The Uncertain Benefit from Implantable Cardioverter-Defibrillators in Nonischemic Cardiomyopathy: How to Guide Clinical Decision-Making?

Life-threatening dysrhythmias remain a significant cause of mortality in patients with nonischemic cardiomyopathy (NICM). Implantable cardioverter-defibrillators (ICD) effectively reduce mortality in patients who have survived a life-threatening arrhythmic event. The evidence for survival benefit of primary prevention ICD for patients with high-risk NICM on guideline-directed medical therapy is not as robust, with efficacy questioned by recent studies. In this review, we summarize the data on the risk of life-threatening arrhythmias in NICM, the recommendations, and the evidence supporting the efficacy of primary prevention ICD, and highlight tools that may improve the identification of patients who could benefit from primary prevention ICD implantation.

Left Atrium Reverse Remodeling in Fusion CRT Pacing: Implications in Cardiac Resynchronization Response and Atrial Fibrillation Incidence

Background: When compared to biventricular pacing, fusion CRT pacing was linked to a decreased incidence of atrial fibrillation (AF). There is a gap in the knowledge regarding exclusive fusion CRT without interference with RV pacing, and all the current data are based on populations of patients with intermittent fusion pacing. Purpose: To assess left atrium remodeling and AF incidence in a real-life population of permanent fusion CRT-P. Methods: Retrospective data were analyzed from a cohort of patients with exclusive fusion CRT-P. Device interrogation, exercise testing, transthoracic echocardiography (TE), and customized medication optimization were all part of the six-monthly individual follow-up. Results: Study population: 73 patients (38 males) with non-ischemic dilated cardiomyopathy aged 63.7 ± 9.3 y.o. Baseline characteristic: QRS 159.8 ± 18.2 ms; EF 27.9 ± 5.1%; mitral regurgitation was severe in 38% of patients, moderate in 47% of patients, and mild in 15% of patients; 43% had type III diastolic dysfunction (DD), 49% had type II DD, 8% had type I DD. Average follow-up was 6.4 years ± 27 months: 93% of patients were responders (including 31% super-responders); EF increased to 40.4 ± 8.5%; mitral regurgitation decreased in 69% of patients; diastolic profile improved in 64% of patients. Paroxysmal and persistent AF incidence was 11%, with only 2% of patients developing permanent AF. Regarding LA volume, statistically significant LA reverse remodeling was observed. Conclusions: Exclusive fusion CRT-P was associated with important LA reverse remodeling and a low incidence of AF.

Clinical characteristics, treatment, trajectories and outcome of patients with dilated cardiomyopathy in a national heart failure registry

BACKGROUND

Available data on the clinical characteristics and prognosis of patients with heart failure (HF) due to dilated cardiomyopathy (DCM) derive mainly from tertiary care centres for cardiomyopathies or from drug trial sub-studies, which may entail a referral bias.

METHODS

From 2008 to 2021, we enrolled in a nationwide HF Registry 1886 DCM patients and 3899 with ischemic heart disease (IHD).

RESULTS

Patients with DCM were younger, more often female, had more commonly recent onset HF, left bundle branch block, and showed higher LV end-diastolic volume and lower LVEF than IHD. With respect to IHD, DCM patients received more often mineralocorticoid receptor antagonists, renin angiotensin system inhibitors and betablockers, the latter more commonly at doses ≥50% of target, and triple guideline-directed medical therapy (GDMT) (adjusted OR 1.411, 95% CI 1.247-1.595, p < .0001). During one-year follow-up, 819 patients (14.2%) died or were hospitalized for HF [187 (9.9%) DCM, 632 (16.2%) IHD]; DCM was associated with lower risk of the combined end-point (adjusted HR 0.745, 95% CI 0.625- 0.888, p = .0011). Among the 1954 patients with 1-year echocardiograms available, 1483 had LVEF≤40% at baseline; of these,166 (30.6%) DCM and 165 (17.5%) IHD improved their LVEF to >40% (p < .0001). DCM aetiology was associated with higher likelihood of LVEF improvement (adjusted OR 1.722, 95% CI 1.328 -2.233, p < .0001).

CONCLUSIONS

DCM patients have a different clinical profile, greater uptake of GDMT and better outcomes than IHD subjects. A comprehensive management approach is needed to further address the risk of unfavorable outcomes in DCM.

Multimodal explainable artificial intelligence identifies patients with non-ischaemic cardiomyopathy at risk of lethal ventricular arrhythmias

The efficacy of an implantable cardioverter-defibrillator (ICD) in patients with a non-ischaemic cardiomyopathy for primary prevention of sudden cardiac death is increasingly debated. We developed a multimodal deep learning model for arrhythmic risk prediction that integrated late gadolinium enhanced (LGE) cardiac magnetic resonance imaging (MRI), electrocardiography (ECG) and clinical data. Short-axis LGE-MRI scans and 12-lead ECGs were retrospectively collected from a cohort of 289 patients prior to ICD implantation, across two tertiary hospitals. A residual variational autoencoder was developed to extract physiological features from LGE-MRI and ECG, and used as inputs for a machine learning model (DEEP RISK) to predict malignant ventricular arrhythmia onset. In the validation cohort, the multimodal DEEP RISK model predicted malignant ventricular arrhythmias with an area under the receiver operating characteristic curve (AUROC) of 0.84 (95% confidence interval (CI) 0.71-0.96), a sensitivity of 0.98 (95% CI 0.75-1.00) and a specificity of 0.73 (95% CI 0.58-0.97). The models trained on individual modalities exhibited lower AUROC values compared to DEEP RISK [MRI branch: 0.80 (95% CI 0.65-0.94), ECG branch: 0.54 (95% CI 0.26-0.82), Clinical branch: 0.64 (95% CI 0.39-0.87)]. These results suggest that a multimodal model achieves high prognostic accuracy in predicting ventricular arrhythmias in a cohort of patients with non-ischaemic systolic heart failure, using data collected prior to ICD implantation.

Rationale and study protocol for the BRITISH randomized trial (Using cardiovascular magnetic resonance identified scar as the benchmark risk indication tool for implantable cardioverter defibrillators in patients with nonischemic cardiomyopathy and severe systolic heart failure)

BACKGROUND

For patients with nonischemic cardiomyopathy (NICM), current guidelines recommend implantable cardioverter defibrillators (ICD) when left ventricular ejection fraction (LVEF) is ≤35%, but the DANISH trial failed to confirm that ICDs reduced all-cause mortality for such patients. Circumstantial evidence suggests that scar on CMR is predictive of sudden and arrhythmic death in this population. The presence of myocardial scar identified by cardiac magnetic resonance imaging (CMR) in patients with NICM and an LVEF ≤35% might identify patients at higher risk of sudden arrhythmic death, for whom an ICD is more likely to reduce all-cause mortality.

METHODS/DESIGN

The BRITISH trial is a prospective, multicenter, randomized controlled trial aiming to enrol 1,252 patients with NICM and an LVEF ≤35%. Patients with a nonischemic scar on CMR will be randomized to either: (1) ICD, with or without cardiac resynchronization (CRT-D), or (2) implantable loop recorder (ILR) or cardiac resynchronization (CRT-P). Patients who are screened for the trial but are found not to be eligible, predominantly due to an absence of scar or those who decline to be randomized will be enrolled in an observational registry. The primary endpoint is all-cause mortality, which we plan to assess at 3 years after the last participant is randomized. Secondary endpoints include clinical outcomes, appropriate and inappropriate device therapies, symptom severity and well-being, device-related complications, and analysis of the primary endpoint by subgroups with other risk markers.

CONCLUSION

The BRITISH trial will assess whether the use of CMR-defined scar to direct ICD implantation in patients with NICM and an LVEF ≤35% is associated with a reduction in mortality.

The Uncertain Benefit from Implantable Cardioverter-Defibrillators in Nonischemic Cardiomyopathy: How to Guide Clinical Decision-Making?

