Implantable Cardioverter-defibrillator Implantation For Primary Prevention Research Articles

Assisting Black Patients With Decision-Making for Implantable Cardioverter Defibrillator Therapy: Qualitative Findings From the Videos to Reduce Racial Disparities in ICD Therapy via Innovative Designs (VIVID) Trial.

The VIVID (Videos for Addressing Racial Disparities in Implantable Cardioverter Defibrillator Therapy via Innovative Designs) study was a multicenter, randomized controlled trial aimed at evaluating the effectiveness of a video-based decision support tool in enhancing informed consent for implantable cardioverter defibrillator (ICD) implantation among Black patients who met guideline criteria for primary prevention ICDs. Within the broader VIVID randomized trial, a qualitative investigation was conducted to elucidate the decisional factors among Black individuals considering ICD implantation for the primary prevention of sudden cardiac arrest. Between October 2016 and July 2019, in-depth interviews were conducted at 2 time points from randomization, ≈7 days (time interval for the decision) and at 90 days; the time interval for determining ICD implantation. Interview findings were categorized by randomized groups, those assigned to 1 of the 2 encounter-based video decision support tools or standard care (without video). Interview participants were purposefully selected to ensure diversity across gender, age, educational background, research site, and randomization group; participants were sampled from 14 academic and community-based electrophysiology clinics in the United States. Data analysis employed applied thematic analysis techniques. A diverse sample of Black individuals were interviewed at 1 week (n=59; female, 37.3%) and 90 days (n=48; female, 39.6%). The primary factors influencing the decisions of Black individuals considering a primary prevention ICD implantation were (1) their clinicians' recommendations for ICD implantation; (2) their perception of their cardiac health status; and (3) a desire to prolong their lives for the sake of their families. These findings offer valuable insights that may guide clinicians in their communication with Black patients during shared decision-making encounters related to ICD implantation.

Lack of Prognostic Value of T-Wave Alternans for Implantable Cardioverter-Defibrillator Benefit in Primary Prevention.

New methods to identify patients who benefit from a primary prophylactic implantable cardioverter-defibrillator (ICD) are needed. T-wave alternans (TWA) has been shown to associate with arrhythmogenesis of the heart and sudden cardiac death. We hypothesized that TWA might be associated with benefit from ICD implantation in primary prevention. In the EU-CERT-ICD (European Comparative Effectiveness Research to Assess the Use of Primary Prophylactic Implantable Cardioverter-Defibrillators) study, we prospectively enrolled 2327 candidates for primary prophylactic ICD. A 24-hour Holter monitor reading was taken from all recruited patients at enrollment. TWA was assessed from Holter monitoring using the modified moving average method. Study outcomes were all-cause death, appropriate shock, and survival benefit. TWA was assessed both as a contiguous variable and as a dichotomized variable with cutoff points <47 μV and <60 μV. The final cohort included 1734 valid T-wave alternans samples, 1211 patients with ICD, and 523 control patients with conservative treatment, with a mean follow-up time of 2.3 years. TWA ≥60 μV was a predicter for a higher all-cause death in patients with an ICD on the basis of a univariate Cox regression model (hazard ratio, 1.484 [95% CI, 1.024-2.151]; P=0.0374; concordance statistic, 0.51). In multivariable models, TWA was not prognostic of death or appropriate shocks in patients with an ICD. In addition, TWA was not prognostic of death in control patients. In a propensity score-adjusted Cox regression model, TWA was not a predictor of ICD benefit. T-wave alternans is poorly prognostic in patients with a primary prophylactic ICD. Although it may be prognostic of life-threatening arrhythmias and sudden cardiac death in several patient populations, it does not seem to be useful in assessing benefit from ICD therapy in primary prevention among patients with an ejection fraction of ≤35%.

New York Heart Association functional class and implantable cardioverter-defibrillator in non-ischaemic heart failure with reduced ejection fraction: Extended follow-up of the DANISH trial.

