Cha, Yong‐Mei

Introduction: Carcinoid heart disease (CHD) is a rare sequelae of hormonally active neuroendocrine tumors that often requires cardiac surgical intervention. Little is reported on cardiac implantable electronic device (CIED) implantation in the CHD patient population. Hypothesis: We sought to establish the safety and efficacy of CIED implantation in patients with CHD. Methods: We retrospectively reviewed patients with a diagnosis of CHD who underwent CIED implantation at our institution (Mayo Clinic) and evaluated indications for implant, perioperative complications, and mortality. Results: A total of 27 patients with a cumulative follow up of 75 patient-years were identified during the study period. The most common indication for device implant was high grade atrioventricular block (n=18, 66.7%). 14 (51.8%) had baseline conduction disease and 26 (96.2%) underwent cardiac surgery prior to CIED implant. The majority of devices implanted were dual chamber permanent pacemakers (PPM) (n=17, 63.0%), while other devices included single chamber PPM, epicardial PPM, chronic resynchronization devices, and intracardiac defibrillators. Peri-operative complication occurred in 6 patients (22.2%), with 2 patients requiring ICU level care. No patient suffered carcinoid crisis during implantation and there was no peri-implant mortality. Long term, 3 patients required device extraction: 1 for infection, 1 for lead related pain, and 1 for generator migration. The median time to death from implant was 2.5 years, with one-year mortality at 15%. Conclusions: In this unique cohort of patients with CHD, CIED can be performed safely. CIED most often occurred in the post cardiac surgical period and carcinoid crisis was uncommon.

Introduction: Surgically implanted epicardial left ventricular (eLV) lead has been used as an alternative approach when implantation of transvenous LV (tLV) lead in patients requiring cardiac resynchronization therapy (CRT) has failed. Recent literatures noted similarities in clinical response between tLV and eLV-CRT patients. However, comparison between CRT patients with ischemic (ICM) and dilated cardiomyopathy (DCM) is currently lacking in eLV-CRT patients. Hypothesis: We hypothesize that DCM patients respond better to eLV-CRT than ICM patients. Methods: Of 1038 patients who underwent tLV-CRT implantation at UCSD and Mayo Clinics between 2002 and 2013, 44 (Age 63±15, 28M) had failed tLV lead placement and received eLV-CRT. Electronic Medical Records of these patients were reviewed. NYHA class and echocardiograph were assessed before and after successful CRT implantation. Results: Following eLV-CRT implantation, improvements were noted in LVEF (26% vs. 31%, p < 0.01), NYHA class (2.9 vs. 2.3, p < 0.01) and LVESD (57mm vs. 52mm, p = 0.03) in the study cohort. In patients with DCM (n=19), the NYHA class (3.0 vs. 2.3, p = 0.01), LVEF (24% vs. 30%, p = 0.02) and LVESD (57mm vs. 52mm, p = 0.04) had significantly improved following CRT implantation compared to baseline (figures). No statistically significant changes in NYHA class, LVEF and LVESD were observed in patients with ICM (all p > 0.05). Conclusion: In this two-center study, eLV-CRT patients with DCM benefited significantly after CRT, as compared to ICM patients. Although larger scaled studies are needed, eLV-CRT may be considered a viable alternative to tLV-CRT, especially in patients with DCM.

Introduction: Surgically implanted epicardial left ventricular (eLV) lead is an alternative approach when transvenous LV (tLV) lead implantation in CRT patients has failed. With advancement in surgical technique and free from limitations of cardiac venous anatomy, operators have the freedom to choose the most optimal LV pacing site. Recent literatures noted differential clinical response in tLV-CRT patients with different LV lead locations. However, to the best of the authors’ knowledge, no such analysis has been published for eLV-CRT patients. Hypothesis: We hypothesize that optimal LV lead location in eLV-CRT is similar to tLV-CRT and similar clinical response is expected. Methods: After unsuccessful attempt(s) of tLV-CRT implantation, 44 (Age 63±15, 28M) patients received eLV-CRT from UCSD and Mayo Clinics between 2002 and 2013. Two-view (PA, lateral) chest radiographs were used to determine lead location by blinded independent observers. 9 patients were partially excluded from lead location analysis due to congenital cardiac anomaly or unavailable lateral chest radiograph. eLV lead locations were classified as basal, mid, or apical on the PA view; and anterior, anterolateral, lateral, posterolateral, or posterior on the lateral view. Survival data were collected from the national death and location database. Results: During an average follow up of 65 months, 15 patients have died following eLV-CRT implant. No death was attributed to acute surgical complication to eLV-CRT implantation. Kaplan-Meyer survival estimate showed anterior and apical eLV lead positions had lower survival rate as compared to non-anterior (p<0.01, figure A) and non-apical location (p=0.07, figure B). Conclusion: In this two-center study, apical and anterior eLV lead locations were associated with significantly lower survival rate. The study implies apical and/or anterior locations should be avoided, if possible, during eLV-CRT implantation.

