What is the PASCAL classification?

The PASCAL classification is a system used to categorize patients with a PFO based on the severity and characteristics of their condition, including the anatomical features and associated clinical implications.

Is the PASCAL classification validated for use in PFO?

Yes, the PASCAL classification has undergone validation in clinical studies, demonstrating its reliability in categorizing PFO cases and predicting outcomes.

GENERAL NEUROLOGY

PASCAL classification

(PFO-Associated Stroke Causal Likelihood)

David Goldemund M.D.
Updated on 15/10/2024, published on 09/10/2024

the prevalence of the patent foramen ovale (PFO) in the general population is ~ 25%
the discovery of a PFO in a stroke patient is not synonymous with a diagnosis of paradoxical embolism
the 10-point Risk of Paradoxical Embolism (RoPE) score has been proposed to help establish the relationship between cryptogenic stroke and PFO; it is based on age and vascular risk factors and ignores anatomic and physiologic characteristics of the PFO

The PASCAL (PFO-Associated Stroke Causal Likelihood) classification system combines the RoPE score with PFO characteristics (Kent, 2023):
- features that increase the likelihood of PFO-stroke mechanisms: high-risk PFO physiologic and structural features of a large shunt or atrial septal aneurysm
- features that increase the likelihood of an occult non-PFO stroke mechanism: older age, vascular risk factors as quantified in the RoPE score
based on a combination of these factors, the PASCAL Classification assigns a likelihood of causality to one of five levels: definite, highly probable, probable, possible, and unlikely
this classification improves clinical decision-making, particularly regarding PFO closure in cryptogenic stroke patients

Risk Grade	Features	Causal Relatedness
Risk Grade	Features	Low RoPE Score	High RoPE Score (> 7)
very high risk	PFO + straddling thrombus	definitive	definitive
high risk	PFO + ASA or large shunt PFO AND PE or DVT preceding index infarct	probable	highly probable
medium risk	PFO + ASA AND/OR Large shunt PFO	possible	probable
low risk	small shunt PFO without ASA	unlikely	probable

a higher RoPE score (> 7 points) increases the probability of a causal association between PFO and stroke
ASA – atrial septal aneurysm
the shunt is assessed either by TEE or, even better, by the TCCD bubble test