The incidence, diagnosis, and management of pulmonary vein stenosis as a complication of atrial fibrillation ablation

Pulmonary Vein Intervention for Severe Pulmonary Vein Stenosis After Atrial Fibrillation Ablation - A Retrospective Cohort Study

BACKGROUND

Pulmonary vein (PV) stenosis (PVS) is a serious complication of atrial fibrillation (AF) ablation. The objective of this study was to describe interventional treatments for PVS after AF ablation and long-term outcomes in Japanese patients.

METHODS AND RESULTS

This multicenter retrospective observational study enrolled 30 patients (26 [87%] male; median age 55 years) with 56 severe PVS lesions from 43 PV interventional procedures. Twenty-seven (90%) patients had symptomatic PVS and 19 (63%) had a history of a single AF ablation. Of the 56 lesions, 41 (73%) were de novo lesions and 15 (27%) were retreated. Thirty-three (59%) lesions were treated with bare metal stents, 14 (25%) were treated with plain balloons, and 9 (16%) were treated with drug-coated balloons. All lesions were successfully treated without any systemic embolic event. Over a median follow-up of 584 days (interquartile range 265-1,165 days), restenosis rates at 1 and 2 years were 35% and 47%, respectively. Multivariate Cox regression analysis revealed devices <7 mm in diameter (hazard ratio [HR] 2.52; 95% confidence interval [CI] 1.04-6.0; P=0.040) and totally occluded lesions (HR 3.33; 95% CI 1.21-9.15; P=0.020) were independent risk factors for restenosis.

CONCLUSIONS

All PVS lesions were successfully enlarged by the PV intervention; however, restenosis developed in approximately half the lesions within 2 years.

Pathogenesis, Evaluation, and Management of Pulmonary Vein Stenosis: JACC Review Topic of the Week

Pulmonary vein stenosis (PVS) can arise from several etiologies, including congenital, acquired, and iatrogenic sources. PVS presents insidiously, leading to significant delays in diagnosis. A high index of suspicion and dedicated noninvasive evaluation are key to diagnosis. Once diagnosed, both noninvasive and invasive evaluation may afford further insights into the relative contribution of PVS to symptoms. Treatment of underlying reversible pathologies coupled with transcatheter balloon angioplasty and stenting for persistent severe stenoses are established approaches. Ongoing refinements in diagnostic modalities, interventional approaches, postintervention monitoring, and medical therapies hold promise to further improve patient outcomes.

Cardiovascular magnetic resonance pulmonary perfusion for functional assessment of pulmonary vein stenosis

BACKGROUND

Cardiovascular magnetic resonance (CMR) imaging allows to combine pulmonary perfusion measurements and pulmonary venous angiography during a single-session examination with both imaging modules representing the basis for accurate diagnosis and therapeutic stratification of pulmonary vein (PV) stenosis. The present study investigated the clinical utility of dynamic pulmonary perfusion imaging integrated into a comprehensive CMR protocol for the evaluation of patients with suspected PV stenosis.

METHODS

162 patients with clinically suspected PV stenosis after catheter ablation of atrial fibrillation underwent a combined single-session CMR examination (cardiac cine imaging, dynamic pulmonary perfusion, and three-dimensional PV angiography). CMR angiography was used for visual grading of PV stenoses; dynamic pulmonary perfusion imaging was evaluated per lung lobe visually and quantitatively.

RESULTS

All PV stenosis ≥90% showed a visible perfusion deficit of the corresponding lung lobe (60/60, 100%) while all PVs with luminal narrowing <50% exhibited normal pulmonary perfusion (680/680, 100%). However, every third 70-89% stenosis showed a normal pulmonary perfusion (10/31, 32%) while every fourth 50-69% PV stenosis was associated with hypoperfusion of the corresponding lung lobe (9/39, 23%). For quantitative pulmonary perfusion measurements, ROC analysis demonstrated high discriminatory power regarding PV stenosis detection with the highest AUC values for time-to-peak enhancement (cut-off value, 8.5 s).

CONCLUSIONS

The combination of CMR angiography and CMR pulmonary perfusion allowed for assessment of the anatomical degree of PV stenosis and its hemodynamic impact on the pulmonary parenchymal level. Thus, the proposed comprehensive CMR protocol provided an efficient diagnostic work-up of patients with suspected PV stenosis.

Safety and efficacy of balloon angioplasty compared to stent-based-strategies with pulmonary vein stenosis: A systematic review and meta-analysis

BACKGROUND

Pulmonary vein stenosis (PVS) is an uncommon but known cause of morbidity and mortality in adults and children and can be managed with percutaneous re-vascularization strategies of pulmonary vein balloon angioplasty (PBA) or pulmonary vein stent implantation (PSI).

