Sensitivity for Detection of Patent Foramen Ovale Increased with Increasing Number of Contrast Injections: A Descriptive Study with Contrast Transesophageal Echocardiography

Techniques for Identifying a Patent Foramen Ovale: Transthoracic Echocardiography, Transesophageal Echocardiography, Transcranial Doppler, Right Heart Catheterization

Noninvasive and invasive imaging modalities play important roles for the detection of patent foramen ovale (PFO). Transthoracic echocardiography or transcranial Doppler bubble study can be used for initial noninvasive PFO screening. For diagnostic confirmation, transesophageal echocardiography bubble study can be utilized, a semiinvasive confirmatory test that can directly visualize a PFO. In selective cases when the diagnosis is in doubt, PFO can be accurately diagnosed invasively with right heart catheterization. Understanding the advantages and limitations of each diagnostic option will help clinicians choose the appropriate test for patients presenting with a PFO-associated condition who may benefit from percutaneous device closure.

Comparative evaluation of intracardiac, transesophageal, and transthoracic echocardiography in the assessment of patent foramen ovale: A retrospective single-center study

INTRODUCTION

Certain patent foramen ovale (PFO) characteristics, such as a large right-to-left shunt (RLS) or atrial septal aneurysm, identify patients who may receive the highest clinical benefit from percutaneous PFO closure. This study aimed to compare intracardiac echocardiography (ICE) with standard echocardiographic imaging in the evaluation of high-risk PFO characteristics and RLS severity in patients with PFO-associated stroke.

METHODS

We conducted a retrospective review of all patients aged ≥18 years who underwent percutaneous PFO closure for PFO-associated stroke and received all three ultrasound-based cardiac imaging modalities and had interpretable results (N = 51). We then compared RLS severity, high-risk PFO characteristics, and the proportion of patients with a higher likelihood of PFO-associated stroke by ICE versus transthoracic echocardiogram (TTE) and transesophageal echocardiogram (TEE).

RESULTS

The final cohort had a mean (±SE) age of 48.4 (±1.8) years and was predominantly female (58.8%). ICE was more likely to identify a large RLS versus TTE/TEE combined (66.7% vs. 45.1%; p = 0.03). The use of ICE resulted in significantly more patients being reclassified as having a higher likelihood of PFO-associated stroke (TTE vs. TEE vs. ICE: 10.4% vs. 14.6% vs. 25%; p = 0.03). A high-quality bubble study was found to be the single most important factor associated with identifying a larger RLS across all modalities (ρ [p]; TTE: 0.49 [<0.001], TEE: 0.60 [<0.001], ICE: 0.32 [0.02]). The presence of a hypermobile septum was associated with significantly greater RLS on ICE (ρ [p]: 0.3 [0.03]), especially with poor quality bubble studies (ρ [p]: 0.49 [0.02]).

CONCLUSION

In this observational study of patients with PFO-associated stroke, ICE detected a large RLS more frequently than TTE and TEE; and reclassified some patients as having a higher likelihood of PFO-associated stroke.

Contrast-enhanced transcranial doppler versus contrast transthoracic echocardiography for right-to-left shunt diagnosis

RLS can be diagnosed using US, CT angiography, and right heart catheterization. However, most reliable diagnostic modality remains undetermined. c-TCD was more sensitive than c-TTE in the diagnosis of RLS. This was true especially for the detection of provoked shunts or mild shunts. c-TCD can be used as the preferred screening method for RLS.

Calf muscle pump tensing as a novel maneuver to improve the diagnostic performance of detecting patent foramen ovale during transesophageal echocardiography

Objective

The Valsalva maneuver is the most sensitive provocative maneuver for patent foramen ovale detection. However, nearly half of patients are unable to perform the Valsalva maneuver well. The aim of this study was to investigate the mechanism of action of calf muscle pump tensing (TENSE) as a novel patent foramen ovale (PFO) provocative maneuver and to evaluate the diagnostic value for PFO and the effect on right-to-left shunt volume compared with the Valsalva maneuver.

Methods

This study prospectively investigated 171 patients who were highly suspected to have PFO clinically. Five patients with atrial septal defects newly diagnosed on transesophageal echocardiography (TEE) were excluded. 166 patients were injected with agitated saline under three provocative maneuvers: Valsalva maneuver, TENSE, and Valsalva + TENSE combined maneuver. The patients were divided into the effective Valsalva group (n = 93) and ineffective Valsalva group (n = 73) according to whether they could perform an effective Valsalva maneuver. TENSE consisted of the straightening of both lower limbs, and when the right atrium was filled with microbubbles, the patient performed instantaneous ankle dorsiflexion movements while maintaining dorsiflexion for 3-5 s.

Results

Overall, the PFO detection rate of the Valsalva + TENSE combined maneuver (78 [50.1%]) was significantly higher than that of the Valsalva maneuver (51 [30.7%]) and TENSE maneuver (57 [34.3%]) (P < 0.001). In the patients who were able to perform an effective Valsalva maneuver, the PFO detection rate by TENSE was not significantly different from that by the Valsalva maneuver (Valsalva 37/93 [39.8%] vs. TENSE 31/93 [33.3%], P > 0.05), while for the patients who performed an ineffective Valsalva maneuver, the PFO detection rate by the TENSE maneuver was higher than that by the Valsalva maneuver (TENSE 26/73 [35.6%] vs. Valsalva14/73[19.2%], P = 0.017).

Conclusion

TENSE is a simple and effective provocative maneuver in the diagnosis of PFO using TEE and can assist the Valsalva maneuver. For patients who cannot perform an effective Valsalva maneuver, TENSE can be an alternative to the Valsalva maneuver to some extent.

