Clinical experience with a novel subcutaneous implantable defibrillator system in a single center

Background: Implantable cardioverter-defibrillators (ICDs) reduce mortality in both primary and secondary prevention, but are associated with substantial short- and long-term morbidity. A totally subcutaneous ICD (S-ICD) system has been developed. We report the initial clinical experience of the first 31 patients implanted at our hospital. Methods: All patients had an ICD indication according to the ACC/AHA/ESC guidelines. The first 11 patients were part of the reported CE trial. The implantation was performed without fluoroscopy. The device was implanted subcutaneously in the anterior axillary line, with a parasternal lead tunneled from the xiphoid to the manubrial-sternal junction. Ventricular fibrillation (VF) was induced to assess detection accuracy and defibrillation efficacy using 65 J shocks. Results: Post-implant, 52 sustained episodes of VF were induced. Sensitivity was 100% and induced conversion efficacy was 100% (with standard polarity in 29 patients). Mean time to therapy was 13.9 ± 2.5 s (range 11-21.6 s). Late procedure-related complications were observed in 2 of the first 11 implantations (lead migration). During follow-up, spontaneous ventricular arrhythmias occurred in four patients, with accurate detection of all episodes. Inappropriate therapy was observed in five patients. Recurrences were prevented with reprogramming. Conclusions: The S-ICD system can be implanted without the use of fluoroscopy by using anatomical landmarks only. Episodes of VF were accurately detected using subcutaneous signals, and all induced and clinical episodes were successfully converted. The S-ICD system is a viable alternative to conventional ICD systems for selected patients

Survivors of ventricular fibrillation have persistent cardiovascular risk factors late in follow-up

Objective: Implantable cardioverter-defibrillators (ICDs) prevent arrhythmic death, but do not modify disease progression. The prevalence of persistent cardiovascular risk factors in patients receiving an ICD and their adherence to optimal pharmacological therapy at late follow-up is unknown. The aim of this study was to assess the prevalence of cardiovascular and specific sudden cardiac arrest (SCA) risk factors, and the pharmacological treatment in ICD recipients who survived SCA caused by ventricular fibrillation (VF). Design: Cross-sectional study. A total of 100 consecutive ICD patients who survived SCA due to documented VF, not due to a transient or reversible cause or an arrhythmogenic disease, were interviewed and examined at the routine outpatient clinic. Results: The mean age of the patients was 60 +/- 11 years, and they were analysed at a median interval of 1092 days after SCA. The majority of patients had coronary artery disease. The New York Heart Association class at the time of implantation was >= II in 62%. A single chamber device was used in 49% and a resynchronization device in 12%. At the routine control, the most prevalent risk factors were overweight or obesity (63%), hypertension (41%), and smoking (16%). Pharmacological therapy was suboptimal in 18 -32% of the patients. Eight per cent of the patients had known diabetes and 29% had elevated HbA1c levels. While only 7% had pre-existing overt heart failure, 43% had N-terminal pro-brain natriuretic peptide levels >= 100 pmol/l. High sensitivity C-reactive protein was >= 3 mg/l in 52% of the patients. Family history was positive for sudden cardiac death (SCD) in 46% of the patients. Conclusions: Despite regular medical consultation, a large proportion of the patients had persistent cardiovascular risk factors and were often suboptimally treated. Unexpectedly, latent heart failure and unrecognized diabetes are observed in a large proportion of the patients, as well as elevated inflammatory markers. Genetic analysis may be rewarding, as 46% of the patients had a family history of SCD. Full medical attention, optimizing drug therapy, and counselling of these patients is necessary

Prognostic role of high-sensitivity C-reactive protein and B-type natriuretic peptide in implantable cardioverter-defibrillator patients

