Ventricle Outflow Tract Obstruction Research Articles

Pulmonary Artery Banding and Arch Repair vs Norwood for Unbalanced Atrioventricular Canal Defect

BackgroundThe outcomes of single-ventricle palliation in unbalanced atrioventricular canal defect with coarctation of aorta (uAVC+CoA) have not been well studied. Systemic ventricle outflow tract obstruction has a propensity to develop in these patients after aortic arch repair with pulmonary artery banding (arch-PAB), which may adversely affect survival and Fontan candidacy. MethodsA retrospective review was performed of patients who underwent single-ventricle palliation for uAVC+CoA from 2000 to 2022. Patients were divided into 2 groups based on initial palliation: (1) arch-PAB and (2) Norwood procedure. Demographic and clinical characteristics were analyzed and compared along with survival data. ResultsStage 1 palliation for uAVC+CoA was performed in 41 patients. Arch-PAB was performed in 14 infants and Norwood in 27 infants. Arch-PAB patients had more chromosomal abnormalities (28.6 vs 7.4%, P < .009) and less severe systemic ventricle outflow tract obstruction on baseline echocardiogram (0.0 vs 70.4%, P < .001). Survival to stage 3 palliation was lower for the arch-PAB group (28.6% vs 66.6%, P = .02). Arch-PAB remained a significant risk factor for mortality (hazard ratio, 2.93; 95% CI, 1.05-8.53; P = .04) after adjusting for chromosomal abnormalities and atrioventricular valve regurgitation. After arch-PAB, systemic ventricle outflow tract obstruction was diagnosed in 13 of 14 patients. Echocardiography underestimated the degree of outflow tract obstruction in 10 of 13 arch-PAB patients. ConclusionsArch-PAB has worse outcomes than Norwood for uAVC+CoA. Systemic ventricle outflow tract obstruction develops in almost all patients after arch-PAB. Outflow tract obstruction is underestimated by the echocardiogram and requires a high index of suspicion, along with advanced imaging, to ensure timely diagnosis and management.

Comment on: "Evaluation of perioperative risk factors in pediatric patients with left ventricle outflow tract obstruction".

Comment on: "Evaluation of perioperative risk factors in pediatric patients with left ventricle outflow tract obstruction".

Abstract 14461: Impact of Intermittent vs Persistent Left Ventricle Outflow Tract Obstruction on Left Atrial Strain and Diastolic Function in a Young Hypertrophic Cardiomyopathy Cohort

Background: Adolescents and young adults with hypertrophic cardiomyopathy (HCM) and persistent left ventricular outflow tract obstruction (LVOTO) have larger left atrial volume (LAV) and abnormal diastolic function and left atrial (LA) strain compared to those without resting LVOTO. It is unknown whether intermittent LVOTO with exercise results in smaller LAV and improved diastolic function and LA strain indices compared to persistent LVOTO. Methods: All HCM patients with echo and exercise stress echocardiography (ESE) from 2014-2022 at a single center were enrolled. The cohort was divided into 3 ESE hemodynamics groups: 1) No LVOTO (all gradients &lt; 30 mmHg, n=48); 2) Intermittent LVOTO (no rest gradient, exercise ≥30 mmHg, n=41); 3) Persistent LVOTO (rest/exercise ≥30mm Hg, n=29). LAV (biplane method), LAV Z scores, LV lateral e’, lateral e’ Z scores, LA reservoir (LASr), conduit (LAScd), and contractile (LASct) strain (TOMTEC Arena AutoSTRAIN) were analyzed. For each parameter, mean values were compared across groups using one-way analysis of variance. The Bonferroni method was used to compare Group 2 to 1 and 3. Results: 118 patients (31% F, median age 17 yrs, range 7-39) formed the cohort. Mean LAV was 64.9, 65.1, and 79.5 ml in Groups 1, 2, and 3 respectively. Differences in group means were found for LAV Z score, lateral e’, lateral e’ Z score, LASr, and LAScd (all p≤0.01). In Group 2 vs 3, LAV Z score was significantly lower (0.46 v 1.89) and LV lateral e’, lateral e’ Z score, and LAScd were significantly higher (lateral e’: 13.1 v 9.0 cm/s; lateral e’ Z score: -2.0 v -3.4; LAScd: 26.0 v 21.1%) (Fig 1). LASr did not differ significantly in Group 2 vs 3. No significant differences were found in Group 2 vs 1. Conclusion: In one of the largest young HCM cohorts, intermittent obstruction was associated with smaller LAV, better diastolic indices, and higher LA conduit strain versus persistent obstruction. Longer follow-up is needed to assess change as those with intermittent LVOTO age.

