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BACKGROUND In primary prevention (PP) patients the utilization of implantable cardioverter-defibrillators (ICD) and cardiac resynchronization therapy-defibrillators (CRT-D) remains low in many geographies, despite the proven mortality benefit. PURPOSE The objective of this analysis was to examine the mortality benefit in PP patients by guideline-indicated device type: ICD and CRT-D. METHODS Improve sudden cardiac arrest was a prospective, nonrandomized, nonblinded multicenter trial that enrolled patients from regions where ICD utilization is low. PP patient's CRT-D or ICD eligibility was based upon the 2008 ACC/AHA/HRS and 2006 ESC guidelines. Mortality was assessed according to guideline-indicated device type comparing implanted and nonimplanted patients. Cox proportional hazards methods were used, adjusting for known factors affecting mortality risk. RESULTS Among 2618 PP patients followed for a mean of 20.8 ± 10.8 months, 1073 were indicated for a CRT-D, and 1545 were indicated for an ICD. PP CRT-D-indicated patients who received CRT-D therapy had a 58% risk reduction in mortality compared with those without implant (adjusted hazard ratio [HR]: 0.42, 95% confidence interval [CI]: 0.28-0.61, p

Background In patients with symptomatic paroxysmal atrial fibrillation that has not responded to medication, catheter ablation is more effective than antiarrhythmic drug therapy for mainta...

Implantable cardioverter-defibrillators (ICDs) are underutilized in Asia, Latin America, Eastern Europe, the Middle East, and Africa. The Improve SCA Study is the largest prospective study to evaluate the benefit of ICD therapy in underrepresented geographies. This analysis reports the primary objective of the study.The objectives of this study was to determine whether patients with primary prevention (PP) indications with specific risk factors (1.5PP: syncope, nonsustained ventricular tachycardia, premature ventricular contractions10/h, and low ventricular ejection fraction25%) are at a similar risk of life-threatening arrhythmias as patients with secondary prevention (SP) indications and to evaluate all-cause mortality rates in 1.5PP patients with and without devices.A total of 3889 patients were included in the analysis to evaluate ventricular tachycardia or fibrillation therapy and mortality rates. Patients were stratified as SP (n = 1193) and patients with PP indications. The PP cohort was divided into 1.5PP patients (n = 1913) and those without any 1.5PP criteria (n = 783). The decision to undergo ICD implantation was left to the patient and/or physician. The Cox proportional hazards model was used to compute hazard ratios.Patients had predominantly nonischemic cardiomyopathy. The rate of ventricular tachycardia or fibrillation in 1.5PP patients was not equivalent (within 30%) to that in patients with SP indications (hazard ratio 0.47; 95% confidence interval 0.38-0.57) but was higher than that in PP patients without any 1.5PP criteria (hazard ratio 0.67; 95% confidence interval 0.46-0.97) (P = .03). There was a 49% relative risk reduction in all-cause mortality in ICD implanted 1.5PP patients. In addition, the number needed to treat to save 1 life over 3 years was 10.0 in the 1.5PP cohort vs 40.0 in PP patients without any 1.5PP criteria.These data corroborate the mortality benefit of ICD therapy and support extension to a selected PP population from underrepresented geographies.

The development of treatments for heart failure (HF) is challenged by burdensome clinical trials. Reducing the need for extensive data collection and increasing opportunities for data compatibility between trials may improve efficiency and reduce resource burden. The Heart Failure Collaboratory (HFC) multi-stakeholder consortium sought to create a lean case report form (CRF) for use in HF clinical trials evaluating cardiac devices. The HFC convened patients, clinicians, clinical researchers, the U.S. Food and Drug Administration (FDA), payers, industry partners, and statisticians to create a consensus core CRF. Eight recent clinical trial CRFs for the treatment of HF from 6 industry partners were analyzed. All CRF elements were systematically reviewed. Those elements deemed critical for data collection in HF clinical trials were used to construct the final, harmonized CRF. The original CRFs included 176 distinct data items covering demographics, vital signs, physical examination, medical history, laboratory and imaging testing, device therapy, medications, functional and quality of life assessment, and outcome events. The resulting, minimally inclusive CRF device contains 75 baseline data items and 6 events, with separate modular additions that can be used depending on the additional detail required for a particular intervention. The consensus electronic form is now freely available for use in clinical trials. Creation of a core CRF is important to improve clinical trial efficiency in HF device development in the United States. This living document intends to reduce clinical trial administrative burden, increase evidence integrity, and improve comparability of clinical data between trials.