Advances in the management of cardioembolic stroke associated with patent foramen ovale

Patent foramen ovale (PFO) describes a valve in the interatrial septum that permits shunting of blood or thrombotic material between the atria. PFOs are present in approximately 25% of the healthy population and are not associated with any pathology in the vast majority of cases. However, comparisons between patients with stroke and healthy controls suggest that PFOs may be causative of stroke in certain patients whose stroke is otherwise cryptogenic. Options for the diagnosis of PFO include transthoracic echocardiography, transesophageal echocardiography, and transcranial Doppler ultrasonography. PFOs associated with an interatrial septal aneurysm seem to be more strongly linked to risk of recurrent stroke. Therapeutic options for secondary stroke prevention in the setting of a PFO include antiplatelet therapy, anticoagulation, and percutaneous device closure. Recent randomized clinical trials suggest that percutaneous closure reduces the subsequent risk of stroke in appropriately selected patients, with a large relative benefit but small absolute benefit. Referral for percutaneous PFO closure should therefore be considered in certain patients after a multidisciplinary, patient centered discussion. Areas for future study include structural biomarkers to aid in determining the role of PFO closure in older people with possible PFO associated stroke, the role of direct oral anticoagulants, and very long term outcomes after device closure.

Review: Detection of patient foramen ovale using transcranial Doppler or standard echocardiography

A patent foramen ovale (PFO) is a common remnant of fetal circulation present in up to 25% of the worldwide adult population. Paradoxical embolism occurs when venous blood crosses the PFO into the arterial system, bypassing the pulmonary circulation. This allows for the direct passage of microemboli into cerebral blood vessels, increasing the risk of cryptogenic stroke. This review investigates the current diagnostic procedures used to detect and grade a PFO, including transthoracic echocardiography (TTE), transoesophageal echocardiography (TOE) and transcranial Doppler (TCD). Only a few studies have directly compared the use of TTE with TCD for PFO detection but several have compared TTE and TCD independently against the clinical gold standard TOE. Known pitfalls of TTE and TCD are also discussed, including the difficulty of differentiating between intracardiac shunts and intrapulmonary shunts. This review also discusses methods to optimise imaging, such as performing an adequate Valsalva manoeuvre, the role of abdominal compression and the choice of the injection site for the contrast agent and how these may increase the diagnostic success of detecting a right-to-left shunt when prompted by a clinician.

Agitated Saline Contrast Echocardiography in the Identification of Intra- and Extracardiac Shunts: Connecting the Dots

Agitated saline contrast studies are an essential component of contemporary echocardiography. Agitated saline contrast plays a critical role in the elucidation of intracardiac versus intrapulmonary shunting and can have major therapeutic implications, particularly in light of the evolution of percutaneous treatment options for atrial septal defects or a patent foramen ovale. Despite their perceived simplicity, however, there are numerous pitfalls of these investigations that can occur during their performance and interpretation. As such, the authors review the "bubble study" in identifying intracardiac and extracardiac shunts, including the history of its development, the physics and physiology of contrast enhancement, how to optimally perform and interpret an agitated saline contrast study, and its safety in unique populations.

Recurrent cerebrovascular events in patients after percutaneous closure of patent foramen ovale

BACKGROUND

Recent published trials have shown the efficacy of transcatheter closure of patent foramen ovale (PFO) for preventing recurrent cryptogenic cerebrovascular events. However, the risk of recurrent cerebrovascular events (rCVEs) is up to 5.7%, and the etiology is unclear.

OBJECTIVE

This study aimed to investigate the risk factors for rCVEs after closure of PFO during long-term follow-up.

METHODS

In our center, 282 consecutive patients underwent PFO closure because of a cryptogenic cerebrovascular event between 2006 and 2014. Their Risk of Paradoxical Embolism (RoPE) score was calculated retrospectively. We followed up with the patients by telephone, using hospital records to identify those who suffered from rCVEs. Patients with rCVEs were matched with two control patients of the same sex and RoPE score without rCVEs who underwent PFO closure at approximately the same time. The patients with rCVEs and controls participated in a clinical examination, including contrast transthoracic echocardiography (TTE) and Holter electrocardiography, to investigate the possible cause of rCVEs compared with controls.

RESULTS

Fourteen (5%) out of the 282 consecutive patients who underwent PFO closure suffered from rCVEs during a mean follow-up of 8.4 years (1.7 rCVEs per 100 patient-years). The median RoPE score of the patients was 7. Recurrent CVE occurred in 3.2 patients per 100 patient-years in patients with residual shunting compared with 0.8 patients per 100 patient-years in those without residual shunt. These patients were on antiplatelet treatment or without any effective anticoagulant treatment at the time rCVE occurred. The risk ratio of rCVEs in patients with residual shunting was 2.9-times higher than in patients without residual shunting (95% CI: 1.4-6.1) at follow-up visit. Four patients who had the BioSTAR device implanted suffered from an rCVE despite lack of residual shunting.

CONCLUSIONS

This study indicates that residual shunting and choice of the device may be the major reasons for rCVEs.

Diagnosis of Patent Foramen Ovale: The Combination of Contrast Transcranial Doppler, Contrast Transthoracic Echocardiography, and Contrast Transesophageal Echocardiography

Objectives

To access the distinct values of contrast transcranial Doppler (cTCD), contrast transthoracic echocardiography (cTTE), and contrast transesophageal echocardiography (cTEE) in the diagnosis of right-to-left shunt (RLS) due to patent foramen ovale (PFO) and to define the most practical strategy for the diagnosis of PFO.