Life-threatening dysrhythmias remain a significant cause of mortality in patients with nonischemic cardiomyopathy (NICM). Implantable cardioverter-defibrillators (ICD) effectively reduce mortality in patients who have survived a life-threatening arrhythmic event. The evidence for survival benefit of primary prevention ICD for patients with high-risk NICM on guideline-directed medical therapy is not as robust, with efficacy questioned by recent studies. In this review, we summarize the data on the risk of life-threatening arrhythmias in NICM, the recommendations, and the evidence supporting the efficacy of primary prevention ICD, and highlight tools that may improve the identification of patients who could benefit from primary prevention ICD implantation.

Ischemic Etiology in Advanced Heart Failure: Insight from the HELP-HF Registry

In patients with advanced heart failure (HF), defined according to the presence of at least one I-NEED-HELP criterium, the updated 2018 Heart Failure Association of the European Society of Cardiology (HFA-ESC) criteria for advanced HF identify a subgroup of patients with HF with worse prognosis, but whether ischemic etiology has a relevant prognostic impact in this very high-risk cohort is unknown. Patients from the HELP-HF registry were stratified according to ischemic etiology and presence of advanced HF based on 2018 HFA-ESC criteria. The primary end point was a composite of all-cause death and HF hospitalization at 1 year. Secondary end points were all-cause death, HF hospitalization, and cardiovascular death at 1 year. Ischemic etiology was a leading cause of HF, in both patients with advanced and nonadvanced HF (46.1% and 42.4%, respectively, p = 0.337). The risk of the primary end point (hazard ratio [HR] 1.31, 95% confidence interval [CI] 1.09 to 1.58) and all-cause mortality (HR 1.37, 95% CI 1.06 to 1.76) was increased in ischemic as compared with nonischemic patients. The risk of the primary end point was consistently higher in ischemic patients in both patients with advanced and nonadvanced HF (advanced HF, HR 1.50 95% CI 1.04 to 2.16; nonadvanced HF, HR 1.25 95% CI 1.01 to 1.56, pinteraction = 0.333), driven by an increased risk of mortality, mainly because of cardiovascular causes. In conclusion, ischemic etiology is the most common cause of HF in patients with at least one I-NEED-HELP marker and with or without advanced HF as defined by the 2018 HFA-ESC definition. In both patients with advanced and not-advanced HF, ischemic etiology carried an increased risk of worse prognosis.

Coronary Artery Disease and Prognosis of Heart Failure with Reduced Ejection Fraction

Our aim was to determine the prognostic impact of coronary artery disease (CAD) on heart failure with reduced ejection fraction (HFrEF) mortality and readmissions. From a prospective multicenter registry that included 1831 patients hospitalized due to heart failure, 583 had a left ventricular ejection fraction of <40%. In total, 266 patients (45.6%) had coronary artery disease as main etiology and 137 (23.5%) had idiopathic dilated cardiomyopathy (DCM), and they are the focus of this study. Significant differences were found in Charlson index (CAD 4.4 ± 2.8, idiopathic DCM 2.9 ± 2.4, p < 0.001), and in the number of previous hospitalizations (1.1 ± 1, 0.8 ± 1.2, respectively, p = 0.015). One-year mortality was similar in the two groups: idiopathic DCM (hazard ratio [HR] = 1), CAD (HR 1.50; 95% CI 0.83-2.70, p = 0.182). Mortality/readmissions were also comparable: CAD (HR 0.96; 95% CI 0.64-1.41, p = 0.81). Patients with idiopathic DCM had a higher probability of receiving a heart transplant than those with CAD (HR 4.6; 95% CI 1.4-13.4, p = 0.012). The prognosis of HFrEF is similar in patients with CAD etiology and in those with idiopathic DCM. Patients with idiopathic DCM were more prone to receive heart transplant.

Cardioverter-defibrillator reduces mortality risk in eligible ischemic and non-ischemic cardiomyopathy patients: Sub-analysis of the multi-center Improve SCA study

BACKGROUND & OBJECTIVE

Despite the burden of sudden cardiac arrest (SCA) worldwide, implantable cardioverter-defibrillators (ICDs) are underutilized, particularly in Asia, Latin America, Eastern Europe, the Middle East, and Africa. The Improve SCA trial demonstrated that primary prevention (PP) patients in these regions benefit from an ICD or a cardiac resynchronization therapy defibrillator (CRT-D). We aimed to compare the rate of device therapy and mortality among ischemic and non-ischemic cardiomyopathy (ICM and NICM) PP patients who met guideline indications for ICD therapy and had an ICD/CRT-D implanted.

METHODS

Improve SCA was a prospective, non-randomized, non-blinded multicenter trial that enrolled patients from the above-mentioned regions. All-cause mortality and device therapy were examined by cardiomyopathy (ICM vs NICM) and implantation status. Cox proportional hazards methods were used, adjusting for factors affecting mortality risk.

RESULTS

Of 1848 PP NICM patients, 1007 (54.5%) received ICD/CRT-D, while 303 of 581 (52.1%) PP ICM patients received an ICD/CRT-D. The all-cause mortality rate at 3 years for NICM patients with and without an ICD/CRT-D was 13.1% and 18.3%, respectively (HR 0.51, 95% CI 0.38-0.68, p < 0.001). Similarly, all-cause mortality at 3 years in ICM patients was 13.8% in those with a device and 19.9% in those without an ICD/CRT-D (HR 0.54, 95% CI 0.33-.0.88, p = 0.011). The time to first device therapy, time to first shock, and time to first antitachycardia pacing (ATP) therapy were not significantly different between groups (p ≥ 0.263).

CONCLUSIONS

In this large data set of patients with a guideline-based PP ICD indication, defibrillator device implantation conferred a significant mortality benefit in both NICM and ICM patients. The rate of appropriate device therapy was also similar in both groups.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov ID: NCT02099721.

Predicting the survival benefit of cardiac resynchronization therapy with defibrillator function for non-ischemic heart failure-Role of the Goldenberg risk score

Aims

Primary prevention of sudden cardiac death (SCD) in non-ischemic heart failure (HF) patients remains a topic of debate at cardiac resynchronization therapy (CRT) implantation requiring individual risk assessment. Using the Goldenberg SCD risk score, we aimed to predict, which non-ischemic HF patients will benefit from the addition of an implantable cardioverter defibrillator (ICD) to CRT at long-term.

Methods

Between 2000 and 2018 non-ischemic HF patients undergoing CRT implantation were collected into our retrospective registry. The Goldenberg risk score (GRS) was calculated by the presence of atrial fibrillation, New York Heat Association (NYHA) class > 2, age > 70 years, blood urea nitrogen > 26 mg/dl and QRS > 120 ms. The primary endpoint was all-cause mortality, heart transplantation or left ventricular assist device implantation.

Results

From 667 patients, 347 (52%) underwent cardiac resynchronization therapy-pacemaker (CRT-P), 320 (48%) cardiac resynchronization therapy-defibrillator (CRT-D) implantations. During the median follow up time of 4.3 years, 306 (46%) patients reached the primary endpoint (CRT-D 37% vs. CRT-P 63%; p < 0.001). CRT-D patients were younger (64 vs. 69 years; p < 0.001), infrequently females (26 vs. 39%; p < 0.001), and had a lower ejection fraction (27 vs. 29%; p < 0.01) compared to CRT-P patients. After GRS calculation, patients were dichotomized by low (< 3) and high (≥ 3) scores. CRT-D patients with low GRS showed a mortality benefit compared to CRT-P (HR 0.68; 95% CI 0.48-0.96; p = 0.03), high-risk patients did not (HR 0.84; 95% CI 0.62-1.13; p = 0.26).

Conclusion

In our non-ischemic cohort, patients with low GRS showed a clear long-term mortality benefit by adding ICD to CRT, however, in high-risk patients no further benefit could be observed.

An implantable cardioverter-defibrillator for primary prevention in non-ischemic cardiomyopathy: A systematic review and meta-analysis

BACKGROUND

Recent data regarding the comparison of implantable cardioverter-defibrillator (ICD) therapy and optimal medical treatment in patients with non-ischemic cardiomyopathy has indicated no mortality benefit as a result of ICD therapy. Although the recommendations for ICD implantation did not change, it is worth noting that these findings significantly affected the daily practice of ICD implantation in Europe.

