Atrioventricular Valve Regurgitation Research Articles

Severity of tricuspid regurgitation predicts risk of atrial fibrillation recurrence after pulmonary vein isolation

Abstract Background Atrioventricular valve regurgitation (AVVR) results in atrial remodeling, thus promoting the formation of a substrate for atrial fibrillation (AF). On the other hand, AF may cause functional AVVR by annular dilatation of the atria. In this vicious circle, the identification of the leading pathomechanism and consequently the optimization of treatment can be challenging. Purpose Our aim was to investigate whether the presence of significant AVVR and especially of tricuspid regurgitation (TR) affects the efficacy of catheter-based pulmonary vein isolation (PVI) for AF. Furthermore, we evaluated whether rhythm control for AF through PVI could lead to an improvement of AVVR severity. Finally we examined the effect of concomitant right atrial flutter on the arrhythmic outcome in patients with significant TR . Methods We enrolled patients undergoing first-time PVI for symptomatic AF. We compared the severity of AVVR at the time of the procedure as well as after 6 months, using transthoracic echocardiography. Moderate to severe AVVR was defined as significant. Moreover, we evaluated whether the presence of significant AVVR, at baseline and 6 months after the procedure, could serve as an independent predictor for AF recurrence. Results Out of 320 consecutive patients (mean age 66.3 ± 10 years, 61.6% male, 60% paroxysmal AF) , significant TR at baseline was documented in 13.1%, while significant mitral regurgitation (MR) in 10.9%. Six months after PVI, the proportion of patients with moderate to severe TR (13.1% to 7.2%; p<0.001) and MR (10.9% to 6.6%; p<0.001) decreased significantly. Compared to patients with post-interventional improvement of significant TR, right atrial (RA) dilatation at baseline was more pronounced in patients with persistent significant TR (RA area 20.2 ± 4.4 vs. 26.6 ± 8.3 cm2; p=0.002). The presence of significant TR, particularly without improvement during the follow-up, independently increased the risk of atrial fibrillation recurrences. Even after propensity-score matching, TR at baseline remained an independent risk predictor regarding recurrent atrial fibrillation (HR 2.2 [95% CI, 1.1 - 4.9]; p=0.045). Among patients with significant TR, those with documented right atrial flutter were at high risk for recurrence of atrial arrhythmia (HR 2.69 [95% CI, 1.0 – 6.9]; p=0.039), despite the additional ablation of the cavo-tricuspid isthmus. Significant MR was not associated with increased risk of atrial arrhythmias. Conclusion In patients with symptomatic AF undergoing PVI, the presence of moderate to severe TR, particularly without improvement 6 months after the procedure, was associated with a worse arrhythmic outcome. Further investigations to enhance the understanding of the underlying electrophysiological substrate and the need for tailored ablation strategies are warranted.TR as predictor for AF(propensity score)AVVR improvement after PVI

Patients with scheduled heart valve interventions are at very high risk for acute heart failure during prolonged waiting time

Abstract Funding Acknowledgements None. Background Postponement of non-emergency cardiac interventions is associated with increased rates of emergency hospitalizations. Affected patients show signs of acute heart failure during the waiting time. Since this worse outcome has been proven to persist even long post-procedure, patients at risk must be identified in advance. Purpose This study sought to identify predictors associated with acute heart failure during prolonged waiting time in cardiac patients scheduled for non-emergency interventions. Methods A retrospective, observational cohort study was conducted that included consecutive patients whose non-emergency cardiac intervention was postponed during the first Covid-19 related lockdown between March 19th and April 30th, 2020. The endpoint was heart failure at admission to the procedure performed, indicated by a NT-proBNP level > 900 pg/ml. Cox regression analysis was performed to identify characteristics of patients who met the endpoint. Results After postponing their non-emergency cardiac intervention for an average of 23 days, 89 of 178 postponed patients (59 %) at a mean age slightly above 70 years had a NT-proBNP level > 900 pg/ml. Cox regression analysis showed the criterion "planned heart valve procedure" to independently predict achievement of the endpoint (p < 0.001, OR 12.040, 95 % CI 3.423 – 42.353). Subgroup analysis (n = 49) showed that especially patients with atrioventricular valve regurgitation are at risk with an endpoint rate of 94.74 % compared to 69.00 % in patients undergoing aortic valve replacement (p = 0.008). Moreover, the intervention of the affected patients was performed more frequently as emergency hospitalization (p = 0.005) and lasted longer (p < 0.001). This was accompanied by worse cardiac status at the time of admission including worse NYHA class, higher biomarker levels and lower cardiac function (each p < 0.001). Additionally, worse outcome as demonstrated by higher rates of emergency hospitalization and death persisted even 12, 24 and 36 months after the procedure (each p < 0.001). Conclusion Patients scheduled for heart valve interventions and particularly due to atrioventricular valve regurgitation are at high risk of heart failure in case of prolonged waiting time. Therefore, this population does not appear to be suitable for postponement but, in contrast, seems to require acute cardiovascular care.

