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.

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 .).

CIED infection with either pocket or systemic infection presentation--complete device removal and long-term antibiotic treatment; long-term outcome

OBJECTIVE

Cardiovascular implantable electronic device (CIED) infections are increasing in numbers. The objective was to review the clinical presentation and outcome in patients affected with CIED infections with either local pocket or systemic presentation.

DESIGN

All device removals due to CIED infection during the period from 2005 to 2012 were retrospectively reviewed. CIED infections were categorized as systemic or pocket infections. Treatment included complete removal of the device, followed by antibiotic treatment of six weeks.

RESULTS

Seventy-one device removals due to infection (32 systemic and 39 pocket infections) were recorded during the study period. Median follow-up time was 26 (IQR 9-41) months, 30 day and 12 month mortality were 4% and 14%, respectively. There was no long-term difference in mortality between patients with pocket vs. systemic infection (p = 0.48). During follow-up no relapses and two cases of new infections were noted (2.8%).

CONCLUSIONS

CIED infection with systemic or pocket infection was difficult to distinguish in clinical presentation and outcome. Complete device removal and antibiotic treatment of long duration was safe and without relapses.

Mortality and appropriate and inappropriate therapy in patients with ischaemic heart disease and implanted cardioverter-defibrillators for primary prevention: data from the Danish ICD Register

AIMS

To evaluate the incidences of and risk factors predisposing to appropriate and inappropriate shocks and mortality in a 'real-world' population of patients with ischaemic heart disease (IHD) and implantable cardioverter defibrillators (ICD) for primary prevention of sudden cardiac death (SCD).

METHODS AND RESULTS

In this nationwide cohort, we prospectively followed 1609 patients with IHD and left ventricular dysfunction from the Danish ICD Register who received an ICD for primary prevention of SCD (1 January 2007 to 30 November 2011). Primary study outcomes were appropriate shocks, inappropriate shocks, and all-cause mortality. Secondary study outcomes included the composite endpoints: appropriate therapy and inappropriate therapy (defined as shock or anti-tachycardia pacing). All-cause mortality was 12.1% during a mean follow-up time of 1.9 ± 1.3 years. Inappropriate shocks and therapy occurred in 2.6% and 3.7% during follow-up, respectively. Appropriate shocks and therapy was identified in 7.8% and 13.4%, respectively. Time-dependent multivariable Cox regression analyses were used to identify risk factors of inappropriate/appropriate shock, therapy and mortality. Implantation of a dual-chamber ICD was associated with increased risk of both inappropriate shocks and any inappropriate therapy compared to single-chamber ICD [hazard ratios (HR) = 2.45; confidence intervals (CI):1.16-5.14 and HR = 2.38; CI:1.28-4.42, respectively]. No excess risk of mortality was associated with any device type.

CONCLUSION

In this nationwide study of IHD patients with an ICD for primary prevention of SCD, the incidence of appropriate shocks as well as inappropriate shocks were significantly lower than reported in randomized trials. Implantation of a dual-chamber ICD was associated with more inappropriate shocks compared with single chamber devices.

Attitudes towards implantable cardioverter-defibrillator therapy: a national survey in Danish health-care professionals

AIMS

The aim of this study was to examine health-care professionals attitudes towards implantable cardioverter-defibrillator (ICD) therapy and issues discussed with patients.

METHODS AND RESULTS

Survey of 209 health-care professionals providing specialized treatment and care of ICD patients at the five implanting centres in Denmark. Questions pertained to gender, age, years of experience within the field, knowledge of the ongoing critical debate on ICD therapy, and personal experience with ICD treatment, and/or sudden cardiac arrest within family and/or friends. Of all participants, 185 (88.5%) completed the survey. Physicians spent less time informing patients about ICD treatment prior to implantation (mean min = 17.7 ± 11.2 vs. 28.6 ± 19.4; P < 0.001). They were more likely to discuss clinical issues but less likely to discuss psychosocial issues with patients compared with non-physicians. Physicians were less likely to believe that their personal attitude towards ICD treatment has no influence on how they deal professionally with patients (27.8 vs. 43.6%; P = 0.04). Physicians and non-physicians were equally positive towards ICD therapy as primary prophylaxis in ischaemic cardiomyopathy (87.6 vs. 82.1%; P = 0.40) but not in non-ischaemic cardiomyopathy (57.3 vs. 83.9%; P < 0.001). Physicians were more positive towards ICD therapy as secondary prophylaxis (98.9 vs. 84.2%; P = 0.001) compared with non-physicians.

CONCLUSIONS

Physicians focus on clinical rather than psychosocial issues when discussing ICD treatment with candidate patients. At the same time, physicians are more aware that their attitude towards ICD treatment may influence how they deal professionally with patients compared with non-physicians.