Applicability of Transthoracic Contrast Echocardiography for the Diagnosis and Treatment of Idiopathic Pulmonary Arteriovenous Malformations

Objective: To explore the preferred test to screen for pulmonary arteriovenous malformations (PAVMs) and to predict the probability of interventional embolization.Methods: We performed a retrospective observational study evaluating patients with idiopathic PAVMs from 2009 to 2019. After clinical evaluation, a total of 105 patients were studied, including 71 patients with positive digital subtraction pulmonary angiography (DSPA) findings and 34 with negative DSPA findings. The following patient data were assessed: blood test, chest radiograph, transthoracic contrast echocardiography (TTCE), and DSPA findings.Results: The majority of patients with idiopathic PAVMs were female (66.2% with positive DSPA findings). We found a good κ-coefficient of 0.77 with strong consistency for inter observer agreement concerning the pulmonary right-to-left shunt (RLS) grade on TTCE, which was superior to conventional chest radiographs. The positive predictive value (PPV) of the radiographic features for PAVMs on DSPA was 0.83 (95% CI 0.64–1.0) and 0.44 for the possibility of embolization (95% CI 0.19–0.70). The PPV of the shunt grade of PAVMs on DSPA was 0.14 (95% CI 0.01–0.29) for grade 1, 0.74 (95% CI 0.60–0.88) for grade 2, and 0.97 (95% CI 0.92–1.0) for grade 3. The PPVs of pulmonary shunt grades 2 and 3 on TTCE for the possibility of embolization for PAVMs were 0.21 (95% CI, 0.05–0.36) and 0.87 (95% CI, 0.79–0.99), respectively.Conclusion: TTCE is the preferred screening test for PAVMs. The pulmonary RLS grade on TTCE not only identifies the likelihood of PAVMs but also predicts the probability for embolization.

Possibilities of contrast transthoracic echocardiography in the diagnosis of thrombosis of the left atrial appendage

В основе контрастного трансторакального исследования ушка левого предсердия (УЛП) лежит возможность оценки его тромбоза у пациентов с пароксизмальной и персистирующей формами мерцательной аритмии с высоким риском тромбоэмболических событий. Известно, что причиной развития ишемического инсульта у больных с фибрилляцией предсердий более чем в 90% случаев является образование и дисло- кация тромба в УЛП. До настоящего времени основным методом диагностики тромбоза УЛП является чреспищеводная эхокардиография. Однако не во всех случаях она может быть использована. Внедрение современных эхокардиографических технологий, а также появление ультразвуковых контрастов нового поколения сподвигло нас к проведению данного исследования. Метод трансторакальной контрастной эхокардиографии в сочетании с технологией спекл-трекинг эхокардиографии позволил визуализировать тромбы в УЛП у больных, а также выявить пациентов с высокой степенью спонтанного эхоконтрастирования The contrast transthoracic echocardiography of the left atrial appendage (LAA) is based on the possibility of assessing its thrombosis in patients with paroxysmal and persistent forms of atrial fibrillation with a high risk of thromboembolic events. It is known that the cause of ischemic stroke in patients with AF in more than 90% of cases is the formation and dislocation of a thrombus in the LAA. Until now the main method for diagnosing LAA thrombosis is transesophageal echocardiography. However, it cannot be used in all cases. The introduction of modern echocardiographic technologies, as well as the emergence of a new generation of ultrasound contrasts, prompted us to conduct this study. The method of transthoracic contrast echocardiography in combination with speckle-tracking echocardiography technology made it possible to visualize thrombi in the LA in patients, as well as to identify patients with a high degree of spontaneous echocontrast

Comparison of Contrast Enhanced Magnetic Resonance Angiography to Computed Tomography in Detecting Pulmonary Arteriovenous Malformations

Background: Computed tomography (CT) is considered the imaging modality of choice to diagnose pulmonary arteriovenous malformations PAVMs. The drawback of this technique is that it requires ionizing radiation. Magnetic resonance (MR) imaging does not have the limitation, but little is known about the performance of MR compared to CT for the detection of PAVMs. The aim of this study is to investigate the sensitivity of contrast-enhanced MR angiography (CE-MRA) in the detection of PAVMs with feeding artery diameters (FAD) > 2 mm. Methods: Patients with a grade 2 or 3 shunt on screening transthoracic contrast echocardiography (TTCE) were asked to participate. Included patients underwent chest CT and CE-MRA. CT was considered the reference standard. CT and CE-MRA scans were anonymized and assessed for the presence of PAVMs with FAD > 2 mm by one and two readers respectively. Data analysis was performed on per patient and per PAVM basis. Results: Fifty-three patients were included. 105 PAVMs were detected on CT, 45 with a FAD ≥ 2 mm. In per patient analysis, sensitivity and specificity of CE-MRA were 92% and 97% respectively for reader 1 and 92% and 62% for reader 2. Negative and positive predictive value (NPV/PPV) were 93% and 96% for R1 and 90% and 67% for R2. In per PAVM analysis, sensitivity, specificity, NPV and PPV were 96%, 99%, 100% and 86% for R1 and 93%, 96%, 100% and 56% for R2, respectively. Conclusions: CE-MRA has excellent sensitivity and NPV for detection of PAVMs with FAD ≥ 2 mm and can therefore be used to detect these PAVMs. We are hopeful that future advancements in CE-MRA technology will reduce false positive rates and allow for more broad use of CE-MRA in PAVM diagnosis and management.

