Reassessment of cardiovascular parameters and comorbidities in implantable cardioverter-defibrillator patients at the time of first replacement

Selection and outcome of ICD and CRT-D patients - Comparison of 4384 patients from the German Device Registry to randomized controlled trials

BACKGROUND

Registry data adds important information to randomized controlled trials (RCT) on real-life aspects of implantable cardioverter-defibrillator (ICD) patients with and without cardiac resynchronization therapy (CRT-D). This analysis of the prospectively conducted German Device Registry aims at comparing mortality rates, comorbidities, complication rates to results from RCT.

METHODS

The German Device registry (DEVICE) prospectively collected data on ICD and CRT-D first implantations from 50 German centres. Demographic data, details on cardiac disease, electrocardiogram (ECG), medication, and data about procedure, complications and hospital stay were stored in electronic case report forms. One year after device implantation patients were contacted for follow-up.

RESULTS

DEVICE included n=4384 first ICD/CRT-D implantations (29.3% CRT-D devices). We found a strong adherence to guidelines with over 90% of patients being on ß-blocker and ACE-inhibitor medication and adequate QRS width in the majority of CRT-D patients. Patients receiving a CRT-D were older (67.6±11.0 years vs. 63.9±13.4 years, p<0.001) and had lower ejection fractions (mean 25% vs. 30%, p<0.001) compared to ICD patients. Dilated cardiomyopathy was the predominant underlying heart disease in CRT-D (53.3%), coronary artery disease in ICD patients (64.7%). Compared to RCT our DEVICE patients had more comorbidities (17.9% chronic kidney disease (CKD)) and higher one-year mortality rates (10.7% ICD group, 12.3% CRT group). In multivariate analysis, CKD patients had an almost 2-fold higher risk of 1-year mortality.

CONCLUSION

Despite relevant limitations of registry data, DEVICE highlights important differences between RCT and real-world registry data and the impact of comorbidities on mortality of ICD and CRT-D recipients. This article is protected by copyright. All rights reserved.

Reassessment of clinical variables in cardiac resynchronization defibrillator patients at the time of first replacement: Death after replacement of CRT (DARC) score

Introduction

Cardiac resynchronization defibrillator (CRT‐D) as primary prevention is known to reduce mortality. At the time of replacement, higher age and comorbidities may attenuate the benefit of implantable cardioverter‐defibrillator (ICD) therapy. The purpose of this study was to evaluate the progression of comorbidities after implantation and their association with mortality following CRT‐D generator replacement. In addition, a risk score was developed to identify patients at high risk for mortality after replacement.

Methods and Results

We identified patients implanted with a primary prevention CRT‐D (n = 648) who subsequently underwent elective generator replacement (n = 218) from two prospective ICD registries. The cohort consisted of 218 patients (median age: 70 years, male gender: 73%, mean left ventricular ejection fraction [LVEF]: 36 ± 11% at replacement). Median follow‐up after the replacement was 4.2 years during which 64 patients (29%) died and 11 patients (5%) received appropriate ICD shocks. An increase in comorbidities was observed in 77 patients (35%). The 5‐year mortality rate was 41% in patients with ≥2 comorbidities at the time of replacement. A risk score incorporating age, gender, LVEF, atrial fibrillation, anemia, chronic kidney disease, and history of appropriate ICD shocks at time of replacement accurately predicted 5‐year mortality (C‐statistic 0.829). Patients with a risk score of greater than 2.5 had excess mortality at 5‐year postreplacement compared with patients with a risk score less than 1.5 (57% vs. 6%; p < .001).

Conclusion

A simple risk score accurately predicts 5‐year mortality after replacement in CRT‐D patients, as patients with a risk score of greater than 2.5 are at high risk of dying despite ICD protection.

Ongoing Risk of Ventricular Arrhythmias and All-Cause Mortality at Implantable Cardioverter Defibrillator Generator Change: A Systematic Review and Meta-Analysis

[Figure: see text].

Reassessment of cardiovascular parameters and comorbidities in implantable cardioverter-defibrillator patients at the time of first replacement

BACKGROUND

Guidelines provide extensive recommendations regarding implantable cardioverter-defibrillator (ICD) implantation. However, ICD replacement at the time of battery depletion is rarely studied.

HYPOTHESIS

Our objectives were to identify patients at high-risk of death after ICD replacement, with a reassessment of changes in risk factors and comorbidities at the time of replacement, and to determine predictors for subsequent mortality.

METHODS

Patients undergoing ICD replacement for regular battery depletion were selected from a prospective single-center ICD registry. Both at implant and replacement, 3 demographic parameters, 9 cardiovascular parameters, 5 comorbidities, and 4 laboratory parameters were collected. Cox proportional hazard analyses were used.

RESULTS

We included 308 patients who were predominantly male (86%) with a median age at ICD replacement of 66 years. Replacement was performed 65 months (interquartile range, 52-91) after implantation. Median follow-up after replacement was 41 months, during which 82 patients (27%) died. Multivariable analysis revealed 4 independent predictors of mortality after ICD replacement: age/year (hazard ratio [HR]: 1.05, 95% confidence interval [CI]: 1.03-1.08, P = 0.01), worsening heart failure by 1 class (HR: 1.53, 95% CI: 1.15-2.03, P = 0.003), presence of left bundle branch block (HR: 1.98, 95% CI: 1.22-3.23, P = 0.006), and ICD therapy prior to replacement (HR: 2.22, 95% CI: 1.37-3.58, P = 0.001). Incorporated into a dichotomous score, they strongly correlated with mortality at 5 years after replacement (5% with 0 parameters, 15% with 1 parameter, and 30%-55% with >2 parameters).

CONCLUSIONS

Focused reassessment of selected patient characteristics at the time of ICD replacement correlates with subsequent mortality and can impact decision making at this point in time.