Developing a risk model for in-hospital adverse events following implantable cardioverter-defibrillator implantation: a report from the NCDR (National Cardiovascular Data Registry)

Distinguishing Primary Prevention From Secondary Prevention Implantable Cardioverter Defibrillators Using Administrative Health and Cardiac Device Registry Data

Background

Administrative health data and cardiac device registries can be used to empirically evaluate outcomes and costs after implantable cardioverter defibrillator (ICD) implantation. These datasets often have incomplete information on the indication for implantation (primary vs secondary prevention of sudden cardiac death).

Methods

We used 16 years of population-based cardiac device registry and administrative health data from British Columbia, Canada, to derive and internally validate statistical models that predict the likely indication for ICD implantation. We used chart review data as the reference standard for ICD indication in the Cardiac Device Registry database (CDR; 2004-2012 [Cardiac Services BC]) and nonmissing indication as the reference standard in the Heart Information System registry database (HEARTis; 2013-2019 [Cardiac Services BC]). We created 3 logistic regression prediction models in each database: one using only registry data, one using only administrative data, and one using both registry and administrative data. We assessed the predictive performance of each model using standard metrics after optimism correction with 200 bootstrap resamples.

Results

Models that used registry data alone demonstrated excellent predictive performance (sensitivity ≥ 89%; specificity ≥ 87%). Models that used only administrative data performed well (sensitivity ≥ 84%; specificity ≥ 70%). Models that used both registry and administrative data showed modest gains over those that used registry data alone (sensitivity ≥ 90%; specificity ≥ 89%).

Conclusions

Administrative health data and cardiac device registry data can distinguish secondary prevention ICDs from primary prevention ICDs with acceptable sensitivity and specificity. Imputation of missing ICD indication might make these data resources more useful for research and health system monitoring.

Is it time to consider a "time-out" before primary prevention implantable cardioverter-defibrillator placement in currently or recently hospitalized older patients with heart failure?

BACKGROUND

Trajectories of mortality after primary prevention implantable cardioverter-defibrillator (ICD) placement for older patients with heart failure during or soon after acute hospitalization have not been assessed.

OBJECTIVE

The purpose of this study was to compare trajectories of mortality after primary prevention ICD placement during or soon after acute cardiac or non-cardiac hospitalization.

METHODS

We identified older patients with heart failure undergoing primary prevention ICD placement using 20% Medicare data (2008-2018). Placement settings were as follows: (1) Current-H-during current hospitalization, (2) Recent-H-within 90 days of hospitalization, or (3) Chronic stable. Hospitalization was categorized as cardiac vs non-cardiac. Interval mortality rates and hazard ratios (HRs) using Cox regression were estimated at 0-30, 31-90, and 91-365 days after ICD placement.

RESULTS

Of the 61,710 patients (mean age 76 years; 35% female; 85% white), 19% (11,947), 25% (15,147), and 56% (34,616) had ICDs in Current-H, Recent-H, and Chronic stable settings. Mortality rates (per 100 person-years) were highest during 0-30 days, with 38 (34-42) and 22 (19-24) for Current-H and Recent-H, which declined to 21 (20-22) and 16 (15-17) during 91-365 days, respectively. Compared to Chronic stable, HRs were highest during 0-30 days post-ICD placement (5.5 [4.5-6.8] for Current-H and 3.4 [2.8-4.2] for Recent-H) and decreased during 91-365 days (2.0 [1.8-2.1] for Current-H and 1.6 [1.5-1.7] for Recent-H). HR pattens were similar for cardiac and non-cardiac hospitalizations.

CONCLUSION

Primary prevention ICD placement during or soon after hospitalization for any reason was associated with worse mortality with diminishing risks after 90 days. Hospitalization likely identifies a sicker population in whom early mortality with or without ICD may be higher. Our results support careful consideration regarding ICD placement during the 90 days after hospitalization.

