The efficacy and safety of cardiac resynchronization therapy combined with implantable cardioverter defibrillator for heart failure: a meta-analysis of 5674 patients

Paradigm Shifts in Cardiac Pacing: Where Have We Been and What Lies Ahead?

The history of cardiac pacing dates back to the 1930s with externalized pacing and has evolved to incorporate transvenous, multi-lead, or even leadless devices. Annual implantation rates of cardiac implantable electronic devices have increased since the introduction of the implantable system, likely related to expanding indications, and increasing global life expectancy and aging demographics. Here, we summarize the relevant literature on cardiac pacing to demonstrate the enormous impact it has had within the field of cardiology. Further, we look forward to the future of cardiac pacing, including conduction system pacing and leadless pacing strategies.

Innovative Managed Care May Be Related to Improved Prognosis for Acute Myocardial Infarction Survivors

BACKGROUND

Mortality following discharge in myocardial infarction survivors remains high. Therefore, we compared outcomes in myocardial infarction survivors participating and not participating in a novel, nationwide managed care program for myocardial infarction survivors in Poland.

METHODS

We used public databases. We included all patients hospitalized due to acute myocardial infarction in Poland between October 1, 2017 and December 31, 2018. We excluded from the analysis all patients aged <18 years as well as those who died during hospitalization or within 10 days following discharge from hospital. All patients were prospectively followed. The primary end point was defined as death from any cause.

RESULTS

The mean follow-up was 324.8±140.5 days (78 034.1 patient-years; 340.0±131.7 days in those who did not die during the observation). Participation in the managed care program was related to higher odds ratio of participating in cardiac rehabilitation (4.67 [95% CI, 4.44-4.88]), consultation with a cardiologist (7.32 [6.83-7.84]), implantable cardioverter-defibrillator (1.40 [1.22-1.61]), and cardiac resynchronization therapy with cardioverter-defibrillator implantation (1.57 [1.22-2.03]) but lower odds of emergency (0.88 [0.79-0.98]) and nonemergency percutaneous coronary intervention (0.88 [0.83-0.93]) and coronary artery bypass grafting (0.82 [0.71-0.94]) during the follow-up. One-year all-cause mortality was 4.4% among the program participants and 6.0% in matched nonparticipants. The end point consisting of all-cause death, myocardial infarction, or stroke occurred in 10.6% and 12.0% (P<0.01) of participants and nonparticipants respectively, whereas all-cause death or hospitalization for cardiovascular reasons in 42.2% and 47.9% (P<0.001) among participants and nonparticipants, respectively. The difference in outcomes between patients participating and not participating in the managed care program could be explained by improved access to cardiac rehabilitation, cardiac care, and cardiac procedures.

CONCLUSIONS

Managed care following myocardial infarction may be related to improved prognosis as it may facilitate access to cardiac rehabilitation and may provide a higher standard of outpatient cardiac care.

Sex Differences in Physical Activity and Its Association With Cardiac Death and All-Cause Mortality in Patients With Implantable Cardioverter-Defibrillators

Objective: To clarify the impact of sex on physical activity (PA) levels among patients with implantable cardioverter-defibrillators/cardiac resynchronization therapy defibrillators (ICD/CRT-D) and its association with cardiac death and all-cause mortality.

Methods: Overall, data of 820 patients with ICD/CRT-D from the SUMMIT registry were retrospectively analyzed. Baseline PA from 30 to 60 days after device implantation was measured using Biotronik accelerometer sensors. The primary and secondary endpoints were cardiac death and all-cause mortality, respectively.

Results: Baseline PA levels were significantly higher in male patients than in female patients (11.40 ± 5.83% vs. 9.93 ± 5.49%, P = 0.001). Males had higher predictive PA cut-off values for cardiac death (11.16 vs. 7.15%) and all-cause mortality (11.33 vs. 7.17%). During the median follow-up time of 75.7 ± 29.1 months, patients with baseline PA<cut-off values had higher cumulative incidence of cardiac death and all-cause mortality in both males and females. At a PA level between the cut-off values of males and females, males had a higher risk of cardiac death (hazard ratio = 4.952; 95%CI = 1.055-23.245, P = 0.043) and all-cause mortality (hazard ratio = 2.432; 95%CI = 1.095-5.402, P = 0.029).

Conclusions: Males had higher predictive PA cut-off values for cardiac death and all-cause mortality in patients with ICD/CRT-D. Sex should be considered as an important contributing factor when deciding for PA targets.