METHODS

To assess the effect of ICD implantation in comparison to pharmacotherapy in the non- -ischemic cardiomyopathy heart failure population through a systematic review and meta-analysis of the available carefully designed prospective randomized controlled trials. Only prospective randomized controlled trials comparing ICD implantation in primary prevention vs. optimal pharmacological therapy or placebo and reporting mortality results were included in the meta-analysis. The authors have chosen to include the following trials: CAT, AMIOVIRT, DEFINITE, and DANISH.

RESULTS

A meta-analysis of pooled hazard ratios (HR) from all trials conducted on a total of 1789 patients found that ICD therapy decreased all-cause mortality in comparison to optimal pharmacological treatment, with a HR of 0.48 (95% confidence interval [CI] 0.67-1.01); p = 0.06. The data from the AMIOVIRT, DANISH, and DEFINITE trials, with a total of 1677 participants, showed a significant reduction of sudden cardiac deaths as a result of ICD implantation, with a HR of 0.48 (95% CI 0.31-0.67); p < 0.001.

CONCLUSIONS

In comparison with optimal medical treatment, ICD implantation in patients with heart failure improves the long-term prognosis in terms of sudden cardiac death, with a strong tendency towards all-cause mortality reduction.

Spanish implantable cardioverter-defibrillator registry. 18th official report of the Heart Rhythm Association of the Spanish Society of Cardiology (2021)

INTRODUCTION AND OBJECTIVES

This article presents the data corresponding to implantable cardioverter-defibrillator (ICD) implantations in Spain in 2021.

METHODS

The data were drawn from implanting centers, which voluntarily completed a data collection sheet during the procedure.

RESULTS

In 2021, 7496 implant data sheets were received, compared with 7743 reported by Eucomed (European Confederation of Medical Suppliers Associations), indicating that data were collected from 96.8% of the devices implanted in Spain. Data completion ranged from 99.9% for "name of implanting hospital" to 8.9% for "implanting hospital". In 2021, 199 hospitals participated in the registry, exceeding the figures of previous years, with around 170 participating hospitals. The total rate of registered implants was 158/million inhabitants (163 according to Eucomed), making 2021 the year with the highest activity. However, the registry continues to show significant differences among the various autonomous communities and the lowest implantation rate of all the European countries participating in Eucomed.

CONCLUSIONS

The Spanish implantable cardioverter-defibrillator registry for 2021 recorded an increase in the number of ICD implantations, reflecting the recovery of hospital activity after the initial impact of the COVID-19 pandemic in 2020. Although the total number of implants has increased in Spain, figures are still much lower than the European Union average, with differences persisting among Spanish autonomous communities.

The development of a decision aid for shared decision making in the Dutch implantable cardioverter defibrillator patient population: A novel approach to patient education

Background

Counseling of Implantable Cardioverter-defibrillator (ICD) patients with regard to individual risks and benefits is challenging. An evidence-based decision aid tailored to the needs of Dutch ICD patients is not yet available. The objective of this pilot project was to structurally evaluate the current clinical practice in The Netherlands and the ICD patient experience, in order to develop an online decision aid to facilitate shared decision making in ICD procedures.

Methods

Between June 2016 and December 2017, a Dutch web-based decision aid was developed according to the Patient Decision Aid Standards (IPDAS) using the RAND-UCLA/multi-stepped Delphi model. Development process consisted of 5 stages in which the Dutch clinical practice was reviewed (stage 1), patients' needs and their history of decision making was structurally assessed (stages 2A and B) and a modified Delphi consensus process was performed with an expert panel consisting of representatives from different medical fields (stage 3). Results from stages 1-3 were used to design and structure the content of an online-based decision aid (stage 4) which was finally evaluated in a usability testing by patients in stage 5.

Results and conclusion

This study describes the evidence-based approach to the development of the Dutch ICD decision aid. In our population, levels of shared decision-making experience were low. The ICD decision aid was structurally developed for the Dutch ICD patient population. Our upcoming multicenter stepped wedge clustered randomized trial will further evaluate the ICD decision aid in clinical practice.

Fifteen-Year Differences in Indications for Cardiac Resynchronization Therapy in International Guidelines-Insights from the Heart Failure Registries of the European Society of Cardiology

Cardiac resynchronization therapy (CRT) applied to selected patients with heart failure (HF) improves their prognosis. In recent years, eligibility criteria for CRT have regularly changed. This study aimed to investigate the changes in eligibility of real-life HF patients for CRT over the past fifteen years. We reviewed European and North American guidelines from this period and applied them to HF patients from the ESC-HF Pilot and ESC-Long-Term Registries. Taking into consideration the criteria assessed in this study (including all classes of recommendations i.e., class I, IIa and IIb, as well as patients with AF and SR), the 2013 (ESC) guidelines would have qualified the most patients for CRT (266, 18.3%), while the 2015 (ESC) guidelines would have qualified the least (115, 7.9%; p-value for differences between all analyzed papers <0.0001). There were only 26 patients (1.8%) who would be eligible for CRT using the class I recommendations across all of the guidelines. These results demonstrate the variability in recommendations for CRT over the years. Moreover, this data indicates underuse of this form of pacing in HF and highlights the need for more studies in order to improve the outcomes of HF patients and further personalize their management.

Ischemic Cardiomyopathy versus Non-Ischemic Dilated Cardiomyopathy in Patients with Reduced Ejection Fraction- Clinical Characteristics and Prognosis Depending on Heart Failure Etiology (Data from European Society of Cardiology Heart Failure Registries)

Personalized management involving heart failure (HF) etiology is crucial for better prognoses for HF patients. This study aimed to compare patients with ischemic cardiomyopathy (ICM) and patients with non-ischemic dilated cardiomyopathy (NIDCM) in terms of baseline characteristics and prognosis. We assessed 895 patients with HF with reduced left ventricular ejection fraction participating in the Polish part of the European Society of Cardiology (ESC)-HF registries. ICM was present in 583 patients (65%), NIDCM in 312 patients (35%). The ICM patients were older (p < 0.001) and had more comorbidities. The NIDCM patients more frequently had atrial fibrillation (p = 0.04) and lower LVEF (p = 0.01); therefore, they were treated more often with anticoagulants (p = 0.01) and digitalis (p < 0.001). The NIDCM patients were prescribed aldosterone antagonists more often (p = 0.01). There were no other differences as regards the use of HF guideline-recommended medications, implantable cardioverter defibrillators or cardiac resynchronization therapy. The ICM patients were more likely to be treated with statins (p < 0.001) and antiplatelet agents (p < 0.001). All-cause death, as well as all-cause death and readmissions for HF at 12 months, occurred more often in the ICM group compared with the NIDCM group (15.9% vs. 10%, p = 0.016; and 40.9% vs. 28.6%, p = 0.00089, respectively). ICM etiology was an independent predictor of the composite endpoint in the total cohort (p = 0.003). The ICM patients were older and had more comorbidities, whereas the NIDCM patients had lower LVEF. One-year prognosis was worse in the ICM patients than in the NIDCM patients. ICM etiology was independently associated with a worse one-year outcome.