Predicting Major Adverse Events in Patients Undergoing Transcatheter Left Atrial Appendage Occlusion

BACKGROUND

The National Cardiovascular Data Registry Left Atrial Appendage Occlusion Registry (LAAO) includes the vast majority of transcatheter LAAO procedures performed in the United States. The objective of this study was to develop a model predicting adverse events among patients undergoing LAAO with Watchman FLX.

METHODS

Data from 41 001 LAAO procedures with Watchman FLX from July 2020 to September 2021 were used to develop and validate a model predicting in-hospital major adverse events. Randomly selected development (70%, n=28 530) and validation (30%, n=12 471) cohorts were analyzed with 1000 bootstrapped samples, using forward stepwise logistic regression to create the final model. A simplified bedside risk score was also developed using this model.

RESULTS

Increased age, female sex, low preprocedure hemoglobin, no prior attempt at atrial fibrillation termination, and increased fall risk most strongly predicted in-hospital major adverse events and were included in the final model along with other clinically relevant variables. The median in-hospital risk-standardized adverse event rate was 1.50% (range, 1.03%-2.84%; interquartile range, 1.42%-1.64%). The model demonstrated moderate discrimination (development C-index, 0.67 [95% CI, 0.65-0.70] and validation C-index, 0.66 [95% CI, 0.62-0.70]) with good calibration. The simplified risk score was well calibrated with risk of in-hospital major adverse events ranging from 0.26% to 3.90% for a score of 0 to 8, respectively.

CONCLUSIONS

A transcatheter LAAO risk model using National Cardiovascular Data Registry and LAAO Registry data can predict in-hospital major adverse events, demonstrated consistency across hospitals and can be used for quality improvement efforts. A simple bedside risk score was similarly predictive and may inform shared decision-making.

Defibrillation Threshold Testing and Long-term Follow-up in Chagas Disease

BACKGROUND

Sudden cardiac death is the most common cause of death in chronic Chagas cardiomyopathy (CCC). Because most CCC patients who are candidates for implantable cardioverter-defibrillators (ICD) meet criteria for high defibrillation threshold values, a defibrillator threshold test (DTT) is suggested.

OBJECTIVES

We investigated the use of DTT in CCC patients, focusing on deaths related to ICD and arrhythmic events, as well as treatment during long-term follow-up.

METHODS

We retrospectively evaluated 133 CCC patients who received an ICD mainly for secondary prevention. Demographic, clinical, laboratory data, Rassi score, and DTT data were collected, with p < 0.05 considered significant.

RESULTS

The mean patient age was 61 (SD, 13) years and 72% were men. The baseline left ventricular ejection fraction was 40 (SD, 15%) and the mean Rassi score was 10 (SD, 4). No deaths occurred during DTT and no ICD failures were documented. There was a relationship between higher baseline Rassi scores and higher DTT scores (ANOVA = 0.007). The mean time to first shock was 474 (SD, 628) days, although shock was only necessary for 28 (35%) patients with ventricular tachycardia, since most cases resolved spontaneously or through antitachycardia pacing. After a mean clinical follow-up of 1728 (SD, 1189) days, 43 deaths occurred, mainly related to progressive heart failure and sepsis.

CONCLUSIONS

A routine DTT may not be necessary for CCC patients who receive an ICD for secondary prevention. High DTT values seem to be unusual and may be related to high Rassi scores.

Institutional Variation in 30‐Day Complications Following Catheter Ablation of Atrial Fibrillation

Background

Complications are a measure of procedural quality, yet variation in complication rates following catheter ablation of atrial fibrillation (AF) among hospitals has not been systematically examined. We examined institutional variation in the risk‐standardized 30‐day complication rates (RSCRs) following AF ablation which may suggest variation in care quality.