AIM

To study the safety and efficacy outcomes of PBA vs PSI in all patient categories with PVS.

METHODS

We performed a literature search of all studies comparing outcomes of patients evaluated by PBA vs PSI for PVS. We selected all published studies comparing PBA vs PSI for PVS with reported outcomes of restenosis and procedure-related complications in all patient categories. In adults, PVS following atrial fibrillation ablation and in children PVS related to congenital etiology or post-procedural PVS following total or partial anomalous pulmonary venous return repair were included. The patient-centered outcomes were risk of restenosis requiring re-intervention and procedural-related complications. The meta-analysis was performed by computing odds ratios (ORs) using the random effects model based on underlying statistical heterogeneity.

RESULTS

Eight observational studies treating 768 severe PVS in 487 patients met our inclusion criteria. The age range of patients was 6 months to 70 years and 67% were males. The primary outcome of the re-stenosis requiring re-intervention occurred in 196 of 325 veins in the PBA group and 111 of 443 veins in the PSI group. Compared to PSI, PBA was associated with a significantly increased risk of re-stenosis (OR 2.91, 95%CI: 1.15-7.37, P = 0.025, I² = 79.2%). Secondary outcomes of the procedure-related complications occurred in 7 of 122 patients in the PBA group and 6 of 69 in the PSI group. There were no statistically significant differences in the safety outcomes between the two groups (OR: 0.94, 95%CI: 0.23-3.76, P = 0.929), I² = 0.0%).

CONCLUSION

Across all patient categories with PVS, PSI is associated with reduced risk of re-intervention and is as safe as PBA and should be considered first-line therapy for PVS.

A rare case of right heart failure with the necessity for veno-arterial extracorporeal membrane oxygenation following pulmonary vein stenosis after radiofrequency ablation for atrial fibrillation

Pulmonary vein stenosis (PVS) after radiofrequency energy-mediated percutaneous pulmonary vein isolation as a treatment option for atrial fibrillation is a serious complication and the prevalence in historical reports varies between 0% and 42%. Symptoms of PVS are nonspecific and can include general symptoms such as dyspnea, cough, recurrent pneumonia, and chest pain. Pathophysiologically it increases the postcapillary pressure in the pulmonary circuit and may result in pulmonary hypertension (PH). Misdiagnosis and delayed treatment are common. We here report a case of a 59-year-old female with a history of pulmonary vein ablation followed by progressive dyspnea (New York Heart Association IV), right heart failure, CPR, and the need for extracorporeal membrane oxygenation (ECMO). Further treatment strategy includes pulmonary vein dilatation and stenting of both the left superior pulmonary vein and left inferior pulmonary vein, as well as balloon dilatation of RIPV under temporary ECMO support. Symptomatic, severe PVS is a rare complication after catheter ablation of atrial fibrillation. PVS can result in life-threatening complications such as PH with acute right heart failure. Early diagnosis is crucial but challenging. Mechanical cardiopulmonary support by veno-arterial ECMO for bridging to angioplasty could be a lifesaving option.

A Case of Congenital Pulmonary Vein Stenosis with Secondary Post-Capillary Pulmonary Hypertension and Left Sided Congestive Heart Failure in a Cat

A five-month-old, 3.8 kg intact male Maine coon cat presented for dyspnea characterized by increased respiratory effort in addition to open-mouth breathing. Thoracic radiographs showed pectus excavatum, enlarged cardiac silhouette, and generalized interstitial patterns. Echocardiography revealed normal left atrial (LA) and left ventricular dimensions. A large tubular structure, suspected to be a distended pulmonary vein (PV), was identified as draining into the LA. Severe eccentric and concentric right ventricular hypertrophy and paradoxical septal motion were noted. Based on Doppler echocardiography, both pulmonary venous and pulmonary artery pressure was severely elevated. Clinical, radiographic, and echocardiographic abnormalities were hypothesized to result from pulmonary vein stenosis (PVS), causing severely elevated pulmonary venous pressures and resulting in clinical signs of left-sided congestive heart failure (L-CHF) and severe post-capillary pulmonary hypertension (Pc-PH). The prognosis for good quality of life was assessed as poor, and the owner elected euthanasia. Necropsy confirmed the presence of PVS with severe dilation of the PVs draining all but the left cranial lung lobe. All lung lobes except the left cranial lobe had increased tissue density and a mottled cut surface. This case report shows that, in rare cases, both L-CHF and Pc-PH may be present without LA enlargement. To the authors' knowledge, this is the first report on PVS in veterinary medicine.