Vectorcardiography signs of a failing Fontan: Heart rate, PR interval, RtQRSvm, QRSvm and SPQRS-T angle as noninvasive markers of late Fontan complications and mortality

BackgroundLimited data exists on interpreting vectorcardiography (VCG) parameters in the Fontan population. ObjectiveThe purpose of this study was to demonstrate the associations between ECG/VCG parameters and Fontan failure (FF). Methods/results107 patients with a Fontan operation after 1990 and without significant ventricular pacing were included. FF and Fontan survival (FS) groups were compared. The average follow-up after Fontan operation was 11.8 years ±7.1 years. 14 patients had FF (13.1%) which was defined as having protein-losing-enteropathy (1.9%), plastic bronchitis (2.8%), Fontan takedown (1.9%), heart transplant (5.6%), NYHA class III-IV (2.8%) or death (0.9%). A 12‑lead ECG at last follow up or prior to FF was assessed for heart rate, PR interval, QRS duration, Qtc and left/right sided precordial measures (P-wave, QRS and T-wave vector magnitudes, spatial P-R and QRS-T angles). Transthoracic echocardiogram evaluated atrioventricular valve regurgitation and ventricular dysfunction at FF or last follow up. A cox multivariate regression analysis adjusted for LV dominance, ventricular dysfunction, HR, PR, QTc, Pvm, QRSvm, SPQRST-angle, RtPvm, RtQRSvm and RtTvm. Ventricular dysfunction, increased heart rate and prolonged PR interval were significantly associated to FF at the multivariate analysis. ROC analysis and Kaplan-meier analysis revealed an increased total mortality associated with a heart rate > 93 bpm, PR interval > 155 mv, QRSvm >1.91 mV, RtQRSvm >1.8 mV and SPQRST angle >92.3 mV with p values <0.001 to 0.018. ConclusionWe demonstrate the importance of ECG/VCG monitoring in the Fontan population and suggest specific indicators of late complications and mortality.

Predictors of post-operative left atrioventricular valve regurgitation in pediatric patients with complete atrioventricular canal defects.

In infants with complete atrioventricular canal (CAVC) defects, post-operative left atrioventricular valve regurgitation (LAVVR) is a known major cause of morbidity and mortality and a common indication for re-operation. However, there is scarce data to identify risk factors for poor outcomes. Our study aims to find echocardiographic characteristics that predict post-operative LAVVR at discharge and 1-year follow-up. Retrospective cohort study of patients with initial CAVC repair at our hospital who were followed for 1 year between 2013 and 2022. Patients with major co-morbid conditions were excluded. Serial echocardiograms were reviewed. Anatomic details, quantitative and qualitative measure of LAVVR including the number of regurgitant jets, regurgitant jet length and vena contracta width, and ventricular function were collected. The time points measured include pre-operative transthoracic echocardiogram (TTE), post-operative transesophageal echocardiogram (PO-TEE), routine protocol based post-operative day 1 (POD1) TTE, discharge TTE and 1-year post-operative (1yPO) TTE. Paired t-tests, chi-square analysis, and linear regression analysis were performed comparing measured variables to LAVVR outcomes. Fifty-two patients were included; 92% had Trisomy 21. The majority were classified as Rastelli A (71%), others Rastelli C (29%). Only two patients had moderate or greater LAVVR pre-operatively. The mean age at repair was 125 ± 44 days. Pre-operative LAVVR was the only significant predictor of LAVVR severity at 1 year after backward stepwise regression. Of those with<moderate LAVVR on PO-TEE, 20% had worsening to≥moderate at discharge, but only 9% remained that way at 1 year. Of those with≥moderate LAVVR on PO-TEE, 40% improved to<moderate by 1 year. Two patients who worsened at 1 year, both secondary to likely cleft suture dehiscence. Only one patient required reoperation in the immediate post-operative period secondary to severe LAVVR due to suture dehiscence. Routine protocol-based POD1 echo did not have any association with altered outcomes. Pre-operative LAVVR was the only significant predictor of LAVVR severity at 1 year. A significant percentage (40%) of patient with≥moderate LAVVR on PO-TEE improved to<moderate by 1 year. Furthermore, routine protocol-based POD1 echo did not have any association with altered outcomes.

