Predictor Of Appropriate Implantable Cardioverter-defibrillator Therapy Research Articles

Incidence and predictors of sudden cardiac death in arrhythmogenic right ventricular cardiomyopathy: a pooled analysis.

AimsArrhythmogenic right ventricular cardiomyopathy (ARVC), an inherited heart muscle abnormality, is a major cause of sudden cardiac death (SCD). However, the burden of SCD and risk factors in ARVC are not clearly described. Thus, we estimated the rates and predictors of SCD in ARVC in a meta-analysis.Methods and resultsPubMed, Embase, and Web of Science were searched through 7 April 2021. Prospective studies reporting SCD from ARVC cohorts were included. Data were independently extracted by two reviewers and pooled in a random-effects meta-analysis. Fifty-two studies (n = 5485 patients) with moderate-to-low risk of bias were included. The pooled annualized rates of SCD were 0.65 per 1000 [95% confidence interval 0.00–6.43, I2 0.00%] in those with an implantable cardioverter-defibrillator (ICD) and 7.21 (2.38–13.79, I2 0.0%) in non-ICD cohorts: 7.14 in probands and 8.44 for 2010 Task Force Criteria (TFC). Multivariable predictors of life-threatening arrhythmic events including SCD were: age at presentation [adjusted hazard ratio 0.98 (0.97–0.99)], male sex [2.08 (1.29–3.36)], right ventricular (RV) dysfunction [6.99 (2.17–22.49)], QRS fragmentation [6.55 (3.33–12.90)], T-wave inversion [1.12 (1.02–1.24)], syncope at presentation [2.83 (2.40–4.08)], previous non-sustained ventricular tachyarrhythmia [2.53 (1.44–4.45)], and the TFC score [1.96 (1.02–3.76)], (P < 0.05). Predictors of appropriate ICD therapy were RV dysfunction, syncope, and inducible ventricular arrhythmia (P < 0.01).ConclusionThis meta-analysis demonstrates a high burden of SCD in ARVC patients, especially among probands and ARVC defined by the modified TFC. Better strategies are required to improve patient management and prevent SCD in ARVC. PROSPERO ID: CRD42020211761.

Long-term outcomes among a cohort of 4296 implantable cardioverter-defibrillator patients: insights from the UMBRELLA study

Abstract Background Large observational real-world studies describing modern implantable cardioverter-defibrillator (ICD) populations with long-term follow-up are lacking. Purpose To assess the incidence of arrhythmias in a cohort of contemporary patients undergoing ICD implant from 2005 and 2017 and to analyze the arrhythmic risk and mortality according to their clinical profiles. Methods UMBRELLA (NTC01561144) is a prospective, multicentre, nationwide study of ICD patients followed by remote monitoring. All device information was automatically stored through the remote monitoring system and a blinded review of all the stored arrhythmic episodes was performed. The study outcomes were first appropriate ICD therapy and all-cause death. Results The study population consisted of 4296 patients (61.9±12.9 years, ischaemic cardiomyopathy (ICM): n=2150, dilated cardiomyopathy (DCM): n=1166, valvular heart disease (VHD): n=119, hypertrophic cardiomyopathy (HCM): n=294, arrhythmogenic right ventricular cardiomyopathy (ARVC): n=71, Brugada syndrome (BS): n=143, long QT syndrome (LQTS): n=43, and adult congenital heart disease (ACHD): n=60)). Primary prevention (PP) was the main indication (n=2758). During a mean follow-up of 46.6±27.3 months, 16,067 episodes of sustained ventricular arrhythmia (SVA) occurred in 1344 patients. Appropriate ICD therapy was delivered to 85.7% (n=13,767) episodes of SVA in 1173 patients (27.3% of population). A higher risk of first appropriate ICD therapy was observed in VHD (HR: 1.94, 95% CI: 1.43–2.62), ARVC (HR: 1.84, 95% CI: 1.28–2.66), ICM (HR: 1.51, 95% CI: 1.29–1.78), and DCM (HR: 1.28, 95% CI: 1.07–1.53) whereas patients with HCM (HR: 0.72, 95% CI: 0.54–0.96) and BS (HR: 0.25, 95% CI: 0.14–0.45) were at significantly lower risk (Figure 1A). In multivariate analysis (Table 1), age, gender, atrial fibrillation (AF), secondary prevention, LVEF ≤35%, and QRS width emerged as clinical predictors of appropriate ICD therapy, whereas CRT-D correlated with lower risk. An independently higher risk was found in DCM, VHD, and ARVC, and a lower risk in BS patients. At follow-up, 590 deaths (13.4% of population) were reported. Patients with ICM (HR 3.90, 95% CI: 2.58–5.90), DCM (HR 3.33, CI 95%: 2.18–5.10), and VHD (HR 3.97, CI 95%: 2.25–6.99) had worse prognoses and it was significantly better in BS patients (HR 0.11, 95% CI: 0.01–0.67, p=0.017) (Figure 1B). In multivariate analysis, age, gender, AF, renal failure, diabetes and reduced LVEF, emerged as independent predictors of all-cause death (Table 1). Conclusions Irrespective of the aetiology, contemporary ICD patients with an arrhythmic substrate derived from left ventricular systolic dysfunction had a similar risk of ICD life-saving interventions and death. Funding Acknowledgement Type of funding sources: None. Table 1Figure 1

