Background and Purpose:
Pulmonary arteriovenous fistulas (PAVFs) are a treatable cause of acute ischemic stroke (AIS), not mentioned in current American Heart/Stroke Association guidelines. PAVFs are recognized as an important complication of hereditary hemorrhagic telangiectasia.

Methods:
The prevalence of PAVF and hereditary hemorrhagic telangiectasia among patients admitted with AIS in the United States (2005–2014) was retrospectively studied, utilizing the Nationwide Inpatient Sample database. Clinical factors, morbidity, mortality, and management were compared in AIS patients with and without PAVF/hereditary hemorrhagic telangiectasia.

Results:
Of 4 271 910 patients admitted with AIS, 822 (0.02%) were diagnosed with PAVF. Among them, 106 of 822 (12.9%) were diagnosed with hereditary hemorrhagic telangiectasia. The prevalence of PAVF per million AIS admissions rose from 197 in 2005 to 368 in 2014 (Ptrend, 0.026). Patients with PAVF were younger than AIS patients without PAVF (median age, 57.5 versus 72.5 years), had lower age-adjusted inpatient morbidity (defined as any discharge other than home; 39.6% versus 46.9%), and had lower in-hospital case fatality rates (1.8% versus 5.1%). Multivariate analyses identified the following as independent risk markers (odds ratio [95% CI]) for AIS in patients with PAVF: hypoxemia (8.4 [6.3–11.2]), pulmonary hemorrhage (7.9 [4.1–15.1]), pulmonary hypertension (4.3 [4.1–15.1]), patent foramen ovale (4.2 [3.5–5.1]), epistaxis (3.7 [2.1–6.8]), venous thrombosis (2.6 [1.9–3.6]), and iron deficiency anemia (2 [1.5–2.7]). Patients with and without PAVF received intravenous thrombolytics at a similar rate (5.9% versus 5.8%), but those with PAVF did not receive mechanical thrombectomy (0% versus 0.7%).

Conclusions:
Pulmonary arteriovenous fistula–related ischemic stroke represents an important younger demographic with a unique set of stroke risk markers, including treatable conditions such as causal PAVFs and iron deficiency anemia.