A Modular Communicative Leadless Pacing-Defibrillator System.

BACKGROUND: The subcutaneous implantable cardioverter-defibrillator (ICD) is associated with fewer lead-related complications than a transvenous ICD; however, the subcutaneous ICD cannot provide bradycardia and antitachycardia pacing. Whether a modular pacing-defibrillator system comprising a leadless pacemaker in wireless communication with a subcutaneous ICD to provide antitachycardia and bradycardia pacing is safe remains unknown. METHODS: We conducted a multinational, single-group study that enrolled patients at risk for sudden death from ventricular arrhythmias and followed them for 6 months after implantation of a modular pacemaker-defibrillator system. The safety end point was freedom from leadless pacemaker-related major complications, evaluated against a performance goal of 86%. The two primary performance end points were successful communication between the pacemaker and the ICD (performance goal, 88%) and a pacing threshold of up to 2.0 V at a 0.4-msec pulse width (performance goal, 80%). RESULTS: We enrolled 293 patients, 162 of whom were in the 6-month end-point cohort and 151 of whom completed the 6-month follow-up period. The mean age of the patients was 60 years, 16.7% were women, and the mean (±SD) left ventricular ejection fraction was 33.1±12.6%. The percentage of patients who were free from leadless pacemaker-related major complications was 97.5%, which exceeded the prespecified performance goal. Wireless-device communication was successful in 98.8% of communication tests, which exceeded the prespecified goal. Of 151 patients, 147 (97.4%) had pacing thresholds of 2.0 V or less, which exceeded the prespecified goal. The percentage of episodes of arrhythmia that were successfully terminated by antitachycardia pacing was 61.3%, and there were no episodes for which antitachycardia pacing was not delivered owing to communication failure. Of 162 patients, 8 died (4.9%); none of the deaths were deemed to be related to arrhythmias or the implantation procedure. CONCLUSIONS: The leadless pacemaker in wireless communication with a subcutaneous ICD exceeded performance goals for freedom from major complications related to the leadless pacemaker, for communication between the leadless pacemaker and subcutaneous ICD, and for the percentage of patients with a pacing threshold up to 2.0 V at a 0.4-msec pulse width at 6 months. (Funded by Boston Scientific; MODULAR ATP ClinicalTrials.gov NCT04798768.).

Differences of Mortality Rates between Pocket and Nonpocket Cardiovascular Implantable Electronic Device Infections.

BACKGROUND: A steady rise in the use of cardiovascular implantable electronic devices (CIEDs), particularly in the elderly, has led to an increase in device-related infections. Although often studied and reported as a single entity, these complications in fact comprise a heterogeneous group. Specific subgroups may be associated with distinct mortality risks. METHODS: Medical records of all patients who underwent device extraction for CIED-related infection at a single tertiary referral center between 1991 and 2007 were reviewed. Infections were divided into four subgroups: primary pocket site infection (PPSI), pocket site infection with bacteremia, primary/isolated bacteremia (PIB), and device-related infective endocarditis (DRIE). Clinical presentation, laboratory data, and mortality rates were obtained by chart review and by querying the Social Security Death Index. RESULTS: A total of 387 cases were analyzed. The overall in-hospital and 1-year all-cause mortality rates were 7.2% and 25.3%, respectively. Patients with PIB or DRIE had significantly higher mortality rates (hazard ratio [HR] 2.3; 95% confidence interval [CI] 1.2-4.6 and HR 2.5; 95% CI 1.6-4.1, respectively) when compared with patients in the PPSI group. Patients who did not receive a new device during the initial admission also had a higher 1-year mortality rate compared to those who did (HR 2.7; 95% CI 1.8-4.1). CONCLUSIONS: Our patients with CIED-related infections requiring extraction/hospitalization had a significant mortality risk. Presence of pocket site infection carried a more favorable prognosis, regardless of the presence of bacteremia. Early detection and prevention of CIED-related infections with PIB (i.e., no pocket site involvement), especially for high-risk populations, is needed.