The AdaptivCRT algorithm (aCRT) automatically adjusts atrioventricular delays each minute to achieve ventricular fusion through left ventricular (LV) or biventricular (BiV) pacing. aCRT is associated with superior clinical outcomes compared to standard BiV pacing, but the association of aCRT and subsequent atrial fibrillation (AF) in a real-world population has not been fully evaluated.The purpose of this study was to investigate the incidence of AF ≥48 hours with aCRT vs standard BiV pacing after implant.Patients implanted with a cardiac resynchronization therapy (CRT) device between 2013 and 2016 were studied via the de-identified Medtronic CareLink database. For univariate and multivariate survival analyses, Kaplan-Meier and Cox proportional hazards were used, respectively.Of 37,450 patients (mean age 69.1 ± 11.0 years; 67.9% male) followed for a mean 15.5 ± 9.1 months, 9.7% (n = 3647) developed ≥48 hours of AF. In univariate analysis, compared with standard BiV pacing, the aCRT BiV and LV mode was associated with a 54% lower risk of ≥48 hours of AF (P.001) at 2 years, which persisted after multivariate adjustment (hazard ratio 0.53; 95% confidence interval 0.49-0.57; P.001), even when stratified by sensed PR interval ≤200 ms and200 ms. Higher percentages of LV-only pacing with aCRT were associated with lower incidence of AF (comparing92% LV-only pacing vs 0%-5% LV-only pacing: HR 0.05; 95% CI 0.04-0.06; P.001).In a large, real-world population of CRT recipients, aCRT pacing compared to standard BiV pacing was associated with a lower incidence of AF in patients with both long and short PR intervals. A higher percentage of LV-only pacing during aCRT was also associated with lower incidence of AF.

Objectives This study sought to evaluate the impact of baseline PR interval on cardiac resynchronization therapy (CRT) outcomes in the REVERSE (Resynchronization Reverses Remodeling in Systolic Left Ventricular Dysfunction) study. Background The baseline electrocardiogram has important prognostic value to determine response to CRT. Specifically, QRS duration and morphology are strong predictors of response and outcomes; however, the prognostic importance of the PR interval is less clear. Methods REVERSE was a double-blinded, randomized study of CRT in mild heart failure (HF). The primary endpoint was the analysis of patients in sinus rhythm (n = 582) of the time-to–first HF hospitalization or death during the 2-year randomized period of the trial. In addition, the long-term impact of PR interval was assessed in the cohort actively on CRT during the pre-planned 5-year follow-up. Subjects were analyzed by PR interval, grouped by the median (180 ms) in 20-ms bins or as a continuous variable depending on the analysis performed. Secondary endpoints included the clinical composite score and echocardiographic measures of reverse remodeling. Results During the randomized phase of the study, CRT had similar effectiveness for both PR 180 ms (HR: 0.57) subgroups (interaction p = 0.33). Similar results were observed when PR interval was grouped in 20-ms bins or treated as a continuous variable. In multivariable analysis of the long-term follow-up, left bundle branch block morphology, New York Heart Association functional class, HF etiology, and QRS duration, but not PR interval, predicted HF hospitalization or death. Conclusions Baseline PR interval does not affect clinical outcomes or reverse remodeling with CRT in mild HF. (Resynchronization Reverses Remodeling in Systolic Left Ventricular Dysfunction [REVERSE]; NCT00271154)

Objectives This study sought to determine the effects of abnormal left ventricular (LV) architecture on cardiac remodeling and clinical outcomes in mild heart failure (HF). Background Cardiac resynchronization therapy (CRT) is an established treatment for HF that improves survival in part by favorably remodeling LV architecture. LV shape is a dynamic component of LV architecture on which contractile function depends. Methods Transthoracic 2-dimensional echocardiography was used to quantify changes in LV architecture over 5 years of follow-up of patients with mild HF from the REVERSE study. REVERSE was a prospective study of patients with large hearts (LV end-diastolic dimension ≥55 mm), LV ejection fraction 120 ms randomly assigned to CRT-ON (n = 419) and CRT-OFF (n = 191). CRT-OFF patients were excluded from this analysis. LV dimensions, volumes, mass index, and LV ejection fraction were calculated. LV architecture was assessed using the sphericity index, as follows: (LV end-diastolic volume)/(4/3 × π × r3) × 100%. Results LV architecture improved over time and demonstrated significant associations between LV shape, age, sex, and echocardiography metrics. Changes in LV architecture were strongly correlated with changes in LV end-systolic volume index and LV end-diastolic volume index (both p 15% occurred in more than two-thirds of patients, which indicates considerable reverse remodeling. Conclusions We demonstrated that change in LV architecture in patients with mild HF with CRT is associated with structural and functional remodeling. Mean LV filling pressure was elevated, and the inability to lower it was an additional predictor of HF hospitalization or death. (Resynchronization Reverses Remodeling in Systolic Left Ventricular Dysfunction [REVERSE]; NCT00271154)

