Electrophysiologic testing for diagnostic evaluation and risk stratification in patients with suspected cardiac sarcoidosis with preserved left and right ventricular systolic function.

INTRODUCTION: While cardiac sarcoidosis (CS) carries a risk of ventricular arrhythmias (VAs) and sudden cardiac death (SCD), risk stratification of patients with CS and preserved left ventricular/right ventricular (LV/RV) systolic function remains challenging. We sought to evaluate the role of electrophysiologic testing and programmed electrical stimulation of the ventricle (EPS) in patients with suspected CS with preserved ventricular function. METHODS: One hundred twenty consecutive patients with biopsy-proven extracardiac sarcoidosis and preserved LV/RV systolic function underwent EPS. All patients had either probable CS defined by an abnormal cardiac positron emission tomography or cardiac magnetic resonance imaging, or possible CS with normal advanced imaging but abnormal echocardiogram (ECG), SAECG, Holter, or clinical factors. Patients were followed for 4.5 ± 2.6 years for SCD and VAs. RESULTS: Seven of 120 patients (6%) had inducible ventricular tachycardia (VT) with EPS and received an implantable cardioverter defibrillator (ICD). Three patients (43%) with positive EPS later had ICD therapies for VAs. Kaplan-Meier analysis stratified by EPS demonstrated a significant difference in freedom from VAs and SCD (P = 0.009), though this finding was driven entirely by patients within the cohort with probable CS (P = 0.018, n = 69). One patient with possible CS and negative EPS had unrecognized progression of the disease and unexplained death with evidence of CS at autopsy. CONCLUSIONS: EPS is useful in the risk stratification of patients with probable CS with preserved LV and RV function. A positive EPS was associated with VAs. While a negative EPS appeared to confer low risk, close follow-up is needed as EPS cannot predict fatal VAs related to new cardiac involvement or disease progression.

Repeat ablation of refractory ventricular arrhythmias in patients with nonischemic cardiomyopathy: Impact of midmyocardial substrate and role of adjunctive ablation techniques.

INTRODUCTION: Multiple ablations are often necessary to manage ventricular arrhythmias (VAs) in nonischemic cardiomyopathy (NICM) patients. We assessed characteristics and outcomes and role of adjunctive, nonstandard ablation in repeat VA ablation (RAbl) in NICM. METHODS AND RESULTS: Consecutive NICM patients undergoing RAbl were analyzed, with characteristics of the last VA ablations compared between those undergoing 1 versus multiple-repeat ablations (1-RAbl vs. >1RAbl), and between those with or without midmyocardial substrate (MMS). VA-free survival was compared. Eighty-eight patients underwent 124 RAbl, 26 with > 1RAbl, and 26 with MMS. 1-RAbl and > 1-RAbl groups were similar in age (57 ± 16 vs. 57 ± 17 years; P = 0.92), males (76% vs. 69%; P = 0.60), LVEF (40 ± 17% vs. 40 ± 18%; P = 0.96), and amiodarone use (31% vs. 46%, P = 0.22). One-year VA freedom between 1-RAbl vs. > 1RAbl was similar (82% vs. 80%; P = 0.81); adjunctive ablation was utilized more in >1RAbl (31% vs. 11%, P = 0.02), and complication rates were higher (27% vs. 7%, P = 0.01), most due to septal substrate and anticipated heart block. >1-RAbl patients had more MMS (62% vs. 16%, P < 0.01). Although MMS was associated with worse VA-free survival after 1-RAbl (43% vs. 69%, P = 0.01), when >1RAbl was performed, more often with nonstandard ablation, VA-free survival was comparable to non-MMS patients (85% vs. 81%; P = 0.69). More RAbls were required in MMS versus non-MMS patients (2.00 ± 0.98 vs. 1.16 ± 0.37; P < 0.001). CONCLUSION: For NICM patients with recurrent, refractory VAs despite previous ablation, effective arrhythmia control can safely be achieved with subsequent ablation, although >1 repeat procedure with adjunctive ablation is often required, especially with MMS.

Pacing as a Treatment for Reflex-Mediated (Vasovagal, Situational, or Carotid Sinus Hypersensitivity) Syncope: A Systematic Review for the 2017 ACC/AHA/HRS Guideline for the Evaluation and Management of Patients With Syncope: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society.

