Padmanabhan, Deepak

AbstractBackgroundPatients with cardiac amyloidosis (CA) have increased mortality, which can be explained in part by an increased risk of arrhythmias. The burden of arrhythmias in CA, their predictors, and impact on in‐hospital outcomes remains unclear. The role of implantable cardioverter‐defibrillators (ICD) in this population is also uncertain.MethodsWe queried the National Inpatient Sample (NIS) using ICD‐9‐CM codes 277.39 and 425.7 to identify CA. Twelve common arrhythmias were extracted using appropriate, validated ICD‐9‐CM codes. ICD implantation was identified using procedure ICD‐9 codes 37.94 to 37.98, 00.51 and 00.54.ResultsThere were a total of 145,920 CA hospitalizations between 1999 and 2014 in the United States and 56,199 (38.5%) of them were associated with arrhythmias. The prevalence of arrhythmias remained relatively constant from 41.5% in 1999 to 40.2% in 2014. The most common arrhythmia was atrial fibrillation (25.4%). In‐patient mortality was significantly higher in CA patients with arrhythmias (10.4% vs 6.5%, P < .001). ICD implantation was performed in 1,381 (0.94%) patients with CA and analysis revealed an incremental trend in implantation over the study period (0.48% in 1999 to 0.65% in 2014). In‐hospital mortality was significantly lower in patients who underwent ICD implantation (3.7% vs 8%; P = .0078). CA patients with arrhythmias also had an increased cost of hospitalization and length of stay ($65,046 ± 1,079 vs $53,322 ± 687 and 8.3 ± 0.1 vs 7.4 ± 0.1 days, respectively; P < .0001).ConclusionCardiac arrhythmias are common in patients with CA and are associated with worse in‐hospital outcomes, increased length of stay, and cost of hospitalization.

Background Patients with Eisenmenger syndrome are known to have a high incidence of sudden cardiac death ( SCD ), yet the underlying causes are not well understood. We sought to define the predictors of SCD in this population. Methods and Results A retrospective analysis of all patients with Eisenmenger syndrome from 2 large tertiary referral centers was performed. ECGs, prolonged ambulatory recordings, echocardiograms, and clinical histories were reviewed; and the cause of death was identified. A total of 246 patients (85 [34.6%] men) with a mean age of 37.3 (±14.2) years were followed up for a median of 7 years. Over the study period, 136 patients died, with 40 experiencing SCD and 74 experiencing cardiac death (sudden and nonsudden). Age, atrial fibrillation, prolonged QRS duration, complete heart block, right atrial enlargement, right bundle branch block, increased right atrial pressure, impaired biventricular function, and the presence of a pacemaker were associated with increased risk of SCD , whereas advanced pulmonary hypertension therapies were protective. Atrial fibrillation (11.45‐fold increased risk; P <0.001) and QRS duration ≥120 ms (2.06‐fold increased risk; P =0.034) remained significant predictors of SCD in the multivariate analysis, whereas advanced pulmonary hypertension therapies were strongly protective against SCD ( P <0.001). Conclusions Atrial arrhythmias, impaired ventricular function, and conduction system disease were associated with increased risk of SCD in this cohort of patients with Eisenmenger syndrome, providing an opportunity for early risk stratification and potential intervention. Clinical heart failure symptoms (New York Heart Association class ≥ II ) were predictive of increased mortality but not of SCD , suggesting a potential arrhythmic cause behind SCD .

Background: Mechanical injury in the conduction system requiring permanent pacemaker (PPM) associated with transcatheter aortic valve replacement (TAVR) procedure is a common complication. The objective of this study was to use ambulatory monitor BodyGuardian to assess late occurrence of atrioventricular block (AVB) after TAVR. Methods: This prospective study evaluated 365 patients who underwent TAVR at Mayo Clinic, Rochester, Minnesota between June 2016 and August 2017. Patients who received PPM for bradycardia after TAVR before discharge were considered as the PPM group. Those not requiring PPM received a BodyGuardian system (BodyGuardian group) for 30 days of continuous monitoring. Primary end point was Mobitz II or third-degree atrioventricular block (II/III AVB) at 30-day follow-up. Results: Of 365 patients, 74 who had a PPM or an implantable cardioverter-defibrillator before TAVR and 94 who were enrolled in other studies were excluded. Of 197 patients enrolled in the study, 70 (35.5%) received PPM and 127 had BodyGuardian before the hospital dismissal. Eleven of 127 (8.6%) BodyGuardian group required PPM within 30 days after TAVR for late occurrence of symptomatic bradycardia. In total, 33 of 197 (16.7%) patients developed II/III AVB (24 before and 9 after discharge). Thirty-four patients had preexisting right bundle branch block. Of them, 16 (47%) developed II/III AVB. Of 53 patients who developed new left bundle branch block after TAVR, 14% progressed to II/III AVB within 30 days. Conclusions: In patients without a standard post-TAVR pacing indication, yet a potential risk to develop AVB, a strategy of 30-day monitoring identifies additional patients who require permanent pacing.