2017 Comprehensive Update of the Canadian Cardiovascular Society Guidelines for the Management of Heart Failure

Since the inception of the Canadian Cardiovascular Society heart failure (HF) guidelines in 2006, much has changed in the care for patients with HF. Over the past decade, the HF Guidelines Committee has published regular updates. However, because of the major changes that have occurred, the Guidelines Committee believes that a comprehensive reassessment of the HF management recommendations is presently needed, with a view to producing a full and complete set of updated guidelines. The primary and secondary Canadian Cardiovascular Society HF panel members as well as external experts have reviewed clinically relevant literature to provide guidance for the practicing clinician. The 2017 HF guidelines provide updated guidance on the diagnosis and management (self-care, pharmacologic, nonpharmacologic, device, and referral) that should aid in day-to-day decisions for caring for patients with HF. Among specific issues covered are risk scores, the differences in management for HF with preserved vs reduced ejection fraction, exercise and rehabilitation, implantable devices, revascularization, right ventricular dysfunction, anemia, and iron deficiency, cardiorenal syndrome, sleep apnea, cardiomyopathies, HF in pregnancy, cardio-oncology, and myocarditis. We devoted attention to strategies and treatments to prevent HF, to the organization of HF care, comorbidity management, as well as practical issues around the timing of referral and follow-up care. Recognition and treatment of advanced HF is another important aspect of this update, including how to select advanced therapies as well as end of life considerations. Finally, we acknowledge the remaining gaps in evidence that need to be filled by future research.

Avoidance behavior associated with depressive symptoms in patients with implantable cardioverter defibrillators

Objective: Many patients with implantable cardioverter defibrillators experience depressive symptoms. In addition, avoidance behavior is a common problem among patients with implantable cardioverter defibrillators. We examined the association between avoidance behaviors and depressive symptoms in patients with implantable cardioverter defibrillators. Method: We conducted a single-center, cross-sectional study with self-completed questionnaires between May 2010 and March 2011. We measured avoidance behaviors (avoidance of places, avoidance of objects, and avoidance of situations) and depressive symptoms (using the Beck Depression Inventory, Version II) in 119 participants. An avoidance behaviors instrument was developed for this study and we confirmed its internal consistency reliability. Results: Ninety-two (77.3%) patients were aged older than 50 years, and 86 (72.3%) were men. Fifty-one (42.9%) patients reported "avoidance of places", 34 (28.6%) reported "avoidance of objects", and 63 (52.9%) reported "avoidance of activity". Avoidance behavior was associated with increased odds for the presence of depressive symptoms (OR 1.31; 95% CI 1.06-1.62). Conclusions: This was the first study to identify the relationship between avoidance behavior and depressive symptoms among patients with implantable cardioverter defibrillators; however, there are a few methodological limitations.

REmote SUpervision to Decrease HospitaLization RaTe. Unified and integrated platform for data collected from devices manufactured by different companies: Design and rationale of the RESULT study

The number of patients with heart failure implantable cardiac electronic devices (CIEDs) is growing. Hospitalization rate in this group is very high and generates enormous costs. To avoid the need for hospital treatment, optimized monitoring and follow-up is crucial. Remote monitoring (RM) has been widely put into practice in the management of CIEDs but it may be difficult due to the presence of differences in systems provided by device manufacturers and loss of gathered data in case of device reimplantation. Additionally, conclusions derived from studies about usefulness of RM in clinical practice apply to devices coming only from a single company. An integrated monitoring platform allows for more comprehensive data analysis and interpretation. Therefore, the primary objective of Remote Supervision to Decrease Hospitalization Rate (RESULT) study is to evaluate the impact of RM on the clinical status of patients with ICDs or CRT-Ds using an integrated platform. Six hundred consecutive patients with ICDs or CRT-Ds implanted will be prospectively randomized to either a traditional or RM-based follow-up model. The primary clinical endpoint will be a composite of all-cause mortality or hospitalization for cardiovascular reasons within 12 months after randomization. The primary technical endpoint will be to construct and evaluate a unified and integrated platform for the data collected from RM devices manufactured by different companies. This manuscript describes the design and methodology of the prospective, randomized trial designed to determine whether remote monitoring using an integrated platform for different companies is safe, feasible, and efficacious (ClinicalTrials.gov Identifier: NCT02409225).