OBJECTIVES: To determine, using systematic review of the biomedical literature, whether pacing reduces risk of recurrent syncope and relevant clinical outcomes among adult patients with reflex-mediated syncope. METHODS: MEDLINE (through PubMed), EMBASE, and the Cochrane Central Register of Controlled Trials (through October 7, 2015) were searched for randomized trials and observational studies examining pacing and syncope, and the bibliographies of known systematic reviews were also examined. Studies were rejected for poor-quality study methods and for the lack of the population, intervention, comparator, or outcome(s) of interest. RESULTS: Of 3188 citations reviewed, 10 studies met the inclusion criteria for systematic review, including a total of 676 patients. These included 9 randomized trials and 1 observational study. Of the 10 studies, 4 addressed patients with carotid sinus hypersensitivity, and the remaining 6 addressed vasovagal syncope. Among the 6 open-label (unblinded) studies, we found that pacing was associated with a 70% reduction in recurrent syncope (relative risk [RR]: 0.30; 95% confidence interval [CI]: 0.15-0.60). When the 2 analyzable studies with double-blinded methodology were considered separately, there was no clear benefit (RR: 0.73; 95% CI: 0.25-2.1), but confidence intervals were wide. The strongest evidence was from the randomized, double-blinded ISSUE-3 (Third International Study on Syncope of Uncertain Etiology) trial, which demonstrated a benefit of pacing among patients with recurrent syncope and asystole documented by implantable loop recorder. CONCLUSIONS: There are limited data with substantive evidence of outcome ascertainment bias, and only 2 studies with a double-blinded study design have been conducted. The evidence does not support the use of pacing for reflex-mediated syncope beyond patients with recurrent vasovagal syncope and asystole documented by implantable loop recorder.

Use of Cardiac Resynchronization Therapy Among Eligible Patients Receiving an Implantable Cardioverter Defibrillator: Insights From the National Cardiovascular Data Registry Implantable Cardioverter Defibrillator Registry.

Importance: Cardiac resynchronization therapy (CRT) reduces the risk for mortality and heart failure-related events in select patients. Little is known about the use of CRT in combination with an implantable cardioverter defibrillator (ICD) in patients who are eligible for this therapy in clinical practice. Objective: To (1) identify patient, clinician, and hospital characteristics associated with CRT defibrillator (CRT-D) use and (2) determine the extent of hospital-level variation in the use of CRT-D among guideline-eligible patients undergoing ICD placement. Design, Setting, and Participants: Multicenter retrospective cohort from 1428 hospitals participating in the National Cardiovascular Data Registry ICD Registry between April 1, 2010, and June 30, 2014. Adult patients meeting class I or IIa guideline recommendations for CRT at the time of device implantation were included in this study. Main Outcomes and Measures: Implantation of an ICD with or without CRT. Results: A total of 63 506 eligible patients (88.6%) received CRT-D at the time of device implantation. The mean (SD) ages of those in the ICD and CRT-D groups were 67.9 (12.2) years and 68.4 (11.5) years, respectively. In hierarchical multivariable models, black race was independently associated with lower use of CRT-D (odds ratio [OR], 0.77; 95% CI, 0.71-0.83) as was nonprivate insurance (OR, 0.90; 95% CI, 0.85-0.95 for Medicare and OR, 0.73; 95% CI, 0.65-0.82 for Medicaid). Clinician factors associated with greater CRT-D use included clinician implantation volume (OR, 1.01 per 10 additional devices implanted; 95% CI, 1.01-1.01) and electrophysiology training (OR, 3.13 as compared with surgery-boarded clinicians; 95% CI, 2.50-3.85). At the hospital level, the overall median risk-standardized rate of CRT-D use was 79.9% (range, 26.7%-100%; median OR, 2.08; 95% CI, 1.99-2.18). Conclusions and Relevance: In a national cohort of patients eligible for CRT-D at the time of device implantation, nearly 90% received a CRT-D device. However, use of CRT-D differed by race and implanting operator characteristics. After accounting for these factors, the use of CRT-D continued to vary widely by hospital. Addressing disparities and variation in CRT-D use among guideline-eligible patients may improve patient outcomes.

Sleep Disordered Breathing and Risk of Stroke in Older Community-Dwelling Men.