Surgical Debulking of Large Ventricular Fibromas in Children

This study aims to provide an update on the clinical presentation, diagnostic work-up, operative strategies, and mid-term outcomes in children undergoing ventricular fibroma resection. Single-center, retrospective cohort study of patients undergoing ventricular fibroma resection between 2000 and 2023. Among 52 patients, median age at surgery was 2.0 years (IQR 0.8-4.6) and median tumor volume index was 69 milliliters/m2 (IQR 49-169). Tumor distorted the atrioventricular (AV) valve/subvalvar apparatus in 30 (58%) patients and abutted major epicardial coronary arteries in 41 (79%) patients. Surgery was indicated for arrythmia (n=45, 86%), symptoms (n=14, 27%), and/or hemodynamic compromise (n=11, 21%). Tumor was debulked in 34 (65%) patients, including the last 21 patients. Concomitant AV valvuloplasty was performed in 18 patients and ventricular cavity closure in 15 (29%) patients. During a median follow-up of 2.4 years (IQR 0.8-6.2), there was no mortality, cardiac arrests, heart transplants, or single ventricle palliation. The 15-year risk of reoperation and clinical ventricular tachycardia/fibrillation was 6.7% (95% CI 0-14.3%) and 2.4% (95% CI 0-7.2%), respectively. On latest imaging, pre- and post-debulking LV ejection fraction did not significantly differ (P=.069), while no patients had signs of outflow tract obstruction, inflow tract obstruction, or > moderate AV valve regurgitation. Large ventricular fibromas can be resected safely with appropriate surgical planning and an emphasis on debulking. Most children maintain left ventricular function and remain free of recurrent ventricular arrhythmias at follow-up. Extended follow-up is warranted to understand whether patients remain at risk for scar-based ventricular arrhythmias in the future.

Role and Applications of Experimental Animal Models of Fontan Circulation.

Over the last four decades, the Fontan operation has been the treatment of choice for children born with complex congenital heart diseases and a single-ventricle physiology. However, therapeutic options remain limited and despite ongoing improvements in initial surgical repair, patients still experience a multiplicity of cardiovascular complications. The causes for cardiovascular failure are multifactorial and include systemic ventricular dysfunction, pulmonary vascular resistance, atrioventricular valve regurgitation, arrhythmia, development of collaterals, protein-losing enteropathy, hepatic dysfunction, and plastic bronchitis, among others. The mechanisms leading to these late complications remain to be fully elucidated. Experimental animal models have been developed as preclinical steps that enable a better understanding of the underlying pathophysiology. They furthermore play a key role in the evaluation of the efficacy and safety of new medical devices prior to their use in human clinical studies. However, these experimental models have several limitations. In this review, we aim to provide an overview of the evolution and progress of the various types of experimental animal models used in the Fontan procedure published to date in the literature. A special focus is placed on experimental studies performed on animal models of the Fontan procedure with or without mechanical circulatory support as well as a description of their impact in the evolution of the Fontan design. We also highlight the contribution of animal models to our understanding of the pathophysiology and assess forthcoming developments that may improve the contribution of animal models for the testing of new therapeutic solutions.

A multiple variable index and extracardiac-Fontan associated hepatic fibrosis

BackgroundThe serial follow-up of Fontan-associated liver disease is challenging, as laboratory values are frequently normal, especially with mild to moderate liver disease. ObjectiveWe investigated a composite index's correlation with hepatic biopsy total fibrosis scores in extracardiac Fontan patients. MethodsWe identified extracardiac Fontan patients undergoing cardiac catheterization and transvenous hepatic biopsies between June 2013 and September 2023 and liver shear wave elastography between January 2017 and July 2023. We developed a composite index from the following: 1) elastography values, 2) sex, 3) history of a neonatal aortopulmonary shunt for pulmonary flow obstruction, 4) pacemaker, 5) Fontan duration, 6) bilirubin values, 7) univentricular dysfunction, 8) atrioventricular valvar regurgitation, 9) mean Fontan pressures, and 10) venovenous collaterals presence. We correlated the index with hepatic total fibrosis scores (0–8), the sum of pathology grading (0 to 4) performed for sinusoidal and portal fibrosis. We defined a hepatic total fibrosis score of 0–3 as none to mild and 4–8 as moderate to severe fibrosis. ResultsWe identified 62 patients who underwent 92 transvenous liver biopsies, with 30 patients undergoing 2 biopsies. The average age at biopsy was 15 ± 2 years. We found a strong correlation (rho = 0.8, p = .00001) between liver total fibrosis scores and composite index values. A receiver operating characteristic analysis demonstrated that an index cut-off value of ≥26 predicted a total fibrosis score of ≥4 with a sensitivity of 71 % and a specificity of 75 % (AUC = 0.73, 95 % CI 0.63, 0.83, p = .0001). ConclusionsWe developed a composite index with a moderate predictive ability to discriminate none to mild from moderate to severe hepatic fibrosis. Nevertheless, additional data is needed to assist further validation and determine its clinical utility in the serial follow-up of Fontan associated liver disease.

