Cabalka, Allison K.

Introduction: Fontan pathway obstruction is a serious complication characterized by an anatomical or functional narrowing anywhere in the cavo-pulmonary pathways. Here we report the first case where an innovative Fontan conduit rehabilitation procedure with intravascular lithotripsy was used achieving a significant increase in the pathway size. Case: A 28-year-old male with tricuspid atresia status-post Fontan palliation (age 23 months) with bare metal stent implant to treat obstruction at age 15, presented with syncope, ascites and varicose veins. Imaging studies revealed a cirrhotic liver morphology and Fontan pathway obstruction with minimal diameter of 12 mm. Cardiac catheterization confirmed severe Fontan conduit obstruction in addition to LPA stenosis. Serial covered Cheatham-Platinum stents were implanted for conduit coverage followed by Palmaz stents. Non-compliant Atlas balloon dilation to 20 atm was performed without expansion of the Fontan pathway beyond 12 mm due to severe calcification. A 7.0 x 60 mm shock-wave lithotripsy balloon was added alongside the Atlas balloon to modulate the heavily calcified wall with subsequent expansion of the conduit to 21 mm after inflating the Atlas balloon to 14 atm. Discussion: Several studies demonstrated that transcatheter stenting of stenotic Fontan conduits can be safely performed. Intravascular lithotripsy has emerged as a novel therapy for the treatment of coronary vascular calcification. We report the first case of an innovative percutaneous Fontan conduit rehabilitation procedure using a lithotripsy shock wave balloon in an adult with severely calcified Fontan pathway obstruction and prior stents, achieving a 75% increase in the pathway size without significant complications. Further studies are needed to evaluate the long-term safety and efficacy of this novel approach, but this case presents an exciting option for future directions in the percutaneous treatment of Fontan pathway obstruction.

AbstractBackgroundThe Harmony TPV25 transcatheter pulmonary valve (Medtronic Inc.) is constructed with a self‐expanding stent frame comprising six zigged nitinol wires sewn together and covered with knitted polyester fabric, with flared inflow and outflow ends and a porcine pericardial valve sutured to the central portion of the device. It was approved for treatment of pulmonary regurgitation after prior right ventricular outflow tract repair in 2021. Early outcomes of this procedure have been excellent, but little is known about valve durability or ultimate mechanisms of dysfunction.MethodsWe collected data on patients who underwent reintervention for TPV25 dysfunction and described findings related to distortion of the stent frame and tissue accumulation.ResultsWe describe six patients who underwent valve‐in‐valve implant for TPV25 obstruction (peak catheterization gradient peak 28–73 mmHg) 10–28 months after implant. In all cases, there was tissue accumulation within the inflow and valve‐housing segments of the device and deformation of the self‐expanding valve frame characterized by variable circumferential narrowing at the junction between the valve housing and the inflow and outflow portions of the device, with additional geometric changes in all segments. All six patients underwent valve‐in‐valve implant that results in a final peak gradient ≤10 mmHg and no regurgitation.DiscussionThe occurrence of short‐term Harmony TPV25 dysfunction in multiple patients with a similar appearance of frame distortion and tissue accumulation within the inflow and valve housing portions of the device suggests that this may be an important failure mechanism for this valve. Potential causes of the observed findings are discussed. It is possible to treat this mechanism of TPV25 dysfunction with valve‐in‐valve implant using balloon expandable transcatheter valves.