Long-term Follow-up of the The Danish Study to Assess the Efficacy of ICDs in Patients with Non-ischemic Systolic Heart Failure on Mortality (DANISH)

Background: The Danish Study to Assess the Efficacy of Implantable Cardioverter-Defibrillators (ICDs) in Patients with Non-ischemic Systolic Heart Failure on Mortality (DANISH) found that primary-prevention ICD implantation was not associated with an overall survival benefit in patients with non-ischemic systolic heart failure during a median follow-up of 5.6 years, though there was a beneficial effect on all-cause mortality in patients ≤70 years. This study presents an additional four years of follow-up data from DANISH. Methods: In DANISH, 556 patients with non-ischemic systolic heart failure were randomized to receive an ICD and 560 to receive usual clinical care and followed until June 30, 2016. In this long-term follow-up study, patients were followed until May 18, 2020. Analyses were conducted for the overall population and according to age (≤70 and >70 years). Results: During a median follow-up of 9.5 years (25^th-75^th percentile, 7.9-10.9 years), 208/556 patients (37%) in the ICD group and 226/560 patients (40%) in the control group died. Compared with the control group, the ICD group did not have significantly lower all-cause mortality (HR 0.89 [95%CI,0.74-1.08]; P=0.24). In patients ≤70 years (n=829), all-cause mortality was lower in the ICD group than the control group (117/389 [30%] vs 158/440 [36%]; HR 0.78 [95%CI,0.61-0.99]; P=0.04), whereas in patients >70 years (n=287), all-cause mortality was not significantly different between the ICD and control group (91/167 [54%] vs 68/120 [57%]; HR 0.92 [95%CI,0.67-1.28]; P=0.75). Cardiovascular death showed similar trends (overall, 147/556 [26%] vs 164/560 [29%], HR 0.87 [95%CI,0,70-1.09], P=0.20; ≤70 years, 87/389 [22%] vs 122/440 [28%], HR 0.75 [95%CI,0.57-0.98], P=0.04; >70 years, 60/167 [36%] vs 42/120 [35%], HR 0.97 [95%CI,0.65-1.45], P=0.91). The ICD group had a significantly lower incidence of sudden cardiovascular death in the overall population (35/556 [6%] vs 57/560 [10%]; HR 0.60 [95%CI,0.40-0.92]; P=0.02) and in patients ≤70 years (19/389 [5%] vs 49/440 [11%]; HR 0.42 [95%CI,0.24-0.71]; P=0.0008), but not in patients >70 years (16/167 [10%] vs 8/120 [7%]; HR 1.34 [95%CI,0.56-3.19]; P=0.39). Conclusions: During a median follow-up of 9.5 years, ICD implantation did not provide an overall survival benefit in patients with non-ischemic systolic heart failure. In patients ≤70 years, ICD implantation was associated with a lower incidence of all-cause mortality, cardiovascular death, and sudden cardiovascular death. Clinical Trial Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT00542945.

Spanish Implantable Cardioverter-defibrillator Registry. 17th Official Report of the Heart Rhythm Association of the Spanish Society of Cardiology (2020)

INTRODUCTION AND OBJECTIVES

We present the data corresponding to implantable cardioverter-defibrillator (ICD) implants in Spain in 2020.

METHODS

The data in this registry were drawn from implantation centers, which voluntarily completed a data collection sheet.

RESULTS

In 2020, 7056 implant sheets were received compared with 7106 reported by Eucomed (European Confederation of Medical Suppliers Associations), indicating that data were collected from 99% of the devices implanted in Spain. Completion of the implant sheet ranged from 99.8% for the field "name of the implanting hospital" to 2.6% for the variable "referral hospital". A total of 173 hospitals performed ICD implants and participated in the registry, which is a similar figure to that in 2019 (n=172). The total rate of registered implants was 149/million inhabitants (150 according to Eucomed), revealing a slight reduction in implants in Spain in 2020 as a result of the impact of the COVID-19 pandemic. This reduction was uneven among the autonomous communities.

CONCLUSIONS

The Spanish Implantable Cardioverter Defibrillator Registry for 2020 shows an improvement in the rate of implants reported and a reduction in the number of ICD implants, which likely reflects the decrease in hospital activity not related to the treatment of COVID-19 infection. Similar to previous years, the total number of implants in Spain is still much lower than the average for the European Union, with an increase in the differences between Spanish autonomous communities.

Strain echocardiography improves prediction of arrhythmic events in ischemic and non-ischemic dilated cardiomyopathy

BACKGROUND

Recent evidence suggests that an implantable cardioverter defibrillator (ICD) in non-ischemic cardiomyopathy (NICM) may not offer mortality benefit. We aimed to investigate if etiology of heart failure and strain echocardiography can improve risk stratification of life threatening ventricular arrhythmia (VA) in heart failure patients.

METHODS

This prospective multi-center follow-up study consecutively included NICM and ischemic cardiomyopathy (ICM) patients with left ventricular ejection fraction (LVEF) <40%. We assessed LVEF, global longitudinal strain (GLS) and mechanical dispersion (MD) by echocardiography. Ventricular arrhythmia was defined as sustained ventricular tachycardia, sudden cardiac death or appropriate shock from an ICD.

RESULTS

We included 290 patients (67 ± 13 years old, 74% males, 207(71%) ICM). During 22 ± 12 months follow up, VA occurred in 32(11%) patients. MD and GLS were both markers of VA in patients with ICM and NICM, whereas LVEF was not (p = 0.14). MD independently predicted VA (HR: 1.19; 95% CI 1.08-1.32, p = 0.001), with excellent arrhythmia free survival in patients with MD <70 ms (Log rank p < 0.001). Patients with NICM and MD <70 ms had the lowest VA incidence with an event rate of 3%/year, while patients with ICM and MD >70 ms had highest VA incidence with an event rate of 16%/year.

CONCLUSION

Patients with NICM and normal MD had low arrhythmic event rate, comparable to the general population. Patients with ICM and MD >70 ms had the highest risk of VA. Combining heart failure etiology and strain echocardiography may classify heart failure patients in low, intermediate and high risk of VA and thereby aid ICD decision strategies.

The mortality analysis of primary prevention patients receiving a cardiac resynchronization defibrillator (CRT-D) or implantable cardioverter-defibrillator (ICD) according to guideline indications in the improve SCA study

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 < .0001). PP patients with an ICD indication had a 43% risk reduction in mortality with an ICD implant compared with no implant (adjusted HR: 0.57, 95% CI: 0.41-0.81, p = .002).

CONCLUSIONS

This analysis confirms the mortality benefit of adherence to guideline-indicated implantable defibrillation therapy for PP patients in geographies where ICD therapy was underutilized. These results affirm that medical practice should follow clinical guidelines when choosing therapy for PP patients who meet the respective defibrillator device implant indication.

Contemporary ICD Use in Patients with Heart Failure

Despite constant breakthroughs in heart failure (HF) therapy, the population of HF patients resume to grow and is linked to increased mortality and morbidity. Ventricular arrhythmias (VA) are one of the leading causes of mortality in HF subjects. Implantable cardioverter-defibrillators (ICDs) are currently the gold standard in treatment, preventing arrhythmic sudden cardiac death (SCD) episodes. However, the death rates related to HF remain elevated, as not all HF subjects benefit equally. Cardiac resynchronization therapy (CRT) has emerged as a novel approach for HF patients. These devices have been thoroughly investigated in major randomized controlled studies but continue to be underutilized in various countries. This review discusses the use of ICD in HF populations on top of treatments.

Improved Risk Stratification for Ventricular Arrhythmias and Sudden Death in Patients With Nonischemic Dilated Cardiomyopathy

BACKGROUND

Risk stratification for ventricular arrhythmias (VA) and sudden death in nonischemic dilated cardiomyopathy (DCM) remains suboptimal.

OBJECTIVES

The goal of this study was to provide an improved risk stratification algorithm for VA and sudden death in DCM.

METHODS

This was a retrospective cohort study of consecutive patients with DCM who underwent cardiac magnetic resonance with late gadolinium enhancement (LGE) at 2 tertiary referral centers. The combined arrhythmic endpoint included appropriate implantable cardioverter-defibrillator therapies, sustained ventricular tachycardia, resuscitated cardiac arrest, and sudden death.

RESULTS

In 1,165 patients with a median follow-up of 36 months, LGE was an independent and strong predictor of the arrhythmic endpoint (hazard ratio: 9.7; p < 0.001). This association was consistent across all strata of left ventricular ejection fraction (LVEF). Epicardial LGE, transmural LGE, and combined septal and free-wall LGE were all associated with heightened risk. A simple algorithm combining LGE and 3 LVEF strata (i.e., ≤20%, 21% to 35%, >35%) was significantly superior to LVEF with the 35% cutoff (Harrell's C statistic: 0.8 vs. 0.69; area under the curve: 0.82 vs. 0.7; p < 0.001) and reclassified the arrhythmic risk of 34% of patients with DCM. LGE-negative patients with LVEF 21% to 35% had low risk (annual event rate 0.7%), whereas those with high-risk LGE distributions and LVEF >35% had significantly higher risk (annual event rate 3%; p = 0.007).

