Congenital Heart Interventions

Excellent Survival With a Focus on Pulmonary Artery Reinterventions After the Arterial Switch Operation. Selcuk A, Ozturk M, Tongut A, Sterzbecher V, Park IH, Mehta R, Desai M, Yerebakan C, d'Udekem Y.World J Pediatr Congenit Heart Surg. 2024 Jul;15(4):421-429. doi: 10.1177/21501351241239307. Epub 2024 May 16.PMID: 38751363 Take Home Points The arterial switch operation (ASO) achieves a high survival rate in patients with dextro-transposition of the great arteries (d-TGA), with 96.6% surviving beyond the first year. One in five patients (21%) required reintervention, mainly due to pulmonary artery (PA) stenosis. Patients with Taussig-Bing anomaly (TBA) had a notably higher reintervention rate, identifying a high-risk subgroup within the d-TGA population Consistent, long-term follow-up is essential after the ASO, especially in patients with TBA, to monitor and manage PA complications Commentary from Dr. Milan Prsa (Switzerland, Europe), section editor of Congenital Heart Disease Interventions Journal Watch: The ASO is the standard corrective surgery for d-TGA. This study aimed to evaluate the effectiveness of ASO, focusing on survival rates and the incidence of reinterventions for PA stenosis, a common postoperative complication. This retrospective review included 180 patients who underwent ASO for d-TGA between 2002 and 2022 at a single center. Patients were divided into three groups: those with an intact ventricular septum (TGA-IVS), those with a ventricular septal defect (TGA-VSD), and those with Taussig-Bing anomaly (TBA). Kaplan-Meier survival analysis was used to assess overall survival and reintervention-free survival, while regression analyses identified risk factors for PA stenosis and intervention. The study found a one-year survival rate of 96.6%, underscoring the efficacy of ASO in managing d-TGA. However, reinterventions were necessary for 43 patients (24%), primarily due to PA stenosis (86%, 37/43). These 37 patients (21%) underwent 53 PA reinterventions, including 14 reoperations and 39 transcatheter angioplasties (33 ballon dilations and 6 stent implantations). Eight patients (22%, 8/37) required early (prior to discharge) PA reintervention, at a median postoperative day of 31 (IQR 8-39). The median time from ASO to PA angioplasty was six months (IQR 2-13), and from ASO to reoperation was one year (IQR 0.1-8). Freedom from PA reintervention decreased significantly over time, dropping from 97% at one year to 55% at 15 years, indicating a progressive risk for PA stenosis with age. Risk factors for PA reintervention were TBA (OR 6.4), mild PA stenosis at discharge (OR 6.1) and moderate or severe PA stenosis at discharge (OR 12.7). Despite limitations as a single-center retrospective review, this study highlights the long-term success of ASO for d-TGA and the challenges of managing postoperative complications, particularly PA stenosis. It provides valuable insights into the progression of PA stenosis over time, emphasizing the need for careful monitoring and individualized care, especially for patients with more complex anatomy like TBA. The authors suggest that the surgical techniques, such as the level of arterial transection and the type of patch used in neo-PA reconstruction (e.g. glutaraldehyde-treated pericardium) may contribute to PA stenosis. Future studies could focus on refining surgical techniques to reduce PA stenosis, thus improving patient outcomes and minimizing the need for reintervention.

Transcatheter Pulmonary Valve Replacement with the Harmony Valve in Patients Who Do Not Meet Recommended Oversizing Criteria on the Screening Perimeter Plot. McElhinney DB, Gillespie MJ, Aboulhosn JA, Cabalka AK, Morray BH, Balzer DT, Qureshi AM, Hoskoppal AK, Goldstein BH. Circ Cardiovasc Interv. 2024 May;17(5):e013889. doi: 10.1161/CIRCINTERVENTIONS.123.013889. Epub 2024 Apr 12. PMID: 38606564 Take Home Points The Harmony valve was FDA approved for treatment of post intervention pulmonary valve regurgitation in 2021 The stent Medtronic generates a screening report to help determine candidacy for a successful valve implantationis delivered by the Minima Delivery System which has an outer diameter equivalent to a 4 Fr sheath. Successful Harmony valve implantation with good results is possible in some patients that do not technically meet screen in criteria Commentary from Dr. Ryan Romans (Kansas City, MO), section editor of Congenital Heart Disease Interventions Journal Watch:  The Harmony valve received FDA approval in 2021 for transcatheter pulmonary valve replacement (TPVR) for the treatment of post intervention pulmonary regurgitation. The Harmony valve is made of a covered self-expanding nitinol wire frame in an hourglass shape (rows 1 and 2 in the outflow/PA portion of the device, rows 5 and 6 the inflow/RV portion of the device) with a porcine pericardial valve in the center (rows 3 and 4). The inflow and outflow segments are designed to anchor the valve within the RVOT and prevent paravalvar leak. A pre procedure CT angiogram is performed and then analyzed by Medtronic using an algorithm designed to ensure adequate oversizing to secure the device in the RVOT. A screening report is generated and details various important anatomical features of the RVOT, including a perimeter plot (PP) that is generated based on measurements from the CT angiogram at end diastole and peak systole. A patient’s anatomy is typically considered a fit when the screening report predicts adequate oversizing of both the inflow and outflow portions of the device (approximately 70% of screened patients). While the screening report has been very useful with excellent specificity (unsuccessful valve implantation is extremely rare when fit predicted). However, the RVOT anatomy is complex, and it is unclear how many patients that don’t have a positive screening report could still undergo successful transcatheter pulmonary valve replacement. This retrospective multicenter study looked at patients with borderline or inadequate oversizing on the fit analysis who ultimately underwent successful Harmony valve implantation. Perimeter plot with green shading meeting criteria for minimum oversizing, yellow shading borderline oversizing (50-99% recommended), and red shading insufficient oversizing (<50% recommended).  The landing zone is the length for which this oversizing is met.   There were 22 patients at 8 different centers who underwent Harmony TPV25 implant despite not meeting recommended oversizing criteria; 13 of these were coded green-yellow and 9 green-red (meaning all had adequate oversizing on at least 1 end of the device). The RVOT anatomy of these patients were grouped into three different anatomic types with strategy for valve implantation being somewhat specific for each. The figures below show the PP on the left, diastole in the middle, and systole on the right. Type 1 (n=9): Long RVOT with a clear choke point (often at the level of the annulus) and large MPA that flared out toward the branch PAs. More than 50% of these patients had diagnoses other than TOF. The large, flared MPA did not allow for oversizing of both ends simultaneously. The valve was typically implanted in an annular position (valve housing/rows 3-4 at the level of the annulus). Type 2 (n=6): Short RVOT that was often pyramidal with a large degree of MPA expansion (in length and diameter) during systole. The RVOT length was too short during diastole for adequate oversizing of both ends and there was not usually a choke point. The valve was typically implanted high with the outflow rows flowering into the PA bifurcation or within the distensible distal MPA. Type 3 (n=7): Short and bulbous MPA with a discrete choke point that did not screen in because of the large MPA and short RVOT. More than 50% of these patients had diagnoses other than TOF. The valve was typically implanted high or at the annular level. The implant was annular in 15 patients and supra-annular in 7 patients. There was trivial pulmonary regurgitation via echocardiography in 5 patients, trivial paravalvar leak in 3 , and mild paravalvar leak in 2. 41% (9) of patients were started on antiarrhythmic medications for new non-sustained VT/frequent ventricular ectopy.  This study shows that patients with inadequate oversizing at one end of the device on the Harmony valve screening report may still be able to undergo successful Harmony TPVR with excellent short term results as long as there is adequate oversizing at one end of the device. This is possible because the anatomy of the RVOT in these cases allowed for device stability. Also, the anatomy of the RVOT is complex and while there may not be apposition of the device along the entire circumference of the RVOT that may not be necessary to ensure device stability. While it is challenging to draw broad conclusions from this study (it is unclear who screened out that could have undergone successful TPVR and who when attempted would have failed) this study highlights the importance of looking at the individual anatomical features when deciding whether or not to attempt TPVR with the Harmony valve.