Methods

102 patients with a high clinical suspicion for PFO had simultaneous cTCD, cTTE, and cTEE performed. The agitated saline mixed with blood was used to detect right-to-left shunt (RLS).

Results

In all 102 patients, the shunt was detected at rest by cTCD in 60.78% of cases, by cTTE in 42.16%, and by cTEE in 47.06%. The positive results of all 3 techniques with Valsalva maneuver (VM) were significantly improved. cTCD showed higher pick-up rate than cTTE (98.04% vs. 89.22%; χ² = 12.452, p < 0.05) and the cTEE (98.04% vs. 96.08%; nonsignificant difference) in the diagnosis of PFO. Nevertheless, cTEE, compared with cTTE, underestimated shunting in 44% of patients. The diameter of both PFO entrance and exit was significantly greater in patients with a severe shunt compared with a mild shunt (2.8 ± 1.0 mm vs. 2.0 ± 0.7 mm, t = 3.135, p < 0.05) and the cTEE (98.04% vs. 96.08%; nonsignificant difference) in the diagnosis of PFO. Nevertheless, cTEE, compared with cTTE, underestimated shunting in 44% of patients. The diameter of both PFO entrance and exit was significantly greater in patients with a severe shunt compared with a mild shunt (2.8 ± 1.0 mm vs. 2.0 ± 0.7 mm, t = 3.135, p < 0.05) and the cTEE (98.04% vs. 96.08%; nonsignificant difference) in the diagnosis of PFO. Nevertheless, cTEE, compared with cTTE, underestimated shunting in 44% of patients. The diameter of both PFO entrance and exit was significantly greater in patients with a severe shunt compared with a mild shunt (2.8 ± 1.0 mm vs. 2.0 ± 0.7 mm, t = 3.135, p < 0.05) and the cTEE (98.04% vs. 96.08%; nonsignificant difference) in the diagnosis of PFO. Nevertheless, cTEE, compared with cTTE, underestimated shunting in 44% of patients. The diameter of both PFO entrance and exit was significantly greater in patients with a severe shunt compared with a mild shunt (2.8 ± 1.0 mm vs. 2.0 ± 0.7 mm,

Conclusions

The best method to diagnose PFO should be the combination of cTCD, cTTE, and cTEE. And cTCD should be applied as the first choice for screening RLS. Then, cTTE should be performed to quantify the severity of the shunt. Last but not least, cTEE should be performed to assess the morphologies of PFO when the closure is planned. The study provides for clinicians the most practical strategy for diagnosing PFO in the future. However, further trials with a large sample size are required to confirm this finding.

Patent Foramen Ovale: Pivotal Role of Transesophageal Echocardiography in the Indications for Closure, Assessment of Varying Anatomies and Post-procedure Follow-up

Patent foramen ovale (PFO) is present in 15%-30% of the general population and has been associated with various pathologic states, including cryptogenic stroke, platypnea-orthodeoxia syndrome, decompression sickness and migraine with auras. Transesophageal echocardiography (TEE) has a major role in the diagnostic evaluation of PFO, as well as in the post-procedural assessment after transcatheter closure. The goals of this article were to synthesize the echocardiographic transesophageal techniques required for accurate PFO diagnosis and careful anatomic assessment of its anatomic variants, to focus TEE indications for device closure as complementary to clinical indications and to assess the role of TEE in the post-procedure follow-up.

Patent foramen ovale and embolic cryptogenic stroke

The paper considers the actual problem of cryptogenic stroke and patent foramen ovale (PFO). It highlights the issues of pathogenesis and role of paradoxical embolism in the development of cerebral circulation disorders. The features of clinical manifestations and neuroimaging pattern of stroke in the presence of PFO are described. Ultrasound diagnostic techniques used to verify a cardiac anomaly are characterized. Approaches to establishing a cause-and-effect relationship between the presence of PFO and the development of stroke are presented. The current possibilities of secondary prevention in this category of patients, in particular the results of studies of percutaneous PFO occlusion, are discussed.

Provocative maneuvers to improve patent foramen ovale detection: A brief review of the literature

Patent foramen ovale (PFO) is the most common type of inter-atrial shunt, with prevalence as high as 30%. Detection of PFO has implications in patients with stroke, peripheral embolism, decompression illness, and other conditions. Transesophageal echo (TEE) with saline contrast injection is the current standard for PFO detection, but even with TEE, PFOs are sometimes missed. With advances in percutaneous PFO closure therapies and proven long-term benefit of closure, accurate PFO detection takes on cardinal importance. Various provocative maneuvers to enhance PFO detection are in clinical use and have been studied. The Valsalva maneuver has long-held position as the ideal provocation to unmask PFO, but other maneuvers such as cough, sniff, Müller's, and more have gained relevance. In this article, we will examine various maneuvers and discuss their utility in PFO detection.

Reproducibility of right-to-left shunt quantification using transthoracic contrast echocardiography in hereditary haemorrhagic telangiectasia

Aim

Transthoracic contrast echocardiography (TTCE) is recommended for screening of pulmonary arteriovenous malformations (PAVMs) in hereditary haemorrhagic telangiectasia. Shunt quantification is used to find treatable PAVMs. So far, there has been no study investigating the reproducibility of this diagnostic test. Therefore, this study aimed to describe inter-observer and inter-injection variability of TTCE.

Methods

We conducted a prospective single centre study. We included all consecutive persons screened for presence of PAVMs in association with hereditary haemorrhagic telangiectasia in 2015. The videos of two contrast injections per patient were divided and reviewed by two cardiologists blinded for patient data. Pulmonary right-to-left shunts were graded using a three-grade scale. Inter-observer and inter-injection agreement was calculated with κ statistics for the presence and grade of pulmonary right-to-left shunts.