Recurrent pneumonia post atrial fibrillation ablation: do not forget to look for pulmonary vein stenosis

A man in his 50s presented with persistent chest pain, haemoptysis, cough and dyspnoea 5 months after undergoing catheter ablation for atrial fibrillation (AF). Several chest CT scans suggested pneumonia. Despite adequate treatment for recurrent pneumonia, symptoms persisted. While reviewing the initial chest CT, a partial venous infarction of the left lower lobe associated with severe left inferior pulmonary vein stenosis (PVS) was diagnosed. Stenting of the left inferior pulmonary vein with a vascular bare metal stent was performed, guided by fluoroscopy and transoesophageal echocardiography. Dual antiplatelet therapy (aspirin/clopidogrel) was introduced for 3 months, followed by long-term aspirin monotherapy. The treatment resulted in relief of his symptoms and the resolution of pulmonary opacities on chest CT. Despite low frequency, AF ablation remains the most common cause of acquired PVS. As highlighted in this case, symptoms are not specific and include recurrent pulmonary infection with delayed management.

Pulmonary Vein Occlusion After Surgical Atrial Fibrillation Ablation and Left Atrial Appendage Occlusion

We report a case of pulmonary vein (PV) occlusion in a patient with a history of surgical atrial fibrillation ablation and left atrial appendage occlusion with unsuccessful endovascular management. Delayed diagnosis of PV stenosis post-ablation can make interventional treatment options less likely to be successful. (Level of Difficulty: Intermediate.).

A modified sutureless repair for left pulmonary vein obstruction after catheter ablation

A 52-year-old man presented with temporal haemoptysis and chest pain 6 months after radiofrequency catheter ablation for atrial fibrillation. Computed tomography revealed severe stenosis in the left upper pulmonary vein (PV) and complete occlusion of the left lower PV. A modified sutureless repair of the left PV obstruction was successfully performed. This modified procedure provides a feasible, safe and effective means of treating PV obstruction, even in cases with distal extension of stenosis.

Bifurcation pulmonary venoplasty and stenting for recalcitrant pulmonary vein stenosis after surgical pulmonary vein reconstruction

Pulmonary vein stenosis (PVS) is a rare, severe, and potentially fatal complication most often arising from pulmonary vein ablation for medication refractory, symptomatic, and permanent atrial fibrillation. At present, the optimal approach for the management of PVS remains to be defined. Here, we describe a unique case of bifurcation pulmonary venoplasty and stenting in a patient with recalcitrant PVS after surgical reconstruction of her pulmonary veins. To our knowledge, this is the first such report of its kind. <Learning objective: The optimal approach to managing complex pulmonary vein stenosis (PVS) is unclear. Our aim is to illustrate our successful approach for treating recalcitrant and complex PVS using dual transseptal access and kissing balloon bifurcation pulmonary venoplasty.>.

Pulmonary Vein Stenosis After Atrial Fibrillation Ablation: Insights From the ADVICE Trial

BACKGROUND

Pulmonary vein (PV) stenosis is a complication of atrial fibrillation (AF) ablation. The incidence of PV stenosis after routine post-ablation imaging remains unclear and is limited to single-centre studies. Our objective was to determine the incidence and predictors of PV stenosis following circumferential radiofrequency ablation in the multicentre Adenosine Following Pulmonary Vein Isolation to Target Dormant Conduction Elimination (ADVICE) trial.

METHODS

Patients with symptomatic AF underwent circumferential radiofrequency ablation in one of 13 trial centres. Computed tomographic (CTA) or magnetic resonance (MRA) angiography was performed before ablation and 90 days after ablation. Two blinded reviewers measured PV diameters and areas. PVs with stenosis were classified as severe (> 70%), moderate (50%-70%), or mild (< 50%). Predictors of PV stenosis were identified by means of multivariable logistic regression.

RESULTS

A total of 197 patients (median age 59.5 years, 29.4% women) were included in this substudy. PV stenosis was identified in 41 patients (20.8%) and 47 (8.2%) of 573 ablated PVs. PV stenosis was classified as mild in 42 PVs (7.3%) and moderate in 5 PVs (0.9%). No PVs had severe stenosis. Both cross-sectional area and diameter yielded similar classifications for severity of PV stenosis. Diabetes was associated with a statistically significant increased risk of PV stenosis (OR 4.91, 95% CI 1.45-16.66).

CONCLUSIONS

In the first systematic multicentre evaluation of post-ablation PV stenosis, no patient acquired severe PV stenosis. Although the results are encouraging for the safety of AF ablation, 20.8% of patients had mild or moderate PV stenosis, in which the long-term effects are unknown.