CONCLUSIONS

In a large cohort of patients with DCM, LGE was found to be a significant, consistent, and strong predictor of VA or sudden death. Specific high-risk LGE distributions were identified. A new clinical algorithm integrating LGE and LVEF significantly improved the risk stratification for VA and sudden death, with relevant implications for implantable cardioverter-defibrillator allocation.

The Necessity of an ICD-Therapy in Patients with Indications for Primary Prevention of Sudden Cardiac Death. One Center Experience

Aim      Analysis of responses of cardioverter-defibrillators implanted in patients with cardiomyopathies (CMPs) of various origins and a high risk of sudden cardiac death (SCD) to assess the effectiveness of a modern strategy for primary prevention of SCD.Material and methods  In the Federal Center for High Medical Technologies in Kaliningrad from 2014 through 2018, implantable cardioverter-defibrillators (ICD) and cardiac resynchronization therapy defibrillators (CRT-D) were installed in 165 patients. Major indications for device implantation in these patients included left ventricular (LV) systolic dysfunction with ejection fraction (EF) ≤35 %; chronic heart failure (CHF) consistent with the New York Heart Association (NYHA) functional class (FC) II-III (IV for CRT-D) without previous episodes of life-threatening ventricular arrhythmias, circulatory arrest and resuscitation, which was consistent with the current international strategy for primary prevention of SCD. The study patients were divided into two groups based on the CMP origin; group 1 included 101 (61.2 %) patients with CMP of ischemic origin (ICMP) and group 2 consisted of 64 (38.8 %) patients with CMP of non-ischemic origin (NCMP). Information about arrhythmic episodes and device activation was retrieved from the device electronic memory during visits of patients to the clinic and was also transmitted to the clinic by a remote monitoring system. This information was studied and evaluated for the validity and effectiveness of the device triggering. If necessary, the parameters of detection and treatment were adjusted taking into account the obtained information. Information was analyzed and statistically processed with the SPSS Statistics 20.0 software.Results The patients were followed up for 28.3 ± 15.6 months, during which the devices delivered therapy to 55 (33.3%) patients of the entire group. In the ICMP group, the devices were activated in 44 (26.7 %) patients and in the NCMP group, the devices were activated in 11 (6.7 %) patients. In group 1 (ICMP), appropriate triggering was observed in 33 (20.0%) patients and inappropriate triggering was observed in 11 (6.7%) patients. In group 2 (NCMP), appropriate triggering was observed in 2 (1.2 %) patients and inappropriate triggering was observed in 9 (5.5 %) patients. The main cause of inappropriate triggering was atrial fibrillation (AF). 17 (10.3 %) patients with ICMP had sustained ventricular tachycardia (VT), which did not reach the detection frequency for ICD therapy; these VTs were only detected by devices and terminated spontaneously. Intragroup differences in the number of patients who received an appropriate treatment were statistically significant: 33 (32.6 %) in the ICMP group vs. 2 (3.1 %) in the NCMP group (р&lt;0.006). Differences in the number of patients who received an inappropriate treatment were not statistically significant although their number was greater in the NCMP group than in the ICMP group (9 (14.1 %) vs. 11 (10.9 %), р&gt;0.05).Conclusion      A higher requirement for the ICD treatment was revealed in patients with ICMP compared to patients with NCMP. The low demand for the ICD treatment in patients with NCMP and the more frequent inappropriate actuation of the devices in this patient group due to AF allow a conclusion that the criteria for primary prevention of SCD with ICD (LV EF ≤35% and clinically significant CHF) are not equally effective indications for ICD implantation in patients with ICMP and NCMP. It can be assumed that life-threatening ventricular arrhythmias are evident in patients with NCMP before the development of hemodynamically significant LV dysfunction and CHF, which warrants further research in this direction.

Cardiac Resynchronization and Defibrillator Therapy (CRT-D) or CRT Alone (CRT-P) in patients with dilated cardiomyopathy and heart failure without late gadolinium enhancement (LGE) cardiac magnetic resonance imaging (CMRI) high-risk markers - CRT-REALITY study - Study design and rationale

BACKGROUND

Primary preventive implantation of implantable defibrillator (ICD) is according to current guidelines indicated in patients with heart failure NYHA (New York Heart Association) class II/III and LVEF <35%. Thanks to advances in heart failure pharmacotherapy, a decrease in mortality could render a benefit of ICD insufficient to justify its implantation in some patients.

METHODS

Study design: multicenter, prospective, randomized, controlled trial evaluating the benefit of implantation of Cardiac Resynchronization and Defibrillator Therapy (CRT-D) or CRT Alone (CRT-P) in non-ischemic patients with reduced left ventricle ejection fraction (LVEF) and optimal pharmacotherapy without significant mid-wall myocardial fibrosis detected by cardiac magnetic resonance (CMR). The primary end-point: Re-hospitalization for heart failure, ventricular tachycardia, major adverse cardiac events (MACE). The secondary end-points: Sudden cardiac death, cardiovascular death, resuscitated cardiac arrest or sustained ventricular tachycardia, device-related complications, and change in quality of life. Course of the study: After a pharmacotherapy is optimized and significant mid-wall myocardial fibrosis excluded, patients will be randomized 1:1 to CRT-P or CRT-D implantation.

DISCUSSION

If our hypothesis is confirmed, this could provide evidence for the management of these patients with a significant impact on common daily praxis and health care expenditures.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT04139460.

Arrhythmic event prediction in patients with heart failure and reduced ejection fraction

AIMS

Implantable cardioverter defibrillator (ICD) is an effective treatment to reduce mortality in patients with symptomatic heart failure and left ventricular ejection fraction (LVEF) 35% or less. LVEF presents a low sensitivity for predicting arrhythmic events. Aim of this study was to identify predictors of sustained ventricular arrhythmias (SVAs), overall and according to the cause of heart failure.

METHODS

Single-center, retrospective, cohort study of 193 patients (51 nonischemic and 142 ischemic) with chronic heart failure and LVEF less than 35% who had received ICD for primary prevention of sudden cardiac death. We collected clinical data, echocardiographic parameters and SVAs detected by the ICD.

RESULTS

During a median follow-up of 1440 days, 32 (16.2%) patients had SVAs. SVAs incidence was similar in patients with nonischemic (15.6%) and ischemic cause of heart failure (16.9%). Hypertension, diabetes, chronic renal failure, atrial fibrillation, chronic obstructive pulmonary disease, New York Heart Association class at least III were predictors at univariate analysis of SVAs. A clinical score, assigning one point to each of these variables, was associated with a significantly increased risk of SVAs [odds ratio for each point increase = 1.92, 95% confidence interval 1.40-2.65, P < 0.0001, area under the curve (AUC) 0.73], with 72% sensitivity and 60% specificity for a cutoff at least three and remained significant in nonischemic (AUC 0.84) and ischemic (AUC 0.68) patients.

CONCLUSION

Our study shows the benefit of ICD implantation in primary prevention and its independency of cause. A simple clinical score, based on comorbidities, identifies patients with more benefits from ICD implantation.

Spanish Implantable Cardioverter-defibrillator Registry. 16th Official Report of the Heart Rhythm Association of the Spanish Society of Cardiology (2019)

INTRODUCTION AND OBJECTIVES

We present the data corresponding to implantable cardioverter-defibrillator (ICD) implants in Spain in 2019.

METHODS

The data were drawn from implant centers voluntarily completing a data collection sheet.

RESULTS

In 2019, 7003 implant sheets were received compared with the 7389 reported by Eucomed (European Confederation of Medical Suppliers Associations), indicating that data were collected from 94.8% of the devices implanted in Spain. Completion of the implant sheet ranged from 99.7% in the field "name of the implanting hospital" to 17.8% in the variable "reference hospital". In 2019, 172 hospitals performed ICD implants and participated in the registry, a figure similar to that of 2018 (173). The total rate of registered implants was 149/million inhabitants; the rate reported by Eucomed was 157. Although this value represents the highest in the historical series, it is still much lower than the average rate of ICD implants in Europe (303).