Left ventricle outflow tract obstruction after transcatheter mitral valve replacement with a transatrial approach.

Left ventricle outflow tract obstruction after transcatheter mitral valve replacement with a transatrial approach.

Situs inversus with dextrocardia and transposition of great arteries.

Transposition of the great arteries with left ventricle outflow tract obstruction in combination with situs inversus totalis and dextrocardia is a very rare anomaly and carries high morbidity and mortality. Only few cases have been reported with this anomaly. We describe a 21-day of infant girl with transposition of the great arteries and mirror image dextrocardia and pulmonary stenosis who underwent successful neonatal arterial switch operation and left ventricle outflow tract obstruction resection following PDA stent implantation.

Tergitol Based Decellularization Protocol Improves the Prerequisites for Pulmonary Xenografts: Characterization and Biocompatibility Assessment

Right ventricle outflow tract obstruction (RVOTO) is a congenital pathological condition that contributes to about 15% of congenital heart diseases. In most cases, the replacement of the right ventricle outflow in pediatric age requires subsequent pulmonary valve replacement in adulthood. The aim of this study was to investigate the extracellular matrix scaffold obtained by decellularization of the porcine pulmonary valve using a new detergent (Tergitol) instead of Triton X-100. The decellularized scaffold was evaluated for the integrity of its extracellular matrix (ECM) structure by testing for its biochemical and mechanical properties, and the cytotoxicity/cytocompatibility of decellularized tissue was assessed using bone marrow-derived mesenchymal stem cells. We concluded that Tergitol could remove the nuclear material efficiently while preserving the structural proteins of the matrix, but without an efficient removal of the alpha-gal antigenic epitope. Therefore, Tergitol can be used as an alternative detergent to replace the Triton X-100.

PS-C14-9: DIFFERENTIAL DIAGNOSIS OF HYPERTROPHIC CARDIOMYOPATHY AND HYPERTENSIVE HEART DISEASE

Objective: To conduct a differential diagnosis of hypertrophic cardiomyopathy and hypertensive heart. Material and Methods: The study included 40 patients with hypertrophic cardiomyopathy without left ventricle outflow tract obstruction, mean age 57.3 ± 9.5 years, 26 women and 30 patients with hypertensive heart, mean age 49.0 ± 8.7 years, 21 men. Results: The diagnosis of hypertrophic cardiomyopathy was established on the basis of clinical and anamnestic data, electrocardiography and echocardiography, genetics, upon detection of left ventricle myocardial hypertrophy with a maximum wall thickness of &gt; 15 mm without dilatation of its cavity in the absence of other heart diseases. Hypertensive heart was diagnosed in patients with left ventricle myocardial hypertrophy &gt; 12 mm due to hypertension. Hypertonic disease was detected according to the data of 24 hour blood pressure monitoring when systolic blood pressure &gt; 135 mm Hg was recorded during wakefulness, diastolic &gt; 85 mm Hg. The patients of both groups were comparable in terms of gender and age. Left ventricle myocardial mass index, interventricular septum thickness in diastole in patients with hypertrophic cardiomyopathy significantly exceeded those in patients with hypertensive heart. The thickness of the posterior wall of the left ventricle was almost the same in both groups. The maximum pressure gradient in hypertrophic cardiomyopathy at a load of 9 to 22 mm Hg. According to blood pressure monitoring data, arterial hypertension was detected in 65% of patients with hypertrophic cardiomyopathy. The degree of arterial hypertension was higher in patients with hypertensive heart. Exercise tolerance in patients with hypertension was higher than 111.0 ± 22.2. The maximum systolic blood pressure at the peak of physical activity in hypertrophic cardiomyopathy was significantly lower than in hypertensive heart 159.6 ± 21.1 and 196 ± 7.9 mmHg. Dyspnea as a reason for discontinuation of the test was more often observed in hypertrophic cardiomyopathy, 39% and 5%. In 26% of patients with hypertrophic cardiomyopathy, frequent ventricular extrasystole occurred at the height of the load, and no rhythm disturbances were recorded in patients with hypertensive heart. Conclusion: According to echocardiography data, there was no significant difference; systolic blood pressure at the height of the load in patients with hypertensive heart was significantly higher. Despite the above differences between patients with hypertrophic cardiomyopathy and hypertensive heart, it is not possible to single out an absolute sign that allows for a differential diagnosis. Important is the history of the disease, complaints and genetic analysis to identify mutations in hypertrophic cardiomyopathy.