Treatment Complications of Atrial Fibrillation and Their Management

Atrial fibrillation (AF) is a rhythm disturbance defined by irregular, rapid electrical, and mechanical activation of the atria, which causes unsynchronized atrial contraction and promotes thromboembolism. AF is the most common sustained arrhythmia. Its prevalence and incidence are increasing due to aging and improved survival from acute heart diseases. This article is a review on AF management from both a surgical and catheter-based perspective. While both treatment approaches to AF have been shown to be successful in the management of AF, they are not without their own inherent complications. This article seeks to review some of these complications and help to guide treatment.

Comparison of transthoracic echocardiography with computed tomography in evaluation of pulmonary veins

Background

Transesophageal echocardiography may be used to assess pulmonary veins for atrial fibrillation ablation. No study focused on the role of transthoracic echocardiography (TTE) in evaluating the diameter and anatomy of pulmonary veins.

Methods

Among 142 atrial fibrillation patients (57.7% men; mean age, 60.5) hospitalised for catheter ablation, we assessed pulmonary veins and compared the measurements by TTE with cardiac computed tomography (CT) before ablation. Among 17 patients who had follow-up examinations, the second measurements were also studied.

Results

TTE identified and determined the diameters of 140 (98.6%) right and 140 (98.6%) left superior PVs, and 136 (95.7%) right and 135 (95.1%) left inferior PVs. A separate middle PV ostia was identified in 14 out of the 22 patients (63.6%) for the right side and in 2 out of 4 (50.0%) for the left side. The PV diameters before ablation assessed by CT vs. TTE were 17.96 vs. 18.07 mm for right superior, 15.92 vs. 15.51 mm for right inferior, 18.54 vs. 18.42 mm for left superior, and 15.56 vs. 15.45 mm for left inferior vein. The paired differences between the assessments of CT and TTE were not significant (P ≥ 0.31) except for the right inferior vein with a CT-minus-TTE difference of 0.41 mm (P = 0.018). The follow-up PV diameters by both CT (P ≥ 0.069) and TTE (P ≥ 0.093) were not different from baseline measurements in the 17 patients who had follow-up measurements.

Conclusions

With a better understanding of PV anatomy in TTE imaging, assessing PV diameters by non-invasive TTE is feasible. However, the clear identification of anatomic variation might still be challenging.

Acquired Pulmonary Vein Stenosis After Radiofrequency Ablation for Atrial Fibrillation: Single-Center Experience in Catheter Interventional Treatment

OBJECTIVES

The aim of the present study was to analyze and report a single-center experience with catheter interventional treatment of radiofrequency-induced pulmonary vein stenosis (PVS) following atrial fibrillation (AF) ablation.

BACKGROUND

Catheter interventional treatment of radiofrequency-induced PVS following AF ablation remains a challenging field because of a lack of randomized data and treatment guidelines.

METHODS

All patients at a single center who underwent catheter interventional treatment for radiofrequency-induced PVS were retrospectively assessed.

RESULTS

From January 2004 to September 2017, the total rate of PVS following interventional AF ablation was 0.78% (87 of 11,103). Thirty-nine patients with PVS were treated with 84 catheter interventions: 68 (81%) with percutaneous transluminal balloon angioplasty (PTA) and 16 (19%) with stent implantation. The distribution of stent type was 3 drug-eluting stents (19%) and 13 bare-metal stents (81%). The overall restenosis rate was 53% after PTA versus 19% after stent implantation (p = 0.007) after a median follow-up period of 6 months (interquartile range: 3 to 55 months). The total complication rate for PTA was 10% versus 13% for stenting (p = NS).

CONCLUSIONS

This study demonstrates significantly better outcomes in terms of restenosis after stent implantation versus PTA only, with comparable complication rates for these 2 options of interventional treatment of radiofrequency-induced PVS. In summary, despite the lack of randomized studies, the present data and currently available published studies seem to favor stent implantation as a first-line therapy in patients with radiofrequency-induced severe PVS.

Pulmonary Computed Tomography Parenchymal and Vascular Features Diagnostic of Postablation Pulmonary Vein Stenosis

PURPOSE

The purpose of this study was to define the full spectrum of pulmonary computed tomography (CT) changes characteristic of postablation pulmonary vein stenosis (PVS).

MATERIALS AND METHODS

We retrospectively reviewed our pulmonary vein isolation database. PVS was graded as follows: grade 1:<50%, grade 2: 50% to 75%, grade 3: 76% to 99%, and grade 4: total occlusion. CT parenchymal and vascular changes were detected and correlated with clinical course and nuclear scans.