Protection from outpatient sudden cardiac death following ICD removal using a wearable cardioverter defibrillator.

BACKGROUND: An implantable cardioverter defibrillator (ICD) is effective in preventing sudden cardiac death (SCD). Once an ICD is removed and reimplantation is not feasible, a wearable cardioverter defibrillator (WCD) may be an alternative option. We determined the effectiveness of WCD for SCD prevention in patients who were discharged after ICD removal. METHODS: A retrospective study was conducted on all WCD (LifeVest, ZOLL, Pittsburgh, PA, USA) patients who underwent ICD removal due to cardiac device infections (CDIs) at two referral centers between January 1, 2005 and December 31, 2009. Clinical characteristics, device information, and WCD data were analyzed. Sudden cardiac arrest was defined as all sustained ventricular tachycardia (VT) and ventricular fibrillation occurring within a single 24-hour period. RESULTS: Ninety-seven patients (mean age 62.8 ± 13.3, male 80.4%) were included in the study. The median duration of antibiotic use was 14.7 days (interquartile range [IQR] 10-30). The median daily WCD use was 20 hours/day and the median length of use was 21 days (IQR 5-47). A total of three patients were shocked by WCD. Two patients had four episodes of sustained VT, successfully terminated by the WCD. A third patient experienced two inappropriate treatments due to oversensitivity of the signal artifact. Three patients experienced sudden death outside the hospital while not wearing the device. Five patients died while hospitalized. CONCLUSION: WCD can prevent SCD, until ICD reimplantation is feasible in patients who underwent device removals for CDI. However, patient compliance is essential for the effective use of this device.

Percutaneous extraction of ePTFE-coated ICD leads: a single center comparative experience.

BACKGROUND: Percutaneous extraction of standard implantable cardioverter-defibrillator leads is often complicated by ingrowth of fibrotic tissue into the shocking coils. Leads with GORE™ expanded polytetrafluoroethylene (ePTFE) coating (W. L. Gore & Associates, Inc., Newark, DE, USA) designed to inhibit fibrosis are in use, but clinical data regarding their extraction are lacking. The study's purpose was to examine the feasibility, efficacy, and safety of percutaneous extraction involving defibrillator leads coated with ePTFE. METHODS: We analyzed our database to identify all percutaneously extracted leads with ePTFE-coated shocking coils. Lead and procedure characteristics were compared to a cohort of noncoated leads of similar implant duration. RESULTS: One hundred fifty-six leads were extracted from 145 patients; 57 ePTFE-coated leads, with a mean implant duration of 621 days, were extracted and compared to 99 noncoated leads, with a mean implant duration of 763 days (P = 0.0641). Mean extraction time was 5 minutes for coated leads versus 9.75 minutes for noncoated leads (P = 0.0001). Extraction time of less than 1 minute was more frequent with coated leads (61% vs 35%, P = 0.0025). Adjunct extraction tools were required less frequently with coated leads than noncoated leads (39% vs 63%, P = 0.0071). There was no fibrosis where ePTFE covered the shocking coils. Alternatively, 23 of 99 (23%) noncoated leads demonstrated fibrosis adherent to the shock coil. There were no procedure-related complications in either group. CONCLUSIONS: Compared to noncoated leads, ePTFE-coated leads are associated with shorter extraction times and are less likely to require extraction tools for removal. The difference is likely related to the absence of fibrosis over the ePTFE-coated high-energy coils.

Design and rationale of the MODULAR ATP global clinical trial: A novel intercommunicative leadless pacing system and the subcutaneous implantable cardioverter-defibrillator.