Predicting Ventricular Arrhythmias in Cardiac Resynchronization Therapy: The Impact of Persistent Electrical Dyssynchrony

BACKGROUND

Although response to cardiac resynchronization therapy (CRT) has been conventionally assessed with left ventricular volume reduction, ventricular arrhythmias (ventricular tachycardia/ventricular fibrillation [VT/VF]) are of critical importance associated with unfavorable outcomes even in the "superresponders" to therapy. We evaluated the predictors of VT/VF and the association of residual dyssynchrony during follow-up.

METHODS

Ninety-five patients receiving CRT were followed-up for 9 ± 3 months. Post-CRT dyssynchrony was defined as a prolonged QRS duration (QRSd) for persistent electrical dyssynchrony (ED), and a Yu index ≥ 33 ms for persistent mechanical dyssynchrony. The first VT/VF episode, including nonsustained VT detected on device interrogation and/or appropriate antitachycardia pacing or shock for VT/VF, were the end points of the study.

RESULTS

Forty-five patients who reached the study end points had significantly lower mean ΔQRS (baseline QRSd - post-CRT QRSd) values than those without VT/VF (-20.8 ± 28.9 ms vs -6.6 ± 30.7 ms, P = 0.022). Both the baseline and post-CRT QRSds, along with the Yu index values, were not different in two groups. Patients with VT/VF were statistically more likely to have persistent ED (38% vs 9%, P = 0.021). Kaplan-Meier curves showed that a negative ΔQRS was associated with a higher incidence of VT/VF during follow-up (P = 0.016). A multivariate Cox model revealed that QRS prolongation was an independent predictor of VT/VF after CRT (P = 0.029).

CONCLUSIONS

A negative ΔQRS, also called persistent ED, is associated with VT/VF. Narrowest possible QRSd might be a reliable goal of both implantation and optimization of devices to reduce arrhythmic events after CRT.

Tailor-made heart simulation predicts the effect of cardiac resynchronization therapy in a canine model of heart failure

Despite extensive studies on clinical indices for the selection of patient candidates for cardiac resynchronization therapy (CRT), approximately 30% of selected patients do not respond to this therapy. Herein, we examined whether CRT simulations based on individualized realistic three-dimensional heart models can predict the therapeutic effect of CRT in a canine model of heart failure with left bundle branch block. In four canine models of failing heart with dyssynchrony, individualized three-dimensional heart models reproducing the electromechanical activity of each animal were created based on the computer tomographic images. CRT simulations were performed for 25 patterns of three ventricular pacing lead positions. Lead positions producing the best and the worst therapeutic effects were selected in each model. The validity of predictions was tested in acute experiments in which hearts were paced from the sites identified by simulations. We found significant correlations between the experimentally observed improvement in ejection fraction (EF) and the predicted improvements in ejection fraction (P<0.01) or the maximum value of the derivative of left ventricular pressure (P<0.01). The optimal lead positions produced better outcomes compared with the worst positioning in all dogs studied, although there were significant variations in responses. Variations in ventricular wall thickness among the dogs may have contributed to these responses. Thus CRT simulations using the individualized three-dimensional heart models can predict acute hemodynamic improvement, and help determine the optimal positions of the pacing lead.

[We implant too many ICD - contra]

Based on prospective population-based cohort studies from the Netherlands approximately 120,000 sudden cardiac deaths (SCD) have to be assumed in 2014 in Germany for persons older than 55 years of age without an implantable cardioverter defibrillator (ICD). In contrast in 2014 only 30,000 ICD were implanted in Germany. Due to the fact that victims of SCD are difficult to predict many more implantations are actually necessary because only approximately one third of the patients use their ICD during battery running time. Also according to the largest ICD study on ischemic cardiomyopathy at least six patients must be treated with an ICD to save one life after 8 years. Guidelines for ICD implantation are based on 12 randomized studies with more than 9000 patients. In 2014 in Germany 94 % of ICD implantations were carried out in accordance with the guidelines. The most important studies for primary prophylaxis of SCD (MADIT 2 and SCD-HeFT) finished recruitment of patients in 2001 but propensity score-matched ICD patients from a large national data base showed identical survival curves in 2005 and 2006. New ICD developments in recent years, such as suppression of inappropriate ICD therapy by improved programming, cardiac resynchronization, and telemonitoring showed promise for current ICD patients of improved survival in comparison to the original randomized patients from the studies, which led to the indications in the guidelines.