Results of the multicenter early feasibility study (EFS) of the Renata Minima stent as treatment for branch pulmonary artery stenosis and coarctation of aorta in infants. Berman DP, Morray B, Sullivan P, Shahanavaz S, Zahn EM.Catheter Cardiovasc Interv. 2024 Jul;104(1):61-70. doi: 10.1002/ccd.31074. Epub 2024 May 12.PMID: 38736246 Take Home Points The Minima Stent is a symmetrical, closed cell cobalt-chromium stent premounted on either a 6 or 8 mm balloon with in-vitro dilation up to 24 mm in diameter The stent is delivered by the Minima Delivery System which has an outer diameter equivalent to a 4 Fr sheath. In this early feasibility study all 10 patients had successful stent implantation without serious adverse events Commentary from Dr. Jonathon Hagel (C.S. Mott Children’s Hospital, University of Michigan) Endovascular stent implantation for the treatment of branch pulmonary artery stenosis and coarctation of the aorta has become the mainstay of treatment for older children and young adults with stents that can be implanted with a final diameter that can reach adult size. Unfortunately, there remains a gap in the availability of a stent which can be implanted at a size appropriate for infants but that can also be dilated to adult size. Further, current stent technology requires delivery through large delivery sheaths leading to increased risk of vascular injury. The authors of this early feasibility study sought to address the safety and feasibility of the newly developed Renata Minima Stent and delivery system that were specifically designed to meet these needs.  The Minima Stent is a symmetrical, closed cell cobalt-chromium stent which is delivered by the Minima Delivery System which has an outer diameter equivalent to a 4 Fr sheath and can be advanced through a 6 Fr sheath if desired. The stent is premounted on either a 6 or 8 mm balloon with in-vitro dilation up to 24 mm in diameter while maintaining radial strength. The stent has a predictable shortening profile starting at 17mm fully crimped that shortens down to 5mm when dilated to 22mm.  The median age at implant was 9 months with a median weight of 7.6 Kg. The stent was successfully deployed in 10/10 patients and all patients met the predefined primary efficacy endpoint of successful relief of stenosis with >50% increase in vessel diameter and all were free of stent explant at 6 months post-implantation. Two patients treated for coarctation of the aorta developed pulse loss requiring low molecular weight heparin initiation and one patient had malposition of stent placement requiring a second stent to treat the lesion. Five patients have had elective stent re-dilation at a mean of 7 months post-implantation. In this early feasibility study, the Renata Minima Stent is safe and effective at treating infants and young children with native and recurrent branch pulmonary artery stenosis and coarctation of the aorta. This study, by nature of it design, was not able to describe in-human stent characteristics when dilated to adult diameters, though significant stent shortening and long-term radial strength without frame fracture remain uncertain. A multi-center pivotal trial is ongoing targeting the enrollment of 42 patients across 7 centers which will provide a larger cohort with longer follow-up to address some of these ongoing concerns.

Percutaneous Balloon-Expandable Stent Implantation to Treat Transverse Aortic Arch Obstruction: Medium- to Long-Term Outcomes of a Retrospective Multicenter Study. Salavitabar A, Eisner M, Armstrong AK, Boe BA, Chisolm JL, Cheatham JP, Cheatham SL, Forbes T, Jones TK, Krings GJ, Morray BH, Steinberg ZL, Akam-Venkata J, Voskuil M, Berman DP.Circ Cardiovasc Interv. 2024 Jul;17(7):e013729. doi: 10.1161/CIRCINTERVENTIONS.123.013729. Epub 2024 Apr 26.PMID: 38666384 Coronary artery fistulas are rare and are heterogeneous in their anatomy and presentation. Clinically asymptomatic CAFs can be managed conservatively without long-term complications. Commentary from Dr. Subhrajit Lahiri, section editor of Congenital Heart Disease Interventions Journal Watch: The authors begin by stating the importance of transverse arch coarctation and evidence of successful percutaneous treatment in small studies. The objective of this paper was to evaluate the technical, procedural, and mid- and long-term clinical outcomes of percutaneous TAA stent implantation. This was a retrospective, international, multicenter study including patients who had percutaneous stent implantation to treat TAA obstruction from July 2002 to December 2017 at 4 centers. Procedural success was defined as a residual transcatheter gradient of ≤10 mm Hg. The author reports the placement of transverse aortic stents in 146 patients aged 12 months to 120 months. Technical success was achieved in 146 (100%) patients. On univariable analyses, lower patient weight (P=0.018), body surface area (P=0.013), and smaller Minimum Diameter /Descending AO ratio (P<0.001) were associated with a higher baseline Peak Systolic Ejection Gradient (PSEG). Postintervention PSEG was not associated with any patient or anatomic characteristic but was inversely associated with implant balloon (P<0.001) and final dilation (P<0.001) diameters. Of note, most of the stents used in this study were open-celled stents which prevent obstruction of flow to the head and neck vessels that are jailed in most of these cases. The authors discussed the complications/risks in detail. The composite complication rate was 14%. This included stent embolization and intraprocedural aortic wall injuries. On univariable regression, the number of stents at the index procedure was the only variable associated with increased risk of intraprocedural complications (odds ratio, 4.58 [95% CI, 1.95–11.4]; P<0.001). The overall rate of postprocedural aortic wall injury and stent-related complications was 8.2% (n=12). There were no reports of abnormal brain imaging or cerebrovascular accidents immediately post-catheterization. Reintervention was reported in 60 (41%) patients at a median of 84 (22–148) months to first reintervention. Multivariate and univariate analysis showed that a residual gradient >10 mm Hg was associated with increased odds of reintervention at 1 year (odds ratio, 6.3 [95% CI, 1.5–26.8]; P=0.012) and from 1-year to most recent follow-up (odds ratio, 8.4 [95% CI, 2.2–56.1]; P=0.001). Interestingly, hypertension was present in 45% of patients at the latest follow up and the prescription of antihypertensive medications increased due to confidence that providers had to prescribe antihypertensive medications, once the coarctation was relieved by the intervention. This trend then plateaued.  The study can be criticized for the heterogeneity of the pathology, technique, and criteria of stent placement, the essence of which probably cannot be captured by the broad statistics performed. The blood pressure gradients reported were not granular to the level of arch vessels. Also, the lack of follow-up protocol probably fails to capture the exact prevalence of residual coarctation and long-term complications. Nevertheless, this is the largest of similar studies which encourages us to consider transverse aortic arch stent placement in the selected population assuring good technical success and low recurrence and complication rates.

Three-Decade Experience with Management of Coronary Artery Fistulas in Children. Haddad RN, Bonnet D, Malekzadeh-Milani S. Can J Cardiol. 2024 Jun 6:S0828-282X(24)00430-6. doi: 10.1016/j.cjca.2024.05.028. Online ahead of print. PMID: 38851390  Take home points: Coronary artery fistulas are rare and are heterogeneous in their anatomy and presentation. Clinically asymptomatic CAFs can be managed conservatively without long-term complications. Transcatheter closure is effective in appropriately selected patients but carries a relatively high risk of complications making it imperative that providers are prepared to deal them should they arise. Commentary from Dr. Konstantin Averin (Cohen Children’s Heart Center), catheterization section editor of Pediatric Cardiology Journal Watch: Coronary artery fistulas (CAFs) are rare anomalous connections from the normal coronary artery to another cardiac structure. These lesions range in severity from completely asymptomatic to those that can cause myocardial ischemia, primarily driven by the diameter of the orifice and length of the fistulous connection. Data on management and outcomes are limited so the authors sought to describe a 3-decade (1997-2023) single center experience with the management of CAFs in children.During the study period 94 CAFs in 78 patients (33 male) were identified, the median age at diagnosis was 3.4 years (IQR 0.9-6.6 years) and weight 15 kg (IQR 8.9-24.9 kg). Main closure indications were hemodynamically significant shunt, prevention of endocarditis or rupture in an aneurysmal feeder artery, or evidence of myocardial ischemia. Twenty-three patients did not have indications for closure and were managed conservatively, 8 had primary surgical ligation, and the rest (47) underwent trans-catheter closure. The catheterization procedural details are summarized in the table below. A wide variety of approaches (antegrade v retrograde) and devices (coils, vascular plugs, and nitinol occluders) were utilized. Antegrade approaches were utilized more commonly in the later part of the study period likely due to availability of smaller profile closure devices. Trans-catheter closure was successful in 44/47 patients. The rate of procedural complications was high with 31.9% experiencing complications, and almost half of these (6/15) being serious – CA pseudoaneurysm, myocardial infarction, air embolism, RCA dissection, and aortic valve regurgitation requiring surgical repair. There were no significant long-term complications in any of the treatment groups. The authors should be congratulated on a robust demonstration of the heterogeneous nature of CAFs and the various management strategies that can be applied. In the modern era transcatheter closure is effective in appropriately selected patients however the rate of serious complication is relatively high (12%) and requires upfront preparation and the availability of surgical back up. Smaller profile devices that can be delivered via microcatheters and 4-French diagnostic catheter may allow for treatment of more complex fistulas in smaller patients.