Pacemaker Placement Research Articles

68P Clinical implications of cardiotoxicity and pharmacokinetics of alectinib in patients (pts) with anaplastic lymphoma kinase (ALK)-positive non-small cell lung cancer (NSCLC)

Pts with advanced ALK-positive NSCLC experience long term survival when treated with alectinib. Known adverse events (AE) of alectinib include edema and bradycardia, suggesting potential cardiotoxicity. This could threaten safe long-term dosing and lead to dose-reduction which can be detrimental to alectinib’s efficacy as there is a relationship between exposure-response. We hence prospectively investigated alectinib’s cardiotoxicity profile and its exposure-toxicity relationship. In total, 53 pts with ALK-positive NSCLC treated with alectinib were included between 6-2020 – 9-2021. Pts starting with alectinib after 6-2020 underwent a cardiac work-up at our dedicated cardio-oncology clinic < 3 months after start, at 6 months and at 1 year. Pts already receiving alectinib >6 months underwent a cardiac evaluation once. Bradycardia and edema data as well as severe alectinib toxicity (≥3 grade AEs and grade ≥2 AEs leading to dose modifications) were collected. Alectinib steady-state trough concentrations were used for exposure-toxicity analyses. Left ventricular ejection fraction (LVEF) remained normal in all pts who underwent an on-treatment cardiac work-up (n=34; median 62%; inter-quartile range 58%-64%). 7 pts (13%) developed alectinib-related edema. 22 pts (22/53) developed alectinib-related bradycardia (16 grade 1; 5 grade 2; 1 grade 3 resulting in a pacemaker placement) and 9 pts required at least 1 dose reduction. This resulted in a sub-therapeutic Ctrough in 5 pts (therapeutic threshold > 435ng/mL). Pts who experienced severe toxicity had a significantly (38%) higher alectinib Ctrough (735 vs. 533ng/mL; p=0.02). There were no signs of diminished LVEF and alectinib-induced edema does not seem to be cardiac-related. Bradycardia occurred more frequently than previously reported (43%) and was an important reason for dose-modifications, resulting in sub-therapeutic exposure in the majority of these pts. In general, pts with severe toxicity have a relatively high exposure to alectinib well above the therapeutic threshold.

Screening For Arrhythmias In Transthyretin Cardiac Amyloidosis With Long Term Monitoring: Surprising What You Find

<h3>Background</h3> Atrial fibrillation is common in patients with transthyretin cardiac amyloidosis (ATTR-CA) and is associated with a high rate of intracardiac thrombosis and embolism. Anticoagulation is recommended irrespective of the CHA₂DS₂-VASc score and some patients initial presentation is an embolic event. We hypothesized that a significant percentage of patients would have atrial fibrillation on long-term monitoring. <h3>Methods</h3> : This is a retrospective study of patients with ATTR-CA, who underwent long-term monitoring for cardiac arrhythmias between June 2018 and April 2021. Baseline demographics, cardiac biomarkers, New York Heart Association (NYHA) functional class assessment and arrhythmia monitor results were obtained. Gillmore stage was calculated for each patient (1 point for each of NT-proBNP >3000 pg/ml and eGFR < 45 ml/min/m2) for a range of 0 to 2 points corresponding to stages 1 to 3. <h3>Results</h3> Thirty-one patients with ATTR-CA who underwent long-term cardiac monitoring were included (18 with ATTRwt and 13 with ATTRv). Mean age was 77±11 years, 84% male with average NYHA class 2.2±0.7, NT-proBNP of 2,312±1977 pg/ml, hs Troponin T of 50±29 ng/L and eGFR of 53±20 ml/min/m2. Their mean Gillmore stage was 1.6±0.6. Subjects wore the monitor for an average of 13.3±2.4 days (range 2 to 14 days). Seven patients (23%) had atrial fibrillation or flutter of whom 2 (6%) were newly diagnosed. Two patients (6%) had high degree atrioventricular blockade and 1 had prolonged sinus pauses, all of whom underwent placement of a permanent pacemaker (at 2-, 29- and 119-days following results, respectively). Twenty-five patients (81%) had documented non-sustained ventricular tachycardia with an average of 37.2 episodes (range of 1 to 713). No patients had an implantable cardioverter defibrillator placed. <h3>Conclusions</h3> In patients with ATTR-CA there is an equal prevalence of new atrial arrhythmias and significant conduction disease requiring permanent pacing. The burden of ventricular arrhythmias was significantly higher than atrial arrhythmias in this population. This is contrary to other cardiomyopathies in which atrial arrhythmias often precede ventricular arrhythmias.

