Abstract TP577: Prevalence and Associations of Ischemic Stroke in Pulmonary ArterioVenous Fistulas

Introduction: Pulmonary-arteriovenous-fistulas (PAVFs) are pathologic right-to-left shunts resulting in paradoxical embolism causing acute-ischemic-stroke (AIS). Recent single-center studies have identified that in patients with AIS associated with PAVF (AIS-P), traditional stroke risk-factors are not prominent and instead stroke-risk is associated with low serum iron. Single-centre studies have the risk of introducing a selection bias, while multicentre trials are challenging since PAVF still remains a rare and under-recognised entity. We thus seek epidemiological validation of such stroke predictors in patients with PAVF. Methods: We conducted a retrospective analysis of all AIS-admissions within the Nationwide-Inpatient-Sample (NIS) database (2005-2014). Baseline characteristics were compared across AIS populations [AIS-P (with PAVF) and R(routine)-AIS (without PAVF)]. We also compared morbidity, mortality and management trends of AIS in patients with and without PAVF. Results: Of 4,271,910 patients admitted with AIS, 822 (0.02%) were diagnosed with a PAVF. Over this decade the prevalence of PAVF per million AIS-admissions, rose from 197 to 368 (P trend =0.026). Patients with PAVF were younger with a median age (IQR) of 57.5 (42.2 -70.4) years vs. 72.5 (60.8-82.1) years (p<0.001); but had comparable age-adjusted inpatient morbidity (χ 2 p=0.71) and all-cause mortality (χ 2 p=0.26). On multivariate analyses, the odds ratios (95% confidence-interval) favouring PAVF as the cause for AIS were 9.0 (6.79-11.94) for hypoxemia, 4.64 (3.84-5.60) for patent-foramen-ovale, 4.52 (3.42-5.97) for pulmonary hypertension, 4.07(2.23-7.44) for epistaxis, and 2.12 (1.60-2.82) for iron deficiency anaemia [all p-values <0.001]. Conclusion: Pulmonary-arteriovenous-fistula related AIS represents a significantly younger demographic, which suffers inpatient morbidity and mortality comparable to routine ischemic-stroke. They carry a unique set of stroke-risk markers, including treatable conditions such as iron deficiency anemia. Further studies are needed to examine a causal role for such markers on ischemic-stroke risk in this cohort.

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Ischemic Stroke in Patients With Pulmonary Arteriovenous Fistulas

Stroke ◽

10.1161/strokeaha.120.032073 ◽

2021 ◽

Author(s):

Karan K. Topiwala ◽

Smit D. Patel ◽

Mubashir Pervez ◽

Claire L. Shovlin ◽

Mark J. Alberts

Keyword(s):

Ischemic Stroke ◽

Iron Deficiency ◽

Iron Deficiency Anemia ◽

Hereditary Hemorrhagic Telangiectasia ◽

Case Fatality ◽

The United States ◽

Deficiency Anemia ◽

Risk Markers ◽

Arteriovenous Fistulas ◽

Pulmonary Arteriovenous Fistulas

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 ( P trend , 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.

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