Background Studies have shown that magnetic resonance imaging (MRI) conditional pacemakers experience no significant effect from MRI on device function, sensing, or pacing. More recently, similar safety outcomes were demonstrated with MRI conditional defibrillators (implantable cardioverter-defibrillator [ICD]), but the impact on ventricular arrhythmias has not been assessed. Objective The purpose of this study was to assess the effect of MRI on ICD sensing and treatment of ventricular tachyarrhythmias. Methods The Evera MRI Study was a worldwide trial of 156 patients implanted with an ICD designed to be MRI conditional. Device-detected spontaneous and induced ventricular tachycardia/ventricular fibrillation (VT/VF) episodes occurring before and after whole body MRI were evaluated by a blinded episode review committee. Detection delay was computed as the sum of RR intervals of undersensed beats. A ≥5-second delay in detection due to undersensing was prospectively defined as clinically significant. Results Post-MRI, there were 22 polymorphic VT/VF episodes in 21 patients, with 16 of these patients having 17 VT/VF episodes pre-MRI. Therapy was successful for all episodes, with no failures to treat or terminate arrhythmias. The mean detection delay due to undersensing pre- and post-MRI was 0.60 ± 0.59 and 0.33 ± 0.63 seconds, respectively (P = .17). The maximum detection delay was 2.19 seconds pre-MRI and 2.87 seconds post-MRI. Of the 17 pre-MRI episodes, 14 (82%) had some detection delay as compared with 11 of 22 (50%) post-MRI episodes (P = .03); no detection delay was clinically significant. Conclusion Detection and treatment of VT/VF was excellent, with no detection delays or significant impact of MRI observed.

Background The use of systemic prostanoids in severe pulmonary arterial hypertension (PAH) is often limited by patient/physician dissatisfaction with the delivery methods. Complications associated with external pump-delivered continuous therapy include IV catheter-related bloodstream infections and subcutaneous infusion site pain. We therefore investigated a fully implantable intravascular delivery system for treprostinil infusion. Methods A multicenter, prospective, single-arm, clinical trial (DelIVery for Pulmonary Arterial Hypertension) was conducted by using an implantable intravascular delivery system. The implanted pumps were refilled percutaneously at least every 12 weeks. The primary end point was the rate of catheter-related complications using the new model 10642 catheter compared with a predefined objective performance criterion of 2.5 per 1,000 patient-days based on the literature. Results Patients (n = 60) with severe PAH (World Health Organization group 1) receiving a stable dose of IV treprostinil for at least 4 weeks received an implant device and were followed up for 12.1 ± 4.4 months. Six catheter-related complications occurred, corresponding to a complication rate of 0.27 per 1,000 patient-days. The 97.5% upper one-sided confidence bound of 0.59 was less than the predefined criterion of 2.5 per 1,000 patient-days ( P r = 0.91; P P Conclusions The implantable intravascular delivery system delivered treprostinil to patients with PAH with a low rate of catheter-related complications and a high rate of patient satisfaction. Trial Registry ClinicalTrials.gov; No.: NCT01321073; URL: www.clinicaltrials.gov