Atrioventricular valve surgery in patients with univentricular heart and two separate atrioventricular valves.

Atrioventricular valve regurgitation in patients with univentricular heart is a well-known risk factor for adverse outcomes and atrioventricular valve repair remains a particular surgical challenge. We reviewed all surgical atrioventricular valve procedures in patients with univentricular heart and two separate atrioventricular valves who underwent surgical palliation. Endpoints of the study were reoperation-free survival and cumulative incidence of reoperation. Between 1994 and 2021, 202 patients with univentricular heart and two separate atrioventricular valve morphology underwent surgical palliation, with 15.8% (32/202) requiring atrioventricular valve surgery. Primary diagnoses were double inlet left ventricle (n = 14, 43.8%), double outlet right ventricle (n = 7, 21.9%), and congenitally corrected transposition of the great arteries (n = 7, 21.9%). Median weight at valve surgery was 10.6 kg (interquartile range, 7.9-18.9). Isolated left or right atrioventricular valve surgery was required in nine (28.1%) and 22 patients (68.8%), respectively. Concomitant left and right atrioventricular valve surgery was performed in one patient (3.1%). Closure of the left valve was conducted in four patients (12.5%) and closure of the right valve in three (9.4%). Operative and late mortality were 3.1% and 9.7%, respectively. Reoperation-free survival and cumulative incidence of reoperation at 10 years after surgery were 62.3% (standard error of the mean: 6.9) and 30.9% (standard error of the mean: 9.6), respectively. In patients with univentricular heart and two separate atrioventricular valves, surgical intervention on these valves is required in a minority of patients and is associated with low mortality but high incidence of reoperation.

Repair of the complete atrioventricular septal defect-impact of postoperative moderate or more regurgitation.

To study the risk factors for mortality, moderate or more left atrioventricular valve regurgitation (LAVVR) and reoperation after the surgical repair of complete atrioventricular septal defect (cAVSD) in a single centre. The current study is a retrospective review of patients who underwent surgical repair of cAVSD between 2000 and 2021. Patients with unbalanced ventricles not amenable to biventricular repair, double outlet right ventricle and malpositioned great arteries were excluded. The clinical predictors of outcome for end points were analysed with univariate and multivariable Cox regression analysis or Fine-Gray modelling for competing risks. Time-dependent end points were estimated using the Kaplan-Meier curve analysis and cumulative incidence curves. The median follow-up time was 2.3 years. Among 220 consecutive patients were 10 (4.6%) operative and 21 late mortalities (9.6%). A total of 26 patients were identified to have immediate postoperative moderate or more regurgitation and 10 of them ultimately died. By multivariable analysis prematurity and having more than moderate regurgitation immediately after the operation were identified as predictors of overall mortality (P = 0.003, P = 0.012). Five- and ten-year survival rates were lower for patients with immediate postoperative moderate or more LAVVR {51.9% [confidence interval (CI): 27.5-71.7%]} when compared to patients without moderate or more regurgitation [93.2% (CI: 87.1-96.4%) and 91.3% (CI: 83.6-95.5%)]. The patients who undergo cAVSD repair remain subjected to a heavy burden of disease related to postoperative residual LAVVR. Immediate postoperative moderate or more LAVVR contributes significantly to overall mortality. Whether a second run of bypass can decrease this observed mortality should be investigated.

Short-Term Outcomes, Functional Status, and Risk Factors for Requiring Extracorporeal Life Support After Norwood Operation: A Single-Center Retrospective Study.

Patients requiring extracorporeal life support (ECLS) post-Norwood operation constitute an extremely high-risk group. We retrospectively described short-term outcomes, functional status, and assessed risk factors for requiring ECLS post-Norwood operation between January 2010 and December 2020 in a high-volume center. During the study period, 269 patients underwent a Norwood procedure of which 65 (24%) required ECLS. Of the 65 patients, 27 (41.5%) survived to hospital discharge. Mean functional status scale (FSS) score at discharge increased from 6.0 on admission to 8.48 (p < 0.0001). This change was primary in feeding (p < 0.0001) and respiratory domains (p = 0.017). Seven survivors (26%) developed new morbidity, and two (7%) developed unfavorable functional outcomes. In the regression analysis, we showed that patients with moderate-severe univentricular dysfunction on pre-Norwood transthoracic echocardiogram (odds ratio [OR] = 6.97), modified Blalock Taussig Thomas (m-BTT) shunt as source of pulmonary blood flow (OR = 2.65), moderate-severe atrioventricular valve regurgitation on transesophageal echocardiogram (OR = 8.50), longer cardiopulmonary bypass time (OR = 1.16), longer circulatory arrest time (OR = 1.20), and delayed sternal closure (OR = 3.86), had higher odds of requiring ECLS (p < 0.05). Careful identification of these risk factors is imperative to improve the care of this high-risk cohort and improve overall outcomes.

Early and long-term outcomes following cardiac surgery for patients with heterotaxy syndrome

ObjectiveHeterotaxy syndrome is a complex multisystem abnormality historically associated with high morbidity and mortality. We sought to evaluate the early and long-term outcomes after cardiac surgery in heterotaxy syndrome. MethodsThis is a single-center retrospective review of patients with heterotaxy syndrome undergoing single-ventricle palliation or primary or staged biventricular repair from 1998 to 2018. Patients were stratified by single ventricle versus biventricular physiology, and the severity of atrioventricular valve regurgitation. Demographics, anatomic characteristics, and early and late outcomes, including the length of stay, mortality, and surgical or catheter reinterventions, were analyzed. ResultsAmong 250 patients, 150 (60%) underwent biventricular repair. In-hospital mortality was 7.6% (n = 19). Median follow-up was 5.2 (range, 0-16) years. Among survivors to discharge, mortality was 19% (n = 44) and reintervention was 52% (n = 120). Patients with moderate/severe atrioventricular valve regurgitation were older (32 vs 16 months, P = .02), were more likely to experience adverse events during their index surgical admission (72% vs 46%, P < .001), and had longer in-hospital length of stay (20 vs 12 days, P = .009). Among patients with moderate to severe atrioventricular valve regurgitation, single-ventricle palliation is associated with a greater risk of unplanned reintervention compared with patients undergoing biventricular repair (hazard ratio, 2.13; CI, 1.10-4.12; P = .025). ConclusionsThere was no significant difference in early or late outcomes in single-ventricle versus biventricular repair strategies in heterotaxy. In the subgroup of patients with moderate/severe atrioventricular valve regurgitation, patients who underwent single-ventricle palliation were 2.5 times more likely to need a late reintervention compared with those undergoing biventricular repair.

Days alive and out of hospital for children born with single-ventricle heart disease.

This study describes the illness burden in the first year of life for children with single-ventricle heart disease, using the metric of days alive and out of hospital to characterize morbidity and mortality. This is a retrospective single-centre study of single-ventricle patients born between 2005 and 2021 who had their initial operation performed at our institution. Patient demographics, anatomical details, and hospitalizations were extracted from our institutional single-ventricle database. Days alive and out of hospital were calculated by subtracting the number of days hospitalized from number of days alive during the first year of life. A multivariable linear regression with stepwise variable selection was used to determine independent risk factors associated with fewer days alive and out of hospital. In total, 437 patients were included. Overall median number of days alive and out of hospital in the first year of life for single-ventricle patients was 278 days (interquartile range 157-319 days). In a multivariable analysis, low birth weight (<2.5kg) (b = -37.55, p = 0.01), presence of a dominant right ventricle (b = -31.05, p = 0.01), moderate-severe dominant atrioventricular valve regurgitation at birth (b = -37.65, p <0.05), index hybrid Norwood operation (b = -138.73, p < 0.01), or index heart transplant (b = -158.41, p < 0.01) were all independently associated with fewer days alive and out of hospital. Children with single-ventricle heart defects have significant illness burden in the first year of life. Identifying risk factors associated with fewer days alive and out of hospital may aid in counselling families regarding expectations and patient prognosis.

Longitudinal analysis of systemic ventricular function and atrioventricular valve function after the Norwood procedure.