Results

We included 107 persons (accounting for 214 injections) (49.5% male, mean age 45.0 ± 16.6 years). A pulmonary right-to-left shunt was present in 136 (63.6%) and 131 (61.2%) injections for observer 1 and 2, respectively. Inter-injection agreement for the presence of pulmonary right-to-left shunts was 0.96 (95% confidence interval (CI) 0.9–1.0) and 0.98 (95% CI 0.94–1.00) for observer 1 and 2, respectively. Inter-injection agreement for pulmonary right-to-left shunt grade was 0.96 (95% CI 0.93–0.99) and 0.95 (95% CI 0.92–0.98) respectively. There was disagreement in right-to-left shunt grade between the contrast injections in 11 patients (10.3%). Inter-observer variability for presence and grade of the pulmonary right-to-left shunt was 0.95 (95% CI 0.91–0.99) and 0.97 (95% CI 0.95–0.99) respectively.

Conclusion

TTCE has an excellent inter-injection and inter-observer agreement for both the presence and grade of pulmonary right-to-left shunts.

Electronic supplementary material

The online version of this article (10.1007/s12471-018-1094-4) contains supplementary material, which is available to authorized users.

Identification and Quantification of Patent Foramen Ovale-Mediated Shunts: Echocardiography and Transcranial Doppler

Once deemed benign, patent foramen ovale (PFO)-mediated right-to-left shunting has now been linked to stroke, migraine, and hypoxemia. Contrast transesophageal echocardiography is considered the standard technique for identifying a PFO, allowing visualization of the atrial septal anatomy and differentiation from non-PFO right-to-left shunts. Transthoracic echocardiography is the most common method for PFO imaging, being cost-effective, but has the lowest sensitivity. Transcranial Doppler is highly sensitive but is unable to differentiate cardiac from pulmonary shunts; it is the best method to quantitate shunt severity, being more sensitive than transthoracic or transesophageal echocardiography so is our preferred screening method for PFO.

Patent Foramen Ovale and Stroke

A patent foramen ovale (PFO) is common and found in nearly 25% of healthy individuals. The majority of patients with PFO remain asymptomatic and they are not at increased risk for developing a stroke. The presence of PFO, however, has been found to be higher in patients with cryptogenic stroke, suggesting there may be a subset of patients with PFO who are indeed at risk for stroke. Paradoxical embolization of venous thrombi through the PFO, which then enter the arterial circulation, is hypothesized to account for this relationship. Although aerated-saline transesophageal echocardiography is the gold standard for diagnosis, aerated-saline transthoracic echocardiography and transcranial Doppler are often used as the initial diagnostic tests for detecting PFO. Patients with cryptogenic stroke and PFO are generally treated with antiplatelet therapy in the absence of another condition for which anticoagulation is necessary. Based on the findings of 3 large randomized clinical trials, current consensus guidelines do not recommend percutaneous closure, though this is an area of controversy. The following review discusses the relationship of PFO and cryptogenic stroke, focusing on the epidemiology, pathophysiological mechanisms, diagnostic tools, associated clinical/anatomic factors and treatment. (Circ J 2016; 80: 1665-1673).

Patent foramen ovale

Patent foramen ovale (PFO) is the most common congenital heart abnormality of fetal origin and is present in approximately ∼25% of the worldwide adult population. PFO is the consequence of failed closure of the foramen ovale, a normal structure that exists in the fetus to direct blood flow directly from the right to the left atrium, bypassing the pulmonary circulation. PFO has historically been associated with an increased risk of stroke, the mechanism of which has been attributed to the paradoxical embolism of venous thrombi that shunt through the PFO directly to the left atrium. However, several studies have failed to show an increased risk of stroke in asymptomatic patients with a PFO, and the risk of stroke recurrence is low in patients who have had a stroke that may be attributed to a PFO. With the advent of transoesophageal and transthoracic echocardiography, as well as transcranial Doppler, a PFO can be routinely detected in clinical practice. Medical treatment with either antiplatelet or anticoagulation therapy is recommended. At the current time, closure of the PFO by percutaneous interventional techniques does not appear to reduce the risk of stroke compared to conventional medical treatment, as shown by three large clinical trials. Considerable controversy remains regarding the optimal treatment strategy for patients with both cryptogenic stroke and PFO. This Primer discusses the epidemiology, mechanisms, pathophysiology, diagnosis, screening, management and effects on quality of life of PFO.

Body positions in the diagnosis of right-to-left shunt by contrast transcranial Doppler

Contrast transcranial Doppler (c-TCD) is sensitive in detecting right-to-left shunt (RLS). However, the methodology and ideal posture are controversial. Consecutive migraine patients were prospectively examined for RLS using c-TCD. Each patient was examined while at rest and subsequently with the Valsalva maneuver (VM) in three positions: supine, left lateral decubitus and right lateral decubitus. RLS was diagnosed with at least one microbubble detected at any position. RLS was highest in the left lateral decubitus position, both during rest and with VM. The left lateral decubitus position was associated with the highest total number of microbubbles and greater shunt grades. Patients who tested positive in the other two positions had the lowest index position failure rate during rest in the left lateral decubitus position. In some patients in whom RLS is detected at rest, it may not be detected (false negative) under VM. To ensure c-TCD's the sensitivity to RLS, testing in the left lateral decubitus position at rest and under VM is suggested; testing in other positions is necessary to avoid false negatives.

