Paclitaxel drug-eluting stent placement for pulmonary vein stenosis as a bridge to heart-lung transplantation

Systemic Sirolimus to Prevent In-Stent Stenosis in Pediatric Pulmonary Vein Stenosis

Evaluate the efficacy of systemic sirolimus (rapamycin) in preventing in-stent stenosis (ISS) in pediatric intraluminal pulmonary vein stenosis (PVS). Report the adverse events related to sirolimus therapy. There is a high incidence of ISS following stent implantation in PVS. The use of sirolimus in preventing ISS has not been reported. Retrospective review of all patients who received sirolimus (8 week course) for treatment of ISS for PVS between January 2013 and June 2018. Forty stents (37 bare metal, 3 drug-eluting) in 20 patients were treated with sirolimus; 20 at the time of implantation (primary prevention [1P]) and 20 following documented ISS requiring transcatheter reintervention (secondary prevention [2P]). Treated patients were young (median 2 y/o [0.7-5.7]) and most had PVS associated with congenital heart disease (75%, 15/20; 4/15 with TAPVC). In the 1P group, 85% (17/20) of stents were without significant (< 50%) ISS at median of 102 days (range 56-527); the growth rate of ISS in this group was 7.5 ± 7.1%/month. In the 2P group, most stents had a slower growth rate of ISS after sirolimus therapy compared to pre-treatment (median 3.7 [- 0.2 to 13.1] vs. 10.4 [1.3 to 19.5] %/month; p < 0.001). One patient developed pneumonia on drug while concurrently taking another immunosuppressive agent. No other serious adverse events were related to sirolimus therapy. Systemic sirolimus slows the growth rate of ISS following stent implantation in PVS compared to pre-treatment rates and was administered safely in a small number of pediatric patients with complex heart disease.

Pulmonary Vein Stenosis in Infants: A Systematic Review, Meta-Analysis, and Meta-Regression

OBJECTIVE

To quantify outcomes of infants (<1 year of age) diagnosed with pulmonary vein stenosis (PVS).

STUDY DESIGN

MEDLINE (PubMed), Scopus, and Web of Science were searched through February 1, 2017, with no language restrictions. Publications including infants diagnosed with primary PVS, defined as the absence of preceding intervention(s), were considered. The study was performed according to Meta-analysis of Observational Studies in Epidemiology guidelines, the Systematic Reviews, and Meta-Analysis checklist, and registered prospectively. The quality of selected reports was critically examined. Data extraction was independently performed by multiple observers with outcomes agreed upon a priori. Data were pooled using an inverse variance heterogeneity model with incidence of mortality the primary outcome of interest.

RESULTS

Forty-eight studies of 185 infants were included. Studies were highly diverse with regards to the participants, interventions, and outcomes reported. The median (range) age at diagnosis was 5.0 (0.1-11.6) months. Pooled mortality was 58.5% (95% CI 49.8%-67.0%, I² = 21.4%). We observed greater mortality incidence among infants with 3 or 4 vein stenoses than in those with 1 or 2 vein stenoses (83.3% vs 36.1%; P < .01). We observed greater mortality among infants with bilateral than unilateral disease (78.7% vs 26.0%; P < .01).

CONCLUSIONS

Studies of primary PVS during infancy are highly variable in their methodological quality and estimates of clinical outcomes; therefore, estimates of prognosis remain uncertain. Multicenter, interdisciplinary collaborations, including alignment of key outcome measurements, are needed to answer questions beyond the scope of available data.