Background: The subcutaneous implantable cardioverter-defibrillator (S-ICD) has demonstrated safety and efficacy for the treatment of malignant ventricular arrhythmias. However, a limitation of the S-ICD lies in the inability to either pace-terminate ventricular tachycardia or provide prolonged bradycardia pacing support. Objective: The rationale and design of a prospective, single-arm, multinational trial of an intercommunicative leadless pacing system integrated with the S-ICD will be presented. Methods: A technical description of the modular cardiac rhythm management (mCRM) system (EMPOWER leadless pacemaker and EMBLEM S-ICD) and the implantation procedure is provided. MODULAR ATP (Effectiveness of the EMPOWER™ Modular Pacing System and EMBLEM™ Subcutaneous ICD to Communicate Antitachycardia Pacing) is a multicenter, international trial enrolling up to 300 patients at risk of sudden cardiac death at up to 60 centers trial design. The safety endpoint of freedom from major complications related to the mCRM system or implantation procedure at 6 months and 2 years are significantly higher than 86% and 81%, respectively, and all-cause survival is significantly >85% at 2 years. Results: Efficacy endpoints are that at 6 months mCRM communication success is significantly higher than 88% and the percentage of subjects with low and stable thresholds is significantly higher than 80%. Substudies to evaluate rate-responsive features and performance of the pacing module are also described. Conclusion: The MODULAR ATP global clinical trial will prospectively test the safety and efficacy of the first intercommunicating leadless pacing system with the S-ICD. This trial will allow for robust validation of device-device communication, pacing performance, rate responsiveness, and system safety.

Transcatheter Leadless Pacing in Children: A PACES Collaborative Study in the Real-World Setting.

BACKGROUND: Transcatheter Leadless Pacemakers (TLP) are a safe and effective option for adults with pacing indications. These devices may be an alternative in pediatric patients and patients with congenital heart disease for whom repeated sternotomies, thoracotomies, or transvenous systems are unfavorable. However, exemption of children from clinical trials has created uncertainty over the indications, efficacy, and safety of TLP in the pediatric population. The objectives of this study are to evaluate clinical indications, procedural characteristics, electrical performance, and outcomes of TLP implantation in children. METHODS: Retrospective data were collected from patients enrolled in the Pediatric and Congenital Electrophysiology Society TLP registry involving 15 centers. Patients ≤21 years of age who underwent Micra (Medtronic Inc, Minneapolis, MN) TLP implantation and had follow-up of ≥1 week were included in the study. RESULTS: The device was successfully implanted in 62 of 63 registry patients (98%) at a mean age of 15±4.1 years and included 20 (32%) patients with congenital heart disease. The mean body weight at TLP implantation was 55±19 kg and included 8 patients ≤8 years of age and ≤30 kg in weight. TLP was implanted by femoral (n=55, 87%) and internal jugular (n=8, 12.6%) venous approaches. During a mean follow-up period of 9.5±5.3 months, there were 10 (16%) complications including one cardiac perforation/pericardial effusion, one nonocclusive femoral venous thrombus, and one retrieval and replacement of TLP due to high thresholds. There were no deaths, TLP infections, or device embolizations. Electrical parameters, including capture thresholds, R wave sensing, and pacing impedances, remained stable. CONCLUSIONS: Initial results from the Pediatric and Congenital Electrophysiology Society TLP registry demonstrated a high level of successful Micra device implants via femoral and internal venous jugular approaches with stable electrical parameters and infrequent major complications. Long-term prospective data are needed to confirm the reproducibility of these initial findings.

ATPace™: injectable adenosine 5'-triphosphate : Diagnostic and therapeutic indications.