Current guidelines recommend implantable cardioverter-defibrillator (ICD) therapy in patients with heart failure, a left ventricular ejection fraction of ≤35%, and New York Heart Association (NYHA) class II-III. However, the evidence regarding the benefit of primary prevention ICD is less consistent in patients with NYHA class III. We investigated the long-term effects of primary prevention ICD implantation according to NYHA class in an extended follow-up study of the DANISH trial. The DANISH trial randomized 1116 patients with non-ischaemic heart failure with reduced ejection fraction (HFrEF) to ICD implantation or usual care. Outcomes were analysed according to NYHA class at baseline (NYHA class II and III/IV). The primary outcome was all-cause mortality. Of the 1116 patients randomized in the DANISH trial, 597 (53.5%) were in NYHA class II at baseline, 505 (45.3%) in NYHA class III, and 14 (1.3%) in NYHA class IV. During a median follow-up of 9.5 years, NYHA class III/IV, compared with NYHA class II, were associated with a greater long-term rate of all-cause mortality (hazard ratio [HR] 1.52, 95% confidence interval [CI] 1.20-1.93) and cardiovascular death (HR 1.95 [1.47-2.60]). ICD implantation, compared with usual care, did not reduce the long-term rate of all-cause mortality (all participants: HR 0.89 [95% CI 0.74-1.08]; NYHA class II: HR 0.85 [0.64-1.13]; NYHA class III/IV: HR 0.89 [0.69-1.14]; pinteraction = 0.78) or cardiovascular death (all participants: HR 0.87 [95% CI 0.70-1.09]; NYHA class II: HR 0.78 [0.54-1.12]; NYHA class III/IV: HR 0.89 [0.67-1.19]; pinteraction = 0.58), irrespective of NYHA class. Similarly, NYHA class did not modify the beneficial effects of ICD implantation on sudden cardiovascular death (all participants: HR 0.60 [95% CI 0.40-0.92]; NYHA class II: HR 0.73 [0.40-1.36]; NYHA class III/IV: HR 0.52 [0.29-0.94]; pinteraction = 0.39). In patients with non-ischaemic HFrEF, ICD implantation, compared with usual care, did not reduce the overall mortality rate, but it did reduce sudden cardiovascular death, regardless of baseline NYHA class. ClinicalTrials.gov NCT00542945.

Impact of preventive substrate catheter ablation on implantable cardioverter-defibrillator interventions in patients with ischaemic cardiomyopathy and infarct-related coronary chronic total occlusion.

Primary prevention patients with ischaemic cardiomyopathy and chronic total occlusion of an infarct-related coronary artery (CTO) are at a particularly high risk of implantable cardioverter-defibrillator (ICD) therapy occurrence. The trial was designed to evaluate the efficacy of preventive CTO-related substrate ablation strategy in ischaemic cardiomyopathy patients undergoing primary prevention ICD implantation. The PREVENTIVE VT study was a prospective, multicentre, randomized trial including ischaemic patients with ejection fraction ≤40%, no documented ventricular arrhythmias (VAs), and evidence of scar related to the coronary CTO. Patients were randomly assigned 1:1 to a preventive substrate ablation before ICD implantation or standard therapy with ICD implantation only. The primary outcome was a composite of appropriate ICD therapy or unplanned hospitalization for VAs. Secondary outcomes included the primary outcome's components, the incidence of appropriate ICD therapies, cardiac hospitalization, electrical storm, and cardiovascular (CV) mortality. Sixty patients were included in the study. During the mean follow-up of 44.7 ± 20.7 months, the primary outcome occurred in 5 (16.7%) patients undergoing preventive substrate ablation and in 13 (43.3%) patients receiving only ICD [hazard ratio (HR): 0.33; 95% confidence interval (CI): 0.12-0.94; P = 0.037]. Patients in the preventive ablation group also had fewer appropriate ICD therapies (P = 0.039) and the electrical storms (Log-rank: P = 0.01). While preventive ablation also reduced cardiac hospitalizations (P = 0.006), it had no significant impact on CV mortality (P = 0.151). Preventive ablation of the coronary CTO-related substrate in patients undergoing primary ICD implantation is associated with the reduced risk of appropriate ICD therapy or unplanned hospitalization due to VAs.

Long-term reliability of the phospholamban (PLN) p.(Arg14del) risk model in predicting major ventricular arrhythmia: a landmark study.

Recently, a genetic variant-specific prediction model for phospholamban (PLN) p.(Arg14del)-positive individuals was developed to predict individual major ventricular arrhythmia (VA) risk to support decision-making for primary prevention implantable cardioverter defibrillator (ICD) implantation. This model predicts major VA risk from baseline data, but iterative evaluation of major VA risk may be warranted considering that the risk factors for major VA are progressive. Our aim is to evaluate the diagnostic performance of the PLN p.(Arg14del) risk model at 3-year follow-up. We performed a landmark analysis 3 years after presentation and selected only patients with no prior major VA. Data were collected of 268 PLN p.(Arg14del)-positive subjects, aged 43.5 ± 16.3 years, 38.9% male. After the 3 years landmark, subjects had a mean follow-up of 4.0 years (± 3.5 years) and 28 (10%) subjects experienced major VA with an annual event rate of 2.6% [95% confidence interval (CI) 1.6-3.6], defined as sustained VA, appropriate ICD intervention, or (aborted) sudden cardiac death. The PLN p.(Arg14del) risk score yielded good discrimination in the 3 years landmark cohort with a C-statistic of 0.83 (95% CI 0.79-0.87) and calibration slope of 0.97. The PLN p.(Arg14del) risk model has sustained good model performance up to 3 years follow-up in PLN p.(Arg14del)-positive subjects with no history of major VA. It may therefore be used to support decision-making for primary prevention ICD implantation not merely at presentation but also up to at least 3 years of follow-up.

Implantable loop recorder in Brugada syndrome: Insights from a single-center experience

BackgroundThis study aimed to investigate the characteristics and outcomes of patients diagnosed with Brugada syndrome (BrS) who underwent implantable loop recorder (ILR) insertion during routine clinical activity. MethodsWe conducted a comprehensive screening of all consecutive patients diagnosed with BrS at our institution. We analyzed baseline clinical characteristics, arrhythmic findings, and outcomes. ResultsOut of 147 BrS patients, 42 (29 %) received an ILR, 13 (9 %) underwent implantable cardioverter-defibrillator (ICD) placement, and 92 patients (63 %) continued regular cardiological follow-up. Patients who received an ILR had a higher prevalence of suspected arrhythmic syncope (43 % vs. 22 %, p = 0.012) and tended to be younger (median age 38 years, interquartile range 30–52, vs. 43 years, 35–55, p = 0.044) with a higher presence of SCN5A gene mutations (17 % vs. 6 %, p = 0.066) compared to those who continued regular follow-up. Additionally, compared to patients with an ICD, those with an ILR had a significantly lower frequency of positive programmed ventricular stimulation (0 % vs. 91 %, p < 0.001). During a median follow-up period of 14.7 months (4.7–44.8), no deaths occurred among the patients with ILR. Eight individuals (19 %) were diagnosed with arrhythmic findings through continuous ILR monitoring, primarily atrial fibrillation, and asystolic pauses. The median time from insertion to the occurrence of these events was 8.7 months (3.6–46.4). No adverse events related to ILR were reported. ConclusionContinuous monitoring with ILR may facilitate the timely detection of non-malignant rhythm disorders in BrS patients with risk factors but without an indication for primary prevention ICD implantation.

Abstract 15327: Clinical Outcomes of Methamphetamine-Associated Cardiomyopathy Compared to Ischemic Cardiomyopathy: A Single Institution Retrospective Longitudinal Study

Background: Methamphetamine-associated cardiomyopathy (MAC) leads to significant morbidity and mortality. The benefit of implantable cardioverter-defibrillator (ICD) in this population is poorly characterized. Aims: To evaluate ICD use and outcomes in patients with MAC compared to ischemic cardiomyopathy (ICM). Methods: Electronic health record (EHR) was queried for all heart failure hospitalizations using ICD-9 codes between 2011 and 2019. Patients with an EF ≤ 35% were included. The MAC cohort was derived from this population and defined by ICD-9 code or positive urine toxicology and compared to ICM cohort. Baseline characteristics and outcomes were extracted from the EHR. MACE was defined as death, ventricular tachycardia, cardiac arrest, rehospitalization, atrial fibrillation (AF) or stroke. Results: The study included 294 patients in the MAC group and 373 patients in the ICM group. MAC patients were younger (56 vs 61 years, p&lt;0.001) compared to ICM (table 1). Readmission rates for heart failure at one year were similar (13% vs 11.2%, p=ns). Significantly fewer patients with MAC had ICD for primary prevention (15.0% vs 27.9%, p&lt;0.001). Mortality and AF were lower in MAC compared to ICM, however VT (2.38% vs 5.09%, p=0.072) and cardiac arrest (6.1% vs 7.8%, p=0.408) were similar between the two groups. MACE outcomes were worse in the ICM cohort (38.3% vs 21.1%, p=0.012) than MAC. In the MAC cohort, ICD presence was associated with 56.82% incidence of MACE compared to 40.00% without ICD (OR = 1.97, CI 1.032-3.77, p = 0.040) mainly due to higher AF hospitalization (22% vs 8%, p=0.01). Conclusion: ICM patients had higher mortality and atrial fibrillation compared to MAC. ICD implantation for primary prevention was not associated with reduced mortality, however this cohort had higher AF hospitalization. We need further studies to assess the benefit of ICD in MAC.

Abstract 16938: Epicardial Adipose Tissue on the Risk of Lethal Ventricular Arrhythmias in Patients With Nonischemic Cardiomyopathy Receiving Implantable Cardioverter-Defibrillator

Background: The arrhythmic risk stratification in patients with nonischemic cardiomyopathy (NICM) remains challenging. The implication of epicardial adipose tissue (EAT) on incident sudden cardiac death (SCD) is unclear. Objectives: To assess the relationship between EAT and SCD in NICM patients receiving implantable cardioverter-defibrillators (ICD) and compare this risk to patients with ischemic cardiomyopathy (ICM). Methods: A total of 421 patients scheduled for primary or secondary prevention ICD implantation underwent CMR at 1.5 or 3T, including cine and late gadolinium enhancement (LGE) imaging. EAT volume surrounding both ventricles was quantified with manual delineation on cine short-axis images and calculated by summation of EAT volume of each slice using the modified Simpson rule. LGE was semiautomatically quantified by adjusting a grayscale threshold. The primary endpoint was a composite of ICD therapy, including anti-tachycardia pacing and SCD. Results: We identified 265 NICM patients (mean age 54 years, 73% men), with LGE present in 152 patients (57%), including 85 patients (32%) with secondary prevention ICD. During the median follow-up of 2.9 years, 42 patients (16%) experienced the endpoint. Low EAT was associated with an increased risk of SCD in NICM patients (HR ad per 10ml decrease, 1.54; 95%CI, 1.19-1.96, p&lt;0.001), even after adjustment for other relevant disease variables. A continuous relationship was evident between EAT and subsequent ICD therapies (p=0.001). Even when considering 85 patients with secondary prevention ICD as theoretically having an SCD event, the risk of EAT in predicting SCD remained essentially unchanged. In contrast, EAT was not associated with increased SCD risk in ICM patients. Conclusions: Low EAT was associated with increased SCD risk in NICM patients receiving ICD implantation, especially primary prevention ICD. These data suggest a potential role of EAT in identifying NICM patients at risk of SCD.

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.

Electrocardiographic characteristics associated with late gadolinium enhancement and prognostic value in patients with dilated cardiomyopathy.

Late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) imaging has emerged as an important tool for assessment of patients with dilated cardiomyopathy (DCM). Electrocardiography (ECG) is an accessible, reproducible, low-cost diagnostic and prognostic tool. This study aimed to investigate the ECG characteristics associated with LGE, as well as to assess the prognostic significance of ECG in patients with DCM. Consecutive patients diagnosed with DCM by CMR [left ventricular ejection fraction (LVEF) < 50%] between 2011 and 2020 were included. Multivariable analysis was conducted to evaluate ECG predictors associated with LGE. Receiver operating characteristic (ROC) analysis was performed to assess the diagnostic performance of ECG in combination of clinical data and LVEF for LGE. Two composite outcomes were also assessed among patients with and without ECG predictors: (1) sudden cardiac death (SCD), sustained ventricular arrhythmia, or appropriate implantable cardioverter-defibrillator (ICD) therapy, and (2) all-cause death or hospitalization for heart failure. A total of 422 patients, with a mean age of 59.5 ± 16.3 years (58.3% male), were included. LGE was present in 169 (40%) of the patients. Multivariable analysis identified lateral inverted T-waves, intraventricular conduction delay, low voltage, and fragmented QRS as independent predictors of LGE. ROC analysis showed a significant increase in the area under the curve (AUC) when ECG predictors of the four aforementioned characteristics were added to the clinical-LVEF model (AUC 0.66, 95% CI 0.59-0.71 vs. 0.72, 95% CI 0.67-0.78, p = 0.003). During a median follow-up of 2.7 years (IQR 0.8, 5.2), 16 events of SCD, sustained ventricular arrhythmia, or appropriate ICD therapy, and 70 events of all-cause death or hospitalization for heart failure occurred. ECG predictors were independently associated with SCD, sustained ventricular arrhythmia, or appropriate ICD therapy (HR 4.84, 95% CI 1.34-17.40, p = 0.01). However, ECG predictors were not associated with all-cause death or hospitalization for heart failure (HR 1.22, 95% CI 0.76-1.96, p = 0.39). In patients with DCM, lateral inverted T-waves, intraventricular conduction delay, low voltage, and fragmented QRS were independently associated with LGE. Additionally, these ECG predictors had prognostic value for predicting SCD, sustained ventricular arrhythmia, or appropriate ICD therapy, assisting clinicians in stratifying SCD risk and identifying primary prevention ICD implantation candidates.