Introduction: Mitral paravalvular leak (PVL) occurs in 7-17% of patients after mitral valve surgery. The percutaneous closure of these defects has become a novel treatment to prevent repeat operations. Hypothesis: We hypothesize flow dynamics correlate with clinical outcomes of patients undergoing percutaneous mitral PVL closure. Methods: We retrospectively studied 148 patients who underwent percutaneous PVL closure between 2004 and 2014 at Mayo Clinic. We measured the continuous wave (CW) Doppler time velocity integral (TVI), E velocity (as a surrogate for V wave) across the mitral valve and left ventricular ejection fraction (LVEF) by transthoracic echocardiogram within 7 days before and after PVL closure. We identified patients as non-responders if there was moderate to severe residual mitral regurgitation. t-Test was used for continuous variables and Fisher exact test was used mortality. Results: Overall, the mean CW TVI was markedly reduced by PVL closure (93±14 vs. 58±5cm, p<0.02). The E velocity also decreased after closure (3.1±0.4 vs. 1.9±0.1m/sec, p<0.04). LVEF, however, was reduced after PVL closure (62%±2 vs. 53%±1.5, p<0.02). Among non-responders (34/148 patients), there was no significant difference between the CW and E velocity before and after the procedure (CW TVI: 96±16 vs. 83+13cm, E velocity: 2.5±0.5 vs. 2.3±0.3m/sec, p=NS). The estimated 5-year mortality of patients with no or mild residual mitral regurgitation was markedly lower compared to non-responders, 43% vs 71%, p<0.05. Conclusions: The flow dynamics across the mitral valve immediately after PVL closure may correlate with long term clinical outcomes. Real time assessment of flow by transesophageal echocardiogram can be used to guide the extent of PVL closure required to change the long term clinical outcomes. Further validation and prospective studies are required.

AbstractObjectiveWe compared 5‐year outcomes of transcatheter pulmonary valve (TPV) replacement with the Melody TPV in the post‐approval study (PAS) and the investigational device exemption (IDE) trial.BackgroundAs a condition of approval of the Melody TPV after the IDE trial, the Food and Drug Administration required that a PAS be conducted to evaluate outcomes of TPV replacement in a “real‐world” environment. The 5‐year outcomes of the PAS have not been published, and the IDE and PAS trials have not been compared.MethodsThe cohorts comprised all patients catheterized and implanted at 5 IDE sites and 10 PAS sites. Differences in trial protocols were detailed. Time‐related outcomes and valve‐related adverse events were compared between the two trials with Kaplan–Meier curves and log‐rank testing.Results167 patients (median age, 19 years) were catheterized and 150 underwent TPV replacement in the IDE trial; 121 were catheterized (median age, 17 years) and 100 implanted in the PAS. Freedom from hemodynamic dysfunction (p = .61) or any reintervention (p = .74) over time did not differ between trials. Freedom from stent fracture (p = .003) and transcatheter reintervention (p = .010) were longer in PAS, whereas freedom from explant (p = .020) and TPV endocarditis (p = .007) were shorter. Clinically important adverse events (AEs) were reported in 14% of PAS and 7.2% of IDE patients (p = .056); the incidence of any particular event was low in both.ConclusionsHemodynamic and time‐related outcomes in the PAS and IDE trials were generally similar, confirming the effectiveness of the Melody TPV with real‐world providers. There were few significant complications and limited power to identify important differences in AEs. The lack of major differences in outcomes between the two studies questions the usefulness of mandated costly post‐approval studies as part of the regulatory process for Class III medical devices.

Background: Transcatheter mitral valve replacement using aortic transcatheter heart valves has recently become an alternative for patients with degenerated mitral bioprostheses, failed surgical repairs with annuloplasty rings or severe mitral annular calcification who are poor surgical candidates. Outcomes of these procedures are collected in the Society of Thoracic Surgeons/American College of Cardiology/Transcatheter Valve Therapy Registry. A comprehensive analysis of mitral valve-in-valve (MViV), mitral valve-in-ring (MViR), and valve-in-mitral annular calcification (ViMAC) outcomes has not been performed. We sought to evaluate short-term outcomes of early experience with MViV, MViR, and ViMAC in the United States. Methods: Retrospective analysis of data from the Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapy Registry. Results: Nine hundred three high-risk patients (median Society of Thoracic Surgeons score 10%) underwent MViV (n=680), MViR (n=123), or ViMAC (n=100) between March 2013 and June 2017 at 172 hospitals. Median age was 75 years, 59.2% female. Technical and procedural success were higher in MViV. Left ventricular outflow tract obstruction occurred more frequently with ViMAC (ViMAC=10%, MViR=4.9%, MViV=0.7%; P <0.001). In-hospital mortality (MViV=6.3%, MViR=9%, ViMAC=18%; P =0.004) and 30-day mortality (MViV=8.1%, MViR=11.5%, ViMAC=21.8%; P =0.003) were higher in ViMAC. At 30-day follow-up, median mean mitral valve gradient was 7 mm Hg, most patients (96.7%) had mitral regurgitation grade ≤1 (+) and were in New York Heart Association class I to II (81.7%). Conclusions: MViV using aortic balloon-expandable transcatheter heart valves is associated with a low complication rate, a 30-day mortality lower than predicted by the Society of Thoracic Surgeons score, and superior short-term outcomes than MViR and ViMAC. At 30 days, patients in all groups experienced improvement of symptoms, and valve performance remained stable. Registration: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT02245763.