Ventricular Assist Device (VAD) Implantation in a Patient with Complex Congenital Heart Disease (CHD)

<h3>Introduction</h3> VAD implantation in complex CHD patients presents physiologic and anatomic challenges. Few such cases have been described. <h3>Case Report</h3> We report a 41-year-old man with a history of dextrocardia, unbalanced atrioventricular (A-V) septal defect, single ventricle, heterotaxy with right atrial isomerism and asplenia, bilateral superior vena cava, pulmonic stenosis, and systemic hypertension. He had undergone surgical palliation including bilateral BT shunts (age 3 months and 7 years) and central aortopulmonary shunt at age 13 years. At age 14 years, he underwent bilateral bidirectional Glenn and extracardiac Fontan repair, followed by mechanical A-V valve replacement at age 21 years and epicardial pacemaker placement for paroxysmal atrial tachycardia (AT). He had recurrent heart failure hospitalizations requiring inotropes. Echocardiography now demonstrated moderate aortic regurgitation. Cardiac catheterization on milrinone and dobutamine found elevated Fontan pressures to 21 mmHg (panel A), reduced cardiac index to 1.4 L/min/m², normal pulmonary vascular resistance and no transhepatic gradient. An intra-aortic balloon pump was placed with improvement of his Fontan pressures to 17 mmHg. However, he subsequently developed refractory AT and cardiogenic shock. Due to cardiac deterioration, he underwent urgent HeartMate3 implantation and aortic valve repair with Park stitch (B: pre-op; C: post-op image) as a bridge to transplant. Surgical approach was an upper hemisternotomy and an anterior right thoracotomy at the 6th intercostal space. His course was complicated by postoperative bleeding requiring re-exploration of the chest, as well as acute kidney injury requiring temporary hemodialysis with subsequent renal recovery. He was transferred to acute rehab 3 weeks after surgery and was discharged home on guideline-directed medical therapy. <h3>Summary</h3> We report an adult patient with dextrocardia, Fontan repair, and single ventricle who underwent successful VAD implantation.

One Heart, Two Problems: Cardiomyopathy and CPVT Secondary to RYR2 Mutation

<h3>Introduction</h3> RYR2 mutations are known to cause catecholaminergic polymorphic ventricular tachycardia (CPVT), an inherited disorder with risk for life threatening atrial (AT) and ventricular (VT) arrhythmias. Individuals with RYR2 mutation less commonly exhibit arrhythmogenic right ventricular cardiomyopathy (ARVC). We report the first case of a pediatric patient with RYR2 mutation, manifesting with CPVT, ARVC, and severe dysfunction requiring heart transplant (HTx). <h3>Case Report</h3> A 4.5 year old male with developmental delay presented after multiple syncopal episodes both at rest and with activity. A Holter showed AT, and he was started on a beta adrenergic antagonist with decreased frequency of syncopal episodes. He then developed sinus bradycardia with marked sinus pauses, prompting dual chamber pacemaker placement at age 6 years. He later exhibited bidirectional VT and whole exome sequencing identified a de novo, likely pathogenic variant in RYR2. He was medically managed until 16 years of age when he had syncope with exercise and was found to have both frequent AT and moderately depressed ventricular function with an ejection fraction of 45%. Given recurrent syncope with exercise, he underwent uncomplicated sympathectomy and optimization of his medical antiarrhythmic management. Over the next few months, he developed progressive heart failure symptoms and was admitted with worsening biventricular dysfunction and tachyarrhythmias. During his admission, he had a cardiac arrest with initial monitoring demonstrating VT, and was placed on extracorporeal membrane oxygenation support. He was transitioned to a durable left ventricular assist device (VAD), and was eventually listed for HTx. His VAD course was complicated by RV dysfunction needing PDE5 inhibitor; his arrhythmia burden was managed on flecainide, sotalol, and nadolol. After 80 days of VAD support, he underwent HTx. Pathology of his explanted heart revealed biventricular fibrofatty myocardial replacement consistent with ARVC with prominent LV involvement. <h3>Summary</h3> This case highlights an expanded spectrum of RYR2 mutation related disease which may include prominent atrial arrhythmias, ARVC, and developmental delay. Patients with CPVT and RYR2 mutation warrant close monitoring for ventricular dysfunction, especially if there is a significant arrhythmia burden.

Patient-activated anti-tachycardia pacing in adult congenital heart disease.