Patent foramen ovale treatment strategy: an Italian large prospective study

AIM

There is still controversy regarding the benefit of percutaneous closure of patent foramen ovale (PFO) among patients with cryptogenic stroke. Here we aimed to evaluate the factors associated with treatment choice and predictors of adverse events in patients with cryptogenic stroke or transient ischemic attack (TIA) and PFO.

METHODS

Of 418 consecutive patients with PFO and cryptogenic stroke or TIA, 262 underwent percutaneous PFO closure, whereas 156 were medically treated. Multivariable logistic regression models were developed to evaluate factors influencing the treatment strategy and predictors of outcome, a composite of stroke, TIA or all-cause mortality.

RESULTS

Patients with large interatrial right-to-left shunt were more likely treated with percutaneous closure [odds ratio (OR) = 4.79, 95% confidence interval (2.73-8.42); P < 0.0001], whereas those with multiple cerebrovascular accident (CVA) risk factors were more likely treated medically [OR = 0.15 (0.03-0.60); P = 0.023]. Age greater than 55 years [OR = 2.70 (1.05-6.88); P = 0.04], previous CVAs [OR = 2.49 (1.03-6.02); P = 0.02] and atrial septal aneurism [ASA, OR = 2.64 (1.09-6.39); P = 0.02], but not percutaneous closure of PFO [OR = 1.10 (0.44-2.74); P = 0.81], were independent predictors of outcome.

CONCLUSION

Among patients with cryptogenic stroke and PFO, the presence of large interatrial right-to-left shunt and multiple CVA risk factors influenced the treatment choice. Older age, multiple previous CVAs and ASA, but not PFO closure, independently predicted the composite outcome of cryptogenic stroke, TIA or all-cause mortality.

Recurrent stroke in patients with patent foramen ovale: An observational prospective study of percutaneous closure of PFO versus non-closure

AIMS

Observational studies favor percutaneous closure of patent foramen ovale (PFO) over medical therapy to reduce the risk of recurrent stroke, whereas randomized clinical trials have not shown significant differences. This study aims to compare long-term outcomes of PFO closure versus non-closure.

METHODS AND RESULTS

Patients with PFO and stroke considered for PFO closure were invited to a long-term clinical follow-up. Of the 314 patients, 151 (48%) were accepted for closure and 163 (52%) were not accepted (mean age 50 vs. 58 years). The cumulative incidence of all-cause mortality, stroke or transient ischemic attacks (TIAs) for closure vs. non-closure under a mean follow-up time of five years was 10.6% (16 events) vs. 12.9% (21 events), p=0.53. Six patients, 3.7% vs. 3.6%, died in each group, but no deaths were associated with PFO closure, recurrent stroke or TIA. The incidence of recurrent stroke or TIA for closure vs. non-closure was 6.6% (10 events) vs. 9.2% (15 events), p=0.63. The respective event rates for stroke were 3.9% (6 events) vs. 5.5% (9 events), p=0.50 and for TIA, 2.6% (4 events) vs. 3.7% (6 events), p=0.59.

CONCLUSION

PFO closure was associated with a low risk of recurrent events; however, compared to the non-closure group, no significant differences could be demonstrated. Careful patient selection can avoid under- as well as over-treatment of PFO patients.

Echocardiographic findings in simple and complex patent foramen ovale before and after transcatheter closure

AIMS

Percutaneous closure of patent foramen ovale (PFO) in cryptogenic cerebrovascular events is an alternative to medical therapy. The interpretation of residual shunts after implantation of different devices for PFO with different morphologies is controversial.

METHODS AND RESULTS

Transcatheter PFO closure was performed in 123 patients with a history of ≥1 paradoxical embolism using three different devices: Amplatzer (n = 46), Figulla Occlutech (n = 41), and Atriasept Cardia (n = 36). Fifty-six patients presented with simple PFO and 67 patients had complex morphologies. All patients were studied with contrast enhanced transesophageal echocardiography (TEE) before interventional procedure and thereafter at 1 and 6 months and every 6-12 months in case of incomplete closure. Definite closure was confirmed in at least two consecutive TEE studies. Various PFO morphologies were identified by TEE before device implantation. The device size to PFO diameter ratio was significantly increased in patients with complex PFO compared with those patients with a simple PFO morphology (P < 0.05). The difference between the closure rate of S-PFO and C-PFO concerning each device type was significant (Amplatzer P = 0.0027, Figulla P = 0.0043, and Atriasept P < 0.01). The mean follow-up period was 3.4 years (median 2.7 years) with a cerebrovascular re-event rate of 2.4% per year. In three patients, thrombi were detected in the 6-month TEE controls and resolved after medical therapy. In three other patients, the implantation of an adjunctive device was necessary for residual shunt.

CONCLUSION

In our series of patients, the closure rate was dependent on PFO morphology more than occluder size and type. An adjunctive device was implanted in selected cases.

Absence of significant aortic regurgitation seven years after closure of patent foramen ovale

Background

It has been suggested that there is an increase in aortic regurgitation (AR) in the short and medium term after percutaneous closure of patent foramen ovale (PFO). The aim of this study is to determine the long-term effect of percutaneous closure of PFO on the prevalence of AR.

Methods

Patients with cryptogenic stroke or transient ischemic attack who had undergone percutaneous closure of PFO more than five years before the study were invited to an echocardiographic examination.

Results

Out of 83 invited patients, 64 accepted the invitation and were examined with echocardiography. Mild AR was found in one patient (2%), but this was already evident in the patient's echocardiographic result before PFO closure. Trace AR was detected in 11 patients (17%). No case of moderate or severe AR was detected. Patients with AR were more often hypertensive (six out of 12 patients with AR, compared to nine of the 52 without AR, p = 0.025), and the indexed sinus of Valsalva was larger in patients with AR (18.6 mm/m², SD 1.6, as compared to 17.3 mm/m², SD 1.6, p = 0.02).

