Project description:BackgroundLeft ventricular outflow tract (LVOT) obstruction is a leading cause of mortality and exclusion from transcatheter mitral valve replacement (TMVR). Intentional laceration of the anterior mitral valve leaflet to prevent LVOT obstruction (LAMPOON) is a transcatheter mimic of surgical chord-sparing leaflet resection.ObjectivesThe purpose of this prospective multicenter trial was to study LAMPOON with transseptal (Edwards Lifesciences, Irvine, California) TMVR in annuloplasty rings or native mitral annular calcification (MAC).MethodsSubjects at high or extreme surgical risk and prohibitive risk of LVOT obstruction from TMVR were included. Eligibility was modified midtrial to exclude subjects with threatened LVOT obstruction from a Sapien 3 valve fabric skirt. The primary endpoint was procedure survival with successful LAMPOON, with successful TMVR, without reintervention, and with LVOT gradient <30 mm Hg ("optimal") or <50 mm Hg ("acceptable"). Secondary endpoints included 30-day mortality and major adverse cardiovascular events. There was universal source-data verification and independent monitoring. All endpoints were independently adjudicated. Central laboratories analyzed echocardiogram and CT images.ResultsBetween June 2017 and June 2018, 30 subjects were enrolled equally between the MAC and ring arms. LAMPOON traversal and midline laceration was successful in 100%. Procedure survival was 100%, and 30-day survival was 93%. Primary success was achieved in 73%, driven by additional procedures for paravalvular leak (10%) and high-skirt neo-LVOT gradients observed before a protocol amendment. There were no strokes.ConclusionsLAMPOON was feasible in native and annuloplasty ring anatomies in patients who were otherwise ineligible for treatment, with acceptable safety. LAMPOON was effective in preventing LVOT obstruction from TMVR. Despite LAMPOON, TMVR using Sapien 3 in annuloplasty rings and MAC still exhibits important limitations. (NHLBI DIR LAMPOON Study: Intentional Laceration of the Anterior Mitral Leaflet to Prevent Left Ventricular Outflow Tract Obstruction During Transcatheter Mitral Valve Implantation; NCT03015194).
Project description:Transcatheter mitral valve replacement carries a risk of left ventricular outflow tract obstruction associated with mortality. We present a case of left ventricular outflow tract obstruction that resolved spontaneously when chords to the anterior mitral leaflet were found to have ruptured. (Level of Difficulty: Advanced.).
Project description:We describe the first case of successful management of left ventricular outflow tract obstruction developing late after transcatheter aortic valve replacement with right ventricular apical pacing. The possible mechanisms of obstruction resolution are described. (Level of Difficulty: Advanced.).
Project description:An 83-year-old woman was admitted to our center because of heart failure. Transthoracic echocardiography revealed severe mitral annular calcification resulting in a double mitral valve lesion. After discussion by the heart team, transcatheter mitral valve replacement with Tendyne (Abbott Structural, Santa Clara, CA, USA) was performed. Despite having a predicted neo-left ventricular outflow tract (LVOT) above the cut-off value, the patient developed clinically significant LVOT obstruction (LVOTO) refractory to medical treatment. This situation is often treated before the intervention, and dealing with LVOTO afterward can be challenging. After taking the patient's anatomy into consideration, we decided to perform alcohol septal ablation. Applying a combined strategy of medical treatment and intervention led to success. In this case report, we discuss this event and the strategies available for preventing and managing the condition.
Project description:ObjectivesThe authors propose a novel transcatheter transection of the anterior mitral leaflet to prevent iatrogenic left ventricular outflow tract (LVOT) obstruction during transcatheter mitral valve replacement (TMVR).BackgroundLVOT obstruction is a life-threatening complication of TMVR caused by septal displacement of the anterior mitral leaflet.MethodsIn vivo procedures in swine were guided by biplane x-ray fluoroscopy and intracardiac echocardiography. Retrograde transaortic 6-F guiding catheters straddled the anterior mitral leaflet. A stiff 0.014-inch guidewire with polymer jacket insulation was electrified and advanced from the LVOT, through the A2 leaflet base, into the left atrium. The wire was snared and externalized, forming a loop that was energized and withdrawn to lacerate the anterior mitral leaflet.ResultsThe anterior mitral leaflet was successfully lacerated in 7 live and 1 post-mortem swine under heparinization. Lacerations extended to 89 ± 19% of leaflet length and were located within 0.5 ± 0.4 mm of leaflet centerline. The chordae were preserved and retracted the leaflet halves away from the LVOT. LVOT narrowing after benchtop TMVR was significantly reduced with intentional laceration of the anterior mitral leaflet to prevent LVOT obstruction than without (65 ± 10% vs. 31 ± 18% of pre-implantation diameter, p < 0.01). The technique caused mean blood pressure to fall (from 54 ± 6 mm Hg to 30 ± 4 mm Hg, p < 0.01), but blood pressure remained steady until planned euthanasia. No collateral tissue injury was identified on necropsy.ConclusionsUsing simple catheter techniques, the anterior mitral valve leaflet was transected. Cautiously applied in patients, this strategy can prevent anterior mitral leaflet displacement and LVOT obstruction caused by TMVR.
Project description:BACKGROUND:Accessory mitral valve tissue (AMVT) is a rare congenital cardiac anomaly and is usually diagnosed in childhood. The diagnosis of AMVT in adulthood is extremely rare. We present a case report on an adult patient with AMVT that caused a left ventricular outflow tract (LVOT) obstruction. CASE PRESENTATION:A 51-year-old man was diagnosed with AMVT via transesophageal echocardiography, which resulted in an LVOT occlusion (mean gradient 12?mmHg) during systole. Resection of the AMVT was performed under general anesthesia. The patient was hemodynamically stable throughout the surgery and post-operation. There was no abnormity of the mitral valves, including mitral regurgitation. CONCLUSIONS:Although a very rare malformation, particularly in adults, AMVT can cause LVOT obstruction. Examination of the mitral valve using transesophageal echocardiography is important to understand the severity of LVOT obstruction.
Project description:Left ventricular outflow tract obstruction (LVOTO) has been reported with bio-prosthetic and mechanical mitral valves (MV), though it is more common with the former. The obstruction can be dynamic or fixed. We hereby report a case of fixed LVOTO following bio-prosthetic MV replacement (MVR).
Project description:Accessory mitral valve (AMV) is a rare congenital abnormality with a usually early-age clinical onset, being potentially a cause of subvalvular obstruction of the left ventricular outflow tract. This report describes the case of a 60-year-old patient presented with palpitations and chest pain. Primary evaluation revealed a ventricular tachycardia episode while transthoracic echocardiography showed an intracardiac additional structure at the level of the left ventricular outflow tract. After transoesophageal echocardiography and paraclinical investigations this structure was proven to be an AMV tissue which did not provoke left ventricular outflow obstruction. This case presents an unusual late-age clinical onset of AMV without a clinically significant LVOT (left ventricular outflow tract) obstruction and highlights the importance of transthoracic and transoesophageal echocardiography in the diagnosis of this rare cardiological entity.