Single- Versus Dual-Chamber Implantable Cardioverter-Defibrillator for Primary Prevention of Sudden Cardiac Death in the United States.

Background Routine addition of an atrial lead during an implantable cardioverter-defibrillator (ICD) implantation for primary prevention of sudden cardiac death, in patients without pacing indications, was not shown beneficial in contemporary studies. We aimed to investigate the use and safety of single- versus dual-chamber ICD implantations in these patients. Methods and Results Using the National Inpatient Sample database, we identified patients with no pacing indications who underwent primary-prevention ICD implantation in the United States between 2015 and 2019. Sociodemographic and clinical characteristics, as well as in-hospital complications, were analyzed. Multivariable logistic regression was used to identify predictors of in-hospital complications. An estimated total of 15 940 patients, underwent ICD implantation for primary prevention of sudden cardiac death during the study period, 8860 (55.6%) received a dual-chamber ICD. The mean age was 64 years, and 66% were men. In-hospital complication rates in the dual-chamber ICD and single-chamber ICD group were 12.8% and 10.7%, respectively (P<0.001), driven by increased rates of pneumothorax/hemothorax (4.6% versus 3.4%; P<0.001) and lead dislodgement (3.6% versus 2.3%; P<0.001) in the dual-chamber ICD group. Multivariable analyses confirmed atrial lead addition as an independent predictor for "any complications" (odds ratio [OR], 1.1 [95% CI, 1.0-1.2]), for pneumo/hemothorax (odds ratio, 1.1 [95% CI, 1.0-1.4]), and for lead dislodgement (odds ratio, 1.3 [95% CI, 1.1-1.6]). Conclusions Despite lack of evidence for clinical benefit, dual-chamber ICDs are implanted for primary prevention of sudden cardiac death in a majority of patients who do not have pacing indication. This practice is associated with increased risk of periprocedural complications. Avoidance of routine implantation of atrial leads will likely improve safety outcomes.

Comparison and predictors of implantable cardioverter-defibrillator therapy for primary and secondary prevention.

Implantable cardioverter-defibrillators (ICDs) are effective in detecting and treating ventricular arrhythmias. Studies on ICD therapy for different indications (primary and secondary prevention) and possible predictors of ICD therapy are limited. In this study, the incidence and type of ICD therapy were related to the indication and the underlying cardiac pathology. Asingle-centre, retrospective and observational study was performed of 482patients who underwent ICD implantation for primary (53.3%) or secondary prevention (46.7%) between 2015 and 2020 at the Radboud University Medical Centre. During amedian follow-up of 2.4years (interquartile range 0.2-3.9), the occurrence of appropriate ICD therapy for primary versus secondary prevention was 9.7% and 27.6%, respectively (p < 0.001). Time to appropriate ICD therapy was significantly shorter in the secondary prevention group (p < 0.001). No difference in ICD therapy was seen for different underlying aetiologies. In the majority of cases (70%) ICD therapy was given for ventricular tachycardia (VT). The occurrence of adverse events (16.3% vs 17.3%, p = 0.772), hospitalisation for cardiovascular reasons (29.2% vs 35.1%, p = 0.559) and all-cause mortality (12.5% vs 11.6%, p = 0.763) were similar in both groups. Male gender (3.53, 95% confidence interval (CI) (1.003, 12.403), p = 0.049) and secondary prevention indication (4.90, 95% CI (1.495, 16.066), p = 0.009) were predictors of appropriate ICD therapy. The risk associated with appropriate ICD therapy is higher in secondary prevention patients, who have their first therapy within ashorter time frame after device implantation. Rates of complications, hospitalisation and all-cause mortality are comparable. Future treatment options should target the prevention of ICD therapy, mainly by preventing the recurrence of VT.