Long-term follow-up of patients with tetralogy of fallot and implantable cardioverter defibrillator–The DAI-T4F nationwide registry

Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart disease, and sudden cardiac death represents an important mode of death in these patients. Data evaluating the implantable cardioverter defibrillator (ICD) in this patient population remain scarce. We aimed to describe long-term follow-up of TOF patients implanted with ICD through a nationwide French registry. Nationwide French Registry including all TOF patients with an ICD initiated in 2010 by the French Institute of Health and Medical Research. The primary time to event endpoint was the time from ICD implantation to first appropriate ICD therapy. Clinical events were centrally adjudicated by a blinded committee. A total of 165 patients (mean age 42.2 ± 13.3 years, 70.1% males) were included from 40 centers, including 104 (63.0%) in secondary prevention. During a median (IQR) follow-up of 6.8 (2.5–11.4) years, 78 (47.3%) patients received at least one appropriate ICD therapy. The annual incidence of the primary outcome was 10.5% (7.1% and 12.5% in primary and secondary prevention, respectively, P = 0.03). Overall, 71 (43.0%) patients presented with at least one ICD complication, including inappropriate shocks in 42 (25.5%) patients and lead dysfunction in 36 (21.8%) patients. Among 61 (37.0%) primary prevention patients, the annual rate of appropriate ICD therapies was 4.1%, 5.3%, 9.5%, and 13.3% in patients with respectively no, one, two, or ≥ three guideline-recommended risk factors. QRS fragmentation was the only independent predictor of appropriate ICD therapies (HR 3.47, 95% CI 1.19–10.11), and its integration in a model with current criteria increased the 5-year time-dependent area under the curve from 0.68 to 0.81 (P = 0.006) (Fig. 1). Patients with TOF and an ICD experience high rates of appropriate therapies, including those implanted in primary prevention. The considerable long-term burden of ICD-related complications, however, underlines the need for careful candidate selection. A combination of easy-to-use criteria including QRS fragmentation might improve risk stratification.

Prognostic role of left atrial enlargement in patients with implantable cardioverter defibrillators for primary prevention

Purpose Left atrial volume index (LAVI) is a predictor of heart failure and adverse events, irrespective of left ventricular systolic function. The role of LAVI in the prediction of appropriate implantable cardioverter-defibrillator (ICD) therapies is currently unclear and was the focus of this study. Methods Consecutive heart failure patients with ischaemic (ICM) or idiopathic (DCM) aetiology receiving ICD for primary prevention were included. The primary endpoint was the occurrence of appropriate ICD therapies (ATs): shocks or antitachycardia pacing (ATP). Inappropriate ICD shocks were also assessed as secondary endpoint. Results Among 198 included patients, severe left atrial dilatation (SLAE = LAVI ≥ 60 ml/m2) was present in 54 (27%). SLAE patients had a higher prevalence of NYHA class ≥ III, severe mitral regurgitation and atrial fibrillation history. During a median follow-up of 45 months (IQR 25–68), ATs occurred more frequently in SLAE group (33% vs. 15%, p = .007) as well as appropriate shocks (24% vs. 10%, p = .014). At multivariate analysis SLAE was an independent predictor of ATs (OR 3.19, 95% CI 1.38–7.38, p = .007). Inappropriate shocks were associated with AF during implantation (p = .03), but not with SLAE (p = .009). Conclusion In DCM or ICM patients candidate to receive an ICD for primary prevention, a severely enlarged left atrium is a predictive factor for ATs (shocks or ATP). The risk of inappropriate shocks was increased in patients with atrial fibrillation, rather than SLAE.

Long-term follow-up of patients with tetralogy of Fallot and implantable cardioverter defibrillator

