Webster, Tracy L.

Background: Cardiac amyloidosis (CA) is associated with sinus node dysfunction (SND) and conduction system disease (CSD) yet data on pacing indications and outcomes is scarce. Methods: Retrospective review of patients (pts) with CA who had device implantation due to pacing indication at our institution. Results: At total of 51 (mean age 67.2±9.2 years, 90.2% male) pts with immunoglobulin light chain (n=27, 52.9%), hereditary transthyretin (n=7, 13.7%) and wild-type transthyretin (n=17, 33.3%) CA were included. Indication for pacing was exercise intolerance (n=16, 31.4%), syncope (n=16, 31.4%), congestive heart failure (n=5, 9.8%) and palpitation (n=2, 3.9%) with SND (n=23, 45.1%), CSD (17=33.3%) and uncontrolled atrial fibrillation (n=11, 21.6%). 16 (31.4%) pts received defibrillators (ICD) for primary prevention, of whom 8 (15.7%) had left ventricular ejection fraction (LVEF) ≤35%. Atrial (P wave: 1.7±1.2mV, threshold: 1.1±0.5mV/0.5±0.2ms) and right ventricular (RV) (R wave: 7.9±3.8mV, threshold: 0.8±0.4mV/0.4±0.1ms) lead parameters were satisfactory at implantation. During follow-up (mean 36.6±33.6 months), 26 (51%) pts reported symptomatic improvement (SI). Syncope was the only predictor of SI (OR 16.4, 95%CI 1.8-145.2, p=0.01) while exercise intolerance was not (OR 0.09, 95%CI 0.02-0.44, p=0.003). First-time life-threatening ventricular arrhythmias (VA) occurred in 6 (11.8%) pts, 3 (5.9%) had ICD implanted for LVEF ≤35%, 3 (5.9%) without ICD and LVEF ≥35%. Syncope was not predictive of first-time VA. RV lead noise led to inappropriate ICD shocks in 1 patient. Atrial lead sensing failure occurred in 6 (11.8%) and loss of capture in 5 (9.8%). Conclusion: Device implantation in patients with cardiac amyloidosis is safe but atrial lead failure is common. Syncope usually improves with pacing whereas other factors should be considered in those presented with exercise intolerance. Selection of pts who need pacing for prophylactic ICD implantation is challenging as neither left ventricular ejection fraction nor syncope are predictive of arrhythmic events.

Introduction: The subcutaneous implantable cardioverter defibrillator (S-ICD) is an attractive option for patients with congenital heart disease (CHD) in whom a transvenous system is contraindicated. However, more than 10% of adult patients with CHD fail S-ICD screening due to a large T- to R-wave ratio. We hypothesized right-sternal electrodes may permit S-ICD placement in patients who fail left-sternal screen. Methods: We prospectively screened 40 patients with CHD for S-ICD using the standard proprietary approach. We also screened with right sternal electrodes (with left can electrode position). Results: The mean age of the cohort was 46+/-15 years; 24 males were enrolled. CHD anomalies consisted of tetralogy of Fallot (n=11), Ebstein’s anomaly (n=7), atrial septal defect (n=6), dextro-looped transposition of the great artery (n=5) and other (n=11). Left side screening ECG failed in 9 patients (23%), five of whom passed with right sternal electrodes, increasing the pass rate from 77% to 90%. Figure shows the screening ECG and chest x-ray of a patient who failed in all three vectors on the left side but passed in the alternative vector on the right side and underwent right sided implantation. Conclusions: The addition of right sternal electrodes during screening increases S-ICD eligibility and may avoid thoracotomy for high risk patients with CHD.

Introduction: Appropriate selection of patients (pts) with heart failure (HF) who may benefit from cardiac resynchronization therapy (CRT) is difficult. We sought to identify a clinical risk score to better risk stratify patients prior to CRT implantation. Methods: Pts undergoing CRT at Mayo Clinic from 2000 –2005 were included. Multiple clinical variables (age, gender, anemia (Hgb <10g/dL), RF (creatinine clearance ≤ 60ml/min/1.73m 2 ), hyponatremia (Na ≤130mEq/L), elevated BNP level (>500pg/ml), etiology, EF ≤20%, and advanced HF (NYHA functional class III–IV) were assessed with outcomes following CRT. Multivariate analysis was used to determine a clinical risk score. Results: A total of 496 patients (80% males) age 68 ± 12 years (62% ischemic cardiomyopathy, EF 22% ± 8%) were included. In univariate analysis relative risk (RR) was > 1 for RF (RR 1.8, CI 1.3–2.8; p = 0.002), anemia (RR 3.3, CI 1.8 –5.5; p = 0.001), hyponatremia (RR 3.4, CI 1.4 – 6.9; p = 0.008), elevated BNP (RR 2.9, CI 1.6 –5.7; p < 0.001), ischemic cardiomyopathy (ICM) (RR 1.8, CI 1.2–2.7; p < 0.002), EF ≤ 20% (RR 1.5, CI 1.0 –2.1; p = 0.033), and advanced HF (RR 2.5, CI 1.5– 4.9; p < 0.001). Following multivariate analysis RF, anemia, ICM, and advanced HF remained significant predictors of poor outcome (p >0.01 for all). Survival with 3 or more of these clinical risk factors was significantly worse than with less risk factors (p <0.01, Figure ). Conclusions: Pre-implant clinical risk factors including anemia, RF, ICM and advanced HF predict worse outcome following CRT with ≥3 variables predicting >2-fold increased risk of death or heart transplantation. These factors should be considered when selecting pts prior to CRT.

