Association between QRS shortening and mortality after cardiac resynchronization therapy: Results from the DANISH study.

BACKGROUND: Changes in QRS duration (∆QRS) are often used in the clinical setting to evaluate the effect of cardiac resynchronization therapy (CRT), although an association between ∆QRS and outcomes is not firmly established. We aimed to assess the association between mortality and ∆QRS after CRT in patients from the DANISH (Danish Study to Assess the Efficacy of ICDs in Patients with Non-Ischemic Systolic Heart Failure on Mortality) study. METHODS: We included all patients from DANISH who received a CRT device and had available QRS duration data before and after implantation. Cox proportional hazards models were used to assess associations between ∆QRS (post-CRT QRS minus pre-CRT QRS) and mortality. RESULTS: Complete data were available in 572 patients. Median baseline QRS duration was 160 ms (IQR [146;180]). Post-CRT QRS was recorded a median of 48 days (IQR [33;86]) after implantation, and the median ∆QRS was -14 ms (IQR [-38;-3]). During a median follow-up of 4.1 years (IQR [2.5;5.8]), 106 patients died. In crude Cox regression, all-cause mortality was reduced by 6% per 10 ms shortening of QRS (HR 0.94; CI: 0.88-1.00, p = 0.04). The effect did not remain significant after multivariable adjustment (HR 1.01, CI: 0.93-1.10, p = 0.77). Further, no association was found between ∆QRS and improvement of New York Heart Association functional class at 6 months (OR 1.03, CI: 0.96-1.10, p = 0.42). CONCLUSION: In a large cohort of patients with non-ischemic cardiomyopathy, reduction of QRS duration after CRT was not associated with changes in mortality during long-term follow-up.

Efficacy of Implantable Cardioverter Defibrillator in Nonischemic Systolic Heart Failure According to Sex: Extended Follow-Up Study of the DANISH Trial.

BACKGROUND: Men and women may respond differently to certain therapies for heart failure with reduced ejection fraction, including implantable cardioverter defibrillators (ICD). In an extended follow-up study of the DANISH trial (Danish Study to Assess the Efficacy of ICDs in Patients With Non-Ischemic Systolic Heart Failure on Mortality), adding 4 years of additional follow-up, we examined the effect of ICD implantation according to sex. METHODS: In the DANISH trial, 1116 patients with nonischemic systolic heart failure were randomized to receive an ICD (N=556) or usual clinical care (N=550). The primary outcome was all-cause mortality. RESULTS: Of the 1116 patients randomized in the DANISH trial, 307 (27.5%) were women. During a median follow-up of 9.5 years, women had a lower associated rate of all-cause mortality (hazard ratio [HR], 0.60 [95% CI, 0.47-0.78]) cardiovascular death (HR, 0.62 [95% CI, 0.46-0.84]), nonsudden cardiovascular death (HR, 0.59 [95% CI, 0.42-0.85]), and a numerically lower rate of sudden cardiovascular death (HR, 0.70 [95% CI, 0.40-1.25]), compared with men. Compared with usual clinical care, ICD implantation did not reduce the rate of all-cause mortality, irrespective of sex (men, HR, 0.85 [95% CI, 0.69-1.06]; women, HR, 0.98 [95% CI, 0.64-1.50]; Pinteraction=0.51). In addition, sex did not modify the effect of ICD implantation on sudden cardiovascular death (men, HR, 0.57 [95% CI, 0.36-0.92]; women, HR, 0.68 [95% CI, 0.26-1.77]; Pinteraction=0.76). CONCLUSIONS: In patients with nonischemic systolic heart failure, ICD implantation did not provide an overall survival benefit, but reduced sudden cardiovascular death, irrespective of sex. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT00542945.

NT-proBNP and ICD in Nonischemic Systolic Heart Failure: Extended Follow-Up of the DANISH Trial.

OBJECTIVES: In this extended follow-up study of the DANISH (Danish Study to Assess the Efficacy of Implantable Cardioverter Defibrillators in Patients with Non-ischemic Systolic Heart Failure on Mortality) trial, adding 4 years of additional follow-up, we examined the effect of implantable cardioverter-defibrillator (ICD) implantation according to baseline N-terminal pro-B-type natriuretic peptide (NT-proBNP) level. BACKGROUND: In the DANISH trial, NT-proBNP level at baseline appeared to modify the response to ICD implantation. METHODS: In the DANISH trial, 1,116 patients with nonischemic systolic HF were randomized to receive an ICD (N = 556) or usual clinical care (N = 550). Outcomes were analyzed according to NT-proBNP levels (below/above median) at baseline. The primary outcome was death from any cause. RESULTS: All 1,116 patients in the DANISH trial had an available NT-proBNP measurement at baseline (median: 1,177 pg/mL; range: 200-22,918 pg/mL). There was a trend toward a reduction in all-cause death with ICD implantation, compared with usual clinical care, in patients with NT-proBNP levels lower than the median (HR: 0.75 [95% CI: 0.55-1.03]), but not in those with higher NT-proBNP levels (HR: 0.95 [95% CI: 0.74-1.21]) (Pinteraction = 0.28). Similarly, ICD implantation significantly reduced the rate of cardiovascular (CV) and sudden cardiovascular death (SCD) in patients with NT-proBNP levels lower than the median (CV death, HR: 0.69 [95% CI: 0.47-1.00]; SCD, HR: 0.37 [95% CI: 0.19-0.75]), but not in those with higher levels (CV death, HR: 0.94 [95% CI: 0.70-1.25]; SCD, HR: 0.86 [95% CI: 0.49-1.51]) (Pinteraction = 0.20 and 0.08 for CV death and SCD, respectively). CONCLUSIONS: Lower baseline NT-proBNP levels could identify patients with nonischemic systolic HF who may derive benefit from ICD implantation. (Danish Study to Assess the Efficacy of Implantable Cardioverter Defibrillators in Patients with Non-ischemic Systolic Heart Failure on Mortality [DANISH]; NCT00542945).

Periodic Repolarization Dynamics Identifies ICD Responders in Nonischemic Cardiomyopathy: A DANISH Substudy.

BACKGROUND: Identification of patients with nonischemic cardiomyopathy who may benefit from prophylactic implantation of a cardioverter-defibrillator. We hypothesized that periodic repolarization dynamics (PRD), a marker of repolarization instability associated with sympathetic activity, could be used to identify patients who will benefit from prophylactic implantable cardioverter defibrillator (ICD) implantation. METHODS: We performed a post hoc analysis of DANISH (Danish ICD Study in Patients With Dilated Cardiomyopathy), in which patients with nonischemic cardiomyopathy, left ventricular ejection fraction (LVEF) ≤35%, and elevated NT-proBNP (N-terminal probrain natriuretic peptides) were randomized to ICD implantation or control group. Patients were included in the PRD substudy if they had a 24-hour Holter monitor recording at baseline with technically acceptable ECG signals during the night hours (00:00-06:00). PRD was assessed using wavelet analysis according to previously validated methods. The primary end point was all-cause mortality. Cox regression models were adjusted for age, sex, NT-proBNP, estimated glomerular filtration rate, LVEF, atrial fibrillation, ventricular pacing, diabetes, cardiac resynchronization therapy, and mean heart rate. We proposed PRD ≥10 deg2 as an exploratory cut-off value for ICD implantation. RESULTS: A total of 748 of the 1116 patients in DANISH qualified for the PRD substudy. During a mean follow-up period of 5.1±2.0 years, 82 of 385 patients died in the ICD group and 85 of 363 patients died in the control group (P=0.40). In Cox regression analysis, PRD was independently associated with mortality (hazard ratio [HR], 1.28 [95% CI, 1.09-1.50] per SD increase; P=0.003). PRD was significantly associated with mortality in the control group (HR, 1.51 [95% CI, 1.25-1.81]; P<0.001) but not in the ICD group (HR, 1.04 [95% CI, 0.83-1.54]; P=0.71). There was a significant interaction between PRD and the effect of ICD implantation on mortality (P=0.008), with patients with higher PRD having greater benefit in terms of mortality reduction. ICD implantation was associated with an absolute mortality reduction of 17.5% in the 280 patients with PRD ≥10 deg2 (HR, 0.54 [95% CI, 0.34-0.84]; P=0.006; number needed to treat=6), but not in the 468 patients with PRD <10 deg2 (HR, 1.17 [95% CI, 0.77-1.78]; P=0.46; P for interaction=0.01). CONCLUSIONS: Increased PRD identified patients with nonischemic cardiomyopathy in whom prophylactic ICD implantation led to significant mortality reduction.

Long-Term Follow-Up of DANISH (The Danish Study to Assess the Efficacy of ICDs in Patients With Nonischemic Systolic Heart Failure on Mortality).

BACKGROUND: DANISH (The Danish Study to Assess the Efficacy of Implantable Cardioverter Defibrillators [ICDs] in Patients With Nonischemic Systolic Heart Failure on Mortality) found that primary-prevention ICD implantation was not associated with an overall survival benefit in patients with nonischemic systolic heart failure during a median follow-up of 5.6 years, although there was a beneficial effect on all-cause mortality in patients ≤70 years. This study presents an additional 4 years of follow-up data from DANISH. METHODS: In DANISH, 556 patients with nonischemic systolic heart failure were randomized to receive an ICD and 560 to receive usual clinical care and followed until June 30, 2016. In this long-term follow-up study, patients were followed until May 18, 2020. Analyses were conducted for the overall population and according to age (≤70 and >70 years). RESULTS: During a median follow-up of 9.5 years (25th-75th percentile, 7.9-10.9 years), 208/556 patients (37%) in the ICD group and 226/560 patients (40%) in the control group died. Compared with the control group, the ICD group did not have significantly lower all-cause mortality (hazard ratio [HR] 0.89, [95% CI, 0.74-1.08]; P = 0.24). In patients ≤70 years (n = 829), all-cause mortality was lower in the ICD group than the control group (117/389 [30%] versus 158/440 [36%]; HR, 0.78 [95% CI, 0.61-0.99]; P = 0.04), whereas in patients >70 years (n = 287), all-cause mortality was not significantly different between the ICD and control group (91/167 [54%] versus 68/120 [57%]; HR, 0.92 [95% CI, 0.67-1.28]; P = 0.75). Cardiovascular death showed similar trends (overall, 147/556 [26%] versus 164/560 [29%]; HR, 0.87 [95% CI, 0.70-1.09]; P = 0.20; ≤70 years, 87/389 [22%] versus 122/440 [28%]; HR, 0.75 [95% CI, 0.57-0.98]; P = 0.04; >70 years, 60/167 [36%] versus 42/120 [35%]; HR, 0.97 [95% CI, 0.65-1.45]; P = 0.91). The ICD group had a significantly lower incidence of sudden cardiovascular death in the overall population (35/556 [6%] versus 57/560 [10%]; HR, 0.60 [95% CI, 0.40-0.92]; P = 0.02) and in patients ≤70 years (19/389 [5%] versus 49/440 [11%]; HR, 0.42 [95% CI, 0.24-0.71]; P = 0.0008), but not in patients >70 years (16/167 [10%] versus 8/120 [7%]; HR, 1.34 [95% CI, 0.56-3.19]; P = 0.39). CONCLUSIONS: During a median follow-up of 9.5 years, ICD implantation did not provide an overall survival benefit in patients with nonischemic systolic heart failure. In patients ≤70 years, ICD implantation was associated with a lower incidence of all-cause mortality, cardiovascular death, and sudden cardiovascular death. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT00542945.

Prevalence and prognostic association of ventricular arrhythmia in non-ischaemic heart failure patients: results from the DANISH trial.

AIMS: Improved risk stratification to identify non-ischaemic heart failure patients who will benefit from primary prophylactic implantable cardioverter-defibrillator (ICD) is needed. We examined the potential of ventricular arrhythmia to identify patients who could benefit from an ICD. METHODS AND RESULTS: A total of 850 non-ischaemic systolic heart failure patients with left ventricle ≤35% and elevated N-terminal pro-brain natriuretic peptides had a 24-h Holter monitor recording performed. We examined present non-sustained ventricular tachycardia (NSVT), defined as ≥3 consecutive premature ventricular contractions (PVCs) with a rate of ≥100/min, and number of PVCs per hour stratified into low (<30) and high burden (≥30) groups. Outcome measures were overall mortality, sudden cardiac death (SCD), and cardiovascular death (CVD). In total, 193 patients died, 49 from SCD and 125 from CVD. Non-sustained ventricular tachycardia (365 patients) was significantly associated with increased all-cause mortality [hazard ratio (HR) 1.47; 95% confidence interval (CI) 1.07-2.03; P = 0.02] and to CVD (HR 1.89; CI 1.25-2.87; P = 0.003). High burden PVC (352 patients) was associated with increased all-cause mortality (HR1.38; CI 1.00-1.90; P = 0.046) and with CVD (HR 1.78; CI 1.19-2.66; P = 0.005). There was no statistically significant association with SCD for neither NSVT nor PVC. In interaction analyses, neither NSVT (P = 0.56) nor high burden of PVC (P = 0.97) was associated with survival benefit from ICD implantation. CONCLUSION: Ventricular arrhythmia in non-ischaemic heart failure patients was associated with a worse prognosis but could not be used to stratify patients to ICD implantation.

Atrial fibrillation is a marker of increased mortality risk in nonischemic heart failure-Results from the DANISH trial.

BACKGROUND: Atrial fibrillation (AF) in heart failure (HF) patients has been associated with a worse outcome. Similarly, excessive supraventricular ectopic activity (ESVEA) has been linked to development of AF, stroke, and death. This study aimed to investigate AF and ESVEA's association with outcomes and effect of prophylactic implantable cardioverter defibrillator (ICD) implantation in nonischemic HF patients. METHODS: A total of 850 patients with nonischemic HF, left ventricle ejection fraction ≤35%, and elevated N-terminal pro-brain natriuretic peptides underwent 24 hours Holter recording. The presence of AF (≥30 seconds) and ESVEA (≥30 supraventricular ectopic complexes (SVEC) per hour or run of SVEC ≥20 beats) were registered. Outcomes were all-cause mortality, cardiovascular death (CVD), and sudden cardiac death (SCD). RESULTS: AF was identified in 188 patients (22%) and ESVEA in 84 patients (10%). After 4 years and 11 months of follow-up, a total of 193 patients (23%) had died. AF was associated with all-cause mortality (hazard ratio [HR] 1.44; confidence interval [CI] 1.04-1.99; P = .03) and CVD (HR 1.59; CI 1.07-2.36; P = .02). ESVEA was associated with all-cause mortality (HR 1.73; CI 1.16-2.57; P = .0073) and CVD (HR 1.76; CI 1.06-2.92; P = .03). Neither AF nor ESVEA was associated with SCD. ICD implantation was not associated with an improved prognosis for neither AF (P value for interaction = .17), nor ESVEA (P value for interaction = .68). CONCLUSIONS: Both AF and ESVEA were associated with worsened prognosis in nonischemic HF. However, ICD implantation was not associated with an improved prognosis for either group.

Quality of life and the associated risk of all-cause mortality in nonischemic heart failure.

OBJECTIVES: To examine the association between health-related quality of life (HRQoL) and mortality in patients with heart failure (HF). BACKGROUND: The potential association of HRQoL and mortality in patients with HF is unclear. We investigated this association in The Danish Study to Assess the Efficacy of Implantable Cardioverter Defibrillators (ICD) in Patients with Non-ischemic Systolic Heart Failure on Mortality (DANISH). METHODS: In DANISH, a total of 1116 patients with non-ischemic systolic HF on guideline-recommended therapy were randomized to ICD therapy or usual clinical care. HRQoL was assessed at randomization using the disease-specific Minnesota Living with Heart Failure Questionnaire (MLHFQ, 0-105, high score indicating worse HRQoL). Multivariable Cox proportional hazard models were used to compare hazard ratios (HR) for all-cause mortality according to MLHFQ above or below 45, as recommended by a recent meta-analysis, to identify patients with poor HRQoL. RESULTS: HRQoL was completed by 935 (84%) patients at baseline with a median follow-up of 67 months (IQR 47-83). Patients with poor HRQoL (MLHFQ score > 45, median 60 (IQR 53-71),n = 350) had a higher incidence of all-cause mortality than patients with moderate/good HRQoL (MLHFQ ≤45, median 23 (IQR 13-33), n = 585), respectively 26% vs. 18% with an unadjusted HR of 1.57 (95% CI 1.19-2.08, p = .002), and an adjusted HR of 1.39 (95% CI 1.01-1.91, p = .04). CONCLUSION: Poor HRQoL was associated with an increased risk of all-cause mortality after adjustment for traditional risk factors. CLINICAL TRIAL REGISTRATION: https: //clinicaltrials.gov/ct2/show/NCT00542945(DANISH).

Duration of Heart Failure and Effect of Defibrillator Implantation in Patients With Nonischemic Systolic Heart Failure.

BACKGROUND: Patients with nonischemic systolic heart failure (HF) have increased risk of sudden cardiac death (SCD) and death from progressive pump failure. Whether the risk of SCD changes over time is unknown. We seek here to investigate the relation between duration of HF, mode of death, and effect of implantable cardioverter-defibrillator implantation. METHODS AND RESULTS: We examined the risk of all-cause death and SCD according to the duration of HF among patients with nonischemic systolic HF enrolled in the DANISH (Danish Study to Assess the Efficacy of ICDs in Patients with Non-ischemic Systolic Heart Failure on Mortality). In all, 1116 patients were included. Patients were divided according to quartiles of HF duration (≤8, 9≤18, 19≤65, and ≥66 months). Patients with the longest duration of HF were older, more often men, had more comorbidity, and more often received a cardiac resynchronization therapy device. Doubling of HF duration was an independent predictor of both all-cause mortality (hazard ratio [HR], 1.27; 95% CI, 1.17-1.38; P<0.0001), and SCD (HR, 1.29; 95% CI, 1.11-1.50; P=0.0007). The proportion of deaths caused by SCD was not different between HF quartiles (P=0.91), and the effect of implantable cardioverter-defibrillator implantation on all-cause mortality was not modified by the duration of HF (P=0.59). CONCLUSIONS: Duration of HF predicted both all-cause mortality and risk of SCD independently of other risk indicators. However, the proportion of death caused by SCD did not change with longer duration of HF, and the effect of implantable cardioverter-defibrillator was not modified by the duration of HF. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT00542945.

Association between Type D personality and outcomes in patients with non-ischemic heart failure.

PURPOSE: The "distressed" (Type D) personality trait has been reported to be over-represented in patients with heart failure (HF) compared to the background population and may provide prognostic information for mortality. We examined the association between Type D personality and outcomes in the DANISH trial (The Danish Study to Assess the Efficacy of Implantable Cardioverter Defibrillators in Patients with Non-ischemic Systolic Heart Failure on Mortality). METHODS: The DANISH trial included a total of 1116 patients with non-ischemic HF on guideline-recommended therapy. Type D personality was assessed with the Type D Scale (DS14) at baseline and investigated through follow-up accordingly. Multivariable Cox proportional hazard models were used to compare hazard ratios (HR) of cardiovascular and all-cause mortality. RESULTS: Type D personality assessment was completed by 873 (78%) patients at baseline and Type D personality was found in 120 (14%) patients. The median follow-up was 67 months (interquartile range [IQR] 48-83). Among patients with versus without Type D personality, 22% versus 19% died from all-cause yielding similar incidence rates of 4.62 (95% CI 3.14-6.87) versus 3.95 (95% CI 3.37-4.66) per 100 person-years. The adjusted risk of all-cause mortality was not significantly different in patients with versus without Type D personality with an adjusted HR of 1.31 (95% CI 0.84-2.03, p = 0.23) with similar results for cardiovascular death (HR 1.46 (95% CI 0.88-2.44, p = 0.15). CONCLUSION: Type D personality was not significantly associated with increased risk of all-cause mortality or cardiovascular death in patients with non-ischemic HF.

The impact of implantable cardioverter-defibrillator implantation on health-related quality of life in the DANISH trial.

AIM: The Danish Study to Assess the Efficacy of Implantable Cardioverter-Defibrillators (ICD) in Patients with Non-ischaemic Systolic Heart Failure (HF) on Mortality (DANISH) found no overall effect on all-cause mortality. The effect of ICD implantation on health-related quality of life (HRQoL) remains to be established as previous trials have demonstrated conflicting results. We investigated the impact of ICD implantation on HRQoL in patients with non-ischaemic systolic HF, a prespecified secondary endpoint in DANISH. METHODS AND RESULTS: In DANISH, a total of 1116 patients with non-ischaemic systolic HF were randomly assigned (1:1) to ICD implantation or usual clinical care (control). Patients completed disease-specific HRQoL as assessed by Minnesota Living with Heart Failure Questionnaire (MLHFQ; 0-105, high indicating worse). Changes in HRQoL 8 months after randomization were assessed with a mixed-effects model. At randomization, MLHFQ was completed by 935 (84%) patients (n = 472 in the ICD group and n = 463 in the control group) and was reassessed in 274 (58%) and 292 (63%) patients, respectively after 8 months for the primary analysis. Patients in the ICD group vs. the control group had similar improvements in MLHFQ after 8 months [least square mean -7.0 vs. -4.2 (P = 0.13)]. A clinically relevant improvement (decrease ≥5) in the MLHFQ overall score at 8 months was observed in 151 patients in the ICD group and 148 patients in the control group [55% vs. 51%, respectively (P = 0.25)]. CONCLUSION: Implantable cardioverter-defibrillator implantation in patients with non-ischaemic systolic HF did not significantly alter HRQoL compared with patients randomized to usual clinical care.

Single and dual coil shock efficacy and predictors of shock failure in patients with modern implantable cardioverter defibrillators-a single-center paired randomized study.

PURPOSE: Implantable cardioverter defibrillators (ICDs) can treat life-threatening tachyarrhythmia with high-voltage shocks. The aims were to compare the efficacy of single and dual coil shock vectors in modern ICDs and to identify predictors of shock failure. METHODS: This is a single-center paired randomized study including 216 patients with mixed indications and ICDs from four manufacturers. All patients underwent two implant defibrillation tests using single and dual coil vectors with the test order randomized. Tested shock energy differed slightly between manufacturers because of differences in device programmability: first shock approximately 15 J below maximal output-if failed, second shock approximately 10 J below maximal output-if failed, third shock at maximal output. RESULTS: First shock success rate was 399/432 (92.4%). Comparing single and dual coil vectors, no differences were seen in first shock efficacy (91.7% vs. 93.1%, P = 0.629) or lowest tested succesfully stored energy (27.2 J vs. 27.1 J, P = 0.620). All successive internal shocks failed in 4/432 (0.9%) of inductions requiring external rescue shocks to restore circulation. Multivariate predictors of first shock failure were QRS duration (relative risk 0.81 per 10 ms, P = 0.001), amiodarone treatment (relative risk 3.30, P = 0.003), and body height (relative risk 1.70 per 10 cm, P = 0.019). CONCLUSIONS: Implant defibrillation testing of modern intravenous ICD systems demonstrates high shock efficacy with no difference between single and dual coil vectors.

Age and Outcomes of Primary Prevention Implantable Cardioverter-Defibrillators in Patients With Nonischemic Systolic Heart Failure.

BACKGROUND: The DANISH study (Danish Study to Assess the Efficacy of ICDs [Implantable Cardioverter Defibrillators] in Patients With Non-Ischemic Systolic Heart Failure on Mortality) did not demonstrate an overall effect on all-cause mortality with ICD implantation. However, the prespecified subgroup analysis suggested a possible age-dependent association between ICD implantation and mortality with survival benefit seen only in the youngest patients. The nature of this relationship between age and outcome of a primary prevention ICD in patients with nonischemic systolic heart failure warrants further investigation. METHODS: All 1116 patients from the DANISH study were included in this prespecified subgroup analysis. We assessed the relationship between ICD implantation and mortality by age, and an optimal age cutoff was estimated nonparametrically with selection impact curves. Modes of death were divided into sudden cardiac death and nonsudden death and compared between patients younger and older than this age cutoff with the use of χ2 analysis. RESULTS: Median age of the study population was 63 years (range, 21-84 years). There was a linearly decreasing relationship between ICD and mortality with age (hazard ratio [HR], 1.03; 95% confidence interval [CI], 1.003-1.06; P=0.03). An optimal age cutoff for ICD implantation was present at ≤70 years. There was an association between reduced all-cause mortality and ICD in patients ≤70 years of age (HR, 0.70; 95% CI, 0.51-0.96; P=0.03) but not in patients >70 years of age (HR, 1.05; 95% CI, 0.68-1.62; P=0.84). For patients ≤70 years old, the sudden cardiac death rate was 1.8 (95% CI, 1.3-2.5) and nonsudden death rate was 2.7 (95% CI, 2.1-3.5) events per 100 patient-years, whereas for patients >70 years old, the sudden cardiac death rate was 1.6 (95% CI, 0.8-3.2) and nonsudden death rate was 5.4 (95% CI, 3.7-7.8) events per 100 patient-years. This difference in modes of death between the 2 age groups was statistically significant (P=0.01). CONCLUSIONS: In patients with systolic heart failure not caused by ischemic heart disease, the association between the ICD and survival decreased linearly with increasing age. In this study population, an age cutoff for ICD implantation at ≤70 years yielded the highest survival for the population as a whole. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT00542945.

Defibrillator Implantation in Patients with Nonischemic Systolic Heart Failure.

BACKGROUND: The benefit of an implantable cardioverter-defibrillator (ICD) in patients with symptomatic systolic heart failure caused by coronary artery disease has been well documented. However, the evidence for a benefit of prophylactic ICDs in patients with systolic heart failure that is not due to coronary artery disease has been based primarily on subgroup analyses. The management of heart failure has improved since the landmark ICD trials, and many patients now receive cardiac resynchronization therapy (CRT). METHODS: In a randomized, controlled trial, 556 patients with symptomatic systolic heart failure (left ventricular ejection fraction, ≤35%) not caused by coronary artery disease were assigned to receive an ICD, and 560 patients were assigned to receive usual clinical care (control group). In both groups, 58% of the patients received CRT. The primary outcome of the trial was death from any cause. The secondary outcomes were sudden cardiac death and cardiovascular death. RESULTS: After a median follow-up period of 67.6 months, the primary outcome had occurred in 120 patients (21.6%) in the ICD group and in 131 patients (23.4%) in the control group (hazard ratio, 0.87; 95% confidence interval [CI], 0.68 to 1.12; P=0.28). Sudden cardiac death occurred in 24 patients (4.3%) in the ICD group and in 46 patients (8.2%) in the control group (hazard ratio, 0.50; 95% CI, 0.31 to 0.82; P=0.005). Device infection occurred in 27 patients (4.9%) in the ICD group and in 20 patients (3.6%) in the control group (P=0.29). CONCLUSIONS: In this trial, prophylactic ICD implantation in patients with symptomatic systolic heart failure not caused by coronary artery disease was not associated with a significantly lower long-term rate of death from any cause than was usual clinical care. (Funded by Medtronic and others; DANISH ClinicalTrials.gov number, NCT00542945 .).

Prospective nationwide fluoroscopic and electrical longitudinal follow-up of recalled Riata defibrillator leads in Denmark.

BACKGROUND: Recalled St. Jude Medical Riata defibrillator leads are prone to insulation failures with externalized conductors (ECs). Longitudinal studies are needed to guide lead management. OBJECTIVE: The purpose of this study was to describe the dynamic nature of EC and the association with electrical abnormalities and lead extraction outcomes. METHODS: A nationwide cohort established in 2012 of 295 patients with recalled Riata leads with dwell time 5.1 ± 1.1 years, 34 ECs, and 19 electrical abnormalities were followed until death, lead discontinuation with fluoroscopy, or a new 2013 screening with fluoroscopy and device interrogation. RESULTS: Fluoroscopic follow-up of 239 patients with normal baseline fluoroscopy revealed incident overt EC in 8 leads and borderline EC in 2 leads after 1.1 ± 0.2 years, with an incidence rate of 3.7 per 100 person-years (95% confidence interval 2.0-6.9). Fluoroscopic follow-up in 27 patients with baseline EC showed an increase in EC length of 4 ± 1 mm (P <.001) after 1.1 ± 0.3 years. Electrical follow-up in 276 patients with normal baseline electrical function demonstrated 20 incident electrical abnormalities after 1.0 ± 0.3 years, with an incidence rate of 7.1 per 100 person-years (95% confidence interval 4.6-11.0). This rate was significantly higher in leads with baseline EC, with an adjusted incidence rate ratio of 4.4 (95% confidence interval 1.7-11.5, P = .002). In 15 extractions, all leads were removed, with 2 major complications. CONCLUSION: The development of EC is a dynamic process despite long lead dwell time. ECs are associated with a higher risk of electrical abnormalities. Therefore, lead replacement should be considered, especially in patients with a long life expectancy.

Paradoxical thromboembolic stroke during extraction of a recalled St Jude Medical Riata defibrillator lead with conductor externalization.

Recalled St Jude Medical Riata leads have a high rate of insulation failures with potential thrombogenic externalized conductors. We report a paradoxical thromboembolic stroke through a persistent foramen ovale during extraction of a lead with externalization. We suggest mandatory transesophageal echocardiography prior to extraction to screen for lead-related thrombosis and routes of right-to-left shunting to reduce risk of thromboembolic complications.

Effects of high-dose radiotherapy on implantable cardioverter defibrillators: an in vivo porcine study.

INTRODUCTION: Although the effects of radiotherapy (RT) on implantable cardioverter defibrillators (ICDs) have been studied in vitro, and some information has been gathered from case reports and series, no in vivo experiments have previously been performed. METHODS: In vivo effects of photon RT applied directly to five modern ICD generators from different manufacturers implanted in pigs were studied. The devices were interrogated between and after increasing doses of ionizing radiation. Afterwards, the shock function was tested. RESULTS: All ICDs withstood fractionated irradiations with a cumulative dose of 18.5 gray (Gy) of 6 megavolt (MV) photons and 18.5 Gy of 18 MV photons and were still fully functional. Especially, no oversense was recorded. Induced ventricular fibrillation was detected and treated properly by shock therapy in all cases. However, one of the ICDs converted to back-up mode later the same night. CONCLUSION: The animal model is feasible for investigating RT effects on implanted cardiac devices. During irradiations with 37 Gy, one recoverable malfunction was present in the tested devices. Additional animal studies could provide supplementary evidence for treating ICD patients, including recommendations for reprogramming of the ICD during RT and avoidance of relocating the device.

Changes in plasma C-reactive protein and hemostatic factors prior to and after a first myocardial infarction with a median follow-up time of 8 years.

The objective of this study was to determine whether a first myocardial infarction leads to increased plasma levels of hemostatic factors and high sensitive C-reactive protein (hs-CRP) and whether the association between theses biomarkers and myocardial infarction was greater at follow-up compared with baseline. Of more than 36,000 persons screened in northern Sweden, 78 developed a first myocardial infarction (on average 18 months after sampling) in a population-based, prospective, nested patient-referent study. Fifty of these had participated in a follow-up health survey (on average 8 and a half years between surveys) and were sex-matched and age-matched with 56 referents. The mean increases in hs-CRP, tissue plasminogen activator (tPA) mass, plasminogen activator inhibitor-1 mass, and tPA/plasminogen activator inhibitor-1 complex concentration and von Willebrand factor among patients and referents were comparable during follow-up. Conditional logistic regression indicated that hs-CRP was not significantly associated with first myocardial infarction in a univariate analysis, whereas high plasma levels of tPA and creatinine were significantly associated with outcome at baseline and follow-up. tPA/plasminogen activator inhibitor-1 complex was not superior to tPA as a risk marker in this study. A first myocardial infarction did not in this study induce significantly different changes in plasma levels of hs-CRP and hemostatic factors among patients compared with referents during follow-up.

A multicenter experience with novel implantable cardioverter defibrillator configurations in the pediatric and congenital heart disease population.

INTRODUCTION: In pediatric and congenital heart disease patients, transvenous ICD implantation may be limited secondary to patient size, venous, or cardiac anatomy. Epicardial patches require a thoracotomy, and may lead to a restrictive pericardial process. Because of these issues, we have explored novel ICD configurations. METHODS: Retrospective review at 10 centers implanting ICDs without a transvenous shocking coil or epicardial patches. RESULTS: Twenty-two patients underwent implant at a mean age of 8.9 years (range: 0.3-43.5), with a mean weight of 25.5 kg (range: 5.2-70). Diagnoses included complex CHD, intracardiac tumors, cardiomyopathy, idiopathic VT, LV noncompaction, and long QT syndrome. Three configurations were used: subcutaneous array, a transvenous design ICD lead placed on the epicardium, or a transvenous design ICD lead placed subcutaneously. Difficulties were found at implant in 8 patients: 4 had difficulty inducing VT/VF, and 4 had high DFTs. Over a mean follow-up of 2.2 years (range: 0.2-10.5), 7 patients had appropriate shocks. Inappropriate shocks occurred in 4 patients. System revisions were required in 7 patients: 2 generator changes (in 1 patient), 3 pace-sense lead replacement, 1 additional subcutaneous coil placement due to increased DFT, 1 upgrade to a transvenous system, and 1 revision to epicardial patch system. CONCLUSIONS: ICD implantation can be performed without epicardial patches or transvenous high-energy leads in this population, using individualized techniques. This will allow ICD use in patients who have intracardiac shunting or are deemed too small for transvenous ICD leads. The long-term outcome and possible complications are as yet unknown in this population, and they should be monitored closely with follow-up DFTs.