Conclusion

In this long-term study with a minimum follow-up of 5.6 years and a mean of 7.1 years, we found negligible levels of AR. Where present, AR was associated with hypertension and mild dilatation of the aortic root, but there was no indication that device closure per se increased the risk of developing AR.

Patent foramen ovale influences the presentation of decompression illness in SCUBA divers

BACKGROUND

Few have examined the influence of patent foramen ovale (PFO) on the phenotype of decompression illness (DCI) in affected divers.

METHODOLOGY

A retrospective review of our database was performed for 75 SCUBA divers over a 10-year period.

RESULTS

Overall 4,945 bubble studies were performed at our institution during the study period. Divers with DCI were more likely to have positive bubble studies than other indications (p<0.001). Major DCI was observed significantly more commonly in divers with PFO than those without (18/1,000 v.s. 3/1,000, p=0.02). Divers affected by DCI were also more likely to require a longer course of hyperbaric oxygen therapy (HBOT) if PFO was present (p=0.038). If the patient experienced one or more major DCI symptoms, the odds ratio of PFO being present on a transoesophageal echocardiogram was 3.2 (p=0.02) compared to those who reported no major DCI symptoms.

CONCLUSION

PFO is highly prevalent in selected SCUBA divers with DCI, and is associated with a more severe DCI phenotype and longer duration of HBOT. Patients with unexpected DCI with one or more major DCI symptoms should be offered PFO screening if they choose to continue diving, as it may have considerable prognostic and therapeutic implications.

Leftward bulging of atrial septum is provoked by nitroglycerin and by sustained valsalva strain

BACKGROUND

The motion of the interatrial septum primum (septum) is dependent on the interatrial pressure relation, normally with slightly higher pressure in the left atrium and the septum bulging toward the right atrium. The aim of this study was to explore the physiologic mechanisms that reverse interatrial pressures and provoke leftward bulging of septum (LBA). The hypothesis was that both left ventricular unloading with nitroglycerin and sustained Valsalva strain would independently provoke LBA and that their combination would further intensify the effect.

METHODS

Prospectively collected transesophageal echocardiography recordings from 13 patients with obstructive sleep apnea were retrospectively analyzed for the presence or absence of LBA during resting respiration and during Valsalva strain. In each condition, LBA beats were counted at time points before and after nitroglycerin spray had been administered, which enabled a comparison of the independent effects and the combined effect of the nitroglycerin and the Valsalva maneuver. An LBA beat was defined as a heartbeat displaying any LBA during the cardiac cycle.

RESULTS

Nitroglycerin increased the proportion of LBA beats significantly during resting respiration, from 21 ± 27% to 54 ± 43% (P = .008). During Valsalva strain, the proportion increased with nitroglycerin spray from 48 ± 21% to 80 ± 17% (P = .001). After nitroglycerin administration, LBA occurred in at least three beats during strain in all Valsalva periods.

CONCLUSIONS

Unloading of the left ventricle by nitroglycerin administration and by sustained Valsalva strain independently provoked LBA. The combination of these two interventions further intensified the effect.

Seven-year follow-up of percutaneous closure of patent foramen ovale

Background

Observational studies favor percutaneous closure of patent foramen ovale (PFO) over medical treatment to reduce recurrent stroke while randomized trials fail to demonstrate significant superiority of percutaneous PFO closure. Few long-term studies are available post PFO closure. This study reports long-term clinical outcomes after percutaneous PFO closure.

Methods

Between 1997 and 2006, 86 consecutive eligible patients with cerebrovascular events, presumably related to PFO, underwent percutaneous PFO closure. All 86 patients were invited to a long-term follow-up, which was carried out during 2011 and 2012.

Results

Percutaneous PFO closure was successfully performed in 85 of 86 patients. The follow-up rate was 100%. No cardiovascular or cerebrovascular deaths occurred. Two patients (both women) died from lung cancer during follow-up. Follow-up visits were conducted for 64 patients and the remaining 20 patients were followed up by phone. The mean follow-up time was 7.3 years (5 to 12.4 years). Mean age at PFO closure was 49 years. One patient had a minor stroke one month after PFO closure and a transient ischemic attack (TIA) two years afterwards. One other patient suffered from a TIA six years after closure. No long-term device-related complications were observed.

Conclusions

Percutaneous PFO closure was associated with very low risk of recurrent stroke and is suitable in most patients. We observed no mortality and no long-term device-related complications related to PFO closure, indicating that percutaneous PFO closure is a safe and efficient treatment even in the long term.

Patent foramen ovale diagnosed by real-time three-dimensional contrast transesophageal echocardiography: A case report

A 67-year-old man was admitted due to insensitiveness of right upper limb and dysarthria, and treated for suspected lacunar infarction or branch atherosclerotic disease. Carotid ultrasonography showed no abnormalities, and agitated contrast transesophageal echocardiography was performed to detect patent foramen ovale (PFO). Intravenously administered microbubbles did not appear in left atrium by 2-dimensional echocardiography, while contrasts were observed in left atrium using 3-dimensional echocardiography. Real-time 3-dimensional contrast transesophageal echocardiography may be the most useful method for the diagnosis of small PFO. <Learning objective: The presence of patent foramen ovale has been suggested as a potential cause of paradoxical embolism and, in particular, of cerebral emboli in stroke of unknown origin. Transthoracic or transesophageal contrast echocardiography is the method for the detection of the patent foramen ovale, however, real-time 3-dimensional contrast transesophageal echocardiography has an advantage for this purpose.>.