IntroductionIn adults with congenital heart disease, intra‐atrial reentrant tachycardia (IART) is a common arrhythmia that causes significant morbidity and mortality. One treatment option for IART is antitachycardia pacing. Atrial antitachycardia pacing algorithms deliver therapy for IART with ≥2:1 conduction, but most algorithms will not recognize IART with 1:1 conduction. Temporary Patient Activated Rx (TPARx) is Medtronic software that can be installed in antitachycardia pacemakers allowing patients to deliver therapies on demand for IART with 1:1 conduction.MethodsRetrospective chart review at a single institution of all patients who had TPARx installed into their pacemaker.ResultsFour adults with single ventricle congenital heart disease and IART underwent Fontan conversion, arrhythmia surgery, and placement of an epicardial dual‐chamber antitachycardia pacemaker. They had recurrent IART with a long cycle length and 1:1 conduction that failed to trigger antitachycardia pacing therapies. TPARx software was programmed into their pacemakers to allow recognition and treatment of IART with 1:1 conduction. Mean follow‐up duration after TPARx programming was 4.9 years. Each patient received at least one successful antitachycardia pacing therapy via TPARx – range 0.4–26 treated IART episodes per year. There were no atrial or ventricular arrhythmias induced with antitachycardia pacing. Two patients were able to discontinue anticoagulation after TPARx installation.ConclusionThis series demonstrates the use of TPARx software as part of a long‐term IART management strategy in select patients with IART who have failed more conventional therapies.

Severe pre-operative sinus bradycardia improved by mediastinal lymph node dissection

BackgroundWe report a case of bradycardia improved by surgical resection of the paratracheal lymph nodes, which has rarely been reported in the literature.Case presentationA 41-year-old male patient with pre-operative sinus bradycardia was diagnosed with right upper lobe adenocarcinoma. He planned to undergo VATS right upper lobectomy and mediastinal lymph node dissection. Consultation indicated that there was no need to place a temporary pacemaker. Severe sinus bradycardia occurred during induction of anesthesia and heart rate (HR) fell significantly from 52 to 28 bpm. There was no response to atropine. Isoproterenol was administered continuously for two hours at 0.01 µg per kg per minute to keep the patient’s HR around 50 bpm. During the operation, it was noted that the right upper mediastinal lymph nodes (group R2 and R4) were calcified and very close to the vagus nerve. After resection of the lymph nodes, the patient’s HR returned to 60–68 bpm without isoproterenol. There were no post-operative complications and the patient was discharged on the 5th post-operative day. The pathological findings indicated invasive adenocarcinoma with no lymph node metastases. One month after surgery, 24-h Holter monitoring revealed sinus rhythm without bradycardia. Six months after surgery no sinus bradycardia has occurred thus far.ConclusionsPatients with persistent sinus bradycardia pre-operation caused by vagus nerve compression deserve attention. Guidelines on placement of temporary pacemakers and intraoperative anesthesia management may be improved by additional clinical experience.

Clinical impact of Bachmann's bundle pacing defined by electrocardiographic criteria on atrial arrhythmia outcomes.

Evaluate whether Bachmann's bundle pacing (BBp) defined by electrocardiographic (ECG) criteria is associated with less atrial fibrillation/tachycardia (AF/AT) compared with anatomically defined right atrial septal pacing (RASp) and right atrial appendage pacing (RAAp). This is a retrospective study comparing BBp with non-specific RASp and RAAp on new incidence, burden, and recurrence of AF/AT. We included patients who underwent atrial lead placement between 2006 and 2019 and received > 20% atrial pacing. BBp was defined by paced P-wave morphology and fluoroscopic lead position. Compared with RASp (n = 107) and RAAp (n = 108), AF/AT burden was lower in the BBp (n = 134) group by repeated measures ANOVA (P < 0.001). Over 2-year follow-up, AF/AT burden increased in the RASp (P < 0.01) and RAAp (P < 0.01) groups but did not significantly change in the BBp group (P = 0.91). Atrial arrhythmia burden was lower in the BBp group than the RASp and RAAp groups at 12-15, 18-21, and 24-27 months (P < 0.05) after pacemaker placement. Risk of AF/AT recurrence was lower in BBp than RASp (HR 0.43; P < 0.01) and RAAp patients (HR 0.29, P < 0.01). Risk of de novo AF/AT was also lower in BBp than in RASp (OR 0.12; P < 0.01) and RAAp patients (OR 0.20, P < 0.01). Bachmann's bundle pacing defined using P-wave criteria was associated with decreased atrial arrhythmia burden, recurrence, and de novo incidence compared with right atrial septal pacing and right atrial appendage pacing.

