A Comparison of ICD Implantations in the United States Versus Italy

Favorable Trend of Implantable Cardioverter-Defibrillator Service Life in a Large Single-Nation Population: Insights From 10-Year Analysis of the Italian Implantable Cardioverter-Defibrillator Registry

Background Implantable cardioverter-defibrillators (ICDs) are widely employed for the prevention of sudden cardiac death. Despite technological improvements, patients often need to undergo generator replacement, which entails the risk of periprocedural complications. Our aim was to estimate the service life of ICDs over a 10-year interval and to assess the main causes of replacement on the basis of data from the National ICD Registry of the Italian Society of Arrhythmology and Cardiac Pacing (AIAC). Methods and Results The registry includes data from over 400 hospitals in Italy. We included all patients who underwent device replacement from calendar years 2007 to 2016. The median service life of the ICDs and its trend over the years was estimated across the 3 types of devices (single-chamber, dual-chamber, cardiac resynchronization therapy defibrillator) and the indication to implantation. The causes of replacement were also analyzed. We included 29 158 records from 27 676 patients (80.9% men; mean age at device replacement 65.8±12.0 years). The median service life was 57.3 months (interquartile range 27.8 months). Over the years, service life showed an increasing trend. The majority of patients underwent elective replacement because of battery end of life, and over the years there was a significant reduction of replacement for recalls, erosion/infections, and cardiac resynchronization therapy upgrading. Conclusions Our data from a large single-nation population showed that the trend of ICD service life, independently from ICD type, indication, and settings, significantly improved over time. Moreover, there was a striking reduction of interventions for upgrading and infection/erosion. This favorable trend has important clinical, organizational, and financial implications.

Mortality and predictors of appropriate implantable cardioverter defibrillator therapy in Japanese patients with Multicenter Automatic Defibrillator Implantation Trial II criteria

BACKGROUND

Data regarding long-term mortality and factors influencing appropriate therapies in Japanese patients with implantable cardioverter defibrillators (ICD), who satisfy the Multicenter Automatic Defibrillator Implantation Trial II (MADIT II) criteria for primary prevention, remain scarce.

METHODS

A total of 118 consecutive patients who underwent ICD implantation without any prior ventricular arrhythmic event, from January 2000 to December 2012, were enrolled based on the MADIT II criteria: left ventricular ejection fraction (LVEF) of ≤30% with ischemic heart disease and at least 4 weeks after a myocardial infarction. We investigated the mortality and factors influencing appropriate ICD therapies in this population.

RESULTS

The mean age was 69±10 years, and the mean LVEF was 25.1±4.5%. During the median follow up of 1406 days, the mortality rate was 20%, and the incidence of appropriate ICD therapy was 37% at 3 years. Multivariate analysis by using Cox regression model showed that left ventricular diastolic diameter ≥60 mm (hazard ratio [HR], 2.31; 95% confidence interval [CI], 1.07-5.38; P=0.033) and the presence of non-sustained ventricular tachycardia (NSVT) before implantation (HR, 2.26; 95% CI, 1.17-4.39; P=0.015) were independent predictors of appropriate ICD therapy.

CONCLUSIONS

The mortality and incidence of appropriate ICD therapy were 20% and 37%, respectively, at 3 years in Japanese patients who met the MADIT II criteria during ICD implantation for primary prevention of sudden cardiac death. The presence of NSVT and dilated left ventricle independently predicted the incidence of appropriate ICD therapy after implantation.

Predictors of mortality in patients with an implantable cardiac defibrillator: a systematic review and meta-analysis

BACKGROUND

Many current predictors of mortality in heart failure (HF) were evaluated before the use of implantable cardioverter defibrillators (ICDs). We conducted a meta-analysis to identify factors associated with mortality in ICD-HF patients.

METHODS

We searched in MedLine, EMBASE, and CINAHL in May 2012. Two reviewers selected citations that included ambulatory ICD patients and addressed the association between any predictor and mortality using multivariable regression. We meta-analyzed mortality using random-effects models.