AbstractIntroductionVenous stenosis is a well‐recognized complication of transvenous leads (TVLs) that is encountered during lead revisions or device upgrades. We here report the outcomes of TVL placement facilitated by fibroplasty or tunneling (TUN) procedure.MethodsWe conducted a single‐center retrospective cohort study of all patients undergoing TVL implantation requiring fibroplasty or TUN from 2005 to 2017. Medical records and procedure reports were reviewed for relevant data. Outcomes for fibroplasty and TUN to facilitate TVL placement were compared.ResultsSixty patients had fibroplasty and thirty‐five patients had a TUN procedure. There was no difference in procedure success rates between the two groups (97% fibroplasty vs. 100% TUN; p = .98). The fluoroscopy time was longer (fibroplasty = 39.7 ± 21.5 min vs. TUN = 29.2 ± 21.3 min; p = .01) and the total procedural time was shorter in the fibroplasty group (fibroplasty = 247 ± 77.8 min vs. TUN = 287 ± 77.1 min; p = .01). TUN was associated with a significantly higher incidence of acute complications (fibroplasty = 0 vs. TUN = 8; p = .002) most requiring invasive intervention and/or transfusion with blood products. Long‐term complications requiring additional device‐related procedures were comparable between the two groups (fibroplasty = 6 vs. TUN = 6; logrank p = .21).ConclusionsFor patients with venous stenosis requiring additional TVL, balloon fibroplasty is associated with similar rates of success and a significantly decreased incidence of acute complications when compared with subcutaneous TUN.

Background— The effectiveness of implantable cardioverter-defibrillators (ICDs) for primary prevention of sudden death in patients with an ejection fraction (EF) ≤35% and clinical heart failure is well established. However, outcomes after replacement of the ICD generator in patients with recovery of EF to >35% and no previous therapies are not well characterized. Methods and Results— Between 2001 and 2011, generator replacement was performed at 2 tertiary medical centers in 253 patients (mean age, 68.3±12.7 years; 82% men) who had previously undergone ICD placement for primary prevention but subsequently never received appropriate ICD therapy. EF had recovered to >35% in 72 of 253 (28%) patients at generator replacement. During median (quartiles) follow-up of 3.3 (1.8–5.3) years after generator replacement, 68 of 253 (27%) experienced appropriate ICD therapy. Patients with EF ≤35% were more likely to experience ICD therapy compared with those with EF >35% (12% versus 5% per year; hazard ratio, 3.57; P =0.001). On multivariable analysis, low EF predicted appropriate ICD therapy after generator replacement (hazard ratio, 1.96 [1.35–2.87] per 10% decrement; P =0.001). Death occurred in 25% of patients 5 years after generator replacement. Mortality was similar in patients with EF ≤35% and >35% (7% versus 5% per year; hazard ratio, 1.10; P =0.68). Atrial fibrillation (3.24 [1.63–6.43]; P <0.001) and higher blood urea nitrogen (1.28 [1.14–1.45] per increase of 10 mg/dL; P <0.001) were associated with mortality. Conclusions— Although approximately one fourth of patients with a primary prevention ICD and no previous therapy have EF >35% at the time of generator replacement, these patients continue to be at significant risk for appropriate ICD therapy (5% per year). These data may inform decisions on ICD replacement.

The presence of cardiac pacemakers and defibrillators complicates making end-of-life (EOL) medical decisions. Palliative care/medicine consultation (PCMC) may benefit patients and primary providers, but data are lacking. We retrospectively reviewed 150 charts of patients who underwent device deactivation at our tertiary care center (between November 1, 2008, and September 1, 2012), assessing for PCMC and outcomes. Overall, 42% of patients received a PCMC, and 68% of those PCMCs specifically addressed device deactivation. Median survival following deactivation was 2 days, with 42% of deaths occurring within 1 day of deactivation. There was no difference in survival between the groups. The EOL care for patients with implanted cardiac devices is complex, but PCMC may assist with symptom management and clarification of goals of care for such patients.