Implantable cardioverter defibrillator for primary prevention in patients with non-ischemic cardiomyopathy in the era of novel therapeutic agents- meta-analysis.

Evidence regarding the mortality benefit of implantable cardioverter defibrillator (ICD) non-ischemic dilated cardiomyopathy (NIDCM) is inconsistent. The most recent randomized study, the DANISH trial, did not find improved outcomes with ICD. However, based on previous studies and meta-analyses, current guidelines still highly recommend ICD implantation in NIDCM patients. The introduction of novel medications for heart failure improved the clinical outcome dramatically. We aimed in this study to evaluate the effect of Angiotensin Receptor-Neprilysin Inhibitors (ARNi) and sodium-glucose transport protein 2 inhibitors (SGLT2i) on the mortality benefit of ICD in NIDCM. We used a previous metanalysis algorithm and added an updated comprehensive literature search in PubMed for randomized control trials that examined the mortality benefit of ICD in NIDCM vs. optimal medical treatment. The primary outcome included death from any cause. We did a meta-regression analysis to search for a single independent factor affecting mortality. Using previous data, we evaluated the theoretical effect of ICD implementation on patients treated with SGLT2 inhibitors and ARNi. No new articles were added to the results of the previous meta-analysis. 2,622 patients with NIDCM from 5 cohort studies published between 2002 and 2016 were included in the analysis. 50% of them underwent ICD implantation for primary prevention of sudden cardiac death, and 50% did not. ICD was associated with a significantly decreased risk for death from any cause compared to control (OR = 0.79, 95%CI: 0.66-0.95, p = 0.01, I2 = 0%). The theoretical addition of ARNi and the SGLT2 inhibitor dapagliflozin did not change the significant mortality effect of ICD (OR = 0.82, 95%CI: 0.7-0.9, p = 0.001, I2 = 0%) and (OR = 0.82, 95%CI: 0.7-0.9, p = 0.001, I2 = 0%). A meta-regression revealed no association between death from any cause and left bundle branch block (LBBB), use of amiodarone, use of angiotensin-converting enzyme inhibitors (ACEi) or angiotensin receptor blockers, year initiated enrollment, and the year ended enrollment (R2 = 0.0). In patients with NIDCM, the addition of ARNi and SGLT2i did not affect the mortality advantages of ICD for primary prevention. https://www.crd.york.ac.uk/prospero/, identifier: CRD42023403210.

MP-453089-11 DIFFERENCES IN UTILIZATION OF PRIMARY PREVENTION IMPLANTABLE CARDIOVERTER DEFIBRILLATORS IN ARRHYTHMOGENIC RIGHT VENTRICULAR CARDIOMYOPATHY ACROSS NORTH AMERICA AND EUROPE