NAFTNet retrospective report on the treatment of anti-Ro/SSA mediated fetal heart block with dexamethasone

Background Complete atrioventricular block (CAVB) is a complication of maternal antibody positivity and treatment of fetal disease is controversial in terms of efficacy and safety. We hypothesized that dexamethasone treatment for fetal anti-Ro/SSA antibody-mediated cardiac disease leads to better pregnancy outcomes than expectant management. Methods A retrospective multi-center cohort study of anti-Ro/SSA antibody positive pregnancies with fetal conduction disease reported by participating North American Fetal Therapy Network (NAFTNet) centers between January 2010 and December 2018. The primary outcomes included: fetal death, oligohydramnios, growth restriction, preterm delivery, and new maternal comorbidities. Secondary outcomes included: pacemaker prior to 28 days, transplantation, and neonatal death in maternal/fetal dyads treated with dexamethasone versus not. Results In 127 anti-Ro/SSA positive pregnancies, 98 were treated with dexamethasone and 29 were not. Of those treated, 61/96 (63.5%) met the primary outcome including 45/91 (49.4%) premature deliveries; 20 mothers developed comorbidities during treatment (fetal death 5, 10 growth restriction, 14 oligohydramnios, two new/worsening gestational diabetes). In the untreated group, 15/25 (60%) met the primary outcome including 11/22 (50%) premature deliveries and four mothers developing comorbidities during their pregnancy (fetal death 3, one growth restriction, one new onset maternal hypertension). Regarding secondary outcomes, 37/96 (43%) treated fetuses required a pacemaker or died by 28 days, while untreated 13/25 (52%) required pacemaker placement, died prior to 28 days or required listing for transplantation. Excluding terminations, survival without transplant was 17 (68%) in untreated and 85 (89%) in treated patients (p<.01). Conclusions While the use of dexamethasone in anti-Ro/SSA positive pregnancies is associated with a high rate of poor pregnancy outcomes, there was an unexpected similarly high rate in untreated positive pregnancies. This suggests that the maternal disease itself is influencing pregnancy complications independent of dexamethasone. Our data, which show that treatment decreases neonatal morbidity and overall mortality without increasing overall pregnancy complications, warrant further study.

Efficacy and Safety of Emergent Transcatheter Aortic Valve Implantation in Patients with Acute Decompensated Aortic Stenosis: Systematic Review and Meta-Analysis.

Introduction The aim of this systematic review and meta-analysis was to investigate the efficacy and safety of emergent transcatheter aortic valve implantation (TAVI) in patients with decompensated aortic stenosis (AS) by comparing the clinical outcomes with the patients who had received the elective TAVI. Methods By searching PubMed, EMBASE, and Cochrane databases, we obtained the studies comparing the clinical outcomes of emergent TAVI and elective TAVI. Finally, 14 studies were included. Results A total of 14 eligible articles with 73,484 patients were included in this meta-analysis. Emergent TAVI was associated with a higher mortality during hospitalization (HR 2.09, 95% CI [1.39 to 3.14]), 30 days (HR 2.29, 95% CI [1.69 to 3.10]), and 1 year (HR 1.96, 95% CI [1.55 to 2.49]). Consistently, the incidence of acute kidney injury (AKI) (RR 2.48, 95% CI [1.85 to 3.32]), dialysis (RR 2.37, 95% CI [1.95 to 2.88]), bleeding (RR 1.62, 95% CI [1.27 to 2.08]), major bleeding (RR 1.05, 95% CI [1.00 to 1.10]), and 30-day rehospitalization (RR 1.30, 95% CI [1.07, 1.58]) were more common in patients receiving emergent TAVI. No statistical differences were found in the occurrence rate of vascular complications (RR 1.11, 95% CI [0.90, 1.36]), major vascular complications (RR 1.14, 95% CI [0.52, 2.52]), permanent pacemaker (PPM) placement (RR 1.05, 95% CI [0.99, 1.11]), cerebrovascular events (RR 1.11, 95% CI [0.98, 1.25]), moderate to severe paravalvular leakage (PVL) (RR 1.23, 95% [CI 0.94 to 1.61]), and device success (RR 0.99, 95% CI [0.97, 1.01]). Conclusion Emergent TAVI is associated with some postoperative complications and increased mortality compared with elective TAVI. Emergent TAVI should be implemented cautiously and individually.

Congenital Heart Block.

Congenital complete heart block (CCHB) defines atrioventricular conduction abnormalities diagnosed in utero or within the first 27 days of life. Maternal autoimmune disease and congenital heart defects are most commonly responsible. Recent genetic discoveries have highlighted our understanding of the underlying mechanism. Hydroxychloroquine shows promise in preventing autoimmune CCHB. Patients may develop symptomatic bradycardia and cardiomyopathy. The presence of these and other specific findings warrants placement of a permanent pacemaker to relieve symptoms and prevent catastrophic events. The mechanisms, natural history, evaluation, and treatment of patients with or at risk for CCHB are reviewed.