Abstract Background Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart disease, and sudden cardiac death represents an important mode of death in these patients. Data evaluating the implantable cardioverter defibrillator (ICD) in this patient population remain scarce. Purpose We aimed to describe long-term follow-up of patients with TOF and ICD through a large nationwide registry. Methods Nationwide Registry including all TOF patients with an ICD initiated in 2010. The primary outcome was the first appropriate ICD therapy. Secondary outcomes included ICD-related complications, heart transplantation, and death. Clinical events were centrally adjudicated by a blinded committee. Cox proportional hazard models were used to identify predictors of appropriate ICD therapies and ICD-related complications. Results A total of 165 patients (mean age 42.2±13.3 years, 70.1% males) were included from 40 centers, including 104 (63.0%) in secondary prevention. During a median (IQR) follow-up of 6.8 (2.5–11.4) years, 78 (47.3%) patients received at least one appropriate ICD therapy, giving an annual incidence of 10.5% (7.1% and 12.5% in primary and secondary prevention, respectively, p=0.03). Overall, 71 (43.0%) patients presented with at least one complication, including inappropriate ICD shocks in 42 (25.5%) patients and lead/generator dysfunction in 36 (21.8%) patients. Among 61 (37.0%) primary prevention patients, the annual rate of appropriate ICD therapies was 4.1%, 5.3%, 9.5%, and 13.3% in patients with respectively no, one, two, or ≥ three guideline-recommended risk factors. In our cohort, QRS fragmentation was the only independent predictor of appropriate ICD therapies (HR 4.34, 95% CI 1.42–13.23), and its integration in a model with current criteria increased the area under the curve from 0.61 to 0.72 (p=0.006). No patient with left ventricular ejection fraction (LVEF) ≤35% without at least one other risk factor had appropriate ICD therapy. Patients with congestive heart failure and/or reduced LVEF had a higher risk of non-sudden death or heart transplantation (HR=11.01, 95% CI: 2.96–40.95). Conclusions Our findings demonstrate high rates of appropriate therapies in TOF patients with an ICD, including in primary prevention. The considerable long-term burden of ICD-related complications, however, underlines the need for careful candidate selection. A combination of easy-to-use criteria might improve risk stratification beyond low LVEF. Freedom from appropriate ICD therapy Funding Acknowledgement Type of funding source: None

Long-term follow up ventricular tachycardia patients with preserved cardiac function -from Japanese cardiac sarcoidosis nationwide questionnaire survey-

Abstract Background Prior ventricular tachycardia (VT) and low left ventricular ejection fraction (LVEF) are the most important prognostic factors in cardiac sarcoidosis (CS). Recently diagnosis of CS was renewed according to Japanese new guidelines. Patients with preserved cardiac function often have VT events, thus new guidelines recommends to assess the implantable cardioverter defibrillator (ICD) implantation for CS patients with preserved LVEF (35%≤LVEF&amp;lt;50%). However, the long-term prognosis of CS patients with preserved LVEF is unclear. Objective In CS patients with preserved LVEF, we evaluated the prognosis between VT manifestation and non-VT manifestation groups at CS diagnosis from Japanese nationwide questionnaire survey. Methods Total of 757 Japanese patients from 57 hospitals who diagnosed CS were examined. Patients who unsatisfied the criteria of the Japanese new guidelines, who had LVEF≤35%, LVEF&amp;gt;50%, or who underwent cardiac transplantations were excluded. 104 patients with LVEF 35–50% (67 females, mean age 60±15 years old, median follow-up periods 2134 days [interquartile range: 758–2935 days]) were analyzed. The prognosis between VT manifestation and non-VT manifestation groups at CS diagnosis were evaluated. Results 30 patients had VT manifestation at CS diagnosis and 24 patients (80%) received ICDs. 74 patients had no VT manifestation at CS diagnosis and 19 patients (44%) received ICDs during follow up period. All-cause mortality was not different between two groups (Figure). Appropriate ICD therapy of non-VT manifestation group was significantly lower compared with that of VT manifestation group (log-rank p=0.001), however considerable number (n=7, 15%) of non-VT manifestation group had appropriate ICD therapy event during follow-up period. Cox hazard analysis revealed that concomitant non-sustained VT (NSVT) with atrioventricular block (AVB) was a predictor of appropriate ICD therapy in non-VT manifestation group. Conclusion This nationwide survey showed that considerable number of CS patients with preserved LVEF had VT events, independent of VT manifestation. Concomitant NSVT with AVB was a predictor of VT events, and ICD implantation should be assessed. Funding Acknowledgement Type of funding source: None

Long-Term Follow-Up of Patients With Tetralogy of Fallot and Implantable Cardioverter Defibrillator: The DAI-T4F Nationwide Registry.

Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart disease, and sudden cardiac death represents an important mode of death in these patients. Data evaluating the implantable cardioverter defibrillator (ICD) in this patient population remain scarce. A Nationwide French Registry including all patients with tetralogy of Fallot with an ICD was initiated in 2010 by the French Institute of Health and Medical Research. The primary time to event end point was the time from ICD implantation to first appropriate ICD therapy. Secondary outcomes included ICD-related complications, heart transplantation, and death. Clinical events were centrally adjudicated by a blinded committee. A total of 165 patients (mean age, 42.2±13.3 years, 70.1% males) were included from 40 centers, including 104 (63.0%) in secondary prevention. During a median (interquartile range) follow-up of 6.8 (2.5-11.4) years, 78 (47.3%) patients received at least 1 appropriate ICD therapy. The annual incidence of the primary outcome was 10.5% (7.1% and 12.5% in primary and secondary prevention, respectively; P=0.03). Overall, 71 (43.0%) patients presented with at least 1 ICD complication, including inappropriate shocks in 42 (25.5%) patients and lead dysfunction in 36 (21.8%) patients. Among 61 (37.0%) patients in primary prevention, the annual rate of appropriate ICD therapies was 4.1%, 5.3%, 9.5%, and 13.3% in patients with, respectively, 0, 1, 2, or ≥3 guidelines-recommended risk factors. QRS fragmentation was the only independent predictor of appropriate ICD therapies (hazard ratio, 3.47 [95% CI, 1.19-10.11]), and its integration in a model with current criteria increased the 5-year time-dependent area under the curve from 0.68 to 0.81 (P=0.006). Patients with congestive heart failure or reduced left ventricular ejection fraction had a higher risk of nonarrhythmic death or heart transplantation (hazard ratio, 11.01 [95% CI, 2.96-40.95]). Patients with tetralogy of Fallot and an ICD experience high rates of appropriate therapies, including those implanted in primary prevention. The considerable long-term burden of ICD-related complications, however, underlines the need for careful candidate selection. A combination of easy-to-use criteria including QRS fragmentation might improve risk stratification. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03837574.

Primary prevention implantable cardioverter-defibrillators in hypertrophic cardiomyopathy—Are there predictors of appropriate therapy?

Identifying patients with hypertrophic cardiomyopathy (HCM) who warrant a primary prevention implantable cardioverter-defibrillator (ICD) is crucial. ICDs are effective in terminating life-threatening arrhythmias; however, ICDs carry risks of complications. The purpose of this study was to assess the incidence and predictors of appropriate ICD therapies, inappropriate shocks, and device-related complications in patients with HCM and primary prevention ICDs. All patients with HCM who underwent primary prevention ICD implantation at Toronto General Hospital between September 2000 and December 2017 were identified. Therapies (shocks or antitachycardia pacing) for ventricular tachycardia >180 beats/min or ventricular fibrillation were considered appropriate. Three hundred two patients were followed for a mean 6.1 ± 4.3 years (1801 patient-years of follow-up). Thirty-eight patients (12.6%) received at least 1 appropriate ICD therapy (2.3%/y); the 5-year cumulative probability of receiving appropriate ICD therapy was 9.6%. None of the conventional risk factors nor the European Society of Cardiology risk score was associated with appropriate ICD therapy. In multivariable analysis, age < 40 years at implantation and atrial fibrillation were independent predictors of appropriate ICD therapy. In a subgroup of patients who had undergone cardiac magnetic resonance imaging before ICD implantation, severe late gadolinium enhancement was the strongest predictor of appropriate ICD therapies. ICD-related complications or inappropriate shocks occurred in 87 patients (28.8%), with an inappropriate shock rate of 2.1%/y; the 5-year cumulative probability was 10.7%. The incidence of appropriate ICD therapies in patients with HCM and primary prevention ICDs is lower than previously reported; a high proportion of patients suffer from an ICD-related complication. Traditional risk factors have low predictive utility. Severe late gadolinium enhancement, atrial fibrillation, and young age are important predictors of ventricular tachyarrhythmias in HCM.

Revascularization of coronary chronic total occlusions in an infarct‐related artery and recurrence of ventricular arrhythmias among patients with secondary prevention implantable cardioverter defibrillator

To evaluate whether the revascularization of a coronary chronic total occlusion in an infarct-related artery (IRACTO) may be associated with lower recurrence of ventricular arrhythmias (VA) among patients with a secondary prevention implantable cardioverter defibrillator (ICD). IRACTO is increasingly recognized as an independent predictor of VA. It is unknown whether IRACTO revascularization can reduce the burden of VA. Multicenter observational cohort study that included consecutive patients with prior myocardial infarction and secondary prevention ICD. The primary endpoint was any appropriate ICD therapy. Among the 460 patients included, 269 (58%) had at least one IRACTO at the coronary angiogram performed before ICD implantation; of these, 20 (7%) had their IRACTO successfully revascularized (IRACTO-R) afterwards. During a median follow-up of 48 months, 229 patients (49%) had at least one appropriate ICD therapy. Patients with IRACTO not revascularized (IRACTO-NR) had the highest incidence of ICD therapies (65%) while patients with IRACTO-R had the lowest (10%, p < .001). In the entire cohort, IRACTO-NR was an independent predictor of appropriate ICD therapies (HR 2.85, p < .001) and appropriate ICD shocks (HR 2.94, p < .001). Among patients with IRACTO at baseline, IRACTO-R was independently associated with a marked reduction of appropriate ICD therapies (HR 0.12, p = .002) and appropriate ICD shocks (HR 0.21, p = .03). In patients with prior myocardial infarction and secondary prevention ICD, IRACTO revascularization was independently associated with a markedly lower incidence of appropriate ICD therapies and shocks. These results should be corroborated by larger prospective studies.