Evaluation of perioperative risk factors in pediatric patients with left ventricle outflow tract obstruction.

Left ventricular outflow tract obstructions (LVOTO) presents as complex cardiac diseases accompanied by other cardiac anomalies in the pediatric age group. Postoperative complications, especially cardiac, pulmonary, and renal complications, that may develop after pediatric cardiac surgery can become life-threatening. If the perioperative risk factors for these complications are known in pediatric patients with LVOTO, anesthesiologists and surgeons may take precautions to eliminate undesirable outcomes. To evaluate the perioperative risk factors that may contribute to the development of postoperative complications in pediatric patients operated on for LVOTO in a pediatric cardiac surgery clinic. The study retrospectively investigated 58 patients who were operated on for LVOTO in a pediatric cardiac surgery clinic. The patients were divided into two groups, those with and without postoperative complications. Preoperative laboratory test results, anesthesia time, operation time, aortic cross-clamp time, cardiopulmonary bypass (CPB) time, postoperative inotropes, first postoperative laboratory tests, intraoperative and postoperative complications, mechanical ventilation time, intensive care unit stay, and hospital stay were recorded. The most common postoperative complications were endocrine complications, followed by hepatic complications. The preoperative lymphocyte count was significantly higher (p < 0.05), and the neutrophil-to-lymphocyte ratio (NLR) was significantly lower (p < 0.05) in the group with postoperative complications. The postoperative pH, glucose, creatinine, and aspartate aminotransferase (AST) levels were significantly lower (p < 0.05), and the postoperative calcium level was significantly higher (p < 0.05) in the group without postoperative complications. Intraoperative platelet transfusion rate was found to be significantly lower (p < 0.05) in the group with postoperative complications. It is critical to identify predictive factors to prevent postoperative complications in pediatric patients undergoing surgery for LVOTO. Preoperative NLR, intraoperative platelet transfusion, and postoperative calcium, glucose, pH and AST levels may help in the prediction of complications.

Pregnancy and severe left ventricle outflow tract obstruction in Hypertrophic Cardiomyopathy: a case report and review

Pregnancy and severe left ventricle outflow tract obstruction in Hypertrophic Cardiomyopathy: a case report and review

Mitral valve anomalies in transposition of the great arteries: Anatomical features, surgical management and outcomes

