Prevalence of patent foramen ovale in solid organ cancer patients with embolic stroke - A case series.

BACKGROUND

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.