Predictive value of rapid-rate non-sustained ventricular tachycardia in the occurrence of appropriate implantable cardioverter-defibrillator therapy

Rapid-rate non-sustained ventricular tachycardia (RR-NSVT) that meets detection criteria but terminates itself before the delivery of implantable cardioverter-defibrillator (ICD) therapy is not rare in routine ICD interrogation. Whether sustained ventricular tachycardia/fibrillation will occur in a short time after RR-NSVT has not been fully elucidated. Clinical features and follow-up data of 828 ICD patients with home monitoring were retrospectively collected. RR-NSVT characteristics and time interval between the first episode of RR-NSVT and subsequent appropriate ICD therapy were analyzed. During a mean follow-up of 44.75 ± 20.87months, 335 episodes of RR-NSVT were documented in 145 patients. A total of 119 patients had both RR-NSVT and appropriate ICD therapy. In multivariate COX regression models, RR-NSVT was an independent predictor of appropriate ICD therapy (HR 7.599, 95%CI 5.926-9.745, P < 0.001), appropriate shock (HR 6.222, 95%CI 4.667-8.294, P < 0.001), and all-cause mortality (HR 2.156, 95%CI 1.499-3.099, P < 0.001). Appropriate ICD therapy was administered after the first RR-NSVT episode in 101 patients, with a median interval of 21days. Compared to RR-NSVT with appropriate ICD therapy occurring beyond 21days, RR-NSVT within 21days prior to appropriate ICD therapy had a longer median duration time (14s vs. 12s, P = 0.013), but without significant difference in mean RR interval at initial detection and mean RR interval after episode termination. Rapid-rate non-sustained VT was an independent predictor of appropriate ICD therapy and all-cause mortality. The presence of RR-NSVT should be considered a possible herald of more serious cardiac events in ICD patients.

Mean entropy predicts implantable cardioverter-defibrillator therapy using cardiac magnetic resonance texture analysis of scar heterogeneity

Risk stratification of ventricular arrhythmia remains complex in patients with ischemic and nonischemic cardiomyopathy. The purpose of this study was to determine whether scar heterogeneity, quantified by mean entropy, predicts appropriate implantable cardioverter-defibrillator (ICD) therapy. We hypothesized that higher mean entropy calculated from cardiac magnetic resonance texture analysis (CMR-TA) will predict appropriate ICD therapy. Consecutive patients underwent CMR imaging before ICD implantation. Short-axis left ventricular scar was manually segmented. CMR-TA was performed using a Laplacian filter to extract and augment image features to create a scar texture from which histogram analysis of pixel intensity was used to calculate mean entropy. The primary end point was appropriate ICD therapy. A total of 114 patients underwent CMR-TA (ischemic cardiomyopathy [ICM]: n = 70; nonischemic cardiomyopathy [NICM]: n = 44) with a median follow-up of 955 days (interquartile range 691-1185 days). Mean entropy was significantly higher in the ICM group (5.7 ± 0.7 vs 5.5 ± 0.7; P= .045). Overall, 33 patients received appropriate ICD therapy. Using optimized cutoff values from receiver operating characteristic curves, Kaplan-Meier survival analysis demonstrated time until first appropriate therapy was significantly shorter in the high mean entropy group (P = .003). Multivariable analysis showed that mean entropy was the sole predictor of appropriate ICD therapy (hazard ratio 1.882; 95% confidence interval 1.083-3.271; P = .025). In the ICM group, mean entropy remained an independent predictor of appropriate ICD therapy, whereas in the NICM group, precontrast T1 values were the sole predictor. Scar heterogeneity, quantified by mean entropy using CMR-TA, was an independent predictor of appropriate ICD therapy in the mixed cardiomyopathy cohort and ICM-only group, suggesting a potential role for CMR-TA in predicting ventricular arrhythmia and risk-stratifying patients for ICD implantation.

Left ventricular sphericity index analysis for the prediction of appropriate implantable cardioverter-defibrillator therapy.

Implantable cardioverter-defibrillator (ICD) is the most effective therapy currently available to prevent sudden cardiac death (SCD) in patients with left ventricular (LV) dysfunction. Although LV ejection fraction (LVEF) is an excellent marker of SCD in these patients, determining other predictors might help to identify patients who will be benefit more from device implantation. The purpose of this study was to determine whether abnormal LV sphericity index (SI) in transthoracic echocardiography is associated with appropriate ICD therapy in these patients. A total of 140 patients with primary ICD implantation (mean age 62.59±11.36years; 98 [70%] male) were included. The patients were classified into "no ICD therapy" or "ICD therapy" group according to the information of their devices for a maximum of 2 previous years. In four-chamber view image of transthoracic echocardiography, SI was calculated by dividing the major-axis dimension to minor-axis dimension of LV in both groups. Compared with patients with no ICD therapy, patients in ICD therapy group had lower LVEF (31.36±9.58vs 23.24±6.03, P=0.0001) and lower SI (1.79±0.29vs 1.57±0.32, P=0.0001). In multivariant logistic regression analysis, the SI of ≤1.58 was associated with fourfold increase of appropriate ICD therapy, even after adjusting for LVEF (odds ratio, 4.08; 95% confidence interval, 1.71-9.75; P=0.02). Simple echocardiographic sphericity dimension index as a marker of cardiac remodeling may be an important predictor of appropriate ICD therapy in patients with primary prevention ICDs and may provide additive risk stratification in patients with LV systolic dysfunction.