To evaluate longitudinal systemic ventricular function and atrioventricular valve regurgitation in patients after the neonatal Norwood procedure. Serial postoperative echocardiographic images before Fontan completion were assessed in neonates who underwent the Norwood procedure between 2001 and 2020. Ventricular function and atrioventricular valve regurgitation were compared between patients with modified Blalock-Taussig shunt and right ventricle to pulmonary artery conduit. A total of 335 patients were identified including 273 hypoplastic left heart syndrome and 62 of its variants. Median age at Norwood was 8 (7-12) days. Modified Blalock-Taussig shunt was performed in 171 patients and the right ventricle to pulmonary artery conduit in 164 patients. Longitudinal ventricular function and atrioventricular valve regurgitation were evaluated using a total of 4352 echocardiograms. After the Norwood procedure, ventricular function was initially worse (1-30 days) but thereafter better (30 days to stage II) in the right ventricle to pulmonary artery conduit group (P < 0.001). After stage II, the ventricular function was inferior in the right ventricle to the pulmonary artery conduit group (P < 0.001). Atrioventricular valve regurgitation between the Norwood procedure and stage II was more frequent in the modified Blalock-Taussig shunt group (P < 0.001). After stage II, there was no significant difference in atrioventricular valve regurgitation between the groups (P = 0.171). The effect of shunt type on haemodynamics after the Norwood procedure seems to vary according to the stage of palliation. After the Norwood, the modified Blalock-Taussig shunt is associated with poorer ventricular function and worse atrioventricular valve regurgitation compared to right ventricle to pulmonary artery conduit. Whereas, after stage II, modified Blalock-Taussig shunt is associated with better ventricular function and comparable atrioventricular valve regurgitation, compared to the right ventricle to pulmonary artery conduit.

Efficacy of atrioventricular valve regurgitation in the first trimester for the diagnosis of atrioventricular septal defect.

To investigate the efficacy of atrioventricular valve regurgitation (AVVR) for predicting atrioventricular septal defect (AVSD) in the first trimester. We performed a prospective observational study, screening for complicated congenital heart diseases and AVVR in fetuses at 11 to 13+6 weeks of gestation by advanced dynamic flow in four-chamber view and three-vessel-trachea view. 43 549 fetuses at 11 to 13+6 weeks of gestation were screened by echocardiography, of which 37 cases were diagnosed with AVSD, including complete AVSD (31 cases), intermediate AVSD (3 cases) and partial AVSD (1 cases), undiagnosed intermediate AVSD (2 cases), and misdiagnosed case (2 cases). AVVR was observed in 34 cases (34/37) in the first trimester, 59. 46% (22/37) nuchal translucency greater than 95th percentile, 29. 73% (11/37) absence of nasal bone, 32. 43% (12/37) ductus venosus A wave inversion, and 40. 54% (15/37) had tricuspid regurgitation. The sensitivity of common AVVR in predicting AVSD is better than other ultrasonic indexes. AVVR can be used as an ultrasonic indicator to predict AVSD in the first trimester, which is beneficial to detect AVSD.

Echocardiographic values and prevalence of cardiac abnormalities in clinically healthy adult Borzoi dogs.

To develop breed-specific echocardiographic values for normal Borzoi and to report the prevalence of structural cardiac abnormalities. 146 clinically healthy, adult Borzoi dogs. Cardiac auscultation and standard echocardiograms were performed. Longitudinal follow-up was described in a subset of dogs (n = 25). Most Borzoi were structurally normal (119/146, 81.5%), with breed-specific echocardiographic values generated independently for each sex, as females weighed significantly less than males (30.4 ± 3.8 kg vs 38.3 ± 4.1 kg, respectively; P < .001), and a significant impact of sex was found on most measurements. Physiologic heart murmurs were identified in 64/119 (53.8%) normal dogs. Thirty-six (30.2%) structurally normal dogs had trace or mild mitral regurgitation, and 43 (36.1%) had trace or mild tricuspid regurgitation. Structural cardiac disease was identified in 21 dogs (14.4%), including 9 dogs (6.2%) with dilated cardiomyopathy (DCM), 9 dogs (6.2%) with stage B1 myxomatous mitral valve disease (MMVD), and 3 (2.1%) dogs with congenital abnormalities. Seven dogs (4.8%) had equivocal abnormalities. During follow-up, new dogs were diagnosed with occult DCM (n = 3), equivocal DCM (1), and stage B1 MMVD (2). Two dogs originally diagnosed with DCM (1 occult and 1 equivocal) normalized after diet change. Borzoi dogs commonly have physiologic heart murmurs and mild atrioventricular valve regurgitation. Both DCM and MMVD were identified at similar frequencies in healthy Borzoi, although dogs with MMVD all had normal heart sizes. Echocardiographic screening for DCM in Borzoi should be considered, with breed-specific echocardiographic values now available for improved diagnostic confidence.