ATPace™, a novel injectable formulation of adenosine 5'-triphosphate (ATP), is developed by Cordex Pharma, Inc. (Cordex) as a diagnostic and therapeutic drug for the management of cardiac bradyarrhythmias. Extracellular ATP exerts multiple effects in various cell types by activating cell-surface receptors known as P2 receptors. In the heart, ATP suppresses the automaticity of cardiac pacemakers and atrioventricular (AV) nodal conduction via adenosine, the product of its degradation by ecto-enzymes, as well as by triggering a cardio-cardiac vagal reflex. ATP, given as a rapid intravenous bolus injection, has been used since the late 1940s as a highly effective and safe therapeutic agent for the acute termination of reentrant paroxysmal supraventricular tachycardia (PSVT) involving the AV node. In addition, preliminary studies have shown that ATP can also be used as a diagnostic agent for the identification of several cardiac disorders including sinus node dysfunction (sick sinus syndrome), dual AV nodal pathways, long QT syndrome, and bradycardic syncope. The US Food and Drug Administration has approved Cordex formulation for ATP as an Investigational New Drug and two pathways for its marketing approval; one therapeutic, i.e., acute termination of paroxysmal PSVT, and the other diagnostic, i.e., the identification of patients with bradycardic syncope who can benefit from pacemaker therapy. The scientific rationale for the development of ATPace™ is discussed.

Outcomes of Standard Permanent Active Fixation Leads for Temporary Pacing.

OBJECTIVES: This study investigated the performance of Temporary Pacing via an Externalized Active-Fixation (TPEAF) lead. BACKGROUND: The incidence of cardiac implantable electronic device infections is increasing, which necessitates the need for transvenous lead extraction (TLE). Pacemaker-dependent patients require temporary pacing during the guideline-recommended waiting period before reimplantation. Data regarding safety and efficacy of TPEAF leads are very limited. METHODS: We evaluated patients implanted with TPEAF leads post-TLE at our center between April 2004 and December 2017. RESULTS: TPEAF leads were placed in 158 patients. The mean age was 74 ± 11 years. The median duration of the temporary lead was 6 days (range 1 to 29). There were 4 procedural complications (2.5% incidence): 1 patient had cardiac arrest from hyperkalemia, 2 developed cardiac tamponade, and 1 had profuse bleeding from the entry point of the leads. There were 13 complications post-implantation (8.2% incidence): 8 lead dislodgments, 1 elevated pacing threshold, 2 vegetations on the temporary lead, 1 pneumothorax, and 1 loss of capture due to the generator "safety switch." All dislodgements occurred within 24 h, except 1 on day 3. Sixteen patients died during the hospital stay: 10 due to septic shock, 2 due to hyperkalemic cardiac arrest, 3 due to ventricular tachycardia, and 1 due to a massive cerebrovascular accident. CONCLUSIONS: The use of TPEAF leads is safe and efficacious in pacemaker-dependent patients post-TLE. Dislodgement can occur within the first 24 h. The presence of persistent fever and positive blood cultures should raise concern for vegetation on the temporary lead.

Outcomes of subcutaneous implantable cardioverter-defibrillator in dialysis patients: Results from the S-ICD post-approval study.

BACKGROUND: Patients with chronic renal disease on hemodialysis (HD) have limited vascular access and are at high risk of bacteremia. The subcutaneous implantable cardioverter-defibrillator (S-ICD) avoids vascular access, so it may be advantageous in this patient population. OBJECTIVE: The purpose of this study was to report outcomes of patients with end-stage renal disease enrolled in the multicenter S-ICD post-approval study (PAS). METHODS: S-ICD PAS patients were stratified on the basis of the presence (group 1) or absence (group 2) of HD at the time of implantation. Baseline demographic and clinical characteristics were collected. Perioperative and intermediate-term outcomes 365 days postimplantation were compared between the 2 groups. RESULTS: There were 220 patients on HD (13.4%) at the time of implantation out of 1637 patients enrolled in the S-ICD PAS. Patients on HD (group 1) were older (57.4 ± 13.2 years vs 52.5 ± 15.2 years; P < .0001), more likely to be of African descent (48.6% vs 25.1%; P < .0001), and had lower ejection fraction (28.6% ± 11.3% vs 32.6% ± 14.9%; P < .0001) as compared with patients not on HD (group 2). Group 1 had more comorbidities and mortality was higher (17.4% vs 3.7%) than did group 2. The rate of complications calculated using the Kaplan-Meier estimate did not differ between the 2 groups (overall P = .9169), with a 1-year rate of 7.9% and 7.7% for groups 1 and 2, respectively. The rate of appropriate shocks was significantly higher in group 1 (Kaplan-Meier analysis, P = .0003), as was inappropriate shocks (P = .0137). CONCLUSION: S-ICD is associated with similar adverse event rates but a higher risk of inappropriate and appropriate therapy in dialysis patients than in nondialysis patients.