Role of cardiac 123I-mIBG imaging in predicting arrhythmic events in stable chronic heart failure patients with an ICD

BackgroundDespite therapeutic improvement, the prognosis of chronic heart failure (CHF) remains unfavorable partly due to arrhythmia and sudden cardiac death (SCD). This prospective study evaluated myocardial 123I-meta-iodobenzylguanidine (123I-mIBG) scintigraphy as a predictor of arrhythmic events (AE) in CHF patients. Methods170 CHF patients referred for implantable cardioverter-defibrillator (ICD) implantation for both primary and secondary prevention were enrolled. All patients underwent planar and SPECT imaging. Early and late heart-to-mediastinum (H/M) ratio, 123I-mIBG washout (WO), early and late summed SPECT scores were calculated The primary endpoint was an AE: sustained ventricular tachycardia, resuscitated cardiac arrest, appropriate ICD therapy or SCD. The secondary endpoint was appropriate ICD therapy. ResultsDuring a median follow-up of 23.3 months, 69 patients experienced an AE. Early summed score (ESS) was the only independent predictor of AE [HR 1.023 (1.003-1.043)]. Focussing on only patients with an ICD for primary prevention, ESS was the only independent predictor of AE [HR 1.028 (1.007-1.050)]. 123I-mIBG-derived parameters failed to be independent predictors of appropriate ICD therapy. However there was a “bell-shaped” relation between 123I-mIBG scintigraphy-derived parameters and AE and appropriate ICD therapy, i.e., those with intermediate 123I-mIBG abnormalities tended to be at higher risk of events. ConclusionAlthough SPECT 123I-mIBG scintigraphy was associated with AE in CHF patients with ICD implantation for primary and secondary prevention, no association was found between 123I-mIBG scintigraphy-derived parameters and appropriate ICD therapy.

Increased risk of ventricular arrhythmias in survivors of out-of-hospital cardiac arrest with chronic total coronary occlusion

Chronic total occlusion (CTO) is common in out-of-hospital cardiac arrest (OHCA) survivors with coronary artery disease. It is unclear whether CTO contributes to ventricular arrhythmias in this population. This study sought to evaluate the impact of unrevascularized CTOs on the occurrence of appropriate implantable cardioverter-defibrillator (ICD) therapy and all-cause mortality in OHCA survivors with coronary artery disease. This was a retrospective study that included all consecutive OHCA survivors with coronary artery disease who received an ICD from December 1999 until June 2015. Study end points were appropriate ICD therapy and all-cause mortality. We identified 217 OHCA survivors (mean age 63 ± 10 years; 187 men (86%)) with coronary artery disease. Unrevascularized CTO was present in 71 of 217 patients (33%) at the time of ICD implantation. During a median follow-up of 61 months (interquartile range, 28-97 months), 57 of 217 patients (26%) experienced an appropriate ICD therapy. Patients with CTO had a higher incidence of appropriate ICD therapy in comparison to patients without CTO (log-rank, P = .002). Multivariate Cox regression analysis identified CTO (hazard ratio 2.07; 95% confidence interval 1.23-3.50; P=.007) as an independent predictor of appropriate ICD therapy. The presence of CTO was not associated with a higher mortality rate (log-rank, P = .18). In OHCA survivors with coronary artery disease receiving an ICD for secondary prevention, CTO was an independent predictor for the occurrence of ventricular arrhythmias but not for mortality.

Chronic total occlusion in an infarct-related coronary artery and the risk of appropriate ICD therapies.