Efficacy of implantable cardioconverter defibrillator or cardiac resynchronization therapy compared with combined therapy in survival of patients with heart failure: a meta-analysis

The aim of this meta-analysis was to compare the efficacy of implantable cardioverter defibrillators (ICDs) and cardiac resynchronization therapy (CRT) monotherapies with CRT-ICD combined therapy. Databases were searched to identify studies that compared CRT or ICD alone with CRT-ICD combined therapy in patients with heart failure. The primary outcome was rate of death for any cause, and secondary outcomes included rate of death or hospitalization due to heart failure or any cause. Nine studies with 7679 patients were included. Combined data of ICD and CRT monotherapies found that there was a higher risk of all-cause death (odds ratio [OR] 1.348, P < 0.001) and death or hospitalization from heart failure (OR 1.368, P < 0.001) with monotherapy compared with CRT-ICD combined therapy. No significant difference was observed between mono and combined therapy groups for risk of death or hospitalization from any cause (OR 1.292, P = 0.083). Compared with ICD or CRT monotherapy, CRT-ICD therapy had favorable outcomes regarding all-cause death and the risk of hospitalization or death due to heart failure.

Evaluation of synergistic effects of resynchronization therapy and a β-blocker up-titration strategy based on a predefined patient-management program: the RESTORE study

Prior studies have suggested that a substantial number of eligible heart failure (HF) patients fail to receive β-blocker therapy, or receive it at a suboptimal dose. The aim of this study is to assess the benefit of a predefined management program designed for β-blocker up-titration, evaluating the synergistic effect of cardiac resynchronization therapy (CRT) and β-blockers in a HF population. The Resynchronization Therapy and β-Blocker Titration (RESTORE) study is a prospective, case-control, multicenter cohort study designed to test the hypothesis that a β-blocker up-titration strategy based on a predefined management program maximizes the beneficial effect of CRT, increasing the number of patients reaching the target dose of β-blockers and improving their clinical outcome. All study patients receive an implantable defibrillator for CRT delivery in accordance with current guidelines. Enrollments started in December 2011 and are scheduled to end in December 2014. Approximately 250 consecutive patients will be prospectively enrolled in 6 Italian centers and followed up for 24 months after implantation. The primary endpoint is to demonstrate that CRT may allow titration of β-blockers until the optimal dose, or at least to the effective dose, in patients with HF. This study might provide important information about the benefit of a predefined management program for β-blocker up-titration in patients receiving CRT. Moreover, assessment of health-care utilization and the consumption of resources will allow estimating the potential utility of remote monitoring by means of an automated telemedicine system in facilitating the titration of β-blockers in comparison with a standard in-hospital approach.

Cardiac resynchronisation therapy: pacemaker versus internal cardioverter-defibrillator in patients with impaired left ventricular function

OBJECTIVE

Studies have shown beneficial effects of cardiac resynchronisation therapy (CRT) on mortality among patients with heart failure. However the incremental benefits in survival from CRT with a defibrillator (CRT-D) are unclear. The choice of appropriate device remains unanswered.

METHOD

This is a single-centre observational study in a tertiary cardiac centre. Patients (n=500) implanted with a CRT device with pacing alone (CRT-P) (n=354) and CRT-D (n=146) were followed for at least 2 years (mean 29 months, SD 14 months). The primary end point was all-cause mortality.

RESULTS

A total of 116 deaths (23.2%) were recorded: 88 (24.8%) and 28 (19.2%), in the CRT-P and CRT-D groups, respectively. At 1 year there was a trend favouring CRT-D (HR 0.54, 95% CI 0.27 to 1.07, p=0.08) but this was attenuated by the 2nd year and became insignificant at the end of follow-up (HR 0.76, 95% CI 0.50 to 1.170, p=0.21). There was no survival benefit from having an internal cardioverter-defibrillator if patients were deemed non-responders to CRT. 27% of the CRT-P patients with ischaemic cardiomyopathy met indications for potential internal cardioverter-defibrillator implantation for primary prevention. These were older patients with poorer baseline function in comparison with CRT-D patients with devices for primary prevention. Once these differences were adjusted for, there was no difference in outcome between the groups.

CONCLUSIONS

CRT-D did not offer additional survival advantage over CRT-P at longer-term follow-up, as the clinical benefit of a defibrillator attenuated with time. Further work is needed to define which subset of patients benefit from CRT-D.