Methods and Results

This cohort study included all patients >18 years old undergoing AF ablations from 2012 to 2017 in Australia and New Zealand. The primary outcome was procedure‐related complications occurring during the hospital stay and within 30 days of hospital discharge. We estimated the hospital‐specific risk‐standardized complication rates using a hierarchical generalized linear model. A total of 25 237 patients (mean age, 62.5±11.4 years; 30.2% women; median length of stay 1 day [interquartile range, 1–2 days]) were included. Overall, a complication occurred in 1400 (5.55%) patients (4.34% in hospital, 1.46% following discharge, and 0.25% experienced both). Bleeding (3.31%), pericardial effusion (0.74%), and infection (0.44%) were the most common complications while stroke/transient ischemic attack (0.24%), cardiorespiratory failure and shock (0.19%), and death (0.08%) occurred less frequently. Among 46 hospitals that performed ≥25 ablations during the study period, the crude complication rate varied from 0.00% to 21.43% (median, 5.74%). After adjustment for differences in patient and procedural characteristics, the median risk‐standardized complication rate was 5.50% (range, 2.89%–10.31%), with 10 hospitals being significantly different from the national average.

Conclusions

Procedure‐related complications occur in 5.55% of patients undergoing AF ablations, although the risk of complications varies 3‐fold among hospitals, which suggests potential disparities in care quality and the need for efforts to standardize AF ablation practices among hospitals.

Implantable cardioverter-defibrillators and the older patient: the Dutch clinical practice

Background and objective

Balance between benefit and burden of implantable cardioverter-defibrillator (ICD) therapy is more debatable in older patients, compared to younger patients. Of around 6000 yearly implanted ICDs in the Netherlands, 1:4 is received by patients ≥75 years. We aimed to evaluate the current clinical practice in the Netherlands for ICD implants and generator replacements, with a special focus on the older ICD patients.

Research design and methods

Cardiologists from all Dutch ICD implanting centres (n = 28) were interviewed. Questions aimed to evaluate outpatient care, pre-operative patient assessment, end-of-life-care counselling, evaluation of social and cognitive wellbeing, clinical evaluation of all patients prior to ICD replacement, and the consideration of the option to downgrade or not replace a device.

Results

Implanting cardiologists from all 28 implanting centres were approached for an interview. Response rate was 86%. Management appeared diverse. An age ≥80 years was consistently reported as incentive for more extensive patient evaluation. Patients were invited for counselling prior to device replacements in only the minority (46%) of hospitals. Downgrade or non-replacement was performed in rare cases. End-of-life care discussions were not standard procedure in 67% of the hospitals. Evaluation of social and cognitive wellbeing of patients was based solely on the general clinical impression of the physician in 83%, or not at all assessed in 8% of the centres.

Discussion and implication

A structured framework for care and evaluation of cognitive and/or physical limitations is currently absent in most hospitals. At time of ICD (re-)evaluation, several factors may be considered before deciding on (continuation of) ICD therapy: patient preferences and comorbidity, the need for pacemaker therapy, primary vs. secondary prevention, procedural risks, and patient preferences.

EHRA expert consensus statement and practical guide on optimal implantation technique for conventional pacemakers and implantable cardioverter-defibrillators: endorsed by the Heart Rhythm Society (HRS), the Asia Pacific Heart Rhythm Society (APHRS), and the Latin-American Heart Rhythm Society (LAHRS)

With the global increase in device implantations, there is a growing need to train physicians to implant pacemakers and implantable cardioverter-defibrillators. Although there are international recommendations for device indications and programming, there is no consensus to date regarding implantation technique. This document is founded on a systematic literature search and review, and on consensus from an international task force. It aims to fill the gap by setting standards for device implantation.

Periprocedural Risk and Survival Associated With Implantable Cardioverter-Defibrillator Placement in Older Patients With Advanced Heart Failure

Importance

Little is known about the utilization rates and outcomes of implantable cardioverter-defibrillator (ICD) and cardiac resynchronization therapy defibrillator (CRT-D) placement among patients with advanced heart failure (HF).

Objective

To examine utilization rates, patient characteristics, and outcomes of ICD and CRT-D placements among patients with advanced HF.