Introduction of transcatheter edge-to-edge repair in patients with congenital heart disease at a children's hospital.

Atrioventricular valve regurgitation (AVVR) is a devastating complication in children and young adults with congenital heart disease (CHD), particularly in patients with single ventricle physiology. Transcatheter edge-to-edge repair (TEER) is a rapidly expanding, minimally invasive option for the treatment of AVVR in adults that avoids the morbidity and mortality associated with open heart surgery. However, application of TEER in in CHD and in children is quite novel. We describe the development of a peri-procedural protocol including image-derived pre-intervention simulation, with successful application to four patients. To describe the initial experience using the MitraClip system for TEER of dysfunctional systemic atrioventricular valves in patients with congential heart disease within a pediatric hospital. A standardized screening and planning process was developed using cardiac magnetic resonance imaging, three dimensional echocardiography and both virtual and physical simulation. Procedures were performed using the MitraClip G4 system and patients were clinically followed post-intervention. A series of fourCHD patients with at least severe AVVR were screened for suitability for TEER with the MitraClip system: three patients had single ventricle physiology and Fontan palliation, and one had repair of a common atrioventricular canal defect. Each patient had at least severe systemic AVVR and was considered at prohibitively high risk for surgical repair. Each patient underwent a standardized preprocedural screening protocol and image-derived modeling followed by the TEER procedure with successful clip placement at the intended location in all cases. The early results of our protocolized efforts to introduce TEER repair of severe AV valve regurgitation with MitraClip into the CHD population within our institution are encouraging. Further investigations of the use of TEER in this challenging population are warranted.

How Good Are Cardiologists at Predicting Major Adverse Events in Fontan Patients?

BackgroundIt is unknown how well cardiologists predict which Fontan patients are at risk for major adverse events (MAEs). ObjectivesThe purpose of this study was to examine the accuracy of cardiologists' ability to identify the “good Fontan” patient, free from MAE within the following year, and compare that predicted risk cohort to patients who experienced MAE. MethodsThis prospective, multicenter study included patients ≥10 years with lateral tunnel or extracardiac Fontan. The cardiologist was asked the yes/no “surprise” question: would you be surprised if your patient has a MAE in the next year? After 12 months, the cardiologist was surveyed to assess MAE. Agreement between cardiologist predictions of MAE and observed MAE was determined using the simple kappa coefficient. Multivariable generalized linear mixed effects models were performed to identify factors associated with MAE. ResultsOverall, 146 patients were enrolled, and 99/146 (68%) patients w`ere predicted to be a “good Fontan.” After 12 months, 17 (12%) experienced a MAE. The simple kappa coefficient of cardiologists’ prediction was 0.17 (95% CI: 0.02-0.32), suggesting prediction of MAE was 17% better than random chance. In the multivariable cardiologist-predicted MAE (N = 47) model, diuretic/beta-blocker use (P ≤ 0.001) and systolic dysfunction (P = 0.005) were associated with MAE. In the observed multivariable MAE (N = 17) model, prior unplanned cardiac admission (P = 0.006), diuretic/beta-blocker use (P = 0.028), and ≥moderate atrioventricular valve regurgitation (P = 0.049) were associated with MAE. ConclusionsCardiologists are marginally able to predict which Fontan patients are at risk for MAE over a year. There was overlap between factors associated with a cardiologist’s prediction of risk and observed MAE, namely the use of diuretic/beta-blocker.

