Ischemic Stroke in Patients With 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.

Abstract P612: Iron Deficiency Anemia and Ischemic Stroke in Patients With 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.

Clinical Analysis of Transcatheter Embolotherapy for Congenital Pulmonary Arteriovenous Fistulas in Children

Objective: To summarize the clinical features and therapeutic effects of transcatheter embolotherapy for congenital pulmonary arteriovenous fistulas (PAVFs) in children, and to explore the method and therapeutic principle of transcatheter embolotherapy for congenital PAVFs in children.Method: We retrospectively reviewed nine patients with PAVF who underwent transcatheter embolotherapy in the Children’s Hospital of Chongqing Medical University from July 2004 to July 2019, including the demographic characteristics, clinical manifestations, efficiency of closure, and follow-up.Results: Transcatheter embolotherapy was successful in all cases, and the symptom remission rate was 100% during the follow-up. No residual shunts or other complications occurred during the follow-up period. Compared with before embolotherapy, there were significant changes in the percentage of saturated oxyhemoglobin and total hemoglobin level at the last follow-up (t=10.06, P=0.000; t=3.055, P=0.0076). No significant difference was observed in pulmonary artery pressure before and after embolotherapy (t=0.13, P=0.90).Conclusions: Transcatheter embolotherapy offers the advantages of safety, with a decreased risk of trauma and a specific effect of treatment, and therefore is recommended as the first-line treatment for congenital PAVFs in children. However, continued research is necessary to understand the full potential of transcatheter embolotherapy.

Spontaneous Septic Embolic Encephalitis and Endophthalmitis in a Recovering Polytrauma Patient: A Case Report

In polytrauma cases with thoracic injury and long-term chest tube drain, there is a risk of pulmonary arteriovenous fistula formation, which mostly remains undiagnosed. The pulmonary arteriovenous fistulas lead to the right to left shunt and could be a potential source of systemic septic embolism. Here, we describe a recovering polytrauma patient, who spontaneously developed septic embolic encephalitis and endogenous endophthalmitis, with no evident source of septic systemic embolism. We suspect the pulmonary arteriovenous fistulas due to thoracic injury or chest tube drain could be the possible source of septic systemic embolism, which needs to be evaluated in such cases after excluding common causes.

Incidental diagnosis of four pulmonary arteriovenous fistulas during patent foramen ovale closure: a case report

Cryptogenic cerebral ischemia in young patients is commonly ascribed to paradoxical embolism. We report the clinical case of a young patient with cryptogenic stroke and a patent foramen ovale, undergoing percutaneous closure of atrial septal defect. Contrast transoesophageal echocardiography at the end of the procedure demonstrated massive late residual right-to-left shunt, due to the coexistence of pulmonary arteriovenous fistulas that were subsequently closed. Routinary adoption of contrast transoesophageal echocardiography at the end of patent foramen ovale closure interventions may be useful to detect early and late residual shunts. Late residual shunts may be due to pulmonary fistulas, a well-known risk factor for recurrent thromboembolic events.

Efficacy of bubble contrast echocardiography in detecting pulmonary arteriovenous fistulas in children with univentricular heart after total cavopulmonary connection

Background:Development of pulmonary arteriovenous fistulas in patients with cavopulmonary anastomosis may result in a significant morbidity. Although the use of bubble contrast echocardiography with selective injection into both the branch pulmonary arteries in identifying pulmonary arteriovenous fistulas has been increasing, the actual efficacy of this diagnostic modality has not been properly evaluated. Thus, this study aimed to assess the efficacy of bubble contrast echocardiography in detecting pulmonary arteriovenous fistulas in children with total cavopulmonary connection.Methods:A total of 140 patients were included. All patients underwent cardiac catheterisation. Bubble contrast echocardiographic studies were performed by injecting agitated saline solution into the branch pulmonary arteries. Transthoracic echocardiograms that use an apical view were conducted to assess the appearance of bubble contrast in the systemic ventricles. Then, the contrast echocardiogram results and other cardiac parameters were compared.Results:No correlation was found between contrast echocardiogram grade and other cardiac parameters, such as pulmonary capillary wedge saturation and pulmonary artery resistance. Moreover, only 13 patients had negative results on both the right and left contrast echocardiograms, and 127 of the 140 patients had positive results on contrast echocardiograms even though they had normal pulmonary capillary wedge saturation. Results showed that bubble contrast echocardiography was a highly sensitive method and was likely to obtain false-positive results.Conclusions:Bubble contrast echocardiography might be highly false positive in detecting pulmonary arteriovenous fistulas in patients with cavopulmonary anastomosis. We have to consider how we make use of this method. Further standardisation of techniques is required.