STUDY OBJECTIVES: Men with sleep disordered breathing (SDB) may be at increased stroke risk, due to nocturnal hypoxemia, sleep loss or fragmentation, or other mechanisms. We examined the association of SDB with risk of incident stroke in a large cohort of older men. METHODS: Participants were 2,872 community-dwelling men (mean age 76 years) enrolled in the MrOS Sleep Study, which gathered data from 2003 to 2005 at six clinical sites in the Unites States. SDB predictors (obstructive apnea-hypopnea index, apnea-hypopnea index, central apnea index, and nocturnal hypoxemia) were measured using overnight polysomnography. Incident stroke over an average follow-up of 7.3 years was centrally adjudicated by physician review of medical records. RESULTS: One hundred fifty-six men (5.4%) had a stroke during follow-up. After adjustment for age, clinic site, race, body mass index, and smoking status, older men with severe nocturnal hypoxemia (≥ 10% of the night with SpO2 levels below 90%) had a 1.8-fold increased risk of incident stroke compared to those without nocturnal hypoxemia (relative hazard = 1.83; 95% confidence interval 1.12-2.98; P trend = 0.02). Results were similar after further adjustment for other potential covariates and after excluding men with a history of stroke. Other indices of SDB were not associated with incident stroke. CONCLUSIONS: Older men with severe nocturnal hypoxemia are at significantly increased risk of incident stroke. Measures of overnight oxygen saturation may better identify older men at risk for stroke than measures of apnea frequency.

Use of Transesophageal Echocardiography to Improve the Safety of Transvenous Lead Extraction.

OBJECTIVES: The aim of this study was to evaluate the utility of transesophageal echocardiography (TEE) during transvenous lead extraction (TLE) involving both conventional and laser lead removal. BACKGROUND: TLE carries a small but measurable risk of serious adverse events. Few studies have examined the potential benefit of continuous monitoring with TEE during this procedure. METHODS: Continuous TEE monitoring was performed in 100 consecutive patients (67% male; average age, 57 ± 17 years) who underwent TLE in the past 5 years. Lead extraction was attempted for 193 leads. The average time since lead implant was 78 ± 55 months (range, 1.4 to 274.4 months). Indications for extraction were device endocarditis (n = 28), lead fracture (n = 28), recalled lead (n = 21), pocket infection (n = 17), and other (n = 6). RESULTS: Complete success occurred in 181 leads (94%), partial success in 4 leads (2%), and failure in 8 leads (4%). Eighty patients required laser lead extraction (80%). Major complications included 1 right ventricular and 2 right atrial/superior vena cava lacerations, which were detected and localized within 1 to 2 min with the use of TEE and resulted in prompt surgical repair. There was 1 upper gastrointestinal bleed caused by the TEE probe. TEE prevented premature termination and unnecessary surgery in 4 patients with hypotension but no intracardiac abnormalities seen on TEE. In-hospital mortality rate was 0%. In total, TEE provided immediately useful clinical information in 7 patients (7%). CONCLUSIONS: Continuous monitoring with TEE facilitates prompt diagnosis and treatment of intracardiac damage and prevents premature termination of cases with hypotension but no abnormalities on TEE.

Electromagnetic interference caused by common surgical energy-based devices on an implanted cardiac defibrillator.

BACKGROUND: Surgical energy-based devices emit energy, which can interfere with other electronic devices (eg, implanted cardiac pacemakers and/or defibrillators). The purpose of this study was to quantify the amount of unintentional energy (electromagnetic interference [EMI]) transferred to an implanted cardiac defibrillator by common surgical energy-based devices. METHODS: A transvenous cardiac defibrillator was implanted in an anesthetized pig. The primary outcome measure was the average maximum EMI occurring on the implanted cardiac device during activations of multiple different surgical energy-based devices. RESULTS: The EMI transferred to the implanted cardiac device is as follows: traditional bipolar 30 W .01 ± .004 mV, advanced bipolar .004 ± .003 mV, ultrasonic shears .01 ± .004 mV, monopolar Bovie 30 W coagulation .50 ± .20 mV, monopolar Bovie 30 W blend .92 ± .63 mV, monopolar instrument without dispersive electrode .21 ± .07 mV, plasma energy 3.48 ± .78 mV, and argon beam coagulator 2.58 ± .34 mV. CONCLUSION: Surgeons can minimize EMI on implanted cardiac defibrillators by preferentially utilizing bipolar and ultrasonic devices.

In-hospital complications associated with reoperations of implantable cardioverter defibrillators.