AbstractObjectivesTo evaluate the outcomes of transcatheter coronary artery fistula (CAF) closure and to identify anatomic/procedural factors that may impact outcomes.BackgroundDue to the rarity of CAF, reported experience with transcatheter closure remains limited and anatomic and procedural factors that may lead to unsuccessful closure, complications, or recanalization of CAF are unclear.MethodsAll patients who underwent transcatheter CAF closure at Mayo Clinic from 1997 to 2018 were retrospectively reviewed. CAF anatomic characteristics, procedural techniques, and clinical/angiographic outcomes were assessed.ResultsA total of 45 patients underwent transcatheter closure of 56 CAFs. The most commonly used devices were embolization coils in 40 (71.4%) CAFs, vascular occluders in 10 (17.8%), or covered stent in 2 (3.6%). Acute procedural success with no or trivial residual flow occurred in 50 (89.3%) CAFs. Residual flow was small in three (5.4%) and large in three (5.4%). Eight (17.8%) patients had complications, including device migration in three, intracranial hemorrhage from anticoagulation in one, and myocardial infarction (MI) in four. MI was a result of covered stent thrombosis or stagnation of flow after closure of large distal CAF. Twenty‐two patients with 27 CAFs had follow‐up angiography after successful index procedure at median time of 423 (IQ 97‐1348) days. Of these, 23 (85.2%) had no/trace flow and 4 had large flow from recanalization.ConclusionsTranscatheter CAF closure is associated with a favorable acute procedural success and complication rate in selected patients. Procedural success and risk for complication are highly dependent on CAF anatomy and closure technique.

AbstractObjectiveTo understand the clinical and hemodynamic response of patients with stenotic versus regurgitant prosthetic mitral valve degeneration to transseptal transcatheter mitral valve‐in‐ring/‐valve replacement (TMVR).BackgroundPatients with prosthetic mitral valve repair/replacement failure frequently present high‐risk surgical challenges. TMVR has been employed as an alternative to surgery.MethodsForty‐four patients with stenotic/regurgitant degeneration of prior prosthetic mitral annuloplasty and replacement (38) underwent mitral TMVR. Clinical, echocardiographic, and invasive hemodynamic monitoring was conducted at baseline and follow‐up.ResultsRelative to patients with regurgitant degeneration (28), patients with stenotic degeneration had baseline higher mitral valve gradients (12 ± 4 vs. 7 ± 3 mmHg, p < 0.01) and smaller areas (1.0 ± 0.4 vs. 1.5 ± 0.4 cm2, p = 0.01). TMVR yielded significant reduction in left atrial v‐wave pressures in stenotic and regurgitant cohorts (−7 ± 11, p = 0.03, and −11 ± 12 mmHg, p < 0.01, respectively) and significant, sustained symptomatic improvement. Intracardiac pressures overall, including left ventricular end diastolic pressures, remained elevated.ConclusionDespite baseline differences in valvular disease, TMVR leads to significant hemodynamic and clinical improvement in both stenotic and regurgitant prosthetic mitral valve disease. In both cohorts, TMVR reduced intracardiac pressures to similar postprocedural levels, but pressures remained supranormal. This outcome suggests a multifactorial process defines the pathophysiology of patients undergoing TMVR, including contributions from prosthetic degeneration, changes in left atrial compliance, and diastolic dysfunction, and highlights the need to consider such factors in patient evaluation and treatment.