Mitral valve (MV) anomalies can be associated with transposition of the great arteries (TGA), but their influence on the choice of the surgical technique and the outcomes after anatomical repair, mainly mitral regurgitation (MR) and LVOT obstruction, have rarely been addressed. Our study objectives are to describe the MV anomalies found in patients with TGA, the different surgical procedures performed and the fate of the anomalous MV. From 1990 to 2020, 52 patients out of 1590 (3.3%) were identified. Main MV anomalies were a mitral cleft (88%) and anomalies of the subvalvular apparatus (60%) such as abnormal chordae attachments (16/52, 30.8%), straddling (6/52, 11.5%), accessory tissue (7/52, 13.5%) or an abnormal papillary muscle (4/52, 7.7%). The mitral cleft was described as anterior (ejection/outflow tract) in 40 and as AVSD-type in 6. A ventricular septal defect (VSD) was associated in 88.5% (58% outlet) ( Fig. 1 ). Main surgical procedure performed at repair was the arterial switch operation (ASO) ( n = 47, 90.4%). Two patients (3.8%) underwent a Bex-Nikaidoh procedure, 2 (3.8%) a half turned truncal rotation and 1 (1.9%) a “reparation à l’étage ventriculaire” (REV) procedure. Overall survival was 90% at 1 year and 88% at 10 and 20 years during a mean follow-up period of 9.5 years. Ten patients (19.2%) had a concomitant mitral procedure at repair (cleft closure in 7, procedure on the subvalvular apparatus in 6), of which 4 had a preoperative grade ≥ 2 MR. Five patients required reoperation for MR and/or for left ventricle outflow tract obstruction (LVOTO), none of them had previously undergone a mitral procedure at repair. All five underwent cleft closure, with LVOTO relief in 3. Freedom from MV reoperation was 96% at 1 year, 93% at 5 years, and 84.5% at 20 years. Main MV anomalies in TGA are the presence of an anterior cleft and abnormalities of the subvalvular apparatus, frequently associated with an outlet VSD. Mortality and reoperation rates are higher than in the other subtypes of TGA. Mitral repair at initial surgery should be considered only in cases of MR or LVOTO. Reoperation involves cleft closure and LVOTO relief. No MV replacement was required.

Outcome of humanitarian patients with late complete repair of tetralogy of Fallot: A 13-year long single-center experience

BackgroundSurgical repair of tetralogy of Fallot is usually performed between 3 and 6 months of age with pulmonary valve-sparing repair promoted for the best long-term result. Through a humanitarian program from developing countries, late complete surgical repair of tetralogy of Fallot has been performed at our institution for many years. MethodsRetrospective analysis of pre- and perioperative data, as well as 30-days outcome of patients older than one year with a confirmed diagnosis of tetralogy of Fallot who had a complete surgical repair between 2005 and 2018 at our institution. ResultsOne hundred sixty-five patients were included with a median age of 4.5 years [3.0–6.3], median weight of 13.5 kg [10.9 to 16.5], median transcutaneous oximetry of 78% [70 to 85] and median pulmonary valve annulus Z-score of −1.8 [-3.4 to −0.8]. There was no early surgical mortality. By multivariate analysis, only severe right ventricular hypertrophy, severe right ventricle outflow tract obstruction, and hypoplasia of the main pulmonary artery were independent predictors of failure to preserve the pulmonary annulus at surgical repair. ConclusionsLate complete surgical repair of tetralogy of Fallot has low mortality and morbidity even when pulmonary valve-sparing repair cannot be successfully performed. The preservation of the pulmonary valve function is significantly associated with shorter ventilation time, ICU and hospital lengths of stay. In the analyzed group of patients, a pulmonary valve-sparing repair cannot be predicted exclusively based on the dimension of the pulmonary valve annulus.

P291 SUBVALVULAR MITRAL APPARATUS REMODELING DURING HYPERTROPHIC OBSTRUCTIVE CARDIOMYOPATHY SURGERY: A 15–YEARS OF EXPERIENCE