Anti- and pro-arrhythmic effects of cardiac resynchronization therapy: point of view.

Cardiac resynchronization therapy (CRT) in patients with heart failure and bundle branch block (BBB) improves regional muscle mechanics and mechanical pump function of the heart. In addition, modulation of wall motion timing and contraction can exert an antiarrhythmic effect, reducing the potential of sudden cardiac death. This effect of CRT could also be attributed to the improvement in excitation-contraction coupling, mechanical synchronization, and improved myocardial perfusion. However, it can be hypothesized that the BBB results in a concealed reentry, in which a delayed depolarization wave re-enters during phase two of the action potential. This concealed phase 2 reentry can lead to early after depolarizations and cardiac arrhythmias. By synchronizing the two ventricles, CRT eliminates the reentry substrate and the resulting arrhythmias. This hypothesis and the potential arrhythmogenic effects of CRT are discussed with regard to ventricular remodeling and mechano-electrical feedback in this setting.

Effect of pacing for soft indications on mortality and heart failure in the dual chamber and VVI implantable defibrillator (DAVID) trial.

BACKGROUND: The dual chamber and VVI implantable defibrillator (DAVID) trial demonstrated that dual chamber (DDDR) pacing in defibrillator candidates with impaired ventricular function and no established indication for pacing resulted in worsened congestive heart failure (CHF) or death. Many patients had abnormalities for which pacing is often advocated to improve the management of ventricular dysfunction. OBJECTIVES: Evaluate the impact and interaction of nonessential but potentially justifiable reasons to pace ("soft indications"), together with pacing mode, on outcome. METHODS: DAVID patients were stratified by those with and without "soft indications" for pacing (rate < 60 beats/min or first-degree atrioventricular block) (n = 169; n = 335, respectively). This analysis also stratified patients by normal and abnormal QRS conduction (QRS >or= 110 ms), who were previously found to be affected differently by DDDR pacing. Groups were analyzed according to the combined endpoint of mortality or CHF hospitalization. RESULTS: When assigned to treatment that promoted pacing (DDDR), the incidence of death or CHF tended to be higher in patient subgroups with and without "soft indications," consistent with results from DAVID. Patients with, compared to those without, these abnormalities neither benefited nor were less adversely affected when actively paced. The presence or absence of "soft indications" also provided no additional explanation for the differing outcomes in patient cohorts with and without abnormal QRS conduction. CONCLUSIONS: Sinus bradycardia or first-degree atrioventricular block did not ameliorate the poor outcomes associated with dual-chamber compared with VVI pacing, and do not justify conventional dual-chamber pacing in defibrillator recipients with ventricular dysfunction.

Feasibility of extravascular pacing with a novel substernal electrode configuration: The Substernal Pacing Acute Clinical Evaluation study.

BACKGROUND: Subcutaneous implantable cardioverter-defibrillators provide an alternative to transvenous defibrillation but require higher shock outputs and offer no antitachycardia pacing. The Substernal Pacing Acute Clinical Evaluation (SPACE) study evaluated the feasibility of pacing from an extravascular substernal location. OBJECTIVES: The primary purpose of the SPACE study was to characterize pacing from the substernal space. Secondary objectives included evaluating extracardiac stimulation and recording electrograms. METHODS: The SPACE study prospectively evaluated the feasibility of pacing with a commercially available electrophysiology catheter acutely implanted in the substernal space via minimally invasive subxiphoid access. Pacing data were collected in ≥7 vectors using constant current stimulation up to 20 mA and pulse width up to 10 ms. RESULTS: Catheter placement was successful in all 26 patients who underwent the procedure, with a mean placement time of 11.7 ± 10.1 minutes. Eighteen patients (69%) had successful ventricular capture in ≥1 tested vector. The mean pacing threshold at a pulse width of 10 ms was 7.3 ± 4.2 mA across all vectors (5.8 ± 4.4 V). Failed capture was generally associated with suboptimal catheter placement or presumed air ingression. A low level of extracardiac stimulation was observed in 1 patient. The mean R-wave amplitude ranged from 2.98 to 4.11 mV in the unipolar configuration and from 0.83 to 3.95 mV in the bipolar configuration. CONCLUSION: The data from the SPACE study demonstrate that pacing is feasible from the extravascular substernal location. A substernal electrode configuration has the potential to provide pacing in a future extravascular device without need for intracardiac hardware placement.