Implantable cardioverter-defibrillators (ICDs) are critical for preventing sudden cardiac death (SCD) in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC), but differences in their utilization across North America and Europe are unknown. To identify cross-national differences in both utilization of primary prevention ICDs and survival free from ventricular arrhythmia (VA) in patients with ARVC. This was a retrospective analysis of ARVC patients without prior sustained VA enrolled in clinical registries in 11 countries throughout Europe and North America. Patients were classified according to whether they received treatment in North America or Europe. They were further stratified by their calculated 5-year VA risk (low: <10%/5y, intermediate: 10-25%/5y, high: >25%/5y) using the ARVC risk calculator (ARVCrisk.com). Differences in rates of ICD implantation and VA-free survival were assessed using the Kaplan-Meier method and log-rank testing. Differences in VA-free survival were also assessed in the subset of patients without ICD. 1,098 patients were followed for a median of 5.1 years, during which time 554 (50.5%) received a primary prevention ICD. Patients treated in Europe were more likely to be probands (61.5% vs 52.0%, p=0.002) and were diagnosed at older ages (42 vs. 32 years, p<0.001). Baseline 5-year VA risk was similar (19.5% vs 19.4, p-value 0.71). North Americans were twice as likely to receive primary prevention ICDs (13.6%/year vs. 6.4%/year, p<0.001) and had shorter times from diagnosis to ICD implantation (83 days vs. 243 days, p<0.001). Overall, 285 patients (25.9%) experienced a first sustained VA event. Rates of VA were higher in North Americans compared to Europeans (6.0%/year versus 4.2%/year, p<0.001); this increase was driven primarily by higher rates of appropriate ICD therapy in North Americans (70.7% vs 59.3% of events). In sub-analysis of patients without ICD, North Americans had higher rates of VA events than Europeans (3.4%/year vs 2.4%/year, p=0.01). When stratified by baseline VA risk, North Americans received significantly more ICDs at all risk strata despite similar rates of VA events in low and intermediate risk patients (Figure). North American ARVC patients were significantly more likely to receive primary prevention ICDs across all risk strata than their European counterparts. However, a lower rate of primary prevention ICD implantation in Europe was not associated with a higher rate of adverse VA outcomes.

Sudden Cardiac Death in Ischaemic Cardiomyopathy and the Primary Prevention ICD: Time for a More a Personalised Approach?

Guidelines recommend primary prevention implantable cardioverter defibrillator (PPICD) for left ventricular ejection fraction (LVEF) <35% only after 3 months of optimal medical therapy (OMT) or 6 weeks after acute MI with persistent LVEF dysfunction. A 73-year-old woman presented with decompensated heart failure secondary to ischaemic cardiomyopathy. Severe coronary disease with sufficient dysfunctional myocardial segments on cardiac MRI suggested potential benefit from revascularisation. Following discussion with the heart team, she underwent percutaneous coronary intervention (PCI). PPICD implantation was deferred as per guideline recommendations. However, 20 days post-PCI, the patient died from malignant ventricular arrhythmia captured on a Holter monitor. This case demonstrates that some high-risk patients may not receive a potentially life-saving PPICD if guidelines are stringently adhered to. We highlight evidence that LVEF alone is of limited value in a risk assessment of arrhythmogenic death, and postulate that a more personalised ICD prescription should be considered using scar characteristics on cardiac MRI to prompt upstream ICD implantation in high-risk patients.

Relationship between Exercise Test Parameters, Device-Delivered Electric Shock and Adverse Clinical Events in Patients with an Implantable Cardioverter Defibrillator for Primary Prevention.

(1) Background: Receiving the first internal electric shock is a turning point for patients with an implantable cardioverter defibrillator (ICD) for primary prevention. However, no study has investigated whether patients who receive a first device-delivered electric shock have a poor prognosis even at the time of ICD implantation. (2) Methods: We retrospectively identified 55 patients with ischemic (n = 31) or dilated (n = 24) cardiomyopathy who underwent ICD implantation for primary prevention with exercise test at the time of implantation. We recorded baseline characteristics, exercise test parameters, and clinical events. (3) Results: After a median follow-up of 5 years, we observed an association between an appropriate device-delivered electric shock, the occurrence of death or heart transplant, and the occurrence of the composite endpoint. There was also a significant relation between a VE/VCO2 slope >35 and the occurrence of the composite endpoint. Conversely, there was no significant association between negative outcomes on the exercise test and the occurrence of a device-delivered electric shock. (4) Conclusions: The exercise test performed at the time of ICD implantation do not predict the occurrence of device-delivered electric shock. The exercise test and the first electric shock are two independent markers of poor prognosis.

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

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. 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. 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. 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.

Hospital utilisation and the costs associated with complications of ICD implantation in acontemporary primary prevention cohort.