Abstract Background and Aims To assess the role of the mitral valve apparatus (leaflets, chordae and papillary muscles (PM) in left ventricle outflow tract (LVOT) obstruction, and results of the surgical treatment for hypertrophic obstructive cardiomyopathy (HOCM) in a retrospective observational study. Methods Seventy consecutive patients (58±12 years, M/F ratio: 41/29) undergoing HOCM surgery from 2007 to 2021 at our institute were reviewed. End points included the involvement of the mitral valve in LVOT obstruction, mortality, and change in clinical and echocardiographic characteristics after HOCM surgery. Results Secondary chordae tendineae tractioning the anterior mitral leaflet to the interventricular septum were detected in the majority of the patients. Anomalous, hypertrophied, and fused PM with muscularis trabeculae hypertrophy were a common findings. Four patients had posterior leaflet redundancy. Secondary chordae (90%), PM and muscularis trabeculae resection and PM splitting and elongation (77%) were added variably to septal myectomy (100%). Nine procedures (6%) on mitral valve leaflets were performed, involving 6 posterior and 3 anterior mitral leaflets. Long–term follow up was 4.6±3.7 years. There was no hospital mortality, and NYHA was reduced from 3±0.6 to 1±0.7 (p &amp;lt; 0.0001), the LVOT gradient from 91±35 to 21±17 mmHg (p &amp;lt; 0.0001), mitral valve regurgitation from grade 3±1 to 1±0.6 (p &amp;lt; 0.0001), and septum thickness from 19±3 to 14±2 mm (p &amp;lt; 0.0001). Conclusions The mitral valve apparatus with all its components contribute variably to LVOT dynamic obstruction thus, surgical correction in addition to extended myectomy is recommended to achieve the best outcome.

P295 EXERCISE OXYGEN KINETIC IN HYPERTROPHIC CARDIOMYOPATHY: RESULTS FROM A MULTICENTER CARDIOPULMONARY EXERCISE TESTING STUDY

Abstract Aims Reduced cardiac output (CO) has been considered crucial in symptoms’ genesis in hypertrophic cardiomyopathy (HCM). We evaluated the cardiopulmonary exercise testing (CPET) response in HCM focusing on parameters strongly associated with stroke volume (SV) and cardiac output (CO), such as oxygen uptake (VO2) and O2–pulse, considering both their absolute values and temporal behavior during physical exercise. Methods and Results We enrolled 312 non–end stage HCM patients, divided according to left ventricle outflow tract obstruction (LVOTO) at rest or during Valsalva maneuver (72% with LVOTO&amp;lt;30; 10% between 30 and 49 and 18% ≥ 50mmHg). Peak VO2 (percent of predicted), O2–pulse and ventilation to carbon dioxide production (VE/VCO2) slope did not change across LVOTO groups. Ninety–six (31%) HCM patients presented an abnormal O2–pulse temporal behavior, irrespective of LVOTO values. These patients showed lower peak systolic pressure, workload (106±45 vs. 130±49W), VO2 (74±17 vs. 80±20%) and O2–pulse (12 [9–14] vs. 14 [11–17]ml/beat), with higher VE/VCO2 slope (28 [25–31] vs. 27 [24–31]) (p &amp;lt; 0.005 for all). Only 2 patients had an abnormal VO2/work slope. Conclusion None of CPET parameters, either as absolute values or dynamic relationships, were associated with LVOTO. Differently, an abnormal O2–pulse exercise behavior, which is strongly related to inadequate SV during exercise, correlates with reduced functional capacity (peak and anaerobic threshold VO2 and workload) and increased VE/VCO2 slope, helping identifying more advanced disease irrespectively of LVOTO. Adding O2–pulse kinetics evaluation to standard CPET could lead to a potential incremental benefit in terms of HCM prognostic stratification and, then, therapeutic management.

Exercise oxygen pulse kinetics in patients with hypertrophic cardiomyopathy

ObjectivesReduced cardiac output (CO) has been considered crucial in symptoms’ genesis in hypertrophic cardiomyopathy (HCM). Absolute value and temporal behaviour of O2-pulse (oxygen uptake/heart rate (VO2/HR)), and the VO2/work relationship...

Stepwise approach for diagnosis and management of Takotsubo syndrome with cardiac imaging tools.