Repeat implantable cardioverter defibrillator (ICD) procedures are increasing and may be associated with higher risks for complications. To provide more information for clinical decision making, especially in light of recent defibrillator advisories, we examined a large national cohort to characterize repeat ICD procedural outcomes. Using data from the National Cardiovascular Data Registry (ICD Registry), we compared patient characteristics, reasons for ICD implantation, and associated in-hospital adverse events among 92,751 patients receiving their first device and 81,748 patients who underwent repeat procedures with (n = 31,057) and without (n = 50,691) lead involvement. Hierarchical multivariable logistic regression was used to determine the predictors of in-hospital complications. Complication rates were higher in those who underwent repeat ICD procedures with lead involvement (lead implantation or revision), compared with patients who underwent initial implants (3.2% vs 2.6%, p <0.001) or versus those with pocket-only (e.g., generator change only) procedures (3.2% vs 0.6%, p <0.001). There were significantly more in-hospital deaths, lead dislodgements, and infections requiring antibiotics in the lead involvement cohort. Compared with those who had a pocket-only procedure, the multivariable adjusted odds ratio of any complication were increased at 4.20 (95% confidence interval: 3.66 to 4.82, p <0.001) in patients who underwent repeat procedures with lead involvement excluding lead extraction or 7.11 (95% confidence interval: 5.96 to 8.48, p <0.001) in procedures involving lead extractions. In conclusion, repeat ICD procedures, when involving the addition or revision of a lead with or without concurrent lead extraction, are associated with higher complication rates compared with initial implants and with those who underwent pocket-only procedures.

Depression and outcome among veterans with implantable cardioverter defibrillators with or without cardiac resynchronization therapy capability.

BACKGROUND: The impact of depression on outcome in implantable cardioverter defibrillator (ICD) recipients has not been fully appreciated. We assessed the prevalence of depression and its association with heart failure (HF) outcome among veterans with ICDs. METHODS AND RESULTS: Patients enrolled between January 2005 and January 2010 in the Outcomes among Veterans with Implantable Defibrillators Registry were studied. We examined the cross-sectional association of depression with severity of HF functional class as well as the association of depression with the composite outcome of mortality or HF hospitalization over a mean follow-up time of 2.7 years. There were 3,862 patients enrolled. Patients with depression (1,162, 43%) were younger (63.1 ± 9.4 years vs 66.6 ± 9.9 years, P < 0.001), more likely to have a history of tobacco or alcohol abuse (P < 0.0001) or atrial fibrillation (P = 0.05) while having a higher ejection fraction (28.3% vs 27.4%, P = 0.03). Depression was associated with advanced HF class at time of implant; odds ratio (OR; vs class I) for class III: 1.65 (confidence interval [CI] 1.17-2.33), class IV: 1.73 (95% CI 1.08-2.76). Death or HF hospitalization was more likely to occur in patients with depression (35.2% vs 32.0%, HR: 1.15 [95% CI 0.99-1.33]). The predictive value of depression was stronger after multivariable adjustment; HR: 1.25 (95% CI 1.05-1.49). CONCLUSION: Depression was prevalent among veterans with ICDs. Depression was associated with severity of HF. The predictive value of associated depression was significant after multivariable adjustment.

Cardiac perforation from implantable cardioverter-defibrillator lead placement: insights from the national cardiovascular data registry.

BACKGROUND: Cardiac perforation is a feared complication of implantable cardioverter-defibrillator (ICD) lead implantation because of the potential for significant morbidity and mortality. Predictors of perforation and the severity of associated adverse events have not been well studied. We sought to identify predictors of cardiac perforation from ICD lead implantation and subsequent outcomes. METHODS AND RESULTS: We studied 440 251 first-time ICD recipients in the ICD Registry implanted between January 2006 and September 2011. Using hierarchical multivariable logistic regression adjusting for patient, implanting physician, and hospital characteristics, we examined the predictors of perforation and the association of perforation with other major complications, length of stay, and in-hospital mortality. Cardiac perforation occurred in 625 patients (0.14%). After multivariable adjustment, older age, female sex, left bundle branch block, worsened heart failure class, higher left ventricular ejection fraction, and non-single-chamber ICD implant were associated with a greater odds of perforation. Conversely, atrial fibrillation, diabetes mellitus, previous cardiac bypass surgery, and higher implanter procedural volume were associated with a lower odds of perforation (all P<0.05). After adjustment, ICD recipients with perforation had greater odds of other associated major complications (odds ratio, 27.5; 95% confidence interval, 19.9-38.0; P<0.0001), postprocedural hospital stays >3 days (odds ratio, 16.3; 95% confidence interval, 13.7-19.4; P<0.0001), and in-hospital death (odds ratio, 17.7; 95% confidence interval, 12.2-25.6; P<0.0001). CONCLUSIONS: In a large population of ICD recipients, specific patient and implanter characteristics predicted cardiac perforation risk. Cardiac perforation was associated with a substantially increased risk of other major complications, prolonged hospital stays, and death.