Predictors of worsening TR severity after right ventricular lead placement: any added value by post-procedural fluoroscopy versus three \u2013dimensional echocardiography?

BackgroundThe effect of right ventricular (RV) leads on tricuspid valve has been already raised concerns, especially in terms of prognostic implication. For such assessment, three-dimensional transthoracic echocardiography (3D-TTE) has been used previously but there was no data on the use of post-procedural fluoroscopy in the literature.MethodsWe prospectively enrolled 59 patients who underwent clinically indicated placement of pacemaker or implantable cardioverter defibrillator (ICD). Vena contracta (VC) and tricuspid regurgitation (TR) severity were measured using two-dimensional transthoracic echocardiography (2D-TTE) at baseline. Follow up 3D-TTE was performed 6 months after device implantation to assess TR severity and RV lead location.ResultsLead placement position in TV was defined in 51 cases.TR VC was increased after the lead placement, compared to the baseline study (VC: 3.86 ± 2.32 vs 3.18 ± 2.39; p = 0.005), with one grade worsening in TR in 25.4% of cases. The mean changes in VC levels were 1.14 ± 0.67 mm. Among all investigated parameters, VC changes were predicted based on lead placement position only in 3D-TTE (p < 0.001) while the other variables including fluoroscopy parameters were not informative.ConclusionThe RV Lead location examined by 3D-TTE seems to be a valuable parameter to predict the changes in the severity of the tricuspid regurgitation. Fluoroscopy findings did not improve the predictive performance, at least in short term follow up.

Abstract 11780: Longitudinal Echocardiographic Parameters Before and After Pacemaker Placement in Congenital Complete Heart Block

Introduction: Congenital complete heart block (CCHB) is rare, 1:15,000 - 1:20,000 live births, with left ventricular (LV) dysfunction developing in 7-14% of subjects. We investigate longitudinal trajectories of echo parameters in CCHB and the effect of pacemaker implantation on those parameters. Methods: This is a retrospective cohort study of identifiable CCHB subjects at the Children’s Hospital of Philadelphia from 1970-2018, excluding those with structural, genetic, or acquired cardiac conditions. Subjects with echo data available before and after pacemaker implantation are included. LV end diastolic diameter (LVEDD) z-score and LV ejection fraction (EF) are modeled with least-squares regression models, with slopes compared before and after pacemaker placement. Results: Of 114 subjects with CCHB, 52 (40% male, 73% white) have echo data available before and after pacemaker placement. Median age of diagnosis is 0.6 years, age at pacemaker placement 3.4 years, and duration of pacing 10.8 years. Figure 1 displays modeled trajectories of LVEDD z-score and EF over 20 years. Mean LVEDD z-score at pacemaker placement is less than 2 and decreases significantly over time, especially 10 years post placement. Participants have mean LV ejection fraction of 54% at pacemaker placement, rising significantly prior to placement and in the first 10 years post-placement, after which significant decreases are observed. Older age at pacemaker placement is associated with a higher EF at placement but an earlier and steeper decline in EF beginning at 8 years post-placement. LVEDD and EF trajectories do not vary significantly by sex, race, maternal antibody status, age at diagnosis, or initial pacemaker mode. Conclusions: In a cohort of 52 subjects with CCHB, LVEDD z-score steadily decreases over time whereas EF rises for 10 years post-pacemaker placement and subsequently decreases. Pacemaker placement has no apparent immediate effect on trajectories of these echo parameters.

Abstract 11140: Mitral Valve Repair with the Mitraclip System in Patients with Cardiogenic Shock