Implantation of an implantable cardioverter defibrillator (ICD) is standard care for primary prevention of sudden cardiac death. However, ICD-related complications are increasing as the population of ICD recipients grows. ICD-related complications in anational DO-IT Registry cohort of 1442 primary prevention ICD patients were assessed in terms of additional use of hospital care resources and costs. During amedian follow-up of 28.7months (IQR 25.2-33.7) one or more complications occurred in 13.5% of patients. Acomplication resulted in asurgical intervention in 53% of cases and required on average 3.65 additional hospital days. The additional hospital costs were €6,876 per complication or €8,110 per patient, to which clinical re-interventions and additional hospital days contributed most. Per category of complications, infections required most hospital utilisation and were most expensive at an average of €22,892. The mean costs were €5,800 for lead-related complications, €2,291 for pocket-related complications and €5,619 for complications due to other causes. We estimate that the total yearly incidence-based costs in the Netherlands for hospital management of ICD-related complications following ICD implantation for primary prevention are €2.7million. Complications following ICD implantation are related to asubstantial additional need for hospital resources. When performing cost-effectiveness analyses of ICD implantation, including the costs associated with complications, one should be aware that real-world complication rates may deviate from trial data. Considering the economic implications, strategies to reduce the incidence of complications are encouraged.

Abstract 12086: Predicting Long-Term Survival After De Novo Cardioverter-Defibrillator Implantation for Primary Prevention

Introduction: Current guidelines recommend the use of implantable cardioverter-defibrillators (ICDs) for primary prevention of arrhythmia in patients with reduced ejection fraction cardiomyopathy. Little is known about the long-term outcomes of patients with ICDs in clinical practice. Objective: To develop a risk prediction model for 10-year survival after ICD implantation for primary prevention. Methods: In this population-based registry of all ICD patients across 18 centers in Ontario, CA, 5097 patients receiving ICD implant for primary prevention from February 2007 to March 2011 were followed for up to 10 years. Patients were randomly split 2:1 into derivation and internal validation cohorts to develop and validate a prognostic model using Cox regression and predictors measured at initial ICD evaluation. Results: Mean age was 65.3 years (SD 11.0), 664 patients were female (19.5%) and 2344 patients (69.0%) had ischemic cardiomyopathy for primary disease indication. 10-year survival was 45.7% (95% CI 44.0%-47.4%).The final prediction model included age, sex, disease indication, comorbidities and biomarkers at the time of ICD assessment ( Table 1 ). This model had good discrimination in derivation (AUC 0.80; 95% CI 0.78-0.81) and validation samples (0.79, 95% CI 0.77-0.81) and good calibration. Sensitivity analyses showed that the addition of device type, provider factors (implantation site, implanter volume, physician main specialty), sex-related interaction terms, and frailty scores did not significantly improve the prediction model. Conclusion: A combination of demographic and patient factors determined at baseline device evaluation enabled the prediction of 10-year survival in patients undergoing ICD for primary prevention in the clinical practice. Our findings may help identify and monitor individuals at risk of long-term mortality and may be useful in targeting future prevention strategies to enhance longevity in this high-risk population.

Guideline-Directed Medical Therapy Before and After Primary Prevention Implantable Cardioverter Defibrillator Implantation in New Zealand (ANZACS-QI 66).

Guidelines recommend angiotensin converting enzyme inhibitors (ACEi)/angiotensin receptor blockers (ARB)/angiotensin receptor neprilysin inhibitors (ARNI); beta blockers; and mineralocorticoid receptor antagonists (MRA) in patients with symptomatic heart failure and reduced left ventricular ejection fraction before consideration of primary prevention implantable cardioverter defibrillator (ICD). This study aims to investigate dispensing rates of guideline-directed medical therapy (GDMT) before and after primary prevention ICD implantation in New Zealand. All patients receiving a primary prevention ICD between 2009 and 2018 were identified using nationally collected data on all public hospital admissions in New Zealand. This was anonymously linked to national pharmaceutical data to obtain medication dispensing. Medications were categorised as low dose (<50% of target dose), 50-99% of target dose or target dose based on international guidelines. Of the 1,698 patients identified, ACEi/ARB/ARNI, beta blockers and MRA were dispensed in 80.2%, 83.6% and 45.4%, respectively, prior to ICD implant. However, ≥50% target doses of each medication class were dispensed in only 51.8%, 51.8% and 34.5%, respectively. Only 15.8% of patients were receiving ≥50% target doses of all three classes of medications. In the 1,666 patients who survived 1 year after ICD implant, the proportions of patients dispensed each class of medications remained largely unchanged. Dispensing of GDMT was suboptimal in patients before and after primary prevention ICD implantation in New Zealand, and only a minority received ≥50% target doses of all classes of medication. Interventions are needed to optimise use of these standard evidence-based medications to improve clinical outcomes and avoid unnecessary device implantation.