Abstract Background Venous stenosis is a well-recognized complication of transvenous leads when patients require lead revisions or device upgrade. In these cases, balloon venoplasty or alternative venous access with subcutaneous tunneling can be performed. Purpose Compare the outcomes of venoplasty vs. tunneling in patients requiring additional transvenous lead implantation. Methods A single center retrospective cohort study of all patients undergoing lead implantation/revision requiring venoplasty or tunneling from 2005–2017. Chi-squared and Wilcoxon Rank-Sum tests were used to compare categorical and continuous variables. Results Ninety five patients met our inclusion criteria (60 venoplasty & 35 tunneling). There was no difference in procedure success rates (p-value=0.98). Tunneling was associated with less fluoroscopy time but higher incidence of acute complications (0% vs. 23%, p-value=0.002) most requiring invasive intervention and/or blood product transfusion. Long term outcomes were comparable and related to lead failure or infection. Outcomes for tunneling vs. venoplasty Variable Tunneling (n=35) Venoplasty (n=60) p-value Age Y 67 (23–84) 70 (29–91) 0.25 Male (%) 24 (69%) 41 (68%) 0.98 Number of existing leads 2.1 (1–4) 2.4 (0–4) 0.1 Age of oldest lead 7.0 (0–21) 7.2 (0–33) 0.73 Number of new leads 1.2 (1–3) 1.4 (1–3) 0.26 Fluoroscopy time (SD) min 29.2 (21.3) 39.7 (21.5) 0.012 Procedure success (%) 35 (100%) 55 (92%) 0.9 Acute complications (%) 8 (23%)1 0 (0%) 0.0002 Pocket hematoma/bleed 4 (11%)2 Hemothorax 2 (6%)3 Pericarditis 1 (3%) Lead compromise 1 (3%) Follow up M 18 (0–76) 28 (0–98) N/A Long term lead issues (%) 6 (17%) 10 (17%) 0.95 Long term complication requiring intervention 4 (11%) 8 (13%) N/A Procedure success: functional lead placed as a result of venoplasty or tunneling. 1Two patients required blood products. 2Two patients required invasive intervention. 3One patient required chest tube and the other ICU admission. Conclusions Balloon venoplasty is associated with similar rates of success and a less incidence of acute complications when compared subcutaneous tunneling. Acknowledgement/Funding NIH T32 Training Grant HL07111-40

Abstract Recent guideline statements approve the performance of magnetic resonance imaging (MRI) in patients with non-conditional cardiac implantable electronic devices (CIEDs) under certain closely monitored conditions. Data from current registries may have lower power to discern changes that may occur in the CIED after the MRI. Objective We aimed to systematically review the literature to identify the adverse events and significance of changes in device function associated with performing MRI in patients with CIEDs Methods A comprehensive literature search of the databases was performed between 1980- 2017. Two independent reviewers selected studies and extracted data. A random-effects model was used for meta-analysis. Results A total of 7,422 patients underwent 8,865 MRI studies. No death occurred post MRI. Clinical adverse events were extremely rare (mostly less than 1%) and are summarized in Table 1. No significant changes in the pooled mean effect size estimate was noted for the changes in the lead parameters (pacing threshold, sensing and impedance) Binary outcomes post magnetic resonance imaging in patients with non-conditional cardiac implantable electronic devices Outcome Sample size Number of patients Rate SE LL of CI UL of CI Death 7401 0 0 0 0 0 Atrial arrhythmia 7173 10 0.001 0.0004 0.0007 0.0024 Ventricular arrhythmia 7371 9 0.0012 0.0004 0.0006 0.0022 Oversensing 4981 17 0.0034 0.0008 0.0020 0.0053 Inhibition of pacing 7371 6 0.0008 0.0003 0.0003 0.0016 Lead Failure/Generator Failure 7475/7475 2/8 0.0002/0.0011 0.0001/0.0004 0.0001/0.0005 0.0009/0.002 Power on Reset 1388 105 0.0131 0.0014 0.0107 0.0161 Did not complete scan 6851 13 0.0019 0.0005 0.0011 0.0031 Chest pain 7080 11 0.0021 0.0004 0.0008 0.0027. Lead threshold rise (>0.5v/>50%-A/V) 5076/6246 12/16 0.0024/0.0026 0.0007/0.0006 0.0013/0.0015 0.0040/0.0041 Change in Battery voltage >0.04V 7132 42 0.0061 0.0009 0.0043 0.0079 Sensing decrease >50%-A/V 5087/5834 17/9 0.0033/0.0015 0.0008/0.0005 0.0020/0.0008 0.0052/0.0028 Impedance changes >50ohms/>50% 5810 22 0.0038 0.0008 0.0024 0.0057 Rise in cardiac enzymes 1703 26 0.0152 0.0030 0.0102 0.0219 A, atrial; V, ventricular; SE, standard Error; LL, lower limit; UL, upper limit; CI, Confidence intervals. Conclusions MRI in patients with non-conditional CIEDs can be performed with high degree of safety and low rate of clinical events when performed under standardized protocols Acknowledgement/Funding None