RESULTS

Of 10,420 studies reviewed, 72 studies evaluating 63 predictors on 257,692 ICD patients proved eligible. High confidence in estimates was found for age (hazard ratio [HR], 1.45 for 10-year increase; 95% confidence interval [CI], 1.35-1.56), baseline glomerular filtration rate (HR, 1.25 for 15-mL/min decrease; 95% CI, 1.15-1.35), chronic obstructive pulmonary disease (HR, 1.54; 95% CI, 1.38-1.71), diabetes (HR, 1.56; 95% CI, 1.37-1.79), peripheral vascular disease (HR, 1.43; 95% CI, 1.2-1.72), left ventricular ejection fraction (HR, 0.77 for 10% increase; 95% CI, 0.73-0.83), and appropriate or inappropriate ICD shocks (HR, 2.34; 95% CI 1.59-3.44) New York Heart Association class, atrial fibrillation, and congestive HF were strongly associated with mortality but the confidence in estimates was low. Ischemic cardiomyopathy and male sex were not independent predictors of mortality.

CONCLUSIONS

This meta-analysis identified strong reliable mortality predictors in ICD-HF patients. Age, renal dysfunction, chronic obstructive pulmonary disease, diabetes, peripheral vascular disease, decreased left ventricular ejection fraction, and ICD shocks during follow-up were strong predictors of mortality; ischemic cardiomyopathy and male sex were not. Further research is needed to study other potential predictors, particularly biomarkers.

The world survey of cardiac pacing and cardioverter-defibrillators: calendar year 2005 an International Cardiac Pacing and Electrophysiology Society (ICPES) project

BACKGROUND

A worldwide cardiac pacing and implantable cardioverter-defibrillator (ICD) survey was undertaken for calendar year 2005 and compared to a similar survey conducted in 2001.

RESULTS

There were contributions from 43 countries: 16 from Europe, 13 from the Asia Pacific region, four from the Middle East and Africa, and 10 from the Americas. The United States had the largest number of cardiac pacemaker implants (223,425). Virtually all countries showed increases in implant numbers over the 4 years. High-degree atrioventricular block and sick sinus syndrome remain the major indications for implantation of a cardiac pacemaker, although indications data were not available for large implanting regions such as Europe, Australia, and the United States. There remains a high percentage of VVI(R) pacing in the developing countries, although compared to the 2001 survey, virtually all countries had increased the percentage of DDDR implants, together with a fall in single-lead VDD implants. Pacing leads were predominantly transvenous, bipolar, and passive fixation. There was, however, an increased use of active fixation leads in both the atrium and ventricle. All countries surveyed showed a significant rise in the use of ICDs with the largest implanter being the United States (119,121) with 401 new implants per million population.

CONCLUSIONS

Although the numbers of participating countries have fallen, there still remains a group of loyal enthusiastic survey coordinators. Recruitment of new coordinators will hopefully continue in order to obtain a fully global experience of cardiac pacing and ICD usage.

Defibrillation testing at the time of implantation of cardioverter defibrillator in the clinical practice: a nation-wide survey

AIMS

Despite an effective defibrillation testing (DT) is considered mandatory to be consistent with the rules of good clinical practice, some physicians are concerned about the risk of complications related to the induction test, and in real world clinical practice, several implant procedures are performed without any induction test. We conducted a systematic nation-wide retrospective survey in order to determine the DT rate and its complications.

METHODS AND RESULTS

An ad hoc questionnaire was sent to all 343 Italian implanting centres and the data from the 229 (67%) centres that answered were analysed. During the year 2005, a total of 7857 patients underwent a first implantation of cardioverter defibrillator (ICD), 38% of which with cardiac resynchronization therapy (CRT). Of these, 2356 (30%) were implanted without any induction test. In 35 (15%) centres, the induction test was performed in < 25% of the patients, whereas in 136 (59%) centres, it was performed in > 75% of the patients. At multivariable analysis, performed in a subset of 1206 patients from 107 centres, CRT device (OR = 1.82) and primary prevention (OR = 1.47) were independent predictors of the decision to not perform DT. However, altogether, the clinical variables accounted only for 35% of the total variance, whereas the remaining 65% was probably unrelated to clinical factors. There was a total of 22 (0.4%) life-threatening complications as a consequence of the induction test: 4 deaths (0.07%), 8 cardiopulmonary arrests requiring resuscitation manoeuvres (0.15%), 6 cardiogenic shocks (0.11%), 3 strokes (0.05%), and 1 pulmonary embolism (0.02%).

CONCLUSION

In real world practice, DT is not performed in a substantial number of patients, most of these in the absence of legitimate reasons. The clinical impact of DT vs. no DT remains unclear until the not negligible complication rate is compared against the long-term potential benefit.