9 páginas BACKGROUND: Despite available evidence that implantable cardioverter defibrillators (ICDs) reduce all-cause mortality among patients at risk for sudden cardiac death, utilization of ICDs is low especially in developing countries. OBJECTIVE: To summarize reasons for ICD or cardiac resynchronization therapy defibrillator implant refusal by patients at risk for sudden cardiac arrest (Improve SCA) in developing countries. METHODS: Primary prevention (PP) and secondary prevention (SP) patients from countries where ICD use is low were enrolled. PP patients with additional risk factors (syncope, ejection fraction < 25%, nonsustained ventricular tachycardia [NSVT], or frequent premature ventricular complexes) were further categorized as "1.5 PP patients." Candidates who declined implantation were asked for reasons for refusal. Baseline factors that may have influenced the implant decision were examined using logistic regression. RESULTS: Among 3892 patients, the implant refusal rate was 46.5% among PP patients (n = 2700), and 10.3% among SP patients (n = 1192). The most common refusal reason was inability to pay for the device (53.8%), followed by not believing in the benefits of the ICD (19.4%). Among PP ICD candidates, those with no syncope, no NSVT, no premature ventricular contractions, shorter QRS duration, no atrial arrhythmias, and no left bundle branch block were more likely to refuse implant. Among SP candidates, a history of cardiovascular surgery and no sinus node dysfunction were significant predictors of ICD refusal. Additionally, countries had significant differences in patient refusal rates among PP and SP groups. CONCLUSION: Implant refusal among PP patients is high in many countries. Increased reimbursement and better awareness of the benefits of an ICD could increase their utilization.

Background Magnetic resonance imaging (MRI) of patients with conventional implantable cardioverter-defibrillators (ICD) is contraindicated. Objectives This multicenter, randomized trial evaluated safety and efficacy of a novel ICD system specially designed for full-body MRI without restrictions on heart rate or pacing dependency. The primary safety objective was >90% freedom from MRI-related events composite endpoint within 30 days post-MRI. The primary efficacy endpoints were ventricular pacing capture threshold and ventricular sensing amplitude. Methods Subjects received either a single- or dual-chamber ICD. In a 2:1 randomization, subjects either underwent MRI at 1.5-T of the chest, cervical, and head regions to maximize radiofrequency exposure up to 2 W/kg specific absorption rate and gradient field exposure to 200 T/m/s per axis (MRI group, n = 175), or they underwent a 1-h waiting period without MRI (control group, n = 88). A subset of MRI patients underwent ventricular fibrillation induction testing post-MRI to characterize defibrillation function. Results In 42 centers, 275 patients were enrolled (76% male, age 60.4 ± 13.8 years). The safety endpoint was met with 100% freedom from the composite endpoint (p Conclusions This is the first randomized clinical study of an ICD system designed for full-body MRI at 1.5-T. These data support that the system is safe and the MRI scan does not adversely affect electrical performance or efficacy. (Confirmatory Clinical Trial of the Evera MRI System for Conditionally-Safe MRI Access; NCT02117414 )

Background Data from randomized trials have suggested a modest or no effect of conventional cardiac resynchronization therapy (convCRT) on the incidence of atrial fibrillation (AF). AdaptivCRT (aCRT, Medtronic, Mounds View, MN) is a recently described algorithm for synchronized left ventricular (LV) pacing and continuous optimization of cardiac resynchronization therapy (CRT). Objective We compared the long-term effects of aCRT with convCRT pacing on the incidence of AF. Methods The Adaptive CRT trial randomized CRT-defibrillator (CRT-D)–indicated patients (2:1) to receive either aCRT or convCRT pacing. The aCRT algorithm evaluates intrinsic conduction every minute, providing LV-only pacing during normal atrioventricular (AV) conduction and AV and ventriculoventricular timing adjustments during prolonged AV conduction. The primary outcome of this subanalysis was an episode of AF >48 consecutive hours as detected by device diagnostics. Results Over a follow-up period with a mean and standard deviation of 20.2 ± 5.9 months, 8.7% of patients with aCRT and 16.2% with convCRT experienced the primary outcome (hazard ratio [HR] = 0.54; 95% confidence interval [CI] = 0.31–0.93; P = .03). In patients with prolonged baseline AV, the incidence of the primary outcome was 12.8% in patients randomized to aCRT compared with 27.4% in convCRT patients (HR = 0.45; 95% CI=0.24–0.85; P = .01). Also, patients with AF episodes adjudicated as clinical adverse events were less common with aCRT (4.3%) than with convCRT (12.7%) (HR = 0.39; 95% CI=0.19–0.79; P = .01). Conclusion Patients receiving aCRT had a reduced risk of AF compared with those receiving convCRT. Most of the reduction in AF occurred in subgroups with prolonged AV conduction at baseline and with significant left atrial reverse remodeling.