AbstractIntroductionMyocardial infarction (MI) is associated with an increase in subsequent heart failure (HF), recurrent ischemic events, sudden cardiac arrest, and ventricular arrhythmias (SCA‐VA). The primary objective of the study to determine the role of intercurrent HF and ischemic events on the development of SCA‐VA following first type I MI.Methods and resultsA retrospective cohort study of patients experiencing first type 1 MI in Olmsted County, Minnesota (2002‐2012) was conducted by identifying patients using the medical records linkage system (Rochester epidemiology project). Patients aged ≥18 years were followed from the time of MI till death or 31 July, 2017. Intercurrent HF and ischemic events were the primary exposures following MI and their association with outcome SCA‐VA was assessed. Eight hundred and sixty‐seven patients (mean age was 63 ± 14.5 years; 69% male; 49.8% ST‐elevation myocardial infarction) who had their first type I MI during the study period were included. Majority of acute MI patients were revascularized using percutaneous coronary intervention and bypass surgery (628 [72.43%] and 87 [10.03%] respectively). During a mean follow‐up of 7.69 ± 4.17 years, HF, recurrent ischemic events and SCA‐VA occurred in 155 (17.9%), 245 (28.3%), and 40 (4.61%) patients respectively. Low ejection fraction (adjusted hazard ratio [HR] 0.95; 95% confidence interval [CI], 0.93‐0.98; P < .001), intercurrent HF (adjusted HR 3.11; 95% CI, 1.39‐6.95; P = .006) and recurrent ischemic events (adjusted HR 3.47; 95% CI, 1.68‐7.18; P < .001) were associated with subsequent SCA‐VA.ConclusionSCA‐VA occurred in a small proportion of patients after MI and is associated with intercurrent HF and recurrent ischemic events.

Abstract Background Choosing the appropriate animal model for development of novel technologies requires an understanding of anatomy and physiology of these different models. There are little data about the characteristics of different animal models for the study of technologies used for epicardial ablation. We aimed to compare the incidence of ventricular arrhythmias during epicardial radiofrequency ablation between swine and canine models using novel epicardial ablation catheters. Methods We conducted a retrospective study using data obtained from epicardial ablation experiments performed on swine ( Sus Scrofa ) and canine ( Canis familiaris ) models. We compared the incidence of ventricular arrhythmias during ablation between swine and canine using multivariate regression analysis. Six swine and six canine animals underwent successful epicardial radiofrequency ablation. A total of 103 ablation applications were recorded. Results Ventricular arrhythmias requiring cardioversion occurred in 13.11% of radiofrequency ablation applications in swine and 9.75% in canine (relative risk: 117.6%, 95% confidence interval [CI]: 83.97‐164.69, animal‐based odds ratio [OR]: .55, 95% CI: .23‐61.33; P = .184). When adjusting for application position, duration of ablation and power, the odds of developing potentially lethal ventricular arrhythmia in swine increased significantly compared to canine (OR: 3.60, 95% CI: 1.35‐9.55; P = .010). Conclusions The swine myocardium is more susceptible to developing ventricular arrhythmias compared to canine model during epicardial ablation. This issue should be carefully considered in future studies.