Outcomes of subcutaneous implantable cardioverter-defibrillator implantation in patients on hemodialysis.

BACKGROUND: Subcutaneous implantable cardioverter-defibrillator (S-ICD) provides potential benefits in patients on hemodialysis (HD) by reducing the risk of blood stream infection and preserving vascular access sites. We evaluated the safety and efficacy of S-ICD in patients with end-stage renal disease (ESRD) on HD. METHODS: All consecutive patients implanted with S-ICD between October 2012 and April 2015 at our high-volume center were included in this retrospective, single-center study. Baseline demographics, procedural details, and short- as well as long-term outcomes were compared between patients on HD and not on HD. RESULTS: A total of 86 S-ICDs were implanted at our institution during the study period. Eighteen (21%) patients were on HD at the time of implant. HD patients were more likely to be implanted for secondary prevention. There was no statistically significant difference in procedural complications between the two groups. HD patients had a longer duration hospital stay after implant (3.6 ± 5.14 vs. 1.69 ± 2.29 days, p = 0.021). During a mean follow-up of 205 ± 208 days in the HD cohort and 242 ± 238 days in the non-HD cohort (p = 0.268), there was no device or blood stream infection in the HD group, compared with five device infections in the non-HD group. The incidence of inappropriate shocks was similar in both groups. All appropriate shocks were successful in terminating ventricular tachyarrhythmias in both groups. Patients on hemodialysis had worse inpatient as well as long-term mortality after S-ICD implant, compared with non-HD patients. CONCLUSIONS: Our study demonstrates the safety and efficacy of S-ICD in patients on HD. Despite representing a sicker patient population, HD patients implanted with S-ICD had similar procedural outcomes and inappropriate shocks. There was no device or blood stream-related infection in HD patients. All appropriate shocks for ventricular arrhythmias in HD patients were successful.

Quality of life in the antiarrhythmics versus implantable defibrillators trial: impact of therapy and influence of adverse symptoms and defibrillator shocks.

BACKGROUND: Implantable cardioverter defibrillator (ICD) use reduces mortality in patients with serious ventricular arrhythmias compared with antiarrhythmic drug (AAD) use. However, the relative impact of these therapies on self-perceived quality of life (QoL) is unknown. METHODS AND RESULTS: Three self-administered instruments were used to measure generic and disease-specific QoL in Antiarrhythmics Versus Implantable Defibrillators trial participants. Generalized linear models were used to assess the relationships between self-perceived QoL and treatment (AAD versus ICD) and adverse symptoms and ICD shocks. To minimize the impact of missing data, only patients surviving 1 year were included in the primary analyses. Baseline characteristics among QoL participants (n=905) and nonparticipants (n=111) were similar, but participants who survived 1 year (n=800) were healthier at baseline than nonsurvivors (n=105). Of the 800 patients in the primary analysis, characteristics of those randomized to AAD (n=384) versus ICD (n=416) were similar. Overall, ICD and AAD use were associated with similar alterations in QoL. The development of sporadic shocks and adverse symptoms were each associated with reduced physical functioning and mental well-being and increased concerns among ICD recipients, whereas development of adverse symptoms was associated with reduced physical functioning and increased concerns among AAD recipients. CONCLUSIONS: ICD and AAD therapy are associated with similar alterations in self-perceived QoL over 1-year follow-up. Adverse symptoms were associated with reduced self-perceived QoL in both groups, and sporadic shocks were associated with reduced QoL in ICD recipients.