Microtransesophageal Echocardiographic Guidance during Percutaneous Interatrial Septal Closure without General Anaesthesia

Objective. To study the safety and efficacy of microtransesophageal echocardiography (micro-TEE) and TEE during percutaneous atrial septal defect (ASD) and patent foramen ovale (PFO) closure. Background. TEE has proven to be safe during ASD and PFO closure under general anaesthesia. Micro-TEE makes it possible to perform these procedures under local anaesthesia. We are the first to describe the safety and efficacy of micro-TEE for percutaneous closure. Methods. All consecutive patients who underwent ASD and PFO closure between 2013 and 2018 were included. The periprocedural complications were registered. Residual shunts were diagnosed using transthoracic contrast echocardiography (TTCE). All data were compared between the use of TEE or micro-TEE within the ASD and PFO groups separately. Results. In total, 82 patients underwent ASD closure, 46 patients (49.1 ± 15.0 years) with TEE and 36 patients (47.8 ± 12.1 years) using micro-TEE guidance. Median device diameter was, respectively, 26 mm (range 10–40 mm) and 27 mm (range 10–35 mm). PFO closure was performed in 120 patients, 55 patients (48.6 ± 9.2 years, median device diameter 25 mm, range 23–35 mm) with TEE and 65 patients (mean age 51.0 ± 11.8 years, median device diameter 27 mm, range 23–35 mm) using micro-TEE. There were no major periprocedural complications, especially no device embolizations within all groups. Six months after closure, there was no significant difference in left-to-right shunt after ASD closure and no significant difference in right-to-left shunt after PFO closure using TEE or micro-TEE. Conclusion. Micro-TEE guidance without general anaesthesia during percutaneous ASD and PFO closure is as safe as TEE, without a significant difference in the residual shunt rate after closure.

The use of echo density to quantify pulmonary right-to-left shunt in transthoracic contrast echocardiography

Aims Transthoracic contrast echocardiography (TTCE) is the recommended screening tool to detect pulmonary right-to-left shunt (RLS) caused by pulmonary arteriovenous malformations (PAVMs). We assessed a novel method to quantify the RLS using the change in echo density (ED) following contrast injection. Methods and results An analysis of 437 consecutive patients [58% female, 47 years, interquartile range (IQR) 33–60] who underwent TTCE for the detection of a pulmonary RLS. Using ImageJ (National Institutes of Health), the change in ED was measured for each patient. This method was strongly correlated (Spearman’s ρ = 0.89; P < 0.0001) with our standard method based on a four-point grading scale (no, mild, moderate, and severe RLS). In patients without a history of embolotherapy (n = 334), a PAVM was detected with chest computed tomography (CT) in 66 and embolotherapy was judged possible in 35 of these patients. The median increase in ED was higher in the latter: +20.1% (IQR 12.3–34.0) compared to non-treatable PAVM +0.2% (IQR −0.2 to 1.1). The specificity to detect treatable PAVMs increased from 87% to 90% when using the novel method without affecting the sensitivity (of 100%). Using the optimal cut-off value of +4.5% increase in ED, 8/74 (11%) needed chest CT-scans—individuals with a moderate or severe RLS—were no longer required without missing any treatable PAVM. Conclusions The use of ED quantification for pulmonary RLS is promising; resulting in a substantial decrease in the number of chest CT scans needed. However, this method and the threshold should be validated in an independent study population.

Pulmonary arteriovenous malformations in children with hereditary hemorrhagic telangiectasia: a longitudinal study

Pulmonary arteriovenous malformations (PAVMs) often occur in children with hereditary hemorrhagic telangiectasia (HHT). A 14-year longitudinal study of PAVMs in children with HHT was undertaken to assess the prevalence, the clinical impact, and progression of these malformations. This was a retrospective, single-center study from May 2002 to December 2016 of 129 children with HHT diagnosed using Curacao criteria and/or confirmed by genetic testing. Transthoracic contrast echocardiography (TTCE) was the primary screening modality in all patients and PAVMs were diagnosed based on Barzilai criteria. Moderately positive TTCE (Barzilai criteria ≥ 2) was confirmed with subsequent contrast chest CT. New PAVMs were diagnosed with a positive TTCE after an initial negative TTCE. Embolization of PAVMs were performed according to HHT consensus guidelines. Of 129 children with HHT, 76 (59%) were found to have PAVMs. Sixty-seven (88%) were positive for PAVMs on initial screening. Of 63 children without PAVMs on initial screening, 31 were followed for >1 year. Nine of the 31 (29%) developed new PAVMs after initial negative study. Thirty-eight (50%) of the total 76 children with PAVMs had or developed lesions large enough to be treated with embolization. Nine patients with PAVMs initially too small to be treated with embolization, developed progression of disease and ultimately were treated with embolization over time. The majority, 60% (23/38), of the children with large PAVMs had no related clinical symptoms. After embolization, 21% (8/38), of patients underwent repeat interventions. Genetic diagnosis, age, and gender were not associated with risk of having PAVM nor with need for repeat interventions. Nearly 60% of children with HHT develop PAVMs. The risk for new PAVMs to develop, small PAVMs to become large, and previously embolized PAVMs to require further intervention remains throughout childhood. Thus, children with HHT require continued follow-up until adulthood.