Modern management of a patent foramen ovale

A patent foramen ovale (PFO) has been associated with medical conditions such as cryptogenic stroke, migraine with aura, and decompression illness. Whether closure of the PFO has clinical benefit has been suggested from registry studies, but not yet confirmed in multiple randomized trials. Methods of diagnosis of a PFO and a summary of the current evidence for treatment is presented and discussed as a guide to patient-centred decision-making.

Detection of right-to-left atrial communication using agitated saline contrast imaging: experience with 1162 patients and recommendations for echocardiography

BACKGROUND

Right-to-left shunting via a patent foramen ovale (PFO) has a recognized association with embolic events in younger patients. The use of agitated saline contrast injection (ASCi) for detecting atrial shunting is well documented, but the optimal technique is not well described. The purpose of this study was to assess the efficacy and safety of transthoracic echocardiographic (TTE) ASCi for the assessment of right-to-left atrial communication in a large cohort of patients.

METHODS

A retrospective review was undertaken of 1,162 consecutive patients who underwent TTE ASCi, of whom 195 had also undergone clinically indicated transesophageal echocardiography. ASCi shunt results were compared with color flow imaging, and the role of provocative maneuvers (PM) was assessed.

RESULTS

Four hundred three TTE studies (35%) had paradoxical shunting seen during ASCi. Of these, 48% were positive with PM only. There was strong agreement between TTE ASCi and reported transesophageal echocardiographic findings (99% sensitivity, 85% specificity), with six false-positive and two false-negative results. In hindsight, the latter were likely due to suboptimal right atrial opacification and the former to transpulmonary shunting. TTE color flow imaging was found to be insensitive (22%) for the detection of a PFO compared with TTE ASCi.

CONCLUSIONS

TTE color flow imaging is too insensitive for PFO screening. TTE ASCi, however, is simple and highly accurate for the detection of right-to-left atrial communication, on the proviso that a dedicated protocol, including correctly implemented PM, is followed. It is recommended that TTE ASCi with PM be considered the primary diagnostic tool for the detection of PFO in clinical practice.

Patent foramen ovale and obstructive sleep apnoea: from pathophysiology to diagnosis of a potentially dangerous association

Patent foramen ovale and obstructive sleep apnoea are frequently encountered in the general population. Owing to their prevalence, they may coexist fortuitously; however, the prevalence of patent foramen ovale seems to be higher in patients with obstructive sleep apnoea. We have reviewed the epidemiological data, pathophysiology, and the diagnostic and therapeutic options for both patent foramen ovale and obstructive sleep apnoea. We focus on the interesting pathophysiological links that could explain a potential association between both pathologies and their implications, especially on the risk of stroke.

Intracardiac shunting and stroke in children: a systematic review

In adults, patent foramen ovale or other potential intracardiac shunts are established risk factors for stroke via paradoxical embolization. Stroke is less common in children and risk factors differ. The authors examined the literature on intracardiac shunting and stroke in children, identifying the methods employed, the prevalence of detectible intracardiac shunts, associated conditions, and treatments. PubMed searches with keywords related to intracardiac shunting and stroke in children identified articles of interest. Additional articles were identified via citations in these articles or in reviews. The authors found that studies of intracardiac shunting in children with stroke are limited. No controlled studies were identified. Detection methods vary and the prevalence of echocardiographically detectible intracardiac shunting appears lower than reported in adults and autopsy studies. Defining the role of intracardiac shunting in pediatric stroke will require controlled studies with unified detection methods in populations stratified by additional risk factors for paradoxical embolization. Optimal treatment is unclear.

Usefulness of intravenously administered fluid replenishment for detection of patent foramen ovale by transesophageal echocardiography

Patent foramen ovale (PFO) is associated with cryptogenic stroke, migraine headache, decompression sickness, and platypnea-orthodeoxia syndrome. Patients undergoing transesophageal echocardiography are often hypovolemic from preprocedural fasting and might not demonstrate right to left shunting owing to insufficient right atrial pressure generation, despite provocative maneuvers. We hypothesized that volume replenishment with saline loading could potentially unmask a PFO by favorably modulating the interatrial pressure gradient. Our study sought to examine the role of pre- or intraprocedural intravenous fluid replenishment on PFO detection during transesophageal echocardiography. A total of 103 patients were enrolled. An initial series of bubble injections was performed unprovoked and then with provocative maneuvers such as the Valsalva maneuver and coughing. The patients were then given a rapid 500 ml saline bolus, and the same sequence of bubble injections was repeated. The presence, type, and magnitude of the right to left shunts were noted before and after the saline bolus. The detection rate of PFO increased from 10.6% to 26.2% after saline loading without any provocative maneuvers. When combined with provocative maneuvers (Valsalva or cough), saline loading improved the detection rate from 17.4% to 32.0%. Overall, from amongst the 103 enrolled patients, saline bolusing resulted in a de novo diagnosis of PFO in 15 patients, atrial septal aneurysm in 15, PFO coexisting with an atrial septal aneurysm in 10, and pulmonary arteriovenous fistula in 5 patients. In conclusion, saline infusion in appropriately selected patients during transesophageal echocardiography significantly enhances the detection of PFOs and pulmonary arteriovenous fistulas.

Prevalence and prognosis of shunting across patent foramen ovale during acute respiratory distress syndrome

OBJECTIVE

Right-to-left shunting across a patent foramen ovale may occur in acute respiratory distress syndrome as a result of pulmonary hypertension and positive-pressure mechanical ventilation. The shunt may worsen the hypoxemia. The objective of our study was to determine the prevalence, clinical implications, and prognosis of patent foramen ovale shunting during acute respiratory distress syndrome.