Electroanatomical mapping and radiofrequency catheter ablation of atrial tachycardia originating from the recipient heart with recipient-to-donor atrio-atrial conduction after orthotopic heart transplantation.

Atrial tachycardias resulting from recipient-to-donor atrio-atrial conduction after orthotopic heart transplantation are difficult to treat. We present two patients in whom atrial tachycardia originating in the recipient heart were successfully treated by radiofrequency ablation guided by electroanatomical CARTO mapping system. These cases illustrate that such atrial tachycardia are curable by radiofrequency ablation. Electroanatomical CARTO mapping is useful in identifying the site of origin of the tachycardia and the atrio-atrial conduction sites.

Subcutaneous implantable cardioverter-defibrillator implantation in a patient with a left ventricular assist device already in place.

A 56-year-old man with ischemic cardiomyopathy, a biventricular implantable cardioverter-defibrillator (ICD), and a left ventricular assist device (LVAD) developed a pocket hematoma and infection after an ICD generator change. The biventricular ICD was extracted, and the patient was given a full course of antibiotics. Because he had no indications for bradycardia pacing or biventricular pacing, he was implanted with a subcutaneous ICD under full anticoagulation. There was no interference in sensing or shock delivery from the ICD. The LVAD readings were unchanged during and after the procedure. The patient had an uneventful postoperative course, and both devices were functioning normally. To our knowledge, this is the first reported case of the implantation of a subcutaneous ICD in the presence of an LVAD. This report illustrates that both devices can be implanted successfully in the same patient. In addition, the subcutaneous ICD minimizes the risk of bloodstream infections, which can be fatal in patients who have life-supporting devices such as an LVAD.

Effect of surgical revascularization in patients with coronary artery disease and ventricular tachycardia or fibrillation in the Antiarrhythmics Versus Implantable Defibrillators (AVID) Registry.

BACKGROUND: Patients who undergo resuscitation from near-fatal ventricular arrhythmias often have significant coronary artery disease, and revascularization has been shown to reduce myocardial ischemia and cardiac arrest episodes in this patient population. The magnitude of benefit attributed to revascularization has varied by study, and the use of adjunct implantable cardioverter defibrillator (ICD) therapy has not been well-characterized. METHODS AND RESULTS: The Antiarrhythmics Versus Implantable Defibrillators (AVID) registry included 3117 patients with life-threatening ventricular arrhythmias, of whom 2321 (77%) had documented coronary artery disease and 281 (17%) underwent a coronary artery bypass grafting revascularization procedure after the index event. Patients who underwent a revascularization procedure were younger, had a lower incidence rate of prior myocardial infarction and ventricular arrhythmia, had a higher left ventricular ejection fraction, had less congestive heart failure, and were more likely to have had ventricular fibrillation as the presenting arrhythmia. Patients who underwent revascularization had a better survival rate than did those who did not undergo such a procedure after the index event, and adjustment for differing baseline patient covariates did not alter the relative survival rate benefit. Further, ICD implantation offered a similar survival rate advantage to those patients in the AVID registry with coronary artery disease independent of revascularization. CONCLUSION: Coronary revascularization in the AVID registry patients with coronary artery disease effected a survival rate benefit that was not attributable to differences in baseline patient characteristics. The benefit of ICD on patient survival rate was not attenuated by a revascularization procedure.

Usefulness of pindolol for treatment of neurocardiogenic syncope.

This study evaluated the efficacy of pindolol, a noncardioselective beta blocker with intrinsic sympathetic activity, on neurocardiogenic syncope using a head-up tilt-table test in 66 patients. Pindolol was equally effective in men and women and the 2 age groups (>60 and <60 years) of the study cohort. The earliest benefit was seen