Takotsubo syndrome is featured by transient left ventricle dysfunction in the absence of significant coronary artery disease, mainly triggered by emotional or physical stress. Its clinical presentation is similar to acute coronary syndrome; therefore, cardiac imaging tools have a crucial role. Coronary angiography is mandatory for exclusion of pathological stenosis. On the other side, transthoracic echocardiography is the first non-invasive imaging modality for an early evaluation of left ventricle systolic and diastolic function. Left ventricle morphologic patterns could be identified according to the localization of wall motion abnormalities. Moreover, an early identification of potential mechanical and electrical complications such as left ventricle outflow tract obstruction, mitral regurgitation, thrombus formation, right ventricular involvement, cardiac rupture, and cardiac rhythm disorders could provide additional information for clinical management and therapy. Because of the dynamic evolution of the syndrome, comprehensive serial echocardiographic examinations should be systematically performed. Advanced techniques, including speckle-tracking echocardiography, cardiac magnetic resonance, and nuclear imaging can provide mechanistic and pathophysiologic insights into this syndrome. This review focuses on these aspects and provide a stepwise approach of all cardiac imaging tools for the diagnosis and the management of Takotsubo syndrome.

Hybrid telerehabilitation in patients with hypertrophic cardiomyopathy without left ventricular outflow tract obstruction and preserved left ventricular ejection fraction-the randomised clinical trial

Abstract Background Hypertrophic cardiomyopathy (HCM) is the most common hereditary heart disease, and its diagnosis is often associated with limited physical activity. Little is known about cardiac rehabilitation programs for patients with HCM. Therefore the novel hybrid cardiac telerehabilitation (HCTR) model consisting of hospital-based rehabilitation and home-based telemonitored rehabilitation might be an option to improve physical capacity in patients with HCM. Purpose To evaluate the safety, effectiveness and adherence to HCTR in patients with HCM without the left ventricle (LV) outflow tract obstruction and preserved LV ejection fraction. Methods The study group comprised 60 patients with HCM (51.1±13.3 years; NYHA II-III; LV ejection fraction 66.1±6.9%). Patients were randomised (1:1) to either HCTR program (hospital-based rehabilitation [1 month] based on cycloergometer training and home-based telemonitored rehabilitation [2 months] based on Nordic walking, five times a week, at 40–70% of maximal estimated heart rate) - training group (TG), or to a control group (CG). All patients had implantable cardioverter-defibrillator. In order to perform home-based telemonitored rehabilitation, a special device was used which enabled patients to: (1) do Nordic walking training according to a preprogrammed plan, (2) record and send electrocardiograms (ECGs) via mobile phone network to the monitoring centre. The moments of automatic ECGs registration were pre-set and coordinated with exercise training. The effectiveness of HCTR was assessed by changes - delta (Δ) in duration (t) of the workload, peak oxygen consumption (pVO2) in cardiopulmonary exercise test, 6-minute walking test distance (6-MWT) as a result of comparing t (s), pVO2 (ml/kg/min), 6-MWT (m) from the beginning and the end of the program. Results Safety of HCTR. Neither death nor other serious adverse events occurred during HCTR. We did not observe any ICDs intervention during the HCTR. Effectiveness of HCTR: Within-group analysis: t, pVO2, 6-MWT increased significantly in TG: t 657±183 vs 766±181 (p&amp;lt;0.001), pVO2 19.2±5.0 vs 20.6±4.9 (p=0.007), 6-MWT 445±88 vs 551±77 (p&amp;lt;0.001). In the untrained CG, the unfavourable results were observed: 695±198 vs 717±187 (p=0.114), pVO2 21.2±5.1 vs 21.1±5.6 (p=0.723), 6-MWT 512±83 vs 536±84 (p=0.061). Between-group analysis: The differences between TG and CG were statistically significant: in Δt (p&amp;lt;0.001); ΔpVO2 (p=0.012); Δ6-MWT (p&amp;lt;0.001). Adherence to HCTR: In TG 28 patients (93%) completed the HCTR program. Two patients did no undergo HCTR because of personal issues. Conclusion Hybrid cardiac telerehabilitation in patients with HCM without the left ventricle (LV) outflow tract obstruction and preserved LV ejection fraction is safe and effective. The adherence to HCTR is high. Funding Acknowledgement Type of funding sources: Public Institution(s). Main funding source(s): Statutory work in The Cardinal Stefan Wyszyński National Institute of Cardiology in Warsaw, Poland