Background Little is known about the effects of permanent transvenous device leads on bioprosthetic tricuspid valve (BTV) function. Hypothesis The goal of this study was to test the hypothesis that transvalvular device leads promote clinically significant BTV regurgitation. Methods A retrospective review of 58 patients who underwent BTV implantation and subsequently required endocardial pacemaker (n=52) or defibrillator (n=6) lead implantation through the BTV was conducted. Patient and prosthesis characteristics, lead type, and clinical events were collected. The incidence and severity of prosthetic tricuspid regurgitation (TR), determined by Doppler echocardiography, was compared to 265 patients who underwent BTV implantation without undergoing subsequent transvalvular device lead implantation. Results Over a mean follow up of 25 months, 5 patients (9%) with a transvalvular lead developed ≥ moderate prosthetic TR compared to 12 patients (5%) in the control group (P = 0.20). Kaplan Meier survival analysis revealed no significant difference in the incidence of TR in BTV patients with and without transvalvular leads (p = 0.45). Clinically significant prosthetic TR in patients with and without a transvalvular lead more commonly occurred 2 years or later after lead implantation or BTV implantation (4/5, 80% and 10/12, 83%). Conclusions Compared to BTV controls, there was no significant difference in the incidence of ≥ moderate prosthetic TR in patients with a transvalvular pacemaker or defibrillator lead (p = 0.45). Transvalvular lead implantation appears to be an acceptable approach for patients with a BTV who require permanent pacemaker or defibrillator placement.

Introduction: Cardiac remodeling in heart failure (HF) is associated with conduction abnormalities and dyssynchrony which results in poorly coordinated contractions precipitating metabolic heterogeneity and energetic inefficiency. Cardiac resynchronization therapy (CRT) improves HF symptoms, ventricular function and overall survival. The aim of this study was to determine the changes in metabolomic profiles and substrate utilization after CRT. Methods: 18 patients with advanced HF and 7 healthy controls were included in this study. Blood samples were collected from peripheral vein, femoral artery (FA) and coronary sinus (CS) before and 10-min after CRT. Metabolomic profiling of plasma samples were performed using GC/MS and 1 H NMR spectroscopy. Partial Least Squares Discriminant Analysis (PLS-DA) score plots and regression coefficients were used to examine metabolomic profiles. Results: HF patients have altered plasma metabolomic profile (Fig. A) with distinct panel of metabolites including free fatty acids (FFA), glycerol, 2-hydroxybutyrate, glycine, succinate and uric acid important in group classification compared to controls. Increased release of fumarate and glycerol-3-phosphate from myocardium in HF indicate mitochondrial and substrate shuttle dysfunction. Immediately after CRT, transcardiac metabolomic profile of plasma from CS shifted to a different state with increased myocardial uptake and metabolism of FFA and decreased release of creatinine indicating improved energetic conditions (Fig. B). Conclusion: Metabolomic profiling indicates that CRT improves myocardial substrate metabolism and utilization in patients with advanced HF.