Background: High-sensitivity C-reactive protein (hs-CRP) and B-type natriuretic peptide (BNP) are useful biomarkers for cardiovascular risk stratification. Little data are available regarding the prognostic value of hs-CRP and BNP serum levels and future ventricular arrhythmic events triggering implantable cardioverter defibrillator (ICD) therapy. Methods: A total of 100 patients eligible for ICD implantation were enrolled in a prospective cohort study. Serum levels of hs-CRP and BNP were obtained the day before ICD implantation and at scheduled follow-up visits. For risk analysis, the study cohort was dichotomized based on serum level of hs-CRP using a cut-off value of 3 mg/L. The endpoint was appropriate ICD therapy triggered by ventricular arrhythmias during a follow-up of 24 months. Results: Appropriate ICD therapy was delivered in 20% of patients. Median baseline serum level of hsCRP was significantly higher in patients with appropriate ICD therapy than in those without appropriate ICD therapy (5.33 mg/L vs 2.19 mg/L; P = 0.002). The same was true for median serum levels of hs-CRP and BNP during follow-up (5.43 mg/L vs 2.61 mg/L, P = 0.001 and 261.0 pg/mL vs 80.1 pg/mL, P = 0.01, respectively). Multivariate analysis demonstrated that baseline hs-CRP level > 3 mg/L was independently associated with appropriate ICD therapy (odds ratio 4.0, 95% 1.1-14.2; P = 0.03). Conclusion: Elevated preimplantation hs-CRP serum level is independently associated with increased risk for appropriate ICD therapy. Monitoring for elevated BNP levels during follow-up adds to the assessment of risk for future arrhythmias

Clinical experience with a novel subcutaneous implantable defibrillator system in a single center

Implantable cardioverter-defibrillators (ICDs) reduce mortality in both primary and secondary prevention, but are associated with substantial short- and long-term morbidity. A totally subcutaneous ICD (S-ICD) system has been developed. We report the initial clinical experience of the first 31 patients implanted at our hospital. All patients had an ICD indication according to the ACC/AHA/ESC guidelines. The first 11 patients were part of the reported CE trial. The implantation was performed without fluoroscopy. The device was implanted subcutaneously in the anterior axillary line, with a parasternal lead tunneled from the xiphoid to the manubrial-sternal junction. Ventricular fibrillation (VF) was induced to assess detection accuracy and defibrillation efficacy using 65 J shocks. Post-implant, 52 sustained episodes of VF were induced. Sensitivity was 100% and induced conversion efficacy was 100% (with standard polarity in 29 patients). Mean time to therapy was 13.9 +/- A 2.5 s (range 11-21.6 s). Late procedure-related complications were observed in 2 of the first 11 implantations (lead migration). During follow-up, spontaneous ventricular arrhythmias occurred in four patients, with accurate detection of all episodes. Inappropriate therapy was observed in five patients. Recurrences were prevented with reprogramming. The S-ICD system can be implanted without the use of fluoroscopy by using anatomical landmarks only. Episodes of VF were accurately detected using subcutaneous signals, and all induced and clinical episodes were successfully converted. The S-ICD system is a viable alternative to conventional ICD systems for selected patients

Type-D personality but not implantable cardioverter-defibrillator indication is associated with impaired health-related quality of life 3 months post-implantation

Aims: Little is known about the impact of ICD indication (primary vs. secondary) on health-related quality of life (HRQL). Indication may also interact with psychological factors, such as personality. Using a prospective design, we examined whether ICD indication and type-D personality (i.e. experiencing increased negative emotions paired with emotional non-expression) serve as modulators of HRQL at baseline and 3 months post-implantation. Methods and results: Consecutively implanted ICD patients (n = 154) completed the Type-D Scale (DS14) at baseline and the Short-Form Health Survey 36 (SF-36) at baseline and 3 months. Of all patients, 82 (53%) received an ICD due to prophylactic reasons; the prevalence of type-D was 23%. Indication had no influence on HRQL (P = 0.75). Further stratification by personality showed a main effect for type-D personality (P < 0.001), with type-D patients generally experiencing poorer HRQL; there was no main effect for indication (P = 0.45) nor was the interaction effect indication by type-D significant (P = 0.22). There was a significant improvement in HRQL over time (P = 0.001). Type-D remained an independent predictor of impaired HRQL, adjusting for clinical factors and shocks during follow-up (P < 0.001). However, in adjusted analysis there was no longer a significant change in HRQL over time (P = 0.099). Conclusion: Type-D personality but not ICD indication was associated with impaired HRQL at the time of implantation and at 3 months. In the quest for enhancing risk stratification in clinical practice, personality factors, such as type-D, should not be ignored, as both type-D and poor HRQL have been associated with increased risk of mortality in cardiac patients