26 Procedural planning and tip-to-base lampoon to succeed in a complex valve-in-valve TMVR procedure

Abstract Aims Left ventricle outflow tract (LVOT) obstruction is a feared complication of transcatheter mitral valve replacement (TMVR) procedures. Multimodal imaging evaluation is the key to identify at-risk patient and select the best management. Methods and results An 83-year-old woman with a history of mitral valve replacement with a 27-mm Carpentier-Edwards bioprosthesis (Edwards Lifesciences, Irvine, CA) for rheumatic heart disease was admitted to our department complaining worsening effort dyspnoea. Clinical evaluation revealed a grade 3/6 holosystolic murmur. She underwent combined transthoracic and transesophageal echocardiography (TEE) which demonstrated mitral bioprosthesis degeneration leading to severe stenosis (mean gradient = 13 mmHg, PHT-derived area = 0.9 cm2) and moderate regurgitation, with preserved biventricular function, and severe pulmonary hypertension (pulmonary artery systolic pression = 65 mmHg). The patient presented a high estimated risk for redo-surgery (Society of Thoracic Surgeons score estimated mortality: 6%) due to her complex medical history, including advanced chronic kidney disease and permanent atrial fibrillation; therefore, she underwent evaluation for valve-in-valve TMVR. Cardiac computed tomography (CT) revealed bioprosthetic anterior leaflet in tight contact with the septum in systole; predicted neo-LVOT using virtual 26-mm Sapien S3 (Edwards Lifesciences, Irvine, CA) valve was 150 mm2, conferring a high risk of fixed LVOTO. A 26-mm Sapien S3 valve was selected based on CT derived surgical valve ID of 24 mm. After Heart Team discussion, we performed a modified LAMPOON technique to achieve tip-to-base laceration of the bioprosthetic leaflet beside the LVOT, in order to prevent LVOT obstruction. Briefly, after transseptal puncture through right femoral vein access (16 Fr), we crossed the mitral prosthesis using a balloon wedge end-hole catheter, through which we advanced a 300 cm 0.014-inch wire into the ascending aorta, where it was snared from left arterial femoral access (8 Fr) and covered by a micro-catheter. The wire was previously kinked mid-shaft to form a ‘flying-V’ that was focally denuded and positioned at the target bioprosthetic leaflet’s tip using TEE and fluoroscopy. The guidewire was pulled toward the valve ring and electrified at 70 W with continuous 5% dextrose flush until adequate tip-to-base leaflet laceration. Thereafter, we successfully implant a 26-mm Sapien S3 valve. Maximal LVOT gradient post implant was 5 mmHg. The patient was discharged on post-operative day two and she recovered well, reporting functional and symptomatic improvement at 6-month follow-up. Conclusions our case highlights the importance of multimodality imaging and careful procedural planning to succeed even in complex valve-in-valve TMVR procedures. Transcatheter electrosurgery is an emerging tool for percutaneous structural heart interventions.

53 Exercise oxygen kinetic in hypertrophic cardiomyopathy: results from a multicentre cardiopulmonary exercise testing study

Abstract Aims Reduced cardiac output (CO) has been considered crucial in symptoms’ genesis in hypertrophic cardiomyopathy (HCM). We evaluated the cardiopulmonary exercise testing (CPET) response in HCM focusing on parameters strongly associated with stroke volume (SV) and cardiac output (CO), such as oxygen uptake (VO2) and O2-pulse, considering both their absolute values and temporal behaviour during physical exercise. Methods and results We enrolled 312 non-end stage HCM patients, divided according to left ventricle outflow tract obstruction (LVOTO) at rest or during Valsalva manoeuver (72% with LVOTO &amp;lt; 30; 10% between 30 and 49; and 18% ≥50 mmHg). Peak VO2 (percent of predicted), O2-pulse, and ventilation to carbon dioxide production (VE/VCO2) slope did not change across LVOTO groups. Ninety-six (31%) HCM patients presented an abnormal O2-pulse temporal behaviour, irrespective of LVOTO values. These patients showed lower peak systolic pressure, workload (106 ± 45 vs. 130 ± 49 W), VO2 (74 ± 17% vs. 80 ± 20%) and O2-pulse (12 [9–14] vs. 14 [11–17]ml/beat), with higher VE/VCO2 slope (28 [25–31] vs. 27 [24–31]) (P &amp;lt; 0.005 for all). Only two patients had an abnormal VO2/work slope. Conclusions None of CPET parameters, either as absolute values or dynamic relationships, were associated with LVOTO. Differently, an abnormal O2-pulse exercise behaviour, which is strongly related to inadequate SV during exercise, correlates with reduced functional capacity (peak and anaerobic threshold VO2 and workload) and increased VE/VCO2 slope, helping identifying more advanced disease irrespectively of LVOTO. Adding O2-pulse kinetics evaluation to standard CPET could lead to a potential incremental benefit in terms of HCM prognostic stratification and, then, therapeutic management.

Plasma metabolomic profiling of hypertrophic cardiomyopathy patients before and after surgical myectomy suggests postoperative improvement in metabolic function

BackgroundHypertrophic cardiomyopathy (HCM) is a common inherited heart disorder complicated by left ventricle outflow tract (LVOT) obstruction, which can be treated with surgical myectomy. To date, no reliable biomarkers for LVOT obstruction exist. We hypothesized that metabolomic biomarkers for LVOT obstruction may be detectable in plasma from HCM patients.MethodsWe conducted metabolomic profiling on plasma samples of 18 HCM patients before and after surgical myectomy, using a commercially available metabolomics platform.ResultsWe found that 215 metabolites were altered in the postoperative state (p-value < 0.05). 12 of these metabolites were notably significant after adjusting for multiple comparisons (q-value < 0.05), including bilirubin, PFOS, PFOA, 3,5-dichloro-2,6-dihydroxybenzoic acid, 2-hydroxylaurate, trigonelline and 6 unidentified compounds, which support improved organ metabolic function and increased lean soft tissue mass.ConclusionsThese findings suggest improved organ metabolic function after surgical relief of LVOT obstruction in HCM and further underscore the beneficial systemic effects of surgical myectomy.

CHARACTERISATION OF HYPERTROPHIC CARDIOMYOPATHY BY CARDIAC MAGNETIC RESONANCE IMAGING

Background: There are many causes of left ventricular hypertrophy which can result in arrhythmias and sudden cardiac death. Hypertrophic cardiomyopathy (HCM) is one of the commonly encountered cause of sudden cardiac death in young adults. Aim: Identifying the role of Cardiac MRI in characterising the diagnostic parameters of HCM. Materials and methods: 125 patients with clinical suspicion or genetic evidence of HCM referred for cardiac MRI between June 2013 to June 2021 were included under the study. Image interpretations were done by fellowship qualified cardiac imaging radiologist. Categorical variables were expressed using frequency and percentage. Numerical variables were presented using mean and standard deviation. Results: Out of the total population, 119 patients (95 %) had LV wall thickness &gt; 13 mm, 48 patients (38.4%) had Left ventricle outflow tract obstruction (LVOTO) and 32 patients (25.6 %) had mid cavity obstruction, 39 patients (37.9 %) had myocardial scar &gt; 15 % and asymmetric septal hypertrophy was the most frequently encountered left ventricle morphology Conclusion: Cardiac MRI detected HCM has a statistically significant association with the final diagnosis (histopathological and genetic correlation). CMRI hence serves as a reliable tool in identifying and characterising the various diagnostic and non- diagnostic parameters of HCM.