Introduction
Paradoxical embolism from right-to-left shunt through a patent foramen ovale (PFO) is a well-characterized cause of embolic strokes of undetermined source (ESUS). In order to better understand the pathogenic role of atrial septum defects (ASD), we compared them with ESUS of high and low likelihood of being related to PFO.
Methods
In the Acute STroke Registry and Analysis of Lausanne (ASTRAL), we calculated prevalence of PFO and ASD in ESUS patient undergoing echocardiography, and odds ratios (OR) when to compared to non-cryptogenic strokes. Using the Risk of Paradoxical Embolism (RoPE) score, we divided cryptogenic PFO patients in high (HL-PFO, RoPE 8- 10) and low-likelihood (LL-PFO, RoPE 0-4) PFO-related stroke. We then performed univariate comparison of epidemiological, clinical and radiological variables of both group with ESUS ASD patients.
Results
Among all ESUS, prevalence for ASD and PFO were 1.3% and 36.8% respectively. When compared to non-cryptogenic stroke, ASD and PFO were associated with ESUS (OR of 5.2, CI= 1.6-16.6, and 2.8, CI= 2.1-3.8). Compared with HL-PFO, ASD were older, more often female, had more cardiovascular risk factors (CVRF) and silent strokes. Compared with LL-PFO, ASD group was significantly younger, more often female, and had less CVRF. No differences were found for clinical and radiological characteristics and outcome.
Conclusion
In ESUS, ASD seems to be a rare but significant stroke risk factor. Given that characteristics of such patients lie in-between high and low-likelihood paradoxical PFO- stroke, a thorough workup for other stroke mechanisms is warranted in ASD patients before routine ASD closure.