Undergoing Defibrillator Implantation Research Articles

Cardiac defibrillator implantation in patients with syncope and inducible ventricular arrhythmia: insights from the German Device Registry

History of syncope is an independent predictor for sudden cardiac death. Programmed stimulation may be considered for risk stratification, but data remain sparse among different populations. Here, we analyzed the prognostic value of inducible ventricular arrhythmia (VA) regarding clinical outcome in patients with syncope undergoing defibrillator implantation. Among 4196 patients enrolled in the prospective, multi-center German Device Registry, patients with syncope and inducible VA (n = 285, 6.8%) vs. those with a secondary preventive indication (n = 1885, 45.2%), defined as previously documented sustained ventricular tachycardia or ventricular fibrillation, serving as a control group were studied regarding demographics, device implantation and post-procedural adverse events. Patients with syncope and inducible VA (64.9 ± 14.4 years, 81.1% male) presented less frequently with congestive heart failure (15.1% vs. 29.1%; p < 0.001) and any structural heart disease (84.9% vs. 89.3%; p = 0.030) than patients with a secondary preventive indication (65.0 ± 13.8 years, 81.0% male). Whereas dilated cardiomyopathy (16.8% vs. 23.8%; p = 0.009) was less common, hypertrophic cardiomyopathy (5.6% vs. 2.8%; p = 0.010) and Brugada syndrome (2.1% vs. 0.3%; p < 0.001) were present more often. During 1-year-follow-up, mortality (5.1% vs. 8.9%; p = 0.036) and the rate of major adverse cardiac or cerebrovascular events (5.8% vs. 10.0%; p = 0.027) were lower in patients with syncope and inducible VA. Among patients with inducible VA, post-procedural adverse events including rehospitalization (27.6% vs. 21.7%; p = 0.37) did not differ between those with vs. without syncope. Taken together, patients with syncope and inducible VA have better clinical outcomes than patients with a secondary preventive defibrillator indication, but comparable outcomes to patients without syncope, which underlines the relevance of VA inducibility, potentially irrespective of a syncope.

Cardiac defibrillator implantation in patients with syncope and inducible ventricular arrhythmia: insights from the German DEVICE registry

Abstract Funding Acknowledgements Type of funding sources: None. Background Programmed ventricular stimulation may be considered for risk stratification of sudden cardiac death. The history of syncope is an independent predictor for appropriate device discharge and sudden cardiac death, but data remain sparse among different populations. Purpose The aim of this study was to assess the prognostic value of previous syncope and inducible ventricular arrhythmia (VA) during programmed stimulation in patients undergoing defibrillator implantation. Methods Among 4,196 patients enrolled in the prospective, multi-centre German DEVICE Registry undergoing defibrillator implantation, patients with syncope and inducible VA (n=285, 6.8%) vs. those with a secondary preventive indication (n=1,885, 45.2%) serving as a control group were studied. In an additional analysis of patients with inducible VA, those with vs. without (n=86, 2.1%) previous syncope were compared. Results Patients with syncope and inducible VA (64.9±14.4 years, 81.1% male) presented less often with congestive heart failure (15.1% vs. 29.1%; P&amp;lt;0.001) and any underlying structural heart disease (84.9% vs. 89.3%; P=0.030) with a higher left ventricular ejection fraction (43.7±14.2% vs. 38.1±14.2%; P&amp;lt;0.001) than patients with a secondary preventive indication (65.0±13.8 years, 81.0% male). Whereas dilated cardiomyopathy (16.8% vs. 23.8%; P=0.009) was less common in patients with syncope and inducible VA, hypertrophic cardiomyopathy (5.6% vs. 2.8%; P=0.010) and Brugada syndrome (2.1% vs. 0.3%; P&amp;lt;0.001) were found more frequently. Device implantation was performed more often urgently in patients with syncope and inducible VA (46.4% vs. 22.5%; P=0.005). During 1 year of follow-up, mortality (5.1% vs. 8.9%; P=0.036) and the rate of major adverse cardiac or cerebrovascular events (5.8% vs. 10.0%; P=0.027) were lower in patients with previous syncope and inducible VA compared to patients with a secondary preventive indication. Among patients with inducible VA, post-procedural adverse events including rehospitalization (27.6% vs. 21.7%; P=0.37), defibrillator shocks (16.0% vs. 15.0%; P=0.85) and recurrent syncope (3.0% vs. 0%; P=0.32) did not differ between those with vs. without syncope. Conclusions Patients with a history of syncope and inducible VA present less frequently with most cardiac comorbidities resulting in better outcomes following defibrillator implantation than patients with a secondary preventive indication. Nevertheless, patients with inducible VA experience a relevant number of post-procedural adverse events not differing between those with vs. without syncope, which underlines the importance of VA inducibility, potentially irrespective of the history of syncope.