AbstractIntroductionVentricular tachycardia storm or electrical storm (ES) is a common complication following left ventricular assist device (LVAD) implantation. The factors contributing to ES and outcomes are less studied. The study aimed to determine the factors associated with ES and the probability of survival in patients undergoing LVAD in three tertiary centers over a span of 15 years.MethodsWe performed a retrospective cohort study on all patients who underwent LVAD implantation at the Mayo Clinic (Rochester, Phoenix, and Jacksonville) from January 1, 2006 to December 31, 2020. ES was defined as ≥3 episodes of sustained ventricular tachycardia over a period of 24 h with no identifiable reversible cause. Detailed chart reviews of the electronic health records within the Mayo Clinic and outside medical records were performed.ResultsA total of 883 patients who underwent LVAD implantation were included in our study. ES occurred in 7% (n = 61) of patients with a median of 13 days (interquartile range [IQR]: 5–297 days) following surgery. We found 57% of patients (n = 35) developed ES within 30 days, while 43% (n = 26) patients developed ES at a median of 545 (IQR 152–1032) days after surgery. Following ES, 26% of patients died within 1 year. Patients with ES had a significant association with a history of ventricular arrhythmias and implantable cardioverter defibrillator (ICD) shocks before the procedure. ES was significantly associated with reduced survival compared to patients without ES (hazards ratio [HR]: 1.92, 95% CI: 1.39–2.64, p < .001).ConclusionFollowing LVAD implantation, the rate of ES was 7% with majority of ES occurring within 30 days of LVAD. Risk factors for ES included pre‐implant history of ventricular arrhythmias and ICD shock. ES was significantly associated with reduced survival compared to patients without ES.

Abstract Background Long‐term outcomes of sterile lead management strategies of lead abandonment (LA) or transvenous lead extraction (TLE) remain unclear. Methods We performed a retrospective study of a population residing in southeastern Minnesota with follow‐up at the Mayo Clinic and its health systems. Patients who underwent LA or TLE of sterile leads from January 1, 2000, to January 1, 2011, and had follow‐up for at least 10 years or until their death were included. Results A total of 172 patients were included in the study with 153 patients who underwent LA and 19 who underwent TLE for sterile leads. Indications for subsequent lead extraction arose in 9.1% ( n = 14) of patients with initial LA and 5.3% ( n = 1) in patients with initial TLE, after an average of 7 years. Moreover, 28.6% of patients in the LA cohort who required subsequent extraction did not proceed with the extraction, and among those who proceeded, 60% had clinical success and 40% had a clinical failure. Subsequent device upgrades or revisions were performed in 18.3% of patients in the LA group and 31.6% in the TLE group, with no significant differences in procedural challenges (5.2% vs. 5.3%). There was no difference in 10‐year survival probability among the LA group and the TLE group ( p = .64). Conclusion An initial lead abandonment strategy was associated with more complicated subsequent extraction procedures compared to patients with an initial transvenous lead extraction strategy. However, there was no difference in 10‐year survival probability between both lead management approaches.

Abstract Background and Aims Prior reports have demonstrated a favourable safety and efficacy profile of the Micra leadless pacemaker over mid-term follow-up; however, long-term outcomes in real-world clinical practice remain unknown. Updated performance of the Micra VR leadless pacemaker through five years from the worldwide post-approval registry (PAR) was assessed. Methods All Micra PAR patients undergoing implant attempts were included. Endpoints included system- or procedure-related major complications and system revision rate for any cause through 60 months post-implant. Rates were compared through 36 months post-implant to a reference dataset of 2667 transvenous pacemaker patients using Fine–Gray competing risk models. Results 1809 patients were enrolled between July 2015 and March 2018 and underwent implant attempts from 179 centres in 23 countries with a median follow-up period of 51.1 months (IQR: 21.6–64.2). The major complication rate at 60 months was 4.5% [95% confidence interval (CI): 3.6%–5.5%] and was 4.1% at 36 months, which was significantly lower than the 8.5% rate observed for transvenous systems (HR: .47, 95% CI: .36–.61; P &lt; .001). The all-cause system revision rate at 60 months was 4.9% (95% CI: 3.9%–6.1%). System revisions among Micra patients were mostly for device upgrades (41.2%) or elevated thresholds (30.6%). There were no Micra removals due to infection noted over the duration of follow-up. At 36 months, the system revision rate was significantly lower with Micra vs. transvenous systems (3.2% vs. 6.6%, P &lt; .001). Conclusions Long-term outcomes with the Micra leadless pacemaker continue to demonstrate low rates of major complications and system revisions and an extremely low incidence of infection.