Risk stratification for ventricular arrhythmias in patients with ischemic cardiomyopathy needs to be improved. Coronary chronic total occlusions in an infarct-related artery (IRA-CTOs) have been associated with an increased arrhythmic risk. This study aimed to evaluate the association between IRA-CTOs and appropriate implantable cardioverter-defibrillator (ICD) therapies. Observational cohort study that included 342 patients with ischemic cardiomyopathy, an ICD implanted for primary or secondary prevention, and a coronary angiography performed shortly before ICD implantation. The ICD was implanted for primary prevention in 163 patients (48%). IRA-CTO was found in 161 patients (47%). During a median follow-up of 33months, 41% of patients experienced at least one appropriate ICD therapy. Patients with IRA-CTO had higher proportions of appropriate ICD therapies (57%vs. 26%, P < 0.001) and appropriate ICD shocks (40%vs. 17%, P < 0.001). At multivariate Cox regression, IRA-CTO was the only variable that consistently resulted as independent predictor of appropriate ICD therapies and shocks both in the global population of the study (HR 2.3, P < 0.001 and HR 3, P < 0.001, respectively) and when analyzing separately patients with primary or secondary prevention ICD. IRA-CTO is an independent predictor of appropriate ICD therapies, including appropriate ICD shocks. This association is consistent across all the subgroups analyzed. Patients with IRA-CTO have a very high risk of appropriate ICD therapies. These findings may help improving risk stratification as well as the management of ventricular arrhythmias in patients with ischemic cardiomyopathy.

Impact of Chronic Total Coronary Occlusion on Recurrence of Ventricular Arrhythmias in Ischemic Secondary Prevention Implantable Cardioverter-Defibrillator Recipients (VACTO Secondary Study): Insights From Coronary Angiogram and Electrogram Analysis

ObjectivesThis study sought to evaluate the incidence and clinical effect of coronary chronic total occlusions (CTOs) in patients with ischemic cardiomyopathy receiving an implantable cardioverter-defibrillator (ICD) for secondary prevention of sudden cardiac death (SCD). BackgroundCTOs are common in patients with ischemic cardiomyopathy, which is the major cause of SCD. However, the impact of CTO in SCD survivors receiving an ICD is unknown. MethodsA total of 425 patients who had survived an episode of ventricular arrhythmias and underwent ICD implantation for secondary prevention in 8 centers were included. Coronary angiogram, CTO angiographic characteristics, and ventricular arrhythmia pattern were centrally analyzed. Primary and secondary endpoints were appropriate ICD therapies and mortality during a median follow-up of 4.1 years, according to the presence of CTO in the baseline angiogram. ResultsAppropriate ICD therapies were higher in patients with CTO (51.7% vs. 36.3%; p = 0.001 at 4 years). Left ventricular ejection fraction (LVEF) (p = 0.015) and CTO (p = 0.001) were independent predictors of appropriate ICD therapy. Ventricular arrhythmia onset was associated to a shorter coupling interval and lower prematurity index in CTO patients. Defibrillator therapies were independently associated with worse LVEF (p = 0.046) and renal dysfunction (p = 0.023) among patients with CTO, and a tendency was observed in patients with better collateral flow (p = 0.093). Patients with poorer renal function (p = 0.029), LVEF (p = 0.041), and CTO (p = 0.033) experienced higher mortality rate. ConclusionsAmong ICD recipients for secondary prevention of SCD, coronary CTO conferred a higher risk of VA recurrence and mortality in long-term follow-up. Angiographic and VA patterns could provide insights into the mechanisms of SCD and may have implications for the use of interventions designed to limit ICD shocks in this high-risk population.

Left ventricular geometry predicts ventricular tachyarrhythmia in patients with left ventricular systolic dysfunction: a comprehensive cardiovascular magnetic resonance study

BackgroundMost patients with implantable cardioverter-defibrillator (ICD) implantation fail to utilize the device resulting in increasing societal costs and patient exposure to device morbidity. We sought to determine whether volumetric cardiovascular magnetic resonance (CMR) left ventricular (LV) spherical remodeling predicts future ventricular arrhythmias in primary ICD patients with reduced LV ejection fraction (EF).MethodsSixty-eight consecutive patients with transthoracic echocardiographic LVEF <35% referred for CMR prior to ICD implantation for primary prevention of sudden death were identified. Sphericity index was measured as the ratio of LV end-diastolic volume (from cine short axis stack) to the volume of a sphere with a LV end-diastolic 4-chamber length diameter.ResultsDuring a median follow-up of 55 months (interquartile range; 28–88), 15 patients (22%) received appropriate ICD therapy. Multivariable Cox’s proportional hazard modeling identified increased CMR-derived sphericity index as the strongest independent predictor of appropriate ICD therapy (hazard ratio [HR], 1.09; 95% confidence interval [CI], 1.02 to 1.16; p = 0.007). In addition, dichotomized volumetric CMR-derived sphericity index ≥0.57 carried a 4-fold hazard risk for appropriate ICD therapy, controlling for age and LVEF (HR, 4.49; 95% CI, 1.53 to 13.21; p = 0.006). When sphericity index, LVEF and mass index were used in combination, important incremental prognostic information was achieved (net reclassification improvement, 0.42; 95% CI, 0.06 to 0.77).ConclusionsThe combined assessment of LV geometry, mass index and systolic function may provide incremental prognostic information regarding ventricular arrhythmia requiring appropriate ICD therapy in primary prevention patients with reduced LVEF.

