroke: Direct Cause, Risk Factor, or Incidental Finding?” Front Neurol. 2020;11:567. doi:10.3389/fneur.2020.00567
- Handke M et al. “Patent Foramen Ovale and Cryptogenic Stroke in Older Patients.” N Engl J Med. 2007;357(22):2262-8. doi:10.1056/NEJMoa071422
- Homma S, Sacco RL. “Patent Foramen Ovale and Stroke.” Circulation. 2005;112:1063-72. doi:10.1161/CIRCULATIONAHA.104.524371
- Pristipino C et al. “European position paper on the management of patients with patent foramen ovale. General approach and left circulation thromboembolism.” Eur Heart J. 2019;40(38):3182-3195. doi:10.1093/eurheartj/ehz391
- Kent DM et al. “An index to identify stroke-related vs. incidental patent foramen ovale in cryptogenic stroke.” Neurology. 2013;81(7):619-625. doi:10.1212/WNL.0b013e3182a08d59