DESIGN

Prospective study.

SETTING

Medical intensive care unit of a university hospital in Créteil, France.

PATIENTS

Two hundred three consecutive patients with acute respiratory distress syndrome.

INTERVENTIONS

Patent foramen ovale shunting was detected by using transesophageal echocardiography with modified gelatin contrast. Moderate-to-large shunting was defined as right-to-left passage of at least 10 bubbles through a valve-like structure within three cardiac cycles after complete opacification of the right atrium. In 85 patients without and 31 with shunting, the influence of the positive end-expiratory pressure level on shunting was studied.

MEASUREMENTS AND RESULTS

The prevalence of moderate-to-large patent foramen ovale shunting was 19.2% (39 patients). Compared to those in the group without shunting, the patients in group with shunting had larger right ventricle dimensions, higher pulmonary artery systolic pressure, and a higher prevalence of cor pulmonale. Compared to patients without shunting, patients with shunting had a poorer Pa(O(2))/Fi(O(2)) ratio response to positive end-expiratory pressure, more often required prone positioning and nitric oxide as adjunctive interventions, and had fewer ventilator-free and intensive care unit-free days within the first 28 days.

CONCLUSIONS

Moderate-to-large patent foramen ovale shunting occurred in 19.2% of patients with acute respiratory distress syndrome, in keeping with findings from autopsy studies. Patent foramen ovale was associated with a poor oxygenation response to positive end-expiratory pressure, greater use of adjunctive interventions, and a longer intensive care unit stay.

Pitfalls in diagnosing PFO: characteristics of false-negative contrast injections during transesophageal echocardiography in patients with patent foramen ovales

BACKGROUND

Contrast injections during transesophageal echocardiography for patent foramen ovale (PFO) detection may be false negative. The characteristics of false-negative injections were studied retrospectively.

METHODS

Contrast transesophageal echocardiography was analyzed for the presence or absence of two characteristics: leftward bulging of the interatrial septum and dense contrast filling of the region of the right atrium adjacent to the interatrial septum.

RESULTS

Two hundred forty-seven injections were administered to 14 patients with PFOs, and 130 (53%) were false negative. The absence of either characteristic during a single injection resulted in low sensitivity for PFO detection of 7%. When the two characteristics were present at the same time, the sensitivity for PFO detection after a single injection was as high as 95%.

CONCLUSIONS

The simultaneous presence of both leftward bulging of the interatrial septum and dense contrast filling of the region in the right atrium, adjacent to the interatrial septum, is a prerequisite for PFO detection, and if either characteristic is missing, the injection is inconclusive.

Enhanced detection of patent foramen ovale by systematic transthoracic saline contrast echocardiography

OBJECTIVE

We aimed to evaluate the effectiveness of transthoracic saline contrast echocardiography (TSCE) in detecting patent foramen ovale (PFO).

BACKGROUND

Transesophageal echocardiography (TEE) is semi-invasive and not ideal for PFO screening.

METHODS

112 patients (48 males, 46 ± 14 years) with suspected PFO received intravenous agitated-saline contrast at rest and stress (strain and release phases of Valsalva maneuver and coughing). The presence of interatrial shunting was defined as >5 bubbles appearing in the left heart within 3 cardiac cycles. The stage of the maneuver at which interatrial shunting occurred was recorded. The TSCE findings were validated by TEE.

RESULTS

TEE identified PFO in 45% of patients. The sensitivities of TSCE in detecting PFO at rest, during strain and release of Valsalva maneuver, and coughing were 12.0%, 38.0%, 80.0% and 94.0% respectively (each p<0.05 when compared to previous stage). Specificities were similar and >95% for all stages. Moreover, the release phase of the maneuver improved the diagnostic accuracy [defined as (number of true positives+true negatives) divided by total in sample] with incremental value over the preceding strain phase (89.2 vs. 70.5%, p<0.001).

CONCLUSIONS

Patent foramen ovale can be identified confidently with proper conduct of the Valsalva maneuver during the transthoracic saline contrast echocardiography.

Prevalence of intracardiac shunting in children with sickle cell disease and stroke

OBJECTIVE

To determine the prevalence of potential intracardiac shunts, including patent foramen ovale (PFO), in children with sickle cell disease (SCD) and stroke.

STUDY DESIGN

We performed a transthoracic echocardiogram (TTE) on 40 children with SCD (39 with hemoglobin SS and 1 with sickle-beta0 thalassemia) and earlier stroke (overt stroke in 30, silent infarction in 10). We compared 3 TTE techniques: conventional 2-dimensional imaging, color Doppler ultrasound, and intravenous agitated saline contrast injection for the detection of intracardiac shunts. We also evaluated the clinical, laboratory, and radiographic findings of the children with and without shunts.

RESULTS

We identified PFO or other potential intracardiac shunts in 10 of 40 children with SCD and earlier stroke (25%; 95% CI, 11.6-38.4). With contrasted TTE, we failed to detect potential shunts in 2 children. In a comparison group of 60 children with stroke but without SCD, retrospective review of clinical echocardiograms identified PFO in 7 of 60 (11.7%; 95% CI, 3.6-19.8). Clinical features significantly associated with the presence of intracardiac shunts were stroke in the setting of vaso-occlusive crisis (P = .026) and headache at stroke onset (P = .014).

CONCLUSION

One-quarter of children with SCD and stroke have potential intracardiac shunts. A combination of echocardiographic techniques is required for optimal shunt detection. Intracardiac shunting could be a risk factor for stroke in children with SCD because they are predisposed to thrombosis and elevations of right heart pressure, which could promote paradoxical embolization across an intracardiac shunt.