RESULTS

Of 486 patients who underwent pulmonary vein isolation, 56 patients (11%) were symptomatic, prompting referral to CT evaluation. Grades 1, 2, 3, and 4 PVS were documented in 42, 1, 2, and 11 patients, respectively. Apart from PVS, abnormal CT findings were present only in patients with PVS grades 2 to 4. Pulmonary parenchymal changes (consolidation, "ground glass" opacities, interlobular septal thickening, and volume loss) were found in PVS grades 2 to 4. Pulmonary vascular changes (oligemia, "sluggish flow," and collateral mediastinal vessels) were shown in patients with grades 3 to 4 PVS. Concomitant nuclear scans documented reduced lung perfusion. All findings were located to the lobe drained by the affected vein. Complete resolution of pulmonary findings on follow-up CT scans was demonstrated in 20% of patients. Eleven stents were inserted in 7 patients with PVS grades 2 to 4, none of which demonstrated radiologic or clinical resolution.

CONCLUSIONS

A typical CT complex of both parenchymal and vascular findings in the affected lobe is diagnostic of postablation PVS. Lack of clinical and radiologic resolution in most patients, even after stent insertion, further highlights the importance of early recognition of this underdiagnosed condition.

Natural course of acquired pulmonary vein stenosis after radiofrequency ablation for atrial fibrillation-Is routine follow-up imaging indicated or not?

INTRODUCTION

Thermal injury during radiofrequency ablation (RFA) of atrial fibrillation (AF) can lead to pulmonary vein stenosis (PVS). The aim of the present study was to analyze the natural course of RFA-induced PVS with regard to the grade of stenosis, clinical symptoms, and mortality during long-term follow-up.

METHODS AND RESULTS

All patients with follow-up imaging for radiofrequency-induced untreated PVS were retrospectively assessed. From 2004 to 2017, the total rate of PVS following AF ablation in our center was 0.78% (87 of 11 103). Thirty-eight patients with a total of 54 untreated PVS underwent follow-up including imaging scan. The mean degree of stenosis at the time of diagnosis was 57% ± 27% vs 45% ± 35% (P = .05) after a mean follow-up of 43 ± 31 months. There was a shift in severity of the PVS: 18 of 54 (33%) vs 16 of 54 (30%) severe PVS, 19 of 54 (35%) vs 10 of 54 (18%) moderate PVS, and 17 of 54 (32%) vs 28 of 54 (52%) mild PVS (P = .0001). The mean symptom score decreased significantly during follow-up (1.8 ± 1.0 vs 0.4 ± 0.5, P = .0001). Each of the four patients with progression of PVS underwent another pulmonary vein isolation for AF recurrence following pulmonary vein reconduction during follow-up period.

CONCLUSION

This study showed a spontaneous reduction in stenosis grade and symptoms of PVS over a 3.5-year follow-up. Consequently, routine follow-up imaging of PVS seems not to be necessary. However, additional RF energy delivery to stenotic pulmonary veins should be avoided if possible. In case of conduction recovery, the ablation line should be done wide-antrally and follow-up imaging of PVS is recommended.

Late onset cardiac cirrhosis and portal hypertensive ascites after atrial fibrillation ablation

Pulmonary vein stenosis is a potential complication following catheter ablation of atrial fibrillation (AF). We report the case of a patient with refractory ascites late after multiple catheter ablation procedures for AF. This is the first case report of portal hypertensive ascites due to acquired multiple pulmonary vein stenoses resulting in pulmonary hypertension (PH) and cardiac cirrhosis late after AF ablation. Despite extensive surgical reconstruction of the affected pulmonary veins, the patient has PH and right heart failure with persistent ascites and lower extremity edema.

Atrial Fibrillation Mechanisms and Implications for Catheter Ablation

AF is a heterogeneous rhythm disorder that is related to a wide spectrum of etiologies and has broad clinical presentations. Mechanisms underlying AF are complex and remain incompletely understood despite extensive research. They associate interactions between triggers, substrate and modulators including ionic and anatomic remodeling, genetic predisposition and neuro-humoral contributors. The pulmonary veins play a key role in the pathogenesis of AF and their isolation is associated to high rates of AF freedom in patients with paroxysmal AF. However, ablation of persistent AF remains less effective, mainly limited by the difficulty to identify the sources sustaining AF. Many theories were advanced to explain the perpetuation of this form of AF, ranging from a single localized focal and reentrant source to diffuse bi-atrial multiple wavelets. Translating these mechanisms to the clinical practice remains challenging and limited by the spatio-temporal resolution of the mapping techniques. AF is driven by focal or reentrant activities that are initially clustered in a relatively limited atrial surface then disseminate everywhere in both atria. Evidence for structural remodeling, mainly represented by atrial fibrosis suggests that reentrant activities using anatomical substrate are the key mechanism sustaining AF. These reentries can be endocardial, epicardial, and intramural which makes them less accessible for mapping and for ablation. Subsequently, early interventions before irreversible remodeling are of major importance. Circumferential pulmonary vein isolation remains the cornerstone of the treatment of AF, regardless of the AF form and of the AF duration. No ablation strategy consistently demonstrated superiority to pulmonary vein isolation in preventing long term recurrences of atrial arrhythmias. Further research that allows accurate identification of the mechanisms underlying AF and efficient ablation should improve the results of PsAF ablation.

Rate of acquired pulmonary vein stenosis after ablation of atrial fibrillation referred to electroanatomical mapping systems: Does it matter?

BACKGROUND

Thermal injury during radiofrequency ablation (RFA) of atrial fibrillation (AF) can lead to pulmonary vein stenosis (PVS). It is currently unclear if routine screening for PVS by imaging (echocardiography, computed tomography) is clinically meaningful and if there is a correlation between PVS and the electroanatomical mapping system (EAMS) used for the ablation procedure. It was therefore investigated in the current single center experience.

METHODS

All patients from January 2004 to December 2016 with the diagnosis of PVS after interventional ablation of AF by radiofrequency were retrospectively analyzed. From 2004 to 2007, transesophageal echocardiography was routinely performed as screening for RFA-acquired PVS (group A). Since 2008, diagnostics were only initiated in cases of clinical symptoms suggestive for PVS (group B).

RESULTS

The overall PVS rate after interventional RFA for AF of the documented institution is 0.72% (70/9754). The incidence was not influenced by screening: group A had a 0.74% PVS rate and group B a 0.72% rate (NS). Referred to as the EAMS, there were significant differences: 20/4229 (0.5%) using CARTO®, 48/4510 (1.1%) using EnSite®, 1/853 (0.1%) using MediGuide®, and 1/162 (0.6%) using Rhythmia®. Since 2009, no significant difference between technologies was found.

CONCLUSIONS

The present analysis of 9754 procedures revealed 70 cases of PVS. The incidence of PVS is not related to screening but to the application of different EAMS. Possible explanations are technological backgrounds (magnetic vs. electrical), learning curves, operator experience, and work-flow differences. Furthermore, incorporation of new technologies seems to be associated with higher incidences of PVS before workflows are optimized.

Contributors Toward Pulmonary Vein Restenosis Following Successful Intervention

OBJECTIVES

This study sought to identify clinical and procedural risk factors associated with pulmonary vein (PV) restenosis.

BACKGROUND

Pulmonary vein stenosis (PVS) is a rare but morbid complication of PV isolation for atrial fibrillation (AF) ablation. Interventions such as PV balloon angioplasty (BA) or stenting achieve excellent acute success; however, subsequent restenosis is common.

METHODS

A total of 113 patients underwent invasive treatment for severe PVS between 2000 and 2014 and were followed prospectively. Baseline patient and lesion characteristics were abstracted from chart review and analyzed. Univariate and multivariate analyses were performed using patient and procedural characteristics to determine which factors were associated with an increased risk for subsequent PV restenosis.

RESULTS

Over a median follow-up of 4.6 years there was PVS recurrence in 75 veins; 52 veins (57%) were treated with index BA and 23 veins were treated with stenting. After multivariate analysis, the only patient factor that was significantly associated with restenosis was a history of more than 1 AF ablation (hazard ratio [HR]: 1.91; 95% confidence interval [CI]: 1.07 to 3.41; p = 0.03). Multivariate analysis on a per-vein level demonstrated a significantly lower risk of restenosis in veins treated with a stent (HR: 2.84; 95% CI: 1.75 to 4.61; p < 0.0001). In veins treated with BA alone, inflation of the balloon to higher atmospheres significantly reduced the risk of recurrence (HR: 0.87; 95% CI: 0.78 to 0.98; p = 0.02).

CONCLUSIONS

Restenosis is common after a successful PV intervention and the risk of restenosis is highest in those with a history of multiple AF ablations and in those treated with BA. Proceduralists should take into account the number of AF ablations a patient has undergone and should strongly consider stent deployment when intervening on PVS to reduce risk of restenosis.

Long-term follow-up in patients treated by stent implantation for post-ablation pulmonary vein stenosis

PURPOSE

Symptomatic severe pulmonary vein stenosis (PVS) after catheter ablation of atrial fibrillation (AF) is a rare but well-recognized complication. Treatment options include pulmonary vein angioplasty with or without drug eluting balloons or angioplasty with stent implantation. The treatment of choice is unclear. In our center, pulmonary vein stenting is the treatment of choice for significantly stenotic veins. We present the long-term clinical outcome of 9 patients treated with stent implantation.

METHODS

Between 2001 and 2015, 3048 patients with AF were treated with catheter ablation at our institution, of which 9 developed symptomatic PVS. A total of 11 PVS were treated. Pre-procedural imaging (CT, MR, transesophageal echocardiography, angiography) was performed in all patients.

RESULTS

Mean time from ablation to stenting was 18 months. Three patients had recurrent pneumonia and the remaining reduced functional capacity (NYHA 2). All patients were in functional capacity NYHA 1 (p < 0.05) after a mean follow-up of 64 (18-132) months. Three patients still had paroxysmal AF, of which two have undergone repeated ablation.

CONCLUSIONS

Symptomatic PVS after AF ablation can be successfully treated by stent implantation with durable results and good clinical outcome. AF ablation is still a feasible option after stent deployment.

Comprehensive Cross-sectional Imaging of the Pulmonary Veins

The pulmonary veins carry oxygenated blood from the lungs to the heart, but their importance to the radiologist extends far beyond this seemingly straightforward function. The anatomy of the pulmonary veins is variable among patients, with several noteworthy variant and anomalous patterns, including supernumerary pulmonary veins, a common ostium, anomalous pulmonary venous return, and levoatriocardinal veins. Differences in pulmonary vein anatomy and the presence of variant or anomalous anatomy can be of critical importance, especially for preoperative planning of pulmonary and cardiac surgery. The enhancement or lack of enhancement of the pulmonary veins can be a clue to clinically important disease, and the relationship of masses to the pulmonary veins can herald cardiac invasion. The pulmonary veins are also an integral part of thoracic interventions, including lung transplantation, pneumonectomy, and radiofrequency ablation for atrial fibrillation. This fact creates a requirement for radiologists to have knowledge of the pre- and postoperative imaging appearances of the pulmonary veins. Many of these procedures are associated with important potential complications involving the pulmonary veins, for which diagnostic imaging plays a critical role. A thorough knowledge of the pulmonary veins and a proper radiologic approach to their evaluation is critical for the busy radiologist who must incorporate the pulmonary veins into a routine "search pattern" at computed tomography (CT) and magnetic resonance imaging. This article is a comprehensive CT-based imaging review of the pulmonary veins, including their embryology, anatomy (typical and anomalous), surgical implications, pulmonary vein thrombosis, pulmonary vein stenosis, pulmonary vein pseudostenosis, and the relationship of tumors to the pulmonary veins. Online supplemental material is available for this article. ^©RSNA, 2017.

Unilateral Pulmonary Edema in a Patient with Worsening Tricuspid Valve Regurgitation: A Secret Inside Pulmonary Veins

We present the case of a 69-year-old patient who was referred to the Department of Echocardiography for surgical treatment of severe tricuspid valve regurgitation (TVR) with advanced congestive heart failure. In 2013 the patient underwent unsuccessful percutaneous ablation for permanent atrial fibrillation. In 2015, following numerous episodes of atrial fibrillation and congestive heart failure with left pleural effusion, the patient was admitted to another center. A transthoracic echocardiogram showed severe TVR and moderate precapillary pulmonary hypertension, confirmed at right cardiac catheterization. He showed bilateral ankle swelling, mild systolic cardiac murmur and localized leftmost decreased breath sounds. Chest X-ray revealed left-sided pulmonary edema and ipsilateral large pleural effusion. Following percutaneous drainage of the left pulmonary effusion, the patient underwent transthoracic and transesophageal echocardiography (TEE), confirming severe TVR due to annular dilation, severe pulmonary hypertension (60 mmHg) and right ventricular overload. At TEE, we found a narrowed single left pulmonary vein. Coronary artery angiography showed no critical stenosis. The patient underwent cardiac magnetic resonance and Angiography that confirmed ostial stenosis of a single left pulmonary vein. We performed successful bare-metal stent implantation. After the procedure, we observed progressive improvement in the patient's clinical condition, concomitant with reverse pulmonary hypertension, significant TVR reduction and chest X-ray normalization. This is a rare case of unilateral pulmonary edema following percutaneous ablation of atrial fibrillation.

Pulmonary Vein Stenosis After Second-Generation Cryoballoon Ablation

BACKGROUND

Pulmonary vein stenosis (PVST) can occur after first-generation cryoballoon ablation. This study aimed to evaluate the incidence, severity, and characteristics of PVST after second-generation cryoballoon ablation.

METHODS

In total, 103 patients underwent PV isolation of paroxysmal atrial fibrillation using second-generation cryoballoons with a single big-balloon 3-minute freeze technique. Cardiac enhanced multidetector computed tomography (MDCT) was performed both before and a median of 6.0 (4.0-8.0) months after the procedure in all. PVST was classified as follows: minimal (<25%), mild (25-50%), moderate (50-70%), or severe (>70%).

RESULTS

In total, 406 PVs were analyzed. MDCT demonstrated PV stenosis in 10(2.5%) PVs among 8(7.8%) patients. In detail, minimal and mild PVSTs were observed in 6 and 4 PVs, respectively. PVST occurred in the left superior (LSPV), left inferior, and right superior PVs in 6, 1, and 3 PVs, respectively. No stenosis was observed in 15 PVs with active balloon deflations during freezing. All PVSTs had concentric patterns except for 2 PVs with minimal stenosis. Balloon deformities were observed during freezing of 2 PVs with mild stenosis. When the PVST was defined as a >25% decreased diameter, the incidence was 0.98% (4/406; including 3 LSPVs). PVST did not progress further during the follow-up period.

CONCLUSIONS

Although the incidence of PVST was low, it could occur even if a single big-balloon short freeze technique was applied. The risk of PV stenosis significantly differed among the 4 PVs, and reaching balloon temperatures of -60 °C and active balloon deflations during freezing were not associated with any PV stenosis.

Pulmonary vein stenosis: Etiology, diagnosis and management

Pulmonary vein stenosis (PVS) is rare condition characterized by a challenging diagnosis and unfavorable prognosis at advance stages. At present, injury from radiofrequency ablation for atrial fibrillation has become the main cause of the disease. PVS is characterized by a progressive lumen size reduction of one or more pulmonary veins that, when hemodynamically significant, may raise lobar capillary pressure leading to signs and symptoms such as shortness of breath, cough, and hemoptysis. Image techniques (transesophageal echocardiography, computed tomography, magnetic resonance and perfusion imaging) are essential to reach a final diagnosis and decide an appropriate therapy. In this regard, series from referral centers have shown that surgical and transcatheter interventions may improve prognosis. The purpose of this article is to review the etiology, assessment and management of PVS.

Ablation of Myocardial Tissue With Nanosecond Pulsed Electric Fields

Background

Ablation of cardiac tissue is an essential tool for the treatment of arrhythmias, particularly of atrial fibrillation, atrial flutter, and ventricular tachycardia. Current ablation technologies suffer from substantial recurrence rates, thermal side effects, and long procedure times. We demonstrate that ablation with nanosecond pulsed electric fields (nsPEFs) can potentially overcome these limitations.

Methods

We used optical mapping to monitor electrical activity in Langendorff-perfused New Zealand rabbit hearts (n = 12). We repeatedly inserted two shock electrodes, spaced 2–4 mm apart, into the ventricles (through the entire wall) and applied nanosecond pulsed electric fields (nsPEF) (5–20 kV/cm, 350 ns duration, at varying pulse numbers and frequencies) to create linear lesions of 12–18 mm length. Hearts were stained either with tetrazolium chloride (TTC) or propidium iodide (PI) to determine the extent of ablation. Some stained lesions were sectioned to obtain the three-dimensional geometry of the ablated volume.

Results

In all animals (12/12), we were able to create nonconducting lesions with less than 2 seconds of nsPEF application per site and minimal heating (< 0.2°C) of the tissue. The geometry of the ablated volume was smoother and more uniform throughout the wall than typical for RF ablation. The width of the lesions could be controlled up to 6 mm via the electrode spacing and the shock parameters.

Conclusions

Ablation with nsPEFs is a promising alternative to radiofrequency (RF) ablation of AF. It may dramatically reduce procedure times and produce more consistent lesion thickness than RF ablation.

[Relevance of magnetic resonance imaging for catheter ablation of atrial fibrillation]

Currently, atrial fibrillation is the most common form of arrhythmia encountered in clinical practice. Until recently the treatment approach to atrial fibrillation was limited by imprecise risk stratification models and suboptimal therapy options. At present cardiac magnetic resonance imaging (MRI) is an important noninvasive diagnostic modality which aids in the completion of complex electrophysiological and ablation interventions. Cardiac MRI and 3D imaging reconstruction are used clinically to assess the cardiac chambers as well as complex anatomical structures. Through the development of cardiac MRI it has become possible to detect areas of fibrosis in the left atrium which can be the cause of atrial fibrillation. The most recent clinical data suggest that there is a strong correlation between the amount of left atrial fibrosis and recurrent atrial fibrillation following ablation procedures and will in the future allow more individualized treatment strategies for patients with atrial fibrillation. In addition, cardiac MRI allows the direct visualization of catheter-induced lesions after ablation procedures which helps in assessing therapy success and can also assist in the early detection of procedure-related complications. Furthermore, with the implementation of cardiac MRI it appears possible to assess the stroke risk in patients with atrial fibrillation. Promising future developments will allow individualized therapy for patients with atrial fibrillation in addition to improving safety and procedure results after ablation.