Patent foramen ovale was detected in 20% of solid organ cancer patients with embolic stroke who underwent bubble study, with paradoxical embolism identified as likely mechanism in 45% of PFO patients.
Case Series (n=55)
No
In patients with solid organ cancer and embolic stroke, PFO is present in 20% of cases and frequently co-occurs with asymptomatic venous thromboembolism, supporting the use of screening lower extremity ultrasounds in this population.
AbstractBackground Cancer-associated stroke has become increasingly recognized as a subcategory of embolic stroke of undetermined source (ESUS). Paradoxical embolism through a patent foramen ovale (PFO) is frequently cited as a common stroke mechanism in this population, but its prevalence in an ESUS cohort with newly diagnosed cancer is unknown. Objective To determine the prevalence of PFO in patients with solid organ malignancy and ESUS. Methods We searched the Stanford Research Repository for adults with solid organ malignancies who suffered a stroke secondary to an anterior circulation large vessel occlusion within 1 year after their cancer diagnosis. Only subjects who had an echocardiogram with bubble study were included. Chart extraction was completed for clinical/radiographic information. We used descriptive statistics to summarize the data. Results Fifty-five patients were included. Median time from cancer diagnosis to stroke was 65 days (IQR 11–182). The most common primary cancer site was lung (25.5%); 43.6% had metastases; 21/55 (38.2%) transitioned to comfort care during hospitalization. The prevalence of PFO was 20% (11/55). Paradoxical embolism was identified as a likely mechanism of stroke in 5/11 (45%) patients with PFO based on co-occurring venous thromboembolism (VTE). In 4/5 patients, VTE was asymptomatic and diagnosed based on screening studies at presentation. Conclusion The prevalence of PFO among cancer patients with ESUS was 20%, and there was a high (45%) rate of co-occurring VTE. Given the high rates of asymptomatic detection of VTE identified based on screening ultrasounds, these results could support screening for VTE in this population.
Lun et al. (2026) conducted a case series in solid organ malignancy and embolic stroke (n=55). Patent foramen ovale was detected in 20% of solid organ cancer patients with embolic stroke who underwent bubble study, with paradoxical embolism identified as likely mechanism in 45% of PFO patients.