Background Cardiac resynchronization therapy results in improved ejection fraction in patients with heart failure. We sought to determine whether these effects were mediated by changes in contractility, afterload, or volumes. Methods and Results In 610 patients with New York Heart Association class I/ II heart failure from the Re synchronization Reverses Remodeling in Systolic Left Ventricular Dysfunction ( REVERSE ) study, we performed detailed quantitative echocardiography assessment prior to and following cardiac resynchronization therapy. We derived measures of contractility (the slope [end‐systolic elastance] and the volume intercept of the end‐systolic pressure–volume relationship, stroke work, and preload recruitable stroke work), measures of arterial load and ventricular–arterial coupling, and measures of chamber size (volume intercept, end‐systolic and end‐diastolic volumes). At 6 and 12 months, cardiac resynchronization therapy was associated with a reduction in the volume intercept and end‐systolic and end‐diastolic volumes ( P CI 1.04 to 1.63, P =0.02). The volume intercept was associated with mortality (hazard ratio 1.90, 95% CI 1.01 to 3.59, P =0.047) and more modestly with the combined end point of mortality or heart failure hospitalization (hazard ratio 1.48, 95% CI 0.8 to 2.25, P =0.06). In contrast, end‐systolic elastance, stroke work, preload recruitable stroke work, and ventricular–arterial coupling were not associated with any outcomes. Conclusion In patients with NYHA Class I/ II heart failure, cardiac resynchronization therapy exerts favorable changes in left ventricular end‐systolic and end‐diastolic volumes and the volume intercept. The volume intercept may be useful to gain insight into prognosis in heart failure. Clinical Trial Registration URL : https://www.clinicaltrials.gov/ . Unique identifier: NCT 00271154.

Aims This study aims to demonstrate that primary prevention (PP) patients with one or more additional risk factors are at a similar risk of life-threatening ventricular arrhythmias when compared with secondary prevention (SP) patients, and would receive similar benefit from an implantable cardioverter defibrillator (ICD), or cardiac resynchronization therapy-defibrillator (CRT-D) implant. The study evaluates the benefits of therapy for high-risk patients in countries where defibrillation therapy for PP of SCA is underutilized. Methods Enrolment will consist of 4800 ICD-eligible patients from Asia, Latin America, Eastern Europe, the Middle East, and Africa. Upon enrolment, patients will be categorized as SP or PP. Primary prevention patients will be assessed for additional risk factors: syncope/pre-syncope, non-sustained ventricular tachycardia, frequent premature ventricular contractions, and low left ventricular ejection fraction. Those PP patients with one or more risk factors will be categorized as ‘1.5’ patients. Implant of an ICD/CRT-D will be left to the patient and/or physician's discretion. The primary endpoint will compare the appropriate ICD therapy rate between SP and 1.5 patients. The secondary endpoint compares mortality between 1.5 implanted and non-implanted patients. Conclusion The Improve SCA study will investigate a subset of PP patients, believed to be at similar risk of life-threatening ventricular arrhythmias as SP patients. Results may help clinicians identify and refer the highest risk PP patients for ICDs, help local societies expand guidelines to include PP of SCA utilizing ICDs, and provide additional geographical-relevant evidence to allow patients to make an informed decision whether to receive an ICD. Trial registration NCT02099721.

International audience; Background Cardiac resynchronization therapy (CRT) reduces mortality, improves functional status, and induces reverse left ventricular remodeling in selected populations with heart failure (HF). The magnitude of reverse remodeling predicts survival with many HF medical therapies. However, there are few studies assessing the effect of remodeling on long-term survival with CRT. Objective The purpose of this study was to assess the effect of CRT-induced reverse remodeling on long-term survival in patients with mildly symptomatic heart failure. Methods The REsynchronization reVErses Remodeling in Systolic Left vEntricular Dysfunction trial was a multicenter, double-blind, randomized trial of CRT in patients with mild HF. Long-term follow-up of 5 years was preplanned. The present analysis was restricted to the 353 patients who were randomized to the CRT ON group with paired echocardiographic studies at baseline and 6 months postimplantation. The left ventricular end-systolic volume index (LVESVi) was measured in the core laboratory and was an independently powered end point of the REsynchronization reVErses Remodeling in Systolic Left vEntricular Dysfunction trial. Results A 68% reduction in mortality was observed in patients with ≥15% decrease in LVESVi compared to the rest of the patients (P = .0004). Multivariable analysis showed that the change in LVESVi was a strong independent predictor (P = .0002), with a 14% reduction in mortality for every 10% decrease in LVESVi. Other remodeling parameters such as left ventricular end-diastolic volume index and ejection fraction had a similar association with mortality. Conclusion The change in left ventricular end-systolic volume after 6 months of CRT is a strong independent predictor of long-term survival in mild HF