CONCLUSIONS

The Spanish Implantable Cardioverter-Defibrillator Registry for 2019 reflects a growth in the number of ICD implants and is the year with the highest number of ICD implants in Spain. However, similar to previous years, the total number of implants in Spain is still much lower than the European Union average, with substantial differences between Spanish autonomous communities.

Comparison of Mortality and Readmission in Non-Ischemic Versus Ischemic Cardiomyopathy After Implantable Cardioverter-Defibrillator Implantation

Data is lacking on the contemporary risk of death and readmission following implantable cardioverter-defibrillator (ICD) implantation in patients with non-ischemic cardiomyopathies (NICM) compared with ischemic cardiomyopathies (ICM) in a large nationally representative cohort. We performed a retrospective cohort study using the National Cardiovascular Data Registry ICD Registry linked with Medicare claims from April 1, 2010 to December 31, 2013. We established a cohort of NICM and ICM patients with a left ventricular ejection fraction ≤35% who received a de novo, primary prevention ICD. We compared mortality and readmission using Kaplan-Meier curves and Cox proportional hazard regressions models. We also evaluated temporal trends in mortality. In 31,044 NICM and 68,458 ICM patients with a median follow up of 2.4 years, 1-year mortality was significantly higher in ICM patients (12.3%) compared with NICM (7.9%, p < 0.001). The higher mortality in ICM patients remained significant after adjustment for covariates (hazard ratio [HR] 1.40; 95% confidence interval [CI] 1.36 to 1.45), and was consistent in subgroup analyses. These findings were consistent across the duration of the study. ICM patients were also significantly more likely to be readmitted for all causes (adjusted HR 1.15, CI 1.12 to 1.18) and for heart failure (adjusted HR 1.25, CI 1.21 to 1.31). In conclusion, the risks of mortality and hospital readmission after primary prevention ICD implantation were significantly higher in patients with ICM compared with NICM which was consistent across all patient subgroups tested and over the duration of the study.

Cause-specific death and risk factors of one-year mortality after implantable cardioverter-defibrillator implantation: a nationwide study

AIMS

Current treatment guidelines recommend implantable cardioverter-defibrillators (ICDs) in eligible patients with an estimated survival beyond one year. There is still an unmet need to identify patients who are unlikely to benefit from an ICD.We determined cause-specific one-year mortality after ICD implantation and identified associated risk factors.

METHODS AND RESULTS

Using Danish nationwide registries (2000-2017), we identified 14,516 patients undergoing first-time ICD implantation for primary or secondary prevention. Risk factors associated with one-year mortality were evaluated using multivariable logistic regression. The median age was 66 years, 81.3% were male, and 50.3% received an ICD for secondary prevention. The one-year mortality rate was 4.8% (694/14,516). ICD recipients who died within one year were older and more comorbid compared to those who survived (72 vs. 66 years, p < 0.001). Risk factors associated with increased one-year mortality included dialysis (OR:3.26, CI:2.37-4.49), chronic renal disease (OR:2.14, CI:1.66-2.76), cancer (OR:1.51, CI:1.15-1.99), age 70-79 years (OR:1.65, CI:1.36-2.01), and age ≥80 years (OR:2.84, CI:2.15-3.77). The one-year mortality rates for the specific risk factors were: dialysis (13.8%), chronic renal disease (13.1%), cancer (8.5%), age 70-79 years (6.9%), and age ≥80 years (11.0%). Overall, the most common causes of mortality were related to cardiovascular diseases (62.5%), cancer (10.1%), and endocrine disorders (5.0%). However, the most common cause of death among patients with cancer was cancer-related (45.7%).

CONCLUSION

Among ICD recipients, mortality rates were low and could be indicative of relevant patient selection. Important risk factors of increased one-year mortality included dialysis, chronic renal disease, cancer, and advanced age.

Ventricular arrhythmias and ARNI: is it time to reappraise their management in the light of new evidence?

The remarkable scientific progress in the treatment of patients with heart failure (HF) and reduced ejection fraction (HFrEF) has more than halved the risk of sudden cardiac death (SCD) in this setting. However, SCD remains one of the major causes of death in this patient population. Beyond the acknowledged role of beta blockers and inhibitors of the renin-angiotensin-aldosterone system (RAAS), a new class of drugs, the angiotensin receptor neprilysin inhibitors (ARNI), proved to reduce the overall cardiovascular mortality and, more specifically, the risk of SCD in HFrEF patients. The mechanism by which ARNI may reduce the mortality connected with harmful ventricular arrhythmias is not utterly clear. A variety of direct and indirect mechanisms have been suggested, but a favorable left ventricular reverse remodeling seems to play a key role in this setting. Furthermore, the well-known protective effect of implantable cardioverter-defibrillator (ICD) has been debated in HFrEF patients with non-ischemic cardiomyopathy (NICM) arguing against the role of primary prevention ICD in this setting, particularly when ARNI therapy is considered. The purpose of this review was to provide insights into the SCD mechanisms involved in HFrEF patients together with the current role of electrical therapies and new drug agents in this setting. Graphical abstract.

Spanish Implantable Cardioverter-defibrillator Registry. 15th Official Report of the Spanish Society of Cardiology Electrophysiology and Arrhythmias Section (2018)

INTRODUCTION AND OBJECTIVES

This article presents the data corresponding to automated implantable cardioverter-defibrillator (ICD) implants in Spain reported to the Spanish Registry in 2018.

METHODS

The data in this registry include both primary implants and generator replacements and were gathered from a data collection sheet voluntarily completed by implantation centers.

RESULTS

In 2018, 6421 implant sheets were received compared with 7077 reported by Eucomed (European Confederation of Medical Suppliers Associations). This represents data on 90.7% of the devices implanted in Spain. Compliance ranged between 99.6% for the field "name of the implanting hospital" and 12.4% for "population of residence". A total of 173 hospitals reported their data to the registry, representing a slight decrease compared with hospitals participating in 2017 (n=181).

CONCLUSIONS

After the reduction in ICD implants in 2017, the number of implants increased in 2018, with the highest number of ICDs implanted in Spain. The total number of implants remains much lower than the European Union average, with substantial differences between autonomous communities.

Devices in Heart Failure Patients-Who Benefits From ICD and CRT?

Despite advances in heart failure treatment, this condition remains a relevant medical issue and is associated with a high morbidity and mortality. The cause of death in patients suffering from heart failure is not only a result of hemodynamic failure, but can also be due to ventricular arrhythmias. Implantable cardioverter defibrillators (ICDs) are these days the only tool to significantly reduce arrhythmic sudden death; but not all patients benefit to the same extend. In addition, cardiac resynchronization therapy (CRT) is another tool which is used in patients suffering from heart fialure. Even though both devices have been investigated in large randomized trials, both ICD and CRT remain underutilized in many countries. This brief review focuses on various aspects in this regard including a short overview on upcoming device novelties in the near future.

Could autonomic nervous system parameters be still helpful in identifying patients with left ventricular systolic dysfunction at the highest risk of all-cause mortality?

BACKGROUND

Autonomic imbalance is associated with poor prognosis of patients with systolic dysfunction. Most of the previous data were written several years ago and constituted to cardiovascular or arrhythmic mortality. The current treatment of these patients has improved substantially over the last decades, and thus, the population at risk of death may have altered as well. Consequently, data on high-risk patients with systolic dysfunction in the modern era are sparse and those from previous trials may no longer be applicable. The aim herein, was to verify whether well-known autonomic indices - baroreflex sensitivity (BRS) and heart rate variability (HRV) - remain accurate predictors of mortality in patients with systolic dysfunction.

METHODS

Non-invasively obtained BRS and HRV were analyzed in 205 clinically stable patients with left ventricular ejection fraction (LVEF) ≤ 40%. 28 patients died within 28 ± 9 month follow-up.