Design, Setting, and Participants

This cohort study was a post hoc analysis of 81 492 Medicare fee-for-service beneficiaries enrolled in the National Cardiovascular Data Registry ICD Registry between January 2010 and December 2014. Inclusion criteria were patients who had received an HF diagnosis, had a left ventricular ejection fraction of 35% or lower, and showed evidence of advanced HF, which was defined as New York Heart Association (NYHA) class IV symptoms, inotrope use within the last 60 days, left ventricular assist device in situ, or orthotopic heart transplant listing. The comparator group included patients with NYHA class II and no HF hospitalization within the last 12 months, no left ventricular assist device, no orthotopic heart transplant listing, and no current or recent inotrope use. All eligible patients underwent first-time ICD or CRT-D placement for primary prevention of sudden cardiac death. Data were analyzed from January 2010 to December 2014.

Main Outcomes and Measures

All-cause mortality and periprocedural complications.

Results

Of 81 492 Medicare patients, 3343 had advanced HF (4.1%) and 19 424 were in the comparator group (23.8%). Among the advanced HF population, the mean (SD) age of patients was 74 (9) years, and patients were predominantly white individuals (81.5%) and men (71.1%). The all-cause mortality rate at 30 days was 3.1% (95% CI, 2.6%-3.8%) in the advanced HF group vs 0.5% (0.4%-0.6%) in the comparator group (P < .001). In the advanced HF population, the aggregate in-hospital periprocedural complication rate was 3.74% (95% CI, 3.12%-4.44%) vs 1.10% (95% CI, 0.95%-1.25%) in the comparator group (P < .001). Most adverse events in this group were in-hospital fatality (1.82%; 95% CI, 1.40%-2.34%) and resuscitated cardiac arrest (1.05%; 95% CI, 0.73%-1.45%). Patients with NYHA class IV (hazard ratio, 1.40; 95% CI, 1.02-1.93; P = .04), ischemic heart disease (hazard ratio, 1.24; 95% CI, 1.04-1.48; P = .02), or diabetes (hazard ratio, 1.17; 95% CI, 1.04-1.33; P = .01) had a higher risk of death.

Conclusions and Relevance

Among patients undergoing ICD or CRT-D placement for primary prevention of sudden cardiac death, only a small proportion had advanced HF. These patients experienced clinically important periprocedural complication rates associated with in-hospital death and cardiac arrest relative to patients with nonadvanced HF.

Decision-making regarding primary prevention implantable cardioverter-defibrillators among older adults

Most implantable cardioverter defibrillators (ICDs) are implanted for the purpose of primary prevention of sudden cardiac death among older patients with heart failure with reduced ejection fraction. Shared decision‐making prior to device implantation is guideline‐recommended and payer‐mandated. This article summarizes patient and provider attitudes toward device placement, device efficacy and effectiveness, potential periprocedural complications, long‐term events such as shocks, quality of life, costs, and shared decision‐making principles and recommendations. Most patients eligible for an ICD anticipate more than 10 years of survival. Physicians are less likely to offer an ICD to patients ≥80 years of age given a perceived lack of benefit. There is a dearth of data from randomized clinical trials addressing device efficacy among older patients; there is a need for more research in this area. However, currently available data support the use of ICDs irrespective of age provided life expectancy exceeds 1 year. Advanced age is independently associated with complications at the time of device placement but not the risk of device infection. The risk of inappropriate shock may be comparable or lower than that of younger patients. While quality of life is generally not adversely impacted by an ICD, a subset of patients experience post‐traumatic stress disorder. ICDs are cost‐effective from societal and health care sector perspectives; however, out‐of‐pocket costs vary according to insurance type and level. Shared decision‐making encounters may be incremental and iterative in nature. Providers are encouraged to partner with their patients, providing them counsel tailored to their values, preferences, and clinical presentation inclusive of age.

Institutional Variation in Quality of Cardiovascular Implantable Electronic Device Implantation: A Cohort Study

BACKGROUND

Cardiovascular implantable electronic devices (CIEDs) are associated with procedure-related complications, yet little is known about variation in complication rates among institutions that may suggