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Aims: Implantable cardioverter-defibrillator (ICD) treatment is beneficial in selected patients. However, it remains difficult to accurately predict which patients benefit most from ICD implantation. For this purpose, different risk models have been developed. The aim was to validate and compare the FADES, MADIT, and SHFM-D models., Methods and Results: All patients receiving a prophylactic ICD at the Leiden University Medical Center were evaluated. Individual model performance was evaluated by C-statistics. Model performances were compared using net reclassification improvement (NRI) and integrated differentiation improvement (IDI). The primary endpoint was non-benefit of ICD treatment, defined as mortality without prior ventricular arrhythmias requiring ICD intervention. A total of 1969 patients were included (age 63 ± 11 years; 79% male). During a median follow-up of 4.5 ± 3.9 years, 318 (16%) patients died without prior ICD intervention. All three risk models were predictive for event-free mortality (all: P < 0.001). The C-statistics were 0.66, 0.69, and 0.75, respectively, for FADES, MADIT, and SHFM-D (all: P < 0.001). Application of the SHFM-D resulted in an improved IDI of 4% and NRI of 26% compared with MADIT; IDI improved 11% with the use of SHFM-D instead of FADES (all: P < 0.001), but NRI remained unchanged (P = 0.71). Patients in the highest-risk category of the MADIT and SHFM-D models had 1.7 times higher risk to experience ICD non-benefit than receive appropriate ICD interventions [MADIT: mean difference (MD) 20% (95% CI: 7-33%), P = 0.001; SHFM-D: MD 16% (95% CI: 5-27%), P = 0.005]. Patients in the highest-risk category of FADES were as likely to experience ICD intervention as ICD non-benefit [MD 3% (95% CI: -8 to 14%), P = 0.60]., Conclusion: The predictive and discriminatory value of SHFM-D to predict non-benefit of ICD treatment is superior to FADES and MADIT in patients receiving prophylactic ICD treatment., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For permissions please email: journals.permissions@oup.com.)

Background: Although randomized trials have shown the beneficial effect on survival of an implantable cardioverter defibrillator (ICD) as primary prevention therapy in selected patients, data concerning the cost-effectiveness in routine clinical practice remain scarce. Accordingly, the purpose of this study was to assess the cost-effectiveness of primary prevention ICD implantation in the real world., Methods: Patients receiving primary prevention single-chamber or dual-chamber ICD implantation at the Leiden University Medical Center were included in the study. Using a Markov model, lifetime cost, life years (LYs), and gained quality-adjusted life years (QALYs) were estimated for device recipients and control patients. Data on mortality, complication rates, and device longevity were retrieved from our center and entered into the Markov model. To account for model assumptions, one-way deterministic and probabilistic sensitivity analyses were performed. Importantly, calculations for the estimated incremental cost-effectiveness rate (ICER) per QALY gained are based on several numbers of assumptions, and accordingly findings may have over- or underestimated the cost-effectiveness of ICD therapy., Results: Primary prevention ICD implantation adds an estimated mean of 2.07 LYs and 1.73 QALYs. Increased lifetime cost for single-chamber and dual-chamber ICD recipients were estimated at €60,788 and €64,216, respectively. This resulted for single-chamber ICD recipients, in an estimated ICER of €35,154 per QALY gained. In dual-chamber ICD recipients, an estimated ICER of €37,111 per QALY gained was calculated. According to the probabilistic sensitivity analysis, estimated cost per QALY gained are €35,837 (95% confidence interval [CI]: €28,368-€44,460) for single-chamber and €37,756 (95% CI: €29,055-€46,050) for dual-chamber ICDs., Conclusions: On the basis of data and detailed costs, derived from routine clinical practice, ICD therapy in selected patients with a reduced left ventricular ejection fraction appears to be cost-effective., (©2013, The Authors. Journal compilation ©2013 Wiley Periodicals, Inc.)

Objectives: To construct a risk score out of baseline variables to estimate the risk of death without prior implantable cardioverter defibrillator (ICD) in primary prevention ICD patients with ischaemic heart disease., Design: Retrospective cohort study., Setting: Tertiary care facility in The Netherlands., Patients: All patients with ischaemic heart disease who received an ICD for primary prevention of sudden cardiac death at the Leiden University Medical Center, Leiden, The Netherlands in the period 1996-2009., Main Outcome Measure: All-cause mortality without prior appropriate ICD therapy (anti-tachycardia pacing or shock)., Results: 900 patients (87% men, mean age 64±10 years) were included in the analysis. During a median follow-up of 669 days (IQR 363-1322 days), 150 patients (17%) died and 191 (21%) patients received appropriate device therapy. 114 (13%) patients died without prior appropriate therapy. Stratification of the risk for death without prior appropriate therapy resulted in risk categorisation of patients as low, intermediate or high risk. NYHA ≥III, advanced age, diabetes mellitus, left ventricular ejection fraction ≤25% and a history of smoking were significant independent predictors of death without appropriate ICD therapy. 5-year cumulative incidence for death without prior appropriate therapy ranged from 10% (95% CI 6% to 16%) in low-risk patients to 41% (95% CI 33% to 51%) in high-risk patients., Conclusions: The risk of death without prior appropriate ICD therapy can be predicted in primary prevention ICD patients with ischaemic heart disease, which facilitates patient-tailored risk estimation.

Background and Purpose: Left ventricular ejection fraction lacks specificity to predict sudden cardiac death in heart failure. T-wave alternans (TWA; beat-to-beat T-wave instability, often measured during exercise) is deemed a promising noninvasive predictor of major cardiac arrhythmic event. Recently, it was demonstrated that TWA during recovery from exercise has additional predictive value. Another mechanism that potentially contributes to arrhythmogeneity is exercise-recovery hysteresis in action potential morphology distribution, which becomes apparent in the spatial ventricular gradient (SVG). In the current study, we investigated the performance of TWA amplitude (TWAA) during a complete exercise test and of exercise-recovery SVG hysteresis (SVGH) as predictors for lethal arrhythmias in a population of heart failure patients with cardioverter-defibrillators (ICDs) implanted for primary prevention., Methods: We performed a case-control study with 34 primary prevention ICD patients, wherein 17 patients (cases) and 17 patients (controls) had no ventricular arrhythmia during follow-up. We computed, in electrocardiograms recorded during exercise tests, TWAA (maximum over the complete test) and the exercise-recovery hysteresis in the SVG. Statistical analyses were done by using the Student t test, Spearman rank correlation analysis, receiver operating characteristics analysis, and Kaplan-Meier analysis. Significant level was set at 5%., Results: Both SVGH and TWAA differed significantly (P < .05) between cases (mean ± SD, SVGH: -18% ± 26%, TWAA: 80 ± 46 μV) and controls (SVGH: 5% ± 26%, TWAA: 49 ± 20 μV). Values of TWAA and SVGH showed no significant correlation in cases (r = -0.16, P = .56) and in controls (r = -0.28, P = .27). Receiver operating characteristics of SVGH (area under the curve = 0.734, P = .020) revealed that SVGH less than 14.8% discriminated cases and controls with 94.1% sensitivity and 41.2% specificity; hazard ratio was 3.34 (1.17-9.55). Receiver operating characteristics of TWA (area under the curve = 0.699, P = .048) revealed that TWAA greater than 32.5 μV discriminated cases and controls with 93.8% sensitivity and 23.5% specificity; hazard ratio was 2.07 (0.54-7.91)., Discussion and Conclusion: Spatial ventricular gradient hysteresis bears predictive potential for arrhythmias in heart failure patients with an ICD for primary prevention, whereas TWA analysis seems to have lesser predictive value in our pilot group. Spatial ventricular gradient hysteresis is relatively robust for noise, and, as it rests on different electrophysiologic properties than TWA, it may convey additional information. Hence, joint analysis of TWA and SVGH may, possibly, improve the noninvasive identification of high-risk patients. Further research, in a large group of patients, is required and currently carried out by our group., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Aims: The beneficial effects of implantable cardioverter defibrillators (ICDs) in primary and secondary prevention patients are well established. However, data on potential differences between both groups in mortality and ICD therapy rates during long-term follow-up are scarce. The aim of the study was to assess differences in mortality and ICD therapy between secondary and primary prevention ICD recipients., Methods and Results: With the exception of patients with congenital monogenetic cardiac disease, all patients treated with an ICD, regardless of the underlying cardiac pathology, from 1996 to 2008 at the Leiden University Medical Center were included in the current analysis. The study population was grouped by the type of prevention (secondary or primary) for sudden cardiac death. The primary endpoint was all-cause mortality. The secondary endpoint was the occurrence of device therapy (appropriate or inappropriate). A total of 2134 (80% men, mean age 63 ± 12 years) ICD recipients were included. Of these, 1302 (61%) patients received an ICD for primary prevention of sudden cardiac death and 832 (39%) patients for secondary prevention. During a mean follow-up of 3.4 ± 2.8 years, 423 (20%) patients died. The 5-year cumulative incidence of mortality was 25% [95% confidence intervals (CI): 21-29%] for primary prevention patients and 23% (95% CI: 20-26%) for secondary prevention patients. Secondary prevention patients exhibited a 74% increased risk for appropriate therapy when compared with primary prevention patients [hazard ratios (HR): 1.7; P< 0.001]. A comparable risk for inappropriate shocks was observed (HR: 1.0; P= 0.9)., Conclusion: During long-term follow-up, primary prevention patients exhibited a lower risk of appropriate therapy, but comparable mortality rates were observed between both groups. Both groups showed similar occurrence of inappropriate shocks.

Aims: Myocardial excitability is known (amongst other reasons) to be related to the degree of ischaemia, contractile dysfunction and heart failure. It was hypothesized that the right ventricular (RV) stimulation threshold has prognostic value with respect to the occurrence of ventricular arrhythmias (VAs) and patient survival in recipients of an implantable cardioverter defibrillator (ICD)., Methods and Results: Ischaemic heart disease patients receiving an ICD at Leiden University Medical Center as primary prevention for sudden cardiac death were included in this study. Right ventricular thresholds were determined at ICD implant. Data were collected on VAs triggering ICD therapy and on all-cause mortality. A total of 689 consecutive patients were included (87% male, age 63 ± 11 years, left ventricular ejection fraction (LVEF) 29 ± 11%) and followed for a median of 28 months. Post-implant RV-threshold was 0.7 ± 0.5 volt (V) at 0.5 ms pulse duration. Best dichotomous separation was reached at a cut-off of 1 V. During follow-up, 167 (24%) patients received appropriate ICD therapy, 88 (13%) had appropriate shocks and 134 (19%) died. Cumulative appropriate shock incidence for patients with RV threshold ≥ 1 V (n = 166) was 16% at 1 year, 24% at 3 years and 34% at 5 years compared with 4, 11 and 17% for patients with an RV-threshold < 1 V (n = 523). Adjusted hazard ratio of RV threshold ≥ 1 V was 2.0 (95% CI: 1.4-2.9) for appropriate therapy, 3.3 (95% CI: 2.0-5.4) for appropriate shocks and 1.6 (95% CI: 1.1-2.5) for mortality., Conclusion: The RV stimulation threshold at ICD implant has a strong independent prognostic value for the occurrence of VAs triggering appropriate ICD therapy, appropriate shocks and mortality.

Background: In patients with primary prevention implantable cardioverter-defibrillators (ICDs), the incidence of life-threatening ventricular arrhythmias resulting in ICD therapy is relatively low, prompting for better risk stratification. The aim of this study was to assess the value of the QRS-T angle for prediction of ICD therapy and mortality in primary prevention patients with ischemic heart disease., Methods and Results: ICD patients (n=412, 361 men; age, 63+/-11 years) with ischemic heart disease and a left ventricular ejection fraction < or = 40% were included. After device implantation, the occurrence of appropriate ICD therapy and mortality was noted. A survival analysis was performed comparing patients with a planar QRS-T angle < or = 90 degrees (n=124, 30%) with patients with a planar QRS-T angle >90 degrees before device implantation. Furthermore, patients with a spatial QRS-T angle < or = 100 degrees (n=56, 14%) were compared with patients with a spatial QRS-T angle >100 degrees , before implantation. For patients with a planar QRS-T angle >90 degrees as compared with < or = 90 degrees , the adjusted hazard ratio for the occurrence of appropriate device therapy was 2.4 (95% CI, 1.1 to 5.2); a spatial QRS-T angle >100 degrees was associated with an adjusted hazard ratio of 7.3 (95% CI, 1.0 to 53.8). Furthermore, a spatial QRS-T angle < or = 100 degrees exhibited a positive predictive value of 98% (95% CI, 95 to 100) for the prediction of an appropriate therapy-free follow-up., Conclusions: A wide QRS-T angle is a strong predictor of appropriate device therapy in primary prevention ICD recipients with ischemic heart disease. Furthermore, a spatial QRS-T angle < or = 100 degrees might be of value in the identification of patients in whom, although currently indicated, ICD treatment should be reconsidered.

Aims: Implantable cardioverter-defibrillator (ICD) treatment is beneficial in selected patients. However, it remains difficult to accurately predict which patients benefit most from ICD implantation. For this purpose, different risk models have been developed. The aim was to validate and compare the FADES, MADIT, and SHFM-D models.Methods and Results: All patients receiving a prophylactic ICD at the Leiden University Medical Center were evaluated. Individual model performance was evaluated by C-statistics. Model performances were compared using net reclassification improvement (NRI) and integrated differentiation improvement (IDI). The primary endpoint was non-benefit of ICD treatment, defined as mortality without prior ventricular arrhythmias requiring ICD intervention. A total of 1969 patients were included (age 63 ± 11 years; 79% male). During a median follow-up of 4.5 ± 3.9 years, 318 (16%) patients died without prior ICD intervention. All three risk models were predictive for event-free mortality (all: P < 0.001). The C-statistics were 0.66, 0.69, and 0.75, respectively, for FADES, MADIT, and SHFM-D (all: P < 0.001). Application of the SHFM-D resulted in an improved IDI of 4% and NRI of 26% compared with MADIT; IDI improved 11% with the use of SHFM-D instead of FADES (all: P < 0.001), but NRI remained unchanged (P = 0.71). Patients in the highest-risk category of the MADIT and SHFM-D models had 1.7 times higher risk to experience ICD non-benefit than receive appropriate ICD interventions [MADIT: mean difference (MD) 20% (95% CI: 7-33%), P = 0.001; SHFM-D: MD 16% (95% CI: 5-27%), P = 0.005]. Patients in the highest-risk category of FADES were as likely to experience ICD intervention as ICD non-benefit [MD 3% (95% CI: -8 to 14%), P = 0.60].Conclusion: The predictive and discriminatory value of SHFM-D to predict non-benefit of ICD treatment is superior to FADES and MADIT in patients receiving prophylactic ICD treatment. [ABSTRACT FROM AUTHOR]

Aims The beneficial effects of implantable cardioverter defibrillators (ICDs) in primary and secondary prevention patients are well established. However, data on potential differences between both groups in mortality and ICD therapy rates during long-term follow-up are scarce. The aim of the study was to assess differences in mortality and ICD therapy between secondary and primary prevention ICD recipients. Methods and results With the exception of patients with congenital monogenetic cardiac disease, all patients treated with an ICD, regardless of the underlying cardiac pathology, from 1996 to 2008 at the Leiden University Medical Center were included in the current analysis. The study population was grouped by the type of prevention (secondary or primary) for sudden cardiac death. The primary endpoint was all-cause mortality. The secondary endpoint was the occurrence of device therapy (appropriate or inappropriate). A total of 2134 (80% men, mean age 63 ± 12 years) ICD recipients were included. Of these, 1302 (61%) patients received an ICD for primary prevention of sudden cardiac death and 832 (39%) patients for secondary prevention. During a mean follow-up of 3.4 ± 2.8 years, 423 (20%) patients died. The 5-year cumulative incidence of mortality was 25% [95% confidence intervals (CI): 21–29%] for primary prevention patients and 23% (95% CI: 20–26%) for secondary prevention patients. Secondary prevention patients exhibited a 74% increased risk for appropriate therapy when compared with primary prevention patients [hazard ratios (HR): 1.7; P< 0.001]. A comparable risk for inappropriate shocks was observed (HR: 1.0; P= 0.9). Conclusion During long-term follow-up, primary prevention patients exhibited a lower risk of appropriate therapy, but comparable mortality rates were observed between both groups. Both groups showed similar occurrence of inappropriate shocks. [ABSTRACT FROM PUBLISHER]

Aims Myocardial excitability is known (amongst other reasons) to be related to the degree of ischaemia, contractile dysfunction and heart failure. It was hypothesized that the right ventricular (RV) stimulation threshold has prognostic value with respect to the occurrence of ventricular arrhythmias (VAs) and patient survival in recipients of an implantable cardioverter defibrillator (ICD). Methods and results Ischaemic heart disease patients receiving an ICD at Leiden University Medical Center as primary prevention for sudden cardiac death were included in this study. Right ventricular thresholds were determined at ICD implant. Data were collected on VAs triggering ICD therapy and on all-cause mortality. A total of 689 consecutive patients were included (87% male, age 63 ± 11 years, left ventricular ejection fraction (LVEF) 29 ± 11%) and followed for a median of 28 months. Post-implant RV-threshold was 0.7 ± 0.5 volt (V) at 0.5 ms pulse duration. Best dichotomous separation was reached at a cut-off of 1 V. During follow-up, 167 (24%) patients received appropriate ICD therapy, 88 (13%) had appropriate shocks and 134 (19%) died. Cumulative appropriate shock incidence for patients with RV threshold ≥1 V (n = 166) was 16% at 1 year, 24% at 3 years and 34% at 5 years compared with 4, 11 and 17% for patients with an RV-threshold <1 V (n = 523). Adjusted hazard ratio of RV threshold ≥1 V was 2.0 (95% CI: 1.4–2.9) for appropriate therapy, 3.3 (95% CI: 2.0–5.4) for appropriate shocks and 1.6 (95% CI: 1.1–2.5) for mortality. Conclusion The RV stimulation threshold at ICD implant has a strong independent prognostic value for the occurrence of VAs triggering appropriate ICD therapy, appropriate shocks and mortality. [ABSTRACT FROM PUBLISHER]

Aims: To assess survival and to construct a baseline mortality risk score in primary prevention implantable cardioverter defibrillator (ICD) patients with non-ischaemic or ischaemic heart disease. [ABSTRACT FROM PUBLISHER]

Implementation of primary prevention implantable cardioverter-defibrillator (ICD) treatment in the current clinical guidelines led to a significant increase in patients that may benefit from implantation of an ICD. Currently non-guideline-guided patient selection takes place by physicians whereby patients at higher age are more frequently excluded for ICD implantation. This editorial focuses on ICD treatment in the elderly and aims to clarify whether it is justified to withhold ICD treatment in these patients. [ABSTRACT FROM AUTHOR]

The article presents information on the treatment of patients suffering from cardiac arrhythmia by the implantation of an implantable cardioverter-defibrillator (ICD). It informs that cardiac arrhythmia occurs in patients with coronary artery disease. It highlights that ICD therapy is effective and may save many patients sudden death. Information on challenges related to development and implementation of this treatment in high-risk patients is presented.