Persistence of ICD indication at the time of replacement in patients with initial implant for primary prevention indication: Effect on subsequent ICD therapies

BackgroundIndication to implantable cardioverter defibrillator (ICD) for primary prevention of sudden death relies on left ventricular ejection fraction (LVEF). We measured the proportion of patients in whom indication to ICD persisted at the time of generator replacement (GR) and searched for predictors of appropriate therapies after GR. MethodsWe identified all consecutive patients who had received an ICD at our hospital, for LVEF ≤35% and no previous arrhythmias or unexplained syncope. Then, we included the 166 patients who outlived their first device and underwent GR. ResultsAt the time of GR (mean follow-up 59 ± 20 months), ICD indication (i.e. LVEF ≤35% or previously treated ventricular arrhythmias) persisted in 114 (69%) patients. After GR, appropriate ICD therapies were delivered in 30 (26%) patients with persistent ICD indication and in 12 (23%) of the remaining patients (p = 0.656). Nonetheless, the annual rate of therapies was higher in the first group (1.08 versus 0.53 events/year; p < 0.001), as well as the rate of inappropriate therapies (0.03 versus 0 events/year; p = 0.031). The only independent predictor of appropriate ICD therapies after GR was the rate of shocks received before replacement (Hazard Ratio: 1.41; 95% confidence interval: 1.01–1.96; p = 0.041). ConclusionIn heart failure with reduced LVEF, ICD indication persisted at the time of GR in 69% of patients. However, even in the absence of persistent ICD indication at GR, the risk of recurrence of arrhythmic events was not null.

0470: Implantable cardioverter defibrillator in primary prevention for chronic heart failure: incidence and predictors of appropriate therapy

Implantable cardioverter defibrillator (ICD) has been shown to be associated with a significant reduction in the risk of sudden cardiac death. The aim of this study was to assess the prevalence and to identify the clinical predictors of appropriate ICD therapy in patients with chronic heart failure following implantation of an ICD for primary prevention. A monocenter retrospective analysis was performed and all consecutive patients undergoing implantation of ICD for primary prevention were included. Device interrogations were performed and appropriate therapies were recorded. The endpoint follow-up was the last available device interrogation in our center. Of 317 primary prevention patients undergoing ICD implantation, 203 (64%) had ischemic cardiomyopathy (ICM) and 114 had non-ischemic dilated cardiomyopathy (NIDCM). After a mean follow-up time 760±599 days, 56 (17.7%) had received appropriate ICD therapies. Mean LVEF was 26±6%. By univariate comparison, LVDD≥65mm (p=0.035) and lack of diuretic (p=0.024) were predictors for ICD therapy. Absence of cardiac resynchronization therapy device (CRTD) was close to be significant (p=0.055). ICM and NIDCM patients benefit from ICD implantation did not differ (p=0.941). By multivariate analysis, elderly patients ≥65y (HR 1.92, p=0.032), LVDD≥65mm (HR 2.01, p=0.022) and lack of diuretic (HR 0.31, p<0.001) were all significant independent predictors for ICD therapy. Overall, the absence of CRTD device was close to be significant (H 0.53, p=0.062), but was significant in NIDCM population (p=0.007). During follow-up, the onset of atrial fibrillation (p=0.027) and hospitalization for acute heart failure (p=0.002) were significantly associated with ICD-delivered therapy. ICD therapy occurred in 17.7% of primary prevention patients without any difference between ICM and NIDCM. Older age, LV dilatation and absence of diuretic were predictive factors for ICD therapy. Presence of CRTD was close to be significant (figure next page). Abstract 0470 – Figure

High Arrhythmic Burden but Low Mortality during Long-term Follow-up in Arrhythmogenic Right Ventricular Cardiomyopathy

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is associated with a high incidence of ventricular tachyarrhythmia and sudden death. The mainstay of management is the implantable cardioverter defibrillator (ICD). A small number of patient cohorts have generated a large number of reports. Prospective registry data supplemented with clinical and ICD records of 30 patients with ARVC fulfilling the 2010 modified Task Force Criteria. This cohort has not been reported on previously. Median age at diagnosis: 46yrs (range 21-68); 20 (80%) male; six (19%) Maori. Duration of follow-up: 7.4yrs (range 1.7-23). Implantable cardioverter defibrillator implantation in 26; three (12%) for resuscitated sudden cardiac death; 17 (65%) for symptomatic ventricular tachyarrhythmia; three (12%) for syncope; and three (12%) for family history of sudden death attributable to ARVC. Two patients died during follow-up, one had an ICD, though died of a carcinoma. Thirteen (50%) experienced appropriate ICD therapy with median time to therapy 12 months, and four (15%) experienced inappropriate shock therapy. Male gender was an independent predictor of appropriate ICD therapy (HR 1.6, 95% CI 1.5-2.7, P=0.01). The long-term prognosis of patients with ARVC is favourable although high proportions receive appropriate ICD therapy. Male gender is an independent predictor of appropriate ICD therapy.