Abstract 13267: Early Predictors of High-Risk Lymphatic Subtypes on T2-Weighted MRI in Patients After Superior Cavopulmonary Connection

Introduction: Lymphatic subtype as determined by T2-weighted MRI (T2-CMR) after superior cavopulmonary connection (SCPC) is known to predict clinical outcome after Fontan. Factors related to lymphatic subtype development are not well understood. This study aims to identify early predictors of high-risk lymphatic subtypes. Methods: Retrospective cohort study of consecutive patients with pre-Fontan T2-CMR from 2017 to 2021. Patients divided into two groups based on lymphatic subtype: Group 1 - subtypes 1, 2, and 3; Group 2 - subtypes 3+ (defined as type 3 with history of chylothorax) and 4. Pearson’s chi square, Fisher’s exact, Wilcoxon rank sum, univariate and multivariate logistic regression analysis were performed. Results: We identified 171 patients. The groups differed significantly in total hospital, ICU, and chest tube days, number of catheterizations and number of cardiac surgeries (Table 1). Moderate or greater atrioventricular valve regurgitation (Mod+ AVVR), increased catheterizations and increased chest tube days were associated with high-risk lymphatic subtype. Maintenance of antegrade pulmonary blood flow at the time of SCPC was not significant (Table 2). In multivariate analysis, Mod+ AVVR and number of chest tube days remained in the model after adjusting for other covariates. Overall model significance was 0.007 with an area under the curve of 0.777. Conclusions: Mod+ AVVR and increased chest tube days are predictive of high-risk lymphatic subtype. Further study is needed to determine if lymphatic subtype is acquired via clinical exposure or whether native lymphatic subtype may be predictive of clinical course even prior to cavopulmonary connection.

Hybrid stage 1 palliation with simultaneous off-pump ventricular assist device placement in neonates with high-risk single ventricle anatomy: Initial experience

BackgroundInfants with single ventricle heart disease and severe atrioventricular valve regurgitation have poor outcomes following conventional staged palliation. As such, ventricular assist device (VAD) placement along with hybrid stage 1 palliation has been proposed as a bridge to heart transplant. We present a novel surgical technique for VAD implantation concurrent with hybrid stage 1 that avoids cardiopulmonary bypass. MethodsWe performed a retrospective review of our institutional experience with this novel surgical technique. ResultsThree patients (weight, 2.7-3.5 kg; age, 3 to 5 days) underwent hybrid stage 1 with VAD placement, consisting of bilateral 3.5-mm expandable polytetrafluoroethylene (PTFE) pulmonary artery bands, a ductal stent, a 6-mm Berlin Heart outflow cannula onto the main pulmonary trunk with a 10-mm graft, a 6-mm Berlin Heart outflow cannula onto the right atrium, and a 10-mL Berlin Heart pump. In patients with severe aortic arch hypoplasia or coarctation, a 4-mm PTFE graft was sewn from the VAD outflow graft to the innominate artery to protect coronary and cerebral perfusion. Procedures were performed off bypass with minimal blood product use. Patients were extubated on postoperative days 2, 2, and 5. There were no procedural complications. All patients were transferred out of the intensive care unit and demonstrated appropriate weight gain. Anticoagulation strategy was bivalirudin and antiplatelet therapy. The patients underwent transplantation after 149 days, 157 days, and 288 days of support. ConclusionsOff-pump single ventricle VAD placement is technically feasible and can be done at the time of hybrid stage 1 palliation with minimal operative morbidity as a bridge to transplant.

Revisiting predictors of worse atrioventricular valve and left ventricular systolic function following pacemaker therapy.

Predictors of worsening atrioventricular valve regurgitation and left ventricular (LV) systolic function after implantation of a leadless pacemaker (LPM) remain unclear compared with those of a transvenous pacemaker (TPM). We retrospectively analyzed 205 patients who were newly implanted with a permanent pacemaker (119 LPMs and 86 TPMs) and underwent transthoracic echocardiography before and 8±5 months after implantation. We evaluated the worsening of tricuspid and mitral regurgitation (TR and MR), defined as at least one-grade aggravation in severity, and changes in LV ejection fraction (LVEF). Worsening TR occurred more frequently in the LPM group compared to the TPM group (33%vs. 20%, p=.04); however, there was no significant difference between the two groups regarding worsening MR (26%vs. 18%, p=.18) and LVEF change (-2±10%vs. -3±8%, p=.40). In multivariable analysis, independent predictors for worsening TR, MR, and LVEF after implantation were found to be (1) the change from sinus rhythm at baseline to atrioventricular asynchronous right ventricular (RV) pacing (odds ratio [OR]: 5.68, 95% confidence interval [CI]: 1.94-16.70, p<.01); (2) the change from non-pacing ventricular contraction at baseline to RV pacing (OR: 2.42, 95% CI: 1.12-5.24, p=.02); and (3) a higher RV pacing burden (β: -0.05, 95% CI: -0.08--0.02, p<.01), respectively. Worsening TR, MR, and LVEF after pacemaker implantation were not associated with the type of pacing device but loss of atrioventricular synchrony or dependency on RV pacing.