RESULTS

Baroreflex sensitivity, low-frequency (LF) in normalized units, LF to high-frequency ratio and standard deviation of average R-R intervals were significantly associated with mortality; cut-off values of the highest discriminatory power for abovementioned parameters were ≤ 3.0 ms/mmHg, ≤ 41, ≤ 0.7 and ≤ 25 ms, respectively. In bivariate Cox analyses (adjusted for LVEF, New York Heart Association [NYHA] or absence of implantable cardioverter-defibrillator [ICD]) autonomic indices remain significant predictors of death.

CONCLUSIONS

Baroreflex sensitivity and HRV - may still be helpful in identifying patients with left ventricular systolic dysfunction at the highest risk of all-cause mortality, independently of LVEF, NYHA class, and ICD implantation.

Long-term clinical outcomes of cardiac resynchronization therapy with or without defibrillation: impact of the aetiology of cardiomyopathy

Aims

There is a continuing debate as to whether cardiac resynchronization therapy-defibrillation (CRT-D) is superior to CRT-pacing (CRT-P), particularly in patients with non-ischaemic cardiomyopathy (NICM). We sought to quantify the clinical outcomes after primary prevention of CRT-D and CRT-P and identify whether these differed according to the aetiology of cardiomyopathy.

Methods and results

Analyses were undertaken in the total study population of patients treated with CRT-D (n = 551) or CRT-P (n = 999) and in propensity-matched samples. Device choice was governed by the clinical guidelines in the United Kingdom. In univariable analyses of the total study population, for a maximum follow-up of 16 years (median 4.7 years, interquartile range 2.4–7.1), CRT-D was associated with a lower total mortality [hazard ratio (HR) 0.72] and the composite endpoints of total mortality or heart failure (HF) hospitalization (HR 0.72) and total mortality or hospitalization for major adverse cardiac events (MACE; HR 0.71) (all P < 0.001). After propensity matching (n = 796), CRT-D was associated with a lower total mortality (HR 0.72) and the composite endpoints (all P < 0.01). When further stratified according to aetiology, CRT-D was associated with a lower total mortality (HR 0.62), total mortality or HF hospitalization (HR 0.63), and total mortality or hospitalization for MACE (HR 0.59) (all P < 0.001) in patients with ischaemic cardiomyopathy (ICM). There were no differences in outcomes between CRT-D and CRT-P in patients with NICM.

Conclusion

In this study of real-world clinical practice, CRT-D was superior to CRT-P with respect to total mortality and composite endpoints, independent of known confounders. The benefit of CRT-D was evident in ICM but not in NICM.

Management of patients with ventricular arrhythmias and prevention of sudden cardiac death-translating guidelines into practice: results of the European Heart Rhythm Association survey

Prevention of sudden cardiac death (SCD) remains a partly unsolved task in cardiology. The European Society of Cardiology (ESC) guidelines on management of patients with ventricular arrhythmias and prevention of SCD published in 2015 considered the new insights of the natural history of diseases predisposing to SCD. The guidelines improved strategies for management of patients at risk of SCD and included both drug and device therapies. The intention of this survey was to evaluate the extent of the disparities between daily clinical practice and the 2015 SCD ESC guidelines among electrophysiology centres in Europe. The results suggest that the adherence to guidelines is reasonably high and strategies for the management of ischaemic disease are well-established. Implantable cardioverter-defibrillator indications for primary prevention are a difficult topic, particularly in non-ischaemic dilated cardiomyopathy. Disparities in the use of genetic testing are probably due to differences in local availability.

EHRA White Paper: knowledge gaps in arrhythmia management—status 2019

Clinicians accept that there are many unknowns when we make diagnostic and therapeutic decisions. Acceptance of uncertainty is essential for the pursuit of the profession: bedside decisions must often be made on the basis of incomplete evidence. Over the years, physicians sometimes even do not realize anymore which the fundamental gaps in our knowledge are. As clinical scientists, however, we have to halt and consider what we do not know yet, and how we can move forward addressing those unknowns. The European Heart Rhythm Association (EHRA) believes that scanning the field of arrhythmia / cardiac electrophysiology to identify knowledge gaps which are not yet the subject of organized research, should be undertaken on a regular basis. Such a review (White Paper) should concentrate on research which is feasible, realistic, and clinically relevant, and should not deal with futuristic aspirations. It fits with the EHRA mission that these White Papers should be shared on a global basis in order to foster collaborative and needed research which will ultimately lead to better care for our patients. The present EHRA White Paper summarizes knowledge gaps in the management of atrial fibrillation, ventricular tachycardia/sudden death and heart failure.

Risk of death without appropriate defibrillator shock in patients with advanced renal dysfunction

Aims

Heart failure patients with advanced chronic kidney disease (CKD) may experience an increased rate of non-arrhythmic mortality due to associated comorbidities. We aimed to evaluate the risk of mortality without appropriate implantable cardioverter-defibrillator (ICD) shocks in this high-risk population.

Methods and results

The study population comprised 3542 patients who received an ICD, were enrolled, and prospectively followed-up in the Israeli ICD registry. Study patients were categorized into two groups: those with advanced CKD [defined by a glomerular filtration rate of <30 mL/min/1.73 m2 or being on dialysis at time of implantation (n = 197)], and those without advanced CKD (n = 3344). The primary endpoint was the risk of death without receiving appropriate ICD shock. Kaplan–Meier survival analysis showed that at 5 years of follow-up the rates of death without prior ICD shock were significantly higher in the advanced kidney disease group (46%) compared with the non-advanced CKD group (19%; log-rank P-value <0.001). Consistently, multivariate analysis showed that the risk of death without receiving appropriate ICD shock therapy at 5 years was 2.5-fold (P < 0.001) higher among advanced CKD patients. In contrast, the rate of appropriate ICD shock therapy at 5 years among advanced CKD patients was only 9%, with a very high mortality rate (63%) within 3.5 years subsequent to shock therapy.

Conclusion

Nearly one-half of ICD with advanced CKD die within 5 years without receiving an appropriate ICD shock. These findings stress the importance of appropriate patient selection for primary ICD implantation in this high-risk population.

Can we rely on Danish? Real-world data on patients with nonischemic cardiomyopathy from the German Device Registry

According to current guidelines prophylactic implantable cardioverter-defibrillator (ICD) therapy is recommended in patients with significantly impaired left ventricular systolic function. However, the recently published DANISH trial did not find a significantly lower long-term rate of death from any cause compared with usual clinical care in patients with non-ischemic cardiomyopathy. We investigated whether registry data from a multi-center 'real-life' registry on patients with non-ischemic cardiomyopathy are similar to this trial. The German Device Registry (DEVICE) is a nationwide, prospective registry with one-year follow-up investigating 5451 patients receiving device implantations in 50 German centers. The present analysis of DEVICE focused on patients with non-ischemic cardiomyopathy and a left ventricular ejection fraction ≤35% who received a prophylactic ICD. Out of 779 patients with symptomatic heart failure and nonischemic cardiomyopathy, 33.1% received a single chamber ICD (VVI), while 11.0% were implanted with a dual-chamber ICD (DDD), and 55.8% received a defibrillator system for cardiac resynchronization therapy. Median follow-up was 16.1 months. 90.7% were alive at follow-up, 9.3% had died during this period. Overall mortality after one year was 5.4%. Overall mortality one year after implantation was significantly increased in patients 68 years and older(7.9%) as compared to younger patients (59-68 years: 2.5%; < 59 years: 3.8%; p < 0.015). Data from the present registry support the recently published results of the DANISH trial. In particular the influence of an increased age as proven in the DANISH trial might also play a role in the present collective. This limits the potential beneficial effect of ICD therapy in particular in the elderly population.

CRT Pacing: Midterm Follow-Up in LV Only Pacing without RV Lead in Patients with Normal AV Conduction

Background: The aim of our study was to assess the real life cardiac resynchronization therapy (CRT) fusion left ventricular (LV) only pacing in patients with normal AV conduction (NAVc) without right ventricular (RV) lead. Methods: Consecutive NAVc patients with CRT indication were implanted with a right atrium RA/LV DDD pacing system. Complete follow-up at 1, 3 and every 6 months thereafter included echocardiography and stress testing. Results: We analysed 55 patients (62 ± 11 years). All patients were responders with significant LV reverse remodelling (LV end-diastolic volume 193.7 ± 81 vs. 243.2 ± 82 mL at baseline, p < 0.002) and increased LV ejection fraction (38 ± 7.9% vs. 27 ± 5.2% at baseline, p < 0.001). Mitral regurgitation decreased in 38 patients (69%). During follow-up (35 ± 18 months), 20 patients (36%) needed reprogramming sensed/paced AV delay or maximum tracking rate (MTR) because of inadequate or lost LV capture at exercise test; personalized programming to achieve up to 100% fusion pacing was used in all patients. One patient developed Mobitz II second degree AV block and triple chamber CRT-P upgrade was performed; defibrillator upgrade was not necessary. Conclusions: LV only pacing CRT-P without RV lead showed a positive outcome in carefully selected patients.

Implantable cardiac defibrillators for people with non-ischaemic cardiomyopathy

BACKGROUND

There is evidence that implantable cardioverter-defibrillator (ICD) for primary prevention in people with an ischaemic cardiomyopathy improves survival rate. The evidence supporting this intervention in people with non-ischaemic cardiomyopathy is not as definitive, with the recently published DANISH trial finding no improvement in survival rate. A systematic review of all eligible studies was needed to evaluate the benefits and harms of using ICDs for primary prevention in people with non-ischaemic cardiomyopathy.

OBJECTIVES

To evaluate the benefits and harms of using compared to not using ICD for primary prevention in people with non-ischaemic cardiomyopathy receiving optimal medical therapy.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, and the Web of Science Core Collection on 10 October 2018. For ongoing or unpublished clinical trials, we searched the US National Institutes of Health Ongoing Trials Register ClinicalTrials.gov, the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP), and the ISRCTN registry. To identify economic evaluation studies, we conducted a separate search to 31 March 2015 of the NHS Economic Evaluation Database, and from March 2015 to October 2018 on MEDLINE and Embase.

SELECTION CRITERIA

We included randomised controlled trials involving adults with chronic non-ischaemic cardiomyopathy due to a left ventricular systolic dysfunction with an ejection fraction of 35% or less (New York Heart Association (NYHA) type I-IV). Participants in the intervention arm should have received ICD in addition to optimal medical therapy, while those in the control arm received optimal medical therapy alone. We included studies with cardiac resynchronisation therapy when it was appropriately balanced in the experimental and control groups.

DATA COLLECTION AND ANALYSIS

The primary outcomes were all-cause mortality, cardiovascular mortality, sudden cardiac death, and adverse events associated with the intervention. The secondary outcomes were non-cardiovascular death, health-related quality of life, hospitalisation for heart failure, first ICD-related hospitalisation, and cost. We abstracted the log (hazard ratio) and its variance from trial reports for time-to-event survival data. We extracted the raw data necessary to calculate the risk ratio. We summarised data on quality of life and cost-effectiveness narratively. We assessed the certainty of evidence for all outcomes using GRADE.

MAIN RESULTS

We identified six eligible randomised trials with a total of 3128 participants. The use of ICD plus optimal medical therapy versus optimal medical therapy alone decreases the risk of all-cause mortality (hazard ratio (HR) 0.78, 95% confidence interval (CI) 0.66 to 0.92; participants = 3128; studies = 6; high-certainty evidence). An average of 24 patients need to be treated with ICD to prevent one additional death from any cause (number needed to treat for an additional beneficial outcome (NNTB) = 24). Individuals younger than 65 derive more benefit than individuals older than 65 (HR 0.51, 95% CI 0.29 to 0.91; participants = 348; studies = 1) (NNTB = 10). When added to medical therapy, ICDs probably decrease cardiovascular mortality compared to not adding them (risk ratio (RR) 0.75, 95% CI 0.46 to 1.21; participants = 1781; studies = 4; moderate-certainty evidence) (possibility of both plausible benefit and no effect). Implantable cardioverter-defibrillator was also found to decrease sudden cardiac deaths (HR 0.45, 95% CI 0.29 to 0.70; participants = 1677; studies = 3; high-certainty evidence). An average of 25 patients need to be treated with an ICD to prevent one additional sudden cardiac death (NNTB = 25). We found that ICDs probably increase adverse events (possibility of both plausible harm and benefit), but likely have little or no effect on non-cardiovascular mortality (RR 1.17, 95% CI 0.81 to 1.68; participants = 1781; studies = 4; moderate-certainty evidence) (possibility of both plausible benefit and no effect). Finally, using ICD therapy probably has little or no effect on quality of life, however shocks from the device cause a deterioration in quality of life. No study reported the outcome of first ICD-related hospitalisations.

AUTHORS' CONCLUSIONS

The use of ICD in addition to medical therapy in people with non-ischaemic cardiomyopathy decreases all-cause mortality and sudden cardiac deaths and probably decreases mortality from cardiovascular causes compared to medical therapy alone. Their use probably increases the risk for adverse events. However, these devices come at a high cost, and shocks from ICDs cause a deterioration in quality of life.

Spanish Implantable Cardioverter-defibrillator Registry. 14th Official Report of the Spanish Society of Cardiology Electrophysiology and Arrhythmias Section (2017)

INTRODUCTION AND OBJECTIVES

The Spanish Automatic Defibrillator Registry has provided activity data since 2002.

METHODS

The data in this registry are submitted by implantation centers that voluntarily complete a data collection sheet.

RESULTS

During 2017, a total of 6273 implant sheets were received, compared with 6429 reported by Eucomed (European Confederation of Medical Suppliers Associations). Therefore, the registry contains data on 97.6% of the devices implanted in Spain. Compliance ranged from 99.7% for the field "name of the implanting hospital" to 46.1% for the variable "New York Heart Association functional class". A total of 181 hospitals reported data to the registry, representing an increase compared with the number of participating hospitals in 2016 (177) and in previous years (169 in 2015, 162 in 2014, 154 in 2013, and 153 in 2012).

CONCLUSIONS

The number of implants per million inhabitants in Spain increased for several years but decreased in 2017. As in previous years, the total number of implants in Spain is still much lower than the European Union average, and the gap continues to widen. There are still substantial differences between autonomous communities.

Eligibility of cardiac resynchronization therapy patients for subcutaneous implantable cardioverter defibrillators

BACKGROUND

Before subcutaneous implantable cardioverter defibrillator (S-ICD) implantation, the adequacy of sensing is required to be verified through surface ECG screening. Our objective was to determine whether S-ICD can be considered as a supplementary therapy in patients who are receiving biventricular (BIV) pacing.

METHODS

We evaluated 48 patients with BIV devices to determine S-ICD candidacy during BIV, left ventricular (LV), right ventricular (RV) pacing, and intrinsic conduction (left bundle branch block-LBBB) by using an automated screening tool. Eligibility was defined by the presence of at least one appropriate vector in the supine and standing positions.

RESULTS

Eligibility was verified during BIV pacing in 34 (71%) patients. In patients screened-out, QRS duration was longer (p = 0.035) and ischemic cardiomyopathy was more frequent (p = 0.027). LV-only pacing was associated with a lower passing rate (46%) (p < 0.001 versus BIV). The LBBB QRS morphology during inhibited ventricular pacing was acceptable in 51% of patients. The QRS generated by RV pacing was acceptable in 25% of patients. In patients who passed the screening test during BIV, the QRS was not acceptable in 76% during RV pacing (i.e., accidental loss of LV capture). The concomitant adequacy during inhibited ventricular pacing (i.e., possible intrinsic conduction) was not assessed in 40% of patients.

CONCLUSIONS

S-ICD may be a supplemental therapy in the majority of CRT patients. Standard BIV pacing should be preferred to the LV-only pacing mode, as it is more frequently associated with adequacy of S-ICD sensing. Spontaneous LBBB and RV-paced QRS morphologies are frequently inadequate. Therefore, in patients selected for concomitant S-ICD and CRT implantation, accidental loss of LV capture or possible intrinsic conduction must be prevented.