Can the Norton Scale Score Be Used as an Adjunct Tool for Implantable Defibrillator Patient Selection? A Retrospective Single-Center Cohort Study.

(1) Background: Implantable cardioverter defibrillators (ICDs) have become the standard of care in the prevention of sudden cardiac death, yet studies have shown that competing causes of death may limit ICD benefits. The Norton scale is a pressure ulcer risk score shown to have prognostic value in other fields. The purpose of this study was to assess the use of the Norton scale as an aid for ICD patient selection; (2) Methods: The study was comprised of consecutive patients who underwent defibrillator implantation at Sheba Medical Center between 2008 and 2016. A competing risk analysis was performed to assess the likelihood of death prior to device therapy; (3) Results: 695 patients were included. A total of 59 (8.5%) patients had low admission Norton scale score (ANSS) (≤14), 81 (11.7%) had intermediate ANSS (15−17), and the remainder (79.8%) had high (18−20) ANSS. The cumulative probability of all-cause mortality within one year of ICD implantation in patients with low ANSS was 30%, compared with 20% and 7% among the intermediate- and high-ANSS groups, respectively. Moreover, the one-year mortality rate without ICD therapy in low-ANSS patients was over four-fold compared with that of high-ANSS patients (33% versus 7%, p < 0.0001); (4) Conclusions: The Norton scale could be a useful additional tool in predicting the life expectancy of ICD candidates, thereby improving patient selection.

462 RELATIONSHIP BETWEEN PATIENT GENOTYPE, VENTRICULAR INVOLVEMENT AND SUDDEN CARDIAC DEATH IN PATIENTS WITH ARRHYTHMOGENIC CARDIOMYOPATHY

Abstract Introduction Arrhythmogenic cardiomyopathy (AC) is an important cause of sudden cardiac death (SCD). AC is characterized by areas of fibro-fatty replacement of the myocardium of one or both ventricles, which can be characterized through cardiovascular magnetic resonance (CMR). Several mutations have been associated with the development of AC, most commonly in desmosomal genes. The relationship between the genotype and the disease phenotype (i.e., the extent and severity of myocardial disease and patient outcome) is unclear. Methods We evaluated 280 consecutive patients evaluated in a single CMR laboratory over a 10-year timespan and diagnosed with AC according to the Padua criteria, based on a retrospective evaluation of the electronic health records. All these patients had undergone a genetic testing through Sanger sequencing or Next Generation Sequencing (after 2012). Pathogenic or likely pathogenic mutations and variants of unknown significance were considered. CMR scans performed at diagnosis were examined by an expert blinded to the results of genetic testing to retrieve the location and extent of the areas of fibro-fatty replacement and late gadolinium enhancement (LGE), biventricular volumes and function. Follow-up data were also retrieved. The primary endpoint was SCD or aborted SCD (following successful defibrillator discharge). The secondary endpoint included SCD or aborted SCD plus sustained or non-sustained ventricular tachycardia episodes. Results Patients were more often males (67%), with a mean age of 48±16 years. Gene mutations related to cardiomyopathy were found in 123 patients, and 85 patients harbored mutations in desmosomal genes (DSP, n=41; DSG2, n=16; PKP2, n=16; DSC2, n=6; JUP, n=6), while the other mutations were in genes including TMEM43, LMNA, SCN5A, MYH7, and RYR2. Patients with mutations in desmosomal genes had more often LGE in the left ventricle (LV) than patients with other mutations or with no mutations detected (66% vs. 58% vs. 46%, respectively; p=0.025). Patients with mutations in the DSP gene had a greater LGE extent in terms of number of segments affected (p=0.011), or percent of the LV (p&amp;lt;0.001) compared with patients with other desmosomal mutations or no mutations. No differences between patients with desmosomal or non-desmosomal mutations or no mutations were found in terms of fibro-fatty replacement in the LV (51% vs. 32% vs. 48%; p=0.577), nor in terms of LGE presence or fibro-fatty replacement of the right ventricle (RV; data not shown). Median follow-up duration was 4.4 years (interquartile range 1.8-6.4); 22% of patients underwent defibrillator implantation. Primary endpoint events were recorded in 21 patients (7.5%), with 20 aborted SCD episodes. The secondary endpoint occurred in 58 patients (21%). At Cox regression analysis, the mutation status did not reach statistical significance as univariate predictor of the two endpoints, but LGE in the LV, LGE in ≥2 LV segments, or LGE &amp;gt;9% (considered one at the time) independently predicted both endpoints. Conclusions In patients with AC, mutations in desmosomal genes are found in almost half of patients, and are associated with the presence and a larger extent of LGE in the LV. In turn, the presence and extent of LGE are independent predictor of SCD or aborted SCD.

Abstract 12010: Efficacy and Safety of Dofetilide and Sotalol in Patients With Hypertrophic Cardiomyopathy

Introduction: Patients with hypertrophic cardiomyopathy (HCM) often have atrial fibrillation (AF) and ventricular arrhythmias (VA) requiring rhythm control. In the 2014 AF Guidelines, class III anti-arrhythmic drugs are not recommended in patients with left ventricular hypertrophy, but in the 2020 HCM Guidelines, sotalol (STL) and dofetilide (DOF) are deemed “reasonable” for rhythm control, both based on limited data. Methods: We conducted an observational study (2001-2021) of patients with HCM who were treated with DOF or STL for AF and/or VA. Baseline characteristics and drug-related adverse events were analyzed from the electronic medical record, and rates of discontinuation and arrhythmia recurrence at 1 year and by time of chart review were compared using Kaplan Meier curves and log rank test. Results: There were 21 DOF and 52 STL HCM patients with AF, and 18 STL patients with VA. At 1 year, AF patients on DOF or STL had no significant difference in rates of AF recurrence (42.9% vs 44.2%, p=0.664) or drug discontinuation (38.1% vs 29.4%, p=0.582). Recurrence and discontinuation rates of VA on STL were comparable (Figure). Over a median follow up of 1603 days (IQR 994, 4131), there was a trend toward greater efficacy for STL with respect to less AF recurrence (p=0.085) and less frequent discontinuation (p=0.153; Figure). On univariate analysis, only NYHA class predicted AF recurrence. Reasons for discontinuation were most often for inefficacy or mild side-effects. One patient with prior alcohol septal ablation who was on STL for AF developed complete heart block followed by non-sustained torsades de pointes in the setting of a severe influenza infection and later underwent defibrillator implantation. There were no other cases of pro-arrhythmia or sudden death related to DOF. Conclusions: DOF and STL are modestly effective for the treatment of AF and VA in HCM patients, with a low rate of serious adverse events.

Long-term outcome of patients with cardiolaminopathy undergoing defibrillator implantation: single-center experience

Abstract Background Mutations in the LMNA gene are associated with a high arrhythmic risk. The history of the disease in patients undergoing ICD implantation is poorly characterized. Purpose To evaluate the phenotype of patients with cardiolaminopathy at the time of first ICD implantation, the incidence, characteristics and timing of ventricular arrhythmias (VAs) during follow up and the predictive value of the European score (that assigns a point each to non-sustained VT (NSVT), left ventricular ejection fraction (LVEF)&amp;lt;45% at first contact, male sex and non-missense mutations) and of the Wahbi score (that also includes conduction disturbances) for both VAs and heart failure (HF) related outcomes. Methods Patients were identified retrospectively. Clinical and device data were collected at baseline and during follow-up. Results We identified 26 patients (54% male, 42±8 years, 31% with familial history of sudden cardiac death, 31% with non-missense mutation) undergoing ICD implantation, 96% in primary prevention, 47% with single chamber ICD, 38% with dual chamber ICD. At the time of implantation, 30% had skeletal muscle involvement, 15% history of syncope, 4% of cardiac arrest, 62% previous NSVT. Also, 38% had a history of supraventricular arrhythmias and 61% had AV conduction disturbances. LVEF was 41±11%, 35% were in NYHA class ≥2, the mean European and Wahbi scores were 2.1±0.8 and 18.2±8.9, respectively. During 8.3±5 years, 15% were transplanted, 8% died due to HF, 4% underwent LVAD implantation, despite 31% having received an upgrade to CRT-D. Appropriate device interventions occurred in 46% of patients with a median time to first event of 29 months (IQR 13–93), for a total of 137 ATP, 51% of which effective (median 3ATP/patient, IQR 1–8) and of 26 shocks, 96% of which effective (median 2 shocks/patient, IQR 1–3); 12% had an arrhythmic storm. The first treated arrhythmia was a polymorphic VT/VF in 17%, a monomorphic VT in the others (medium cycle length 293±37 msec). Survival free from appropriate ICD interventions at 1 and at 5 years was 75% and 19% respectively in case of a European score ≥3 vs 94% and 82% in case of a score &amp;lt;3 (Logrank test p&amp;lt;0.01), 72% and 46% in case of Wahbi score ≥30 vs 100% and 86% with score &amp;lt;30 (p&amp;lt;0.01), with no differences in terms of death/transplant (figure). At last follow-up, 92% of patients a were taking beta-blocker, 42% amiodarone, 8% sotalol, 4% flecainide, 8% mexiletine. Also, 4% had undergone invasive VT ablation, 8% bilateral cardiac sympathetic denervation. Conclusions Patients with cardiolaminopathy are at a high risk of both arrhythmic and heart failure progression over the first decade after implantation of the first ICD. A European score ≥3 identifies patients with 5-year shock/ATP free survival of less than 20% but does not predict death/transplantation. The first arrhythmic event in these patients is more frequently a rapid monomorphic VT with modest ATP efficacy. Funding Acknowledgement Type of funding sources: None.

Meta-analysis of catheter ablation in patients with post-infarct cardiomyopathy undergoing defibrillator implantation.

Patients with post-infarct cardiomyopathy and ventricular arrhythmias (VT) necessitating implantable cardioverter defibrillators (ICD) are at risk of recurrent shocks with increased morbidity. A comprehensive search of electronic databases for all randomized clinical trials that evaluated the role of catheter ablation as a preventive strategy at the time of secondary prevention ICD implantation was performed. We calculated hazard ratios (HR) and 95% confidence intervals (CI) using random-effects model. Four trials were identified with a total of 505 patients (average age 66.4 ± 9.0years; 87.7% were male). Preventive ablation was associated with a significant reduction in appropriate device therapies (shocks and/or anti-tachycardia therapy) (HR=0.62; 95% CI=0.46-0.82; P<.01), sustained VT (HR=0.74; 95% CI=0.55-0.99; P=.04) compared to control. There were no differences in inappropriate device shocks (HR=0.80; 95% CI=0.38-1.71), all-cause death (HR=0.93; 95% CI=0.53-1.64), cardiac death (HR=0.63; 95% CI=0.29-1.36), arrhythmic death (HR=0.26; 95% CI=0.05-1.31), or cardiac hospitalization (HR=0.79; 95% CI=0.57-1.11) between strategies. Preventive ablation was associated with improved SF-36 physical component (mean difference=2.81; 95% CI-0.53-5.10; P=.02), but not the mental component (mean difference=1.30; 95% CI=-2.06-4.66). Among patients with post-infarct cardiomyopathy and VT, preventive catheter ablation at the time of ICD implantation is associated with a significant reduction of appropriate ICD therapy and sustained VT, and improvement in the physical component of quality-of-life, but no reduction in mortality.

Right Ventricular Function Coupling to the Pulmonary Circulation Predicts Exercise Tolerance in Patients with Heart Failure and Reduced Ejection Fraction. Insight from the Evaluation of Resynchronization Therapy for Heart Failure (EARTH) Trial

Exercise tolerance has important prognostic value in patients with heart failure and reduced ejection fraction (HFrEF). The relationship between right ventricular function and its coupling to pulmonary circulation (RV-PA) and cardiopulmonary exercise tests (CPET) is not fully understood. We aimed to evaluate the value of RV echocardiographic parameters, including RV-PA, to predict exercise tolerance in HFrEF patients. We performed a sub-analysis of EARTH, which enrolled HFrEF patients undergoing defibrillator implantation. At baseline, an echocardiogram and various CPET [peak VO2; minute ventilation/carbon dioxide production slope (VE/VCO2); 6-minute walk distance (6MWD) and submaximal exercise duration (SED)] were performed. The primary outcome was the correlation of RV-PA (using TAPSE/sPAP, tricuspid annular plane systolic excursion on pulmonary artery systolic pressure ratio (T/P)) with peak VO2. Secondary outcomes include correlation between various RV parameters such as size [diameter at inlet and end-diastolic area in apical 4-chamber], RV function [TAPSE; right ventricular fractional area change (RV-FAC); RV myocardial performance index (RV-MPI)], sPAP and tricuspid regurgitation grade (TRG); and CPET variables. Univariate and multivariate linear regression models were used on patients for which both TAPSE and sPAP were available. 205 patients were enrolled in EARTH, with 100 having data on both TAPSE and sPAP (Men: 70.0%; NYHA class II: 55.0%; mean LVEF 26.5±7.8%). T/P was the only parameter found to be predictive of peak VO2 (β=6.8, p<0.01), together with BMI for 6MWD (β=72.4, p=0.04). ROC analysis for T/P value predictive of peak VO2 ≤14mL/kg/min showed sensitivity and specificity of 0.63 and 0.62 respectively, and area under the curve (AUC) of 0.66 (p<0.01) for an optimal threshold ≤0.45. T/P and RV-MPI were both predictors (β=-18.0, p<0.01; β=18.5, p<0.01 respectively) of VE/VCO2 slope, while only TRG and BMI predicted SED (β=-3.2, p=0.03). In HFrEF patients, RV-PA coupling (using TAPSE/sPAP) is a powerful predictor of maximal and submaximal exercise capacity and has a greater predictive value than the usual parameters including age, sex and LVEF.

RIGHT VENTRICULAR FUNCTION COUPLING TO THE PULMONARY CIRCULATION PREDICTS EXERCISE TOLERANCE IN PATIENTS WITH HEART FAILURE AND REDUCED EJECTION FRACTION: INSIGHT FROM THE EVALUATION OF RESYNCHRONIZATION THERAPY FOR HEART FAILURE (EARTH) TRIAL

Purpose Exercise tolerance has important prognostic value in patients with heart failure and reduced ejection fraction (HFrEF). The relationship between right ventricular function and its coupling to pulmonary circulation (RV-PA) and cardiopulmonary exercise tests (CPET) is not fully understood. We aimed to evaluate the value of RV echocardiographic parameters, including RV-PA, to predict exercise tolerance in HFrEF patients. Methods We performed a sub-analysis of EARTH, which enrolled HFrEF patients undergoing defibrillator implantation. At baseline, an echocardiogram and various CPET [peak VO2; minute ventilation/carbon dioxide production slope (VE/VCO2); 6-minute walk distance (6MWD) and submaximal exercise duration (SED)] were performed. The primary outcome was the correlation of RV-PA (using TAPSE/sPAP, tricuspid annular plane systolic excursion on pulmonary artery systolic pressure ratio (T/P)) with peak VO2. Secondary outcomes include correlation between various RV parameters such as size [diameter at inlet and end-diastolic area in apical 4-chamber], RV function [TAPSE; right ventricular fractional area change (RV-FAC); RV myocardial performance index (RV-MPI)], sPAP and tricuspid regurgitation grade (TRG); and CPET variables. Univariate and multivariate linear regression models were used on patients for which both TAPSE and sPAP were available. Results 205 patients were enrolled in EARTH, with 100 having data on both TAPSE and sPAP (Men: 70.0%; NYHA class II: 55.0%; mean LVEF 26.5±7.8%). T/P was the only parameter found to be predictive of peak VO2 (β=6.8, p Conclusion In HFrEF patients, RV-PA coupling (using TAPSE/sPAP) is a powerful predictor of maximal and submaximal exercise capacity and has a greater predictive value than the usual parameters including age, sex and LVEF.

Evaluation of Right Atrial-Coronary Sinus Pressure Gradients in Patients with Left Ventricular Dysfunction Undergoing Defibrillator Implantation. Description of the Phenomenon of Coronary Sinus Flow Reversal and its Incidence

Evaluation of Right Atrial-Coronary Sinus Pressure Gradients in Patients with Left Ventricular Dysfunction Undergoing Defibrillator Implantation. Description of the Phenomenon of Coronary Sinus Flow Reversal and its Incidence

PPA2 gene is involved in neonatal fatal acute dilated cardiomyopathy

Inherited inborn errors of metabolism can cause premature severe dilated cardiomyopathy in infants and cause sudden unexpected death (SUDI). PPA2 gene encoding the mitochondrial pyrophosphatase is involved in many reactions for energy metabolism of the cell. Biallelic mutations induce a mitochondrial disease with a particularly serious cardiac phenotype. In an international consortium, we identified recently 11 new cases from 5 unrelated families, with homozygous or compound heterozygous hypomorphic PPA2 variations. We reviewed the clinical features and outcomes from both our patients and those previously described in the literature. All of the cases ( n = 28) suffered from cardiac defects. MRI, when performed, showed dilated left ventricle while histology of cardiac muscle documented typical diffuse myocardial fibrosis or necrosis. Twenty-four patients (86%) died suddenly from cardiogenic shock at a median age of 11.5 months (range: 11 days to 20 years) even in case of active resuscitation attempt. Ventricular fibrillation was sometimes noted just before the cardiac arrest. Acute myocarditis was basically suspected. Interestingly, three times, very low alcohol consummation was reported as trigger before the death while 5 children had a proved viral disease. Alcohol metabolism and viral illness likely increase the stress of the cells already deprived of adequate ATP. The survivor cases underwent defibrillator implantation. Moreover two of them expressed mild neurological features such as cerebellar syndrome. PPA2 gene plays a significant role in inherited infant dilated cardiomyopathies. According to the genotype, sudden death can happen very early in the childhood or might be triggered with alcohol absorption or common viral illness. PPA2 should be systematically added in the currently used cardiomyopathy genes panels but also in SUDI's since cardiac manifestations can be extremely acute especially in neonates.

PPA2 gene is involved in neonatal fatal acute dilated cardiomyopathy

Inherited inborn errors of metabolism can cause premature severe dilated cardiomyopathy in infants and cause sudden unexpected death (SUDI). PPA2 gene encoding the mitochondrial pyrophosphatase is involved in many reactions for energy metabolism of the cell. Biallelic mutations induce a mitochondrial disease with a particularly serious cardiac phenotype. In an international consortium, we identified recently 11 new cases from 5 unrelated families, with homozygous or compound heterozygous hypomorphic PPA2 variations. We reviewed the clinical features and outcomes from both our patients and those previously described in the literature [1] , [2] . All of the cases ( n = 28) suffered from cardiac defects. MRI, when performed, showed dilated left ventricle while histology of cardiac muscle documented typical diffuse myocardial fibrosis or necrosis. Twenty-four patients (86%) died suddenly from cardiogenic shock at a median age of 11.5 months (range, 11 days to 20 years) even in case of active resuscitation attempt. Ventricular fibrillation was sometimes noted just before the cardiac arrest. Acute myocarditis was basically suspected. Interestingly, three times, very low alcohol consummation was reported as trigger before the death while 5 children had a proved viral disease. Alcohol metabolism and viral illness likely increase the stress of the cells already deprived of adequate ATP. The survivor cases underwent defibrillator implantation. Moreover, two of them expressed mild neurological features such as cerebellar syndrome. PPA2 gene plays a significant role in inherited infant dilated cardiomyopathies. According to the genotype, sudden death can happen very early in the childhood or might be triggered with alcohol absorption or common viral illness. PPA2 should be systematically added in the currently used cardiomyopathy genes panels but also in SUDI's since cardiac manifestations can be extremely acute especially in neonates.

Geriatric Conditions in Patients Undergoing Defibrillator Implantation for Prevention of Sudden Cardiac Death

Geriatric conditions may influence outcomes among patients receiving implantable cardioverter-defibrillators (ICDs). We sought to determine the prevalence of frailty and dementia among older adults receiving primary prevention ICDs and to determine the impact of multimorbidity on mortality within 1 year of ICD implantation. The cohort included 83 792 Medicare patients from the National Cardiovascular Data Registry ICD Registry who underwent first primary prevention ICD implantation between 2006 and 2009. These data were merged with Medicare analytic files to determine the prevalence of frailty, dementia, and other conditions before ICD implantation, as well as 1-year mortality. A validated claim-based algorithm was used to identify frail patients. Mutually exclusive patterns of chronic conditions were examined. The association of each pattern with 1-year mortality was assessed using logistic regression models adjusted for selected patient characteristics. Approximately 1 in 10 Medicare patients with heart failure receiving a primary prevention ICD had frailty (10%) or dementia (1%). One-year mortality was 22% for patients with frailty, 27% for patients with dementia, and 12% in the overall cohort. Several multimorbidity patterns were associated with high 1-year mortality rates: dementia with frailty (29%), frailty with chronic obstructive pulmonary disease (25%), and frailty with diabetes mellitus (23%). These patterns were present in 8% of the cohort. More than 10% of Medicare beneficiaries with heart failure receiving primary prevention ICDs have frailty or dementia. These patients had significantly higher 1-year mortality than those with other common chronic conditions. Frailty and dementia should be considered in clinical decision-making and guideline development.

Clinical impact of defibrillation testing at the time of implantable cardioverter-defibrillator insertion.

Ventricular fibrillation is routinely induced during implantable cardioverter-defibrillator insertion to assess defibrillator performance, but this strategy is experiencing a progressive decline. We aimed to assess the efficacy of defibrillator therapies and long-term outcome in a cohort of patients that underwent defibrillator implantation with and without defibrillation testing. Retrospective observational series of consecutive patients undergoing initial defibrillator insertion or generator replacement. We registered spontaneous ventricular arrhythmias incidence and therapy efficacy, and mortality. A total of 545 patients underwent defibrillator implantation (111 with and 434 without defibrillation testing). After 19 (range 9-31) months of follow-up, the death rate per observation year (4% vs. 4%; p = 0.91) and the rate of patients with defibrillator-treated ventricular arrhythmic events per observation year (with test: 10% vs. without test: 12%; p = 0.46) were similar. The generalized estimating equations-adjusted first shock probability of success in patients with test (95%; CI 88-100%) vs. without test (98%; CI 96-100%; p = 0.42) and the proportion of successful antitachycardia therapies (with test: 87% vs. without test: 80%; p = 0.35) were similar between groups. There was no difference in the annualized rate of failed first shock per patient and per shocked patient between groups (5% vs. 4%; p = 0.94). In this observational study, that included an unselected population of patients with a defibrillator, no difference was found in overall mortality, first shock efficacy and rate of failed shocks regardless of whether defibrillation testing was performed or not.

Implantable Cardioverter-defibrillator Therapy for Hypertrophic Cardiomyopathy: Usefulness in Primary and Secondary Prevention

Introduction and objectivesHypertrophic cardiomyopathy is a frequent cause of sudden death. Clinical practice guidelines indicate defibrillator implantation for primary prevention in patients with 1 or more risk factors and for secondary prevention in patients with a history of aborted sudden death or sustained ventricular arrhythmias. The aim of the present study was to analyze the follow-up of patients who received an implantable defibrillator following the current guidelines in nonreferral centers for this disease. MethodsThis retrospective observational study included all patients who underwent defibrillator implantation between January 1996 and December 2012 in 3 centers in the province of Barcelona. ResultsThe study included 69 patients (mean age [standard deviation], 44.8 [17] years; 79.3% men), 48 in primary prevention and 21 in secondary prevention. The mean number of risk factors per patient was 1.8 in the primary prevention group and 0.5 in the secondary prevention group (P=.029). The median follow-up duration was 40.5 months. The appropriate therapy rate was 32.7/100 patient-years in secondary prevention and 1.7/100 patient-years in primary prevention (P<.001). Overall mortality was 10.1%. Implant-related complications were experienced by 8.7% of patients, and 13% had inappropriate defibrillator discharges. ConclusionsIn patients with a defibrillator for primary prevention, the appropriate therapy rate is extremely low, indicating the low predictive power of the current risk stratification criteria.

Terapia con desfibrilador automático implantable en la miocardiopatía hipertrófica: utilidad en prevención primaria y secundaria

Introduction and objectivesHypertrophic cardiomyopathy is a frequent cause of sudden death. Clinical practice guidelines indicate defibrillator implantation for primary prevention in patients with 1 or more risk factors and for secondary prevention in patients with a history of aborted sudden death or sustained ventricular arrhythmias. The aim of the present study was to analyze the follow-up of patients who received an implantable defibrillator following the current guidelines in nonreferral centers for this disease. MethodsThis retrospective observational study included all patients who underwent defibrillator implantation between January 1996 and December 2012 in 3 centers in the province of Barcelona. ResultsThe study included 69 patients (mean age [standard deviation], 44.8 [17] years; 79.3% men), 48 in primary prevention and 21 in secondary prevention. The mean number of risk factors per patient was 1.8 in the primary prevention group and 0.5 in the secondary prevention group (P=.029). The median follow-up duration was 40.5 months. The appropriate therapy rate was 32.7/100 patient-years in secondary prevention and 1.7/100 patient-years in primary prevention (P<.001). Overall mortality was 10.1%. Implant-related complications were experienced by 8.7% of patients, and 13% had inappropriate defibrillator discharges. ConclusionsIn patients with a defibrillator for primary prevention, the appropriate therapy rate is extremely low, indicating the low predictive power of the current risk stratification criteria.Full English text available from: www.revespcardiol.org/en

Upper limit of vulnerability during defibrillator implantations predicts the occurrence of appropriate shock therapy for ventricular fibrillation.

The utility of the upper limit of vulnerability (ULV) test in patients undergoing defibrillator implantation has been reported, so the purpose of this study was to evaluate the difference in the clinical outcomes between patients with ULV ≤15 J or >15 J. A total of 165 patients receiving an implantable cardioverter-defibrillator underwent a vulnerability test. At the time of the implantation, we delivered a 15-J shock on the T-peak and ±20 ms later to cover the most vulnerable part of the cardiac cycle. The clinical outcomes were prospectively analyzed. A 15-J shock induced ventricular fibrillation (VF) in 30 patients (ULV >15 J) and did not in 135 (ULV ≤15 J). The characteristics of the 2 groups were comparable. After a mean follow-up of 757 days, Kaplan-Meier curve analysis showed that the ULV ≤15 J group experienced less VF than the ULV >15 J group (log-rank P=0.003). The occurrence of ventricular tachycardia was similar between the 2 groups (P=0.140). Furthermore, the effectiveness of ATP was comparable. After adjusting for other known predictors of shock therapy, a ULV >15 J was independently associated with the occurrence of VF (hazard ratio: 6.25; 95% confidence interval: 1.913-20.40; P<0.01). A high ULV value was associated with a high incidence of VF, which suggests that cardiac vulnerability to electrical shock may be linked to electrical instability.

Implantable Cardioverter-Defibrillators in Patients With COPD

COPD is a common comorbidity in heart failure. The efficacy of implantable cardioverter-defibrillator (ICD) therapy has not been determined in patients with heart failure and COPD. We examined the incidence of ICD shocks and mortality in 628 consecutive patients who underwent defibrillator implantation at the Minneapolis Veterans Affairs Medical Center from 2006 to 2010. The mean age of the patients was 67 ± 10 years, and 99% were men. Patients with COPD (n = 246 [39%]) were functionally more limited (P &lt; .0001) and more likely to have an ICD for primary prevention of sudden death (P = .04) than those without COPD. Over a median 4.1 years (interquartile range [IQR] 2.2-5.7) of follow-up, patients with COPD had a higher incidence of appropriate shocks than those without COPD (29% vs 17%; P &lt; .0001), whereas the incidence of inappropriate shocks was similar (9% vs 10%, P = .61). In multivariable analysis, COPD was associated with a twofold increase in the odds of an appropriate ICD shock (95% CI, 1.3-2.9; P = .001). Incidence of ICD shocks did not vary with severity of COPD. Although all-cause mortality was higher in patients with COPD than in those without COPD (29% vs 21%, P = .029), 1-year mortality (5.3% vs 2.6%, P = .08) and the average time from first appropriate ICD shock to death was comparable (median, 2.3 [IQR, 1.2-4.4] vs 2.8 [IQR, 1.4-5.3] years; P = .29). Patients with COPD have a higher incidence of ICD shocks than those without COPD and appear to benefit from ICD therapy.

Prediction of Mortality in Clinical Practice for Medicare Patients Undergoing Defibrillator Implantation for Primary Prevention of Sudden Cardiac Death

The aim of this study was to derive and validate a practical risk model to predict death within 4 years of primary prevention implantable cardioverter-defibrillator (ICD) implantation. ICDs for the primary prevention of sudden cardiac death improve survival, but recent data suggest that a patient subset with high mortality and minimal ICD benefit may be identified. Data from a development cohort (n = 17,991) and validation cohort (n = 27,893) of Medicare beneficiaries receiving primary prevention ICDs from 2005 to 2007 were merged with outcomes data through mid-2010 to construct and validate complete and abbreviated risk models for all-cause mortality using Cox proportional hazards regression. Over a median follow-up period of 4 years, 6,741 (37.5%) development and 8,595 (30.8%) validation cohort patients died. The abbreviated model was based on 7 clinically relevant predictors of mortality identified from complete model results, referred to as the "SHOCKED" predictors: 75 years of age or older (hazard ratio [HR]: 1.70; 95% confidence interval [CI]: 1.62 to 1.79), heart failure (New York Heart Association functional class III) (HR: 1.35; 95% CI: 1.29 to 1.42), out of rhythm because of atrial fibrillation (HR: 1.26; 95% CI: 1.19 to 1.33), chronic obstructive pulmonary disease (HR: 1.70; 95% CI: 1.61 to 1.80), kidney disease (chronic) (HR: 2.33; 95% CI: 2.20 to 2.47), ejection fraction (left ventricular) ≤ 20% (HR: 1.26; 95% CI: 1.20 to 1.33), and diabetes mellitus (HR: 1.43; 95% CI: 1.36 to 1.50). This model had C-statistics of 0.75 (95% CI: 0.75 to 0.76) and 0.74 (95% CI: 0.74 to 0.75) in the development and validation cohorts, respectively. Validation patients in the highest risk decile on the basis of the SHOCKED predictors had a 65% 3-year mortality rate. A nomogram is provided for survival probabilities 1 to 4 years after ICD implantation. This useful model, based on more than 45,000 primary prevention ICD patients, accurately identifies patients at highest risk for death after device implantation and may significantly influence clinical decision making.

Upper Limit of Vulnerability at Defibrillator Implantation Predicts the Occurrence of Shocks

Background and Purpose: The utility of upper limit of vulnerability (ULV) testing in patients undergoing defibrillator implantation has been reported. The purpose of this study was to evaluate the difference of outcome between patients with ULV 15 J. Methods: A total of 94 consecutive patients were underwent ICD or CRT-D implantation from February 2009 to December 2010. ULV test has performed in 74 patients, which were retrospectively reviewed. At implantation, we delivered 15 J shock on the peak of T-wave three times to ensure that the most vulnerable part of the cardiac cycle is scanned. If VF was not induced, it meant ULV 15 J (n=14) and we delivered 20 J shock subsequently. When defibrillation was failed, defibrillation threshold was examined closely as much as possible. Results: Patient characteristics between two groups were comparable. After mean follow-up of 393±196 days, the proportion of appropriate shocks in the two groups was 0% vs 21% (p=0.003). There was no case of failed appropriate shocks and death in both groups. Conclusion: ULV can be applied to a safety-margin strategy without inducing VF, and also, is the predictor of the occurrence of appropriate shock in patients with ICD.