Introduction: The presence of significant mitral regurgitation (MR) in patients with cardiogenic shock (CS) patients is associated with worse prognoses. Limited data exists on the effect of percutaneous mitral valve repair (PMVR) with MitraClip in this population. Hypothesis: We examined short term outcomes of MitraClip PMVR in patients with CS and MR at 30 days and six months. Methods: Single-center, retrospective study of patients with CS and MR undergoing PMVR between January 2015 and December 2020. All patients were followed up for 6 months. Baseline and procedural characteristics as well as 30-day and six-months outcomes of all-cause mortality, heart failure hospitalizations, stroke, new atrial fibrillation, new pacemaker placement, and improvement in MR severity ≥2 grades were assessed. Results: A total of 20 patient were included for analysis. The mean age was 72.8 ± 11.1 years; 9 patients (45%) were men. MR was due to primary pathology in 9 patients (45%), functional in 2 (10%) and mixed in 9 (45%). Characteristics of the population are shown in Table 1. At 30 days all-cause mortality was 20% (n=4), while 2 patients (10%) required HF hospitalization. MR severity improved by at least 2 grades in 10 patients (50%). At six months, all-cause mortality was 40% (n=8), while 4 patients (20%) required heart failure readmission. 10 patients (50%) maintained the improvement in MR severity. There was no incidence of stroke, new atrial fibrillation, or new pacemaker placement at 30 days or 6 months. Conclusions: PMVR with the MitraClip system is a feasible and a safe option for MR in patients with CS. Improved MR severity is maintained at 30 days and 6 months.

Abstract 11942: Contemporary Management and Outcomes of Superior Vena Cava Syndrome in the United States: Insights From the Nationwide Readmissions Database

Introduction: The outcomes of superior vena cava (SVC) syndrome in contemporary clinical practice are not well known. We aimed to evaluate in-hospital mortality and unplanned readmission rates in these patients. Methods: We used the United States Nationwide Readmissions Database from January 2016 to December 2018 to identify patients hospitalized for SVC syndrome. We used ICD 10 codes to identify various treatments utilized in this cohort of patients. We assessed the in-hospital mortality and its independent predictors by using a multivariate logistic regression model. We also evaluated for 30-day unplanned readmission rates in these patients. Results: A total of 554 hospitalizations for SVC syndrome were identified. The most common treatment modalities included endovascular stenting (n=122; 22.0%), catheter-directed thrombolysis (n=54; 9.7%), and percutaneous thrombectomy (n=46; 8.3%). A total of 388 patients (70.0%) were managed non-invasively for their SVC syndrome. Hospitalized patients with SVC syndrome rarely received radiotherapy or open thrombectomy. In-hospital mortality was 3.6% (n=20), and its independent predictors included pulmonary embolism (OR 3.44; 95% CI 1.21-9.79; p=0.020), malignancy (OR 3.71; 95% CI 1.39-9.92; p=0.009), sepsis (OR 9.17; 95% CI 2.22-37.81; p=0.002), and pacemaker placement (OR 70.40; 95% CI 3.94-1257.17; p=0.004). Among patients who survived initial hospitalization and initial discharge (n=485; 87.5%), the unplanned 30-day readmission rate was 22.1% (n=107). Conclusions: In this nationwide observational study endovascular stenting was the most common treatment modality used to treat patients with SVC syndrome. These patients have high readmission rates as well as high in-hospital mortality. The major predictors of in-hospital mortality include pulmonary embolism, malignancy, sepsis, and pacemaker placement.

Abstract 11161: Comparison of Percutaneous Mitral Valve Repair in Patients with Normal vs Severely Reduced Ejection Fraction

Introduction: Percutaneous mitral valve repair (PMVR) has been established as a suitable alternative to mitral valve surgery in patients with severe mitral regurgitation (MR). Patients with severely decreased ejection fraction (EF≤ 30%) constitute a higher risk group for adverse outcomes and peri-operative mortality. Hypothesis: We sought to examine the efficacy and safety of MitraClip implantation in severe heart failure patients in comparison to patients with preserved LV function. Methods: Single-center, retrospective study of patients undergoing PMVR between January 2015 and December 2020. All patients were followed up for 30 days. Baseline and procedural characteristics as well as short term outcomes of all-cause mortality, heart failure hospitalizations, stroke, new atrial fibrillation, new pacemaker placement, and improvement in MR severity ≥2 grades and NYHA class were assessed. Results: Among 86 patients undergoing PMVR, 26 had severely decreased EF. Patients with severely decreased EF were younger and more likely to have diabetes and mixed pathology MR. Additionally they received guideline directed medical therapy at higher rates. Characteristics of the population are shown in Table 1. At 30 days, no significant difference was observed between the two groups in regards to all-cause mortality, HF hospitalization, stroke, new atrial fibrillation, new pacemaker placement, and improvement in MR severity ≥2 grades and NYHA class. Conclusions: PMVR with the MitraClip system is feasible and a safe option for patients with MR and severely reduced EF.

Abstract 14430: 5-year Outcomes After Transcatheter &amp; Surgical Aortic Valve Replacement in Advanced Chronic Kidney Disease Patients

Introduction: Advanced chronic kidney disease (CKD4,5) patients are known to have increased morbidity and mortality when undergoing surgical procedures. While short term outcomes among patients undergoing transcatheter (TAVR) or surgical aortic valve replacement (SAVR) have been studied, research assessing long term outcomes are scant. Therefore, the goal was to assess 5-year outcomes for these patients undergoing TAVR or SAVR. Methods: A retrospective cohort study was done using TriNetX, a national federated real time database of 69 million records. Patient cohorts were identified if they met the criteria for CKD and underwent TAVR or SAVR up until May 2016 for 5 year follow up. A 1:1 matched propensity score analysis was conducted, adjusting for comorbidities and demographics, to calculate adjusted Risk Ratios (aRR) with 95% confidence intervals (CI) for complications of interest. Kaplan Meir (KM) analysis was done to calculate survival probability in 5 years among the 2 cohorts. Results: In a matched sample of 355 patients in each cohort, the TAVR did not show any significant differences in mortality (RR[CI]): (1.07[0.89-1.28]) compared to the SAVR Group. However, KM analysis revealed a significantly lower 5-year survival probability compared to the SAVR group (p&lt;0.035). There were no statistically significant differences among the 2 cohorts in other assessed long-term complications such as stroke (0.67[0.42-1.05]) and new pacemaker placement (1.31[0.81-2.17]). However, redo TAVR/SAVR was higher in the TAVR cohort than the SAVR cohort (3.1[1.54-6.23]). Conclusions: 5-year mortality appears to be similar in advanced CKD patients but repeat TAVR/SAVR were much higher suggesting decreased longevity of TAVR valves in this population.

Abstract 14494: 5 Year Outcomes After Transcatheter &amp; Surgical Aortic Valve Replacements in Chronic Liver Disease Patients

Introduction: Chronic Liver Disease (CLD) patients are known to have increased morbidity and mortality when undergoing surgical procedures. While short term outcomes among patients undergoing transcatheter (TAVR) or surgical aortic valve replacement (SAVR) have been studied, research assessing long term outcomes are scant. Therefore, the goal was to assess 5-year complications among CLD patients undergoing TAVR or SAVR. Methods: A retrospective cohort study was done using TriNetX, a national federated real time database of 69 million records. Patient cohorts were identified if they met the criteria for CLD and underwent TAVR or SAVR up until May 2016 for 5 year follow up. An 1:1 matched propensity score analysis was conducted, adjusting for comorbidities and demographics, to calculate adjusted Risk Ratios (aRR) with 95% confidence intervals (CI) for complications of interest. Kaplan Meir (KM) analysis was done to calculate survival probability in 5 years among the 2 cohorts. Results: In a matched sample of 268 patients in each cohort, the TAVR group showed higher 5-year mortality (RR[CI]): (1.34[1.04-1.73]) compared to the SAVR Group. KM analysis also revealed a significantly lower survival probability in TAVR group (purple) compared to the SAVR group (green) (p&lt;0.001).There were no statistically significant differences among the 2 cohorts in other assessed long-term complications such as stroke (0.66[0.39-1.1]), new pacemaker placement (0.85[0.49-1.44]), and redo TAVR/SAVR (1.3[0.58-2.9]). Conclusions: In CLD patients, there is a higher risk of mortality for patients undergoing TAVR vs SAVR. All other assessed complications revealed no significant difference. Additional research is needed to visit further longer-term impacts in CLD patients.

Abstract 12071: Emergent Temporary Transvenous Pacemakers Were Infrequently Needed for Patients Presenting With Complete Heart Block at a Regional Hospital

Introduction: Patients presenting with Complete heart block (CHB) are emergently referred for placement of a temporary transvenous pacemaker (TTVP) for hemodynamic stability. Data on the immediate management and outcomes of such patients are lacking. Methods: Data collected; through retrospective chart review of patients presenting to the Emergency Department (ED) at a regional hospital from October 2017 to January 2021 with a diagnosis of new CHB; included age, sex, clinical, laboratory and ECG data, medications, interventions and length of stay. Results: There were 71 patients (31 women) of whom 19 were on beta blocker or Calcium channel blockers. Data (see Table 1) for all variables was available in 68 patients. Syncope, lightheadedness and dyspnea were common symptoms. The median age was 77 years. The median heart rate was 41bpm. Atropine was used in 13 patients. Five patients with initial Systolic Blood Pressure (SBP) &lt; 100mmHg received sympathomimetics. Syncope with pause occurred in 3 patients. A TTVP was placed in 12 patients. Among 22 patients with initial SBP &gt; 160mmHg one patient with a recent TAVR had a TTVP placed. All but five were managed in the ICU setting. On Univariate logistic regression (R statistical software 3.6.1) initial SBP, SBP &lt; 100mmHg and Initial Serum K level were clinically significant. In multivariate analysis, SBP was significant with a lower SBP predicting need for a TTVP [OR 0.96 (CI 0.91 - 0.99, p = 0.019)]. A permanent pacemaker (PPM) prior to discharge was placed in 64 patients on average in 1.6 days from presentation. 3 patients with STEMI and TTVP did not need a PPM. 1 transitioned to hospice and 1 patient died of sepsis. In 1 it was attributed to COVID-19 infection. Conclusions: TTVP was infrequently needed (16.66%) among patients presenting to the ED with CHB. Initial SBP and Serum K were clinically relevant factors. Prospective data related to the acute management of CHB is needed to identify predictors that can improve the care for such patients.

Abstract 13727: Prediction of Pacemaker Implantation in Patients With Postoperative Heart Block: A Data Analytics Approach

Introduction: Current guidelines recommend observation for AV node recovery until postoperative days (POD) 7 to 10 for patients with complete heart block (CHB) after congenital cardiac surgery prior to permanent pacemaker (PPM) placement. We created a predictive tool to identify patients at high risk of requiring PPM before POD 7 to aid in surgical decision making. Methods: Postoperative CHB cases from August 2009 to January 2019 were identified. We collected demographic, anatomic, and surgical details. Random forest, logistic regression, and decision tree models were trained and evaluated using 5-fold cross validation, then prospectively validated on data from January 2019 to April 2021. Separate models were developed for all patients on POD 0 and those without recovery on POD 4. Results: Of 101 cases of CHB (22 in validation cohort), 60 (59%) required PPM. Median days [IQR] to AVN recovery was 3 [1-7] and PPM was 10 [7-13]. A decision tree model was used for its performance and interpretability, and included: (1) aortic valve replacement, subaortic stenosis repair, or Konno incision; (2) ventricular L-loop; (3) atrioventricular valve replacement; (4) use of preoperative antiarrhythmic agent (in POD 0 model only; figure 1). The POD 4 model (table 1) had a positive predictive value (PPV) of 0.94 [95% CI 0.81-0.98], which was stable in prospective validation (PPV 1.0). Conclusions: Our decision tool identified patients requiring PPM with high specificity and PPV. On POD 4, patients with left ventricular outflow tract repair, AV valve replacement, or ventricular L-Looping could be considered for PPM placement before POD 7 to reduce risks of temporary pacing and improve care efficiency.

Abstract 11902: Evaluating Right Ventricular Pacing Burden Leading to Pacing Induced Cardiomyopathy

Introduction: Pacing induced cardiomyopathy (PICM) is defined as a drop in left ventricular ejection fraction (LVEF) due to high amount of right ventricular (RV) pacing. Although PICM occurs with chronic, and occasionally, acute high burden RV pacing, the minimum burden of RV pacing inducing PICM is not widely established. Hypothesis: Based on multiple cases at our hospital, we hypothesize that &gt;40% RV pacing would induce PICM. Methods: A single center retrospective analysis was done on patients undergoing permanent pacemaker (PPM) placement between January 2019 and April 2020 at our hospital. Data for 88 patients was collected and analyzed using paired student’s t test, comparing mean LVEF in the two groups. Results: Out of 88 patients, 6 patients with cardiac ischemia and 9 patients with biventricular PPM were excluded. 40 out of the remaining 73 (54.8%) patients had &gt;40% RV pacing, out of which 36 patients had pre-PPM and post-PPM implantation echocardiograms and were included in the final analysis. 33 patients (45.2%) had &lt;40% RV pacing, out of which 30 patients had pre-PPM and post-PPM implantation echocardiograms and were included in the final analysis. Median duration of pacing at the time of analysis was 418 days. There was a statistically significant decrease in LVEF in patients with &gt;40% RV pacing [pre-PPM LVEF= 55.4861%, post-PPM LVEF= 51.5972%, mean difference between post-PPM and pre-PPM LVEF= -3.8889% (p=0.032)], but not in patients with &lt;40% pacing [pre-PPM LVEF= 57.1167%, post-PPM LVEF= 57.4833%, mean difference= 0.3666% (p=0.810)] (Image 1; ns: not significant). Conclusion: Our findings showed a statistically significant decrease in LVEF for patients with &gt;40% RV pacing, but not for patients with &lt;40% RV pacing, suggesting that 40% RV pacing is the likely threshold for producing LV systolic dysfunction and cardiomyopathy. Although this difference is statistically significant, clinical significance of this difference varies case-by-case.