Organ transplantation and drug eluting stents: Perioperative challenges

Patients listed for organ transplant frequently have severe coronary artery disease (CAD), which may be treated with drug eluting stents (DES). Everolimus and zotarolimus eluting stents are commonly used. Newer generation biolimus and novolimus eluting biodegradable stents are becoming increasingly popular. Patients undergoing transplant surgery soon after the placement of DES are at increased risk of stent thrombosis (ST) in the perioperative period. Dual antiplatelet therapy (DAPT) with aspirin and a P2Y12 inhibitor such as clopidogrel, prasugrel and ticagrelor is instated post stenting to decrease the incident of ST. Cangrelor has recently been approved by Food and Drug Administration and can be used as a bridging antiplatelet drug. The risk of ischemia vs bleeding must be considered when discontinuing or continuing DAPT for surgery. Though living donor transplant surgery is an elective procedure and can be optimally timed, cadaveric organ availability is unpredictable, therefore, discontinuation of antiplatelet medication cannot be optimally timed. The type of stent and timing of transplant surgery can be of utmost importance. Many platelet function point of care tests such as Light Transmittance Aggregrometry, Thromboelastography Platelet Mapping, VerifyNow, Multiple Electrode Aggregrometry are used to assess bleeding risk and guide perioperative platelet transfusion. Response to allogenic platelet transfusion to control severe intraoperative bleeding may differ with the antiplatelet drug. In stent thrombosis is an emergency where management with either a drug eluting balloon or a DES has shown superior outcomes. Post-transplant complications often involved stenosis of an important vessel that may need revascularization. DES are now used for endovascular interventions for transplant orthotropic heart CAD, hepatic artery stenosis post liver transplantation, transplant renal artery stenosis following kidney transplantation, etc. Several antiproliferative drugs used in the DES are inhibitors of mammalian target of rapamycin. Thus they are used for post-transplant immunosuppression to prevent acute rejection in recipients with heart, liver, lung and kidney transplantation. This article describes in detail the various perioperative challenges encountered in organ transplantation surgery and patients with drug eluting stents.

Pulmonary Hypertension due to Radiofrequency Catheter Ablation (RFCA) for Atrial Fibrillation: The Lungs, the Atrium or the Ventricle?

Atrial fibrillation is the most common heart rhythm disorder in United States, characterised by rapid and irregular beating of both the atria resulting in the similar ventricular response. While rate and rhythm control using pharmacological regimens remain the primary management strategies in these patients, radiofrequency catheter ablation (RFCA) is rapidly rising as an alternative modality of treatment. Increase in the incidence of RFCA has shed light on complications associated with this procedure. Pulmonary hypertension (PH) is one of the long-term complications that has been observed postcatheter ablation. There have been multiple mechanisms which have been proposed to explain these elevated pulmonary pressures. These include the involvement of the lungs due to pulmonary vein stenosis, pulmonary vein occlusion and, rarely, pulmonary embolism. Radiofrequency catheter ablation can also lead to scarring of the atrium which can cause left atrial diastolic dysfunction leading to elevated pulmonary pressures. Recently, it was also proposed that elevated pulmonary pressure was related to the unmasking of left ventricular diastolic dysfunction occurring after this procedure. In this article, we review all the mechanisms that are associated with the development of pulmonary hypertension in patients undergoing RCFA for atrial fibrillation and the approach to diagnosis and management of such patients.

Pulmonary Vein Stenosis Complicating Radiofrequency Catheter Ablation: Five Case Reports and Literature Review

The aim of this study is to characterize the clinical manifestations and features of pulmonary vein stenosis (PVS) by retrospectively analyzing clinical data of patients in addition to reviewing the literature simultaneously to improve the understanding of PVS complicating radiofrequency catheter ablation and to provide evidence for early diagnosis and timely treatment.Clinical, imaging, and follow-up data of 5 patients with PVS-complicating radiofrequency catheter ablation were retrospectively analyzed between January 2012 and December 2014 in Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, China. Relevant studies previously reported were also reviewed.Three out of 5 patients received pulmonary angiography. The initial symptoms were not specific, presenting chest pain in 3 cases, hemoptysis in 2 cases. The average duration between radiofrequency ablation to the onset of symptoms was 5.8 months. The chest image results were consolidation and pleural effusion mainly. Veins distributed in the left lungs were mostly influenced in 4 patients, and the inferior veins in 3 patients. Cardiac ultrasound examinations showed pulmonary arterial hypertension in 2 patients. Two patients received selective bronchial artery embolization after bronchial artery radiography because of hemoptysis. One patient underwent video-assisted thoracoscopic biopsy because of the suspicion of tumor.PVS is a condition mostly undetected because of its silent manifestations and inconsistent follow-up. The accurate clinical diagnosis is very difficult. A careful review of medical history and follow-up observation may be useful for all the patients who received the radiofrequency catheter ablation to recognize PVS in the early stage.

Management Of Pulmonary Vein Stenosis Following Catheter Ablation Of Atrial Fibrillation

There is limited literature available regarding PV (pulmonary vein) stenosis management. Starting from its incidence, subsequent follow up using imaging technologies to monitor the success and the way of managing different groups pose varied opinions. However, with newer technological advancements and better understanding of mechanism of the atrial fibrillation ablation, the incidence of PV stenosis secondary to catheter ablation is declining. This paper highlights the current trends and future of management of PV stenosis secondary to catheter ablation for atrial fibrillation.

Cryo-balloon angioplasty for pulmonary vein stenosis in pediatric patients

This study sought to determine the safety and effectiveness of cryo-balloon angioplasty (CbA) for pulmonary vein stenosis (PVS) in pediatric patients. Current therapy options for PVS are less than satisfactory due to recurrent progressive restenosis and neointimal proliferation. Catheterization database, hospital records, imaging studies, and pathologic specimens were reviewed for procedural-related and outcomes data in all patients who underwent pulmonary vein (PV) CbA using the Boston Scientific PolarCath Peripheral Dilation System between August 2006 and June 2009. Thirteen patients (19 PVs; median age 13 months [range 3.5 months to 18.5 years] and weight 7.9 kg [range 3.8 to 47.7]) underwent CbA. Mean PVS diameter after CbA increased from 2.19 (± 0.6) to 3.77 (± 1.1) mm (p < 0.001). Mean gradient decreased from 14 (± 7.4) to 4.89 (± 3.2) mm Hg (p < 0.001). Mean stenosis-to-normal vein diameter ratio increased from 0.52 (± 0.15) to 0.89 (± 0.33) (p < 0.001). Eight patients underwent repeat catheterization a mean of 5.6 months (± 3.66) later. Improved PVS diameter was maintained in 2 PVs. Four veins had restenosis but maintained diameters greater than that before initial CbA. In 11 PVs, the diameter decreased from 4.28 (± 1.14) to 2.53 (± 0.9) mm (p = 0.001). Mean gradient increased from 3.55 (± 3.0) to 14.63 (± 9.6) mm Hg (p = 0.011). All vessels underwent repeat intervention with acute relief of PVS. Stroke occurred within 24 h of CbA in 1 patient. CbA of PVS is safe and results in acute relief of stenosis. However, CbA appears minimally effective as the sole therapy in maintaining long-term relief of PVS.

Congenital narrowing of a pulmonary vein: slit-like pulmonary vein ostium

We report the case of a 60-year-old female with a history of refractory paroxysmal atrial fibrillation. Preablation contrast enhanced pulmonary vein computed tomography (CT) scan demonstrated a slit-like narrowing of the left inferior pulmonary vein ostium. The narrowing measured approximately 3 mm, with poststenotic dilation. The patient had no prior history of ablation. The patient subsequently underwent segmental antral isolation of all four pulmonary veins and cavo-tricuspid isthmus ablation with bidirectional block. The diagnosis of preexisting congenital pulmonary vein stenosis had an impact on the type of ablation procedure performed (antral rather than ostial) and will affect the interpretation of postablation CT scans.

Long-term outcome of sirolimus-eluting stent implantation for left main coronary artery stenosis in infancy

Drug-eluting stents (DES) have markedly reduced the incidence of coronary in-stent restenosis. However, DES may be still vulnerable to coronary thrombus, and the long-term outcome remains unknown, especially in infancy. Here, we present a 9-month-old infant, who developed severe stenosis of the left main coronary artery after surgery for Brand-White-Garland syndrome, and was successfully treated with DES. He was healthy and his cardiac function had improved to the normal level at 6 years old. An angiographic examination and computed tomography showed the complete persistence of DES and no evidence of intimal thickening.

Drug-eluting stents ameliorate pulmonary vein stenotic changes in pigs in vivo

The outcome of stent implantation for pulmonary vein stenosis (PVS) in children remains poor. Several reports describe placing drug-eluting stents to treat PVS, but their effectiveness remains unknown. In this study, three bare-metal stents (BMSs) and three sirolimus-eluting stents (SESs) were implanted in 1-month-old pigs. The pigs were killed 8 weeks later to compare in-stent stenosis rates. The extent of neointimal thickness, as measured by injury score, was significantly less in the SES group than in the BMS group (injury score 1: BMS 0.351 + or - 0.033 vs SES 0.226 + or - 0.031 mm; P < 0.01; injury score 2: BMS 1.232 + or - 0.244 vs SES 0.609 + or - 0.208 mm; P < 0.01). The pathologic findings showed confluence of inflammatory cells around the stent wires in BMS-treated areas and granuloma formation. Granuloma formation was not seen with SES. The degree of in-stent stenosis was significantly reduced in the SES group, suggesting that the use of drug-eluting stents is an effective treatment for PVS. Because of the small sample size and the considerable variation in injury scores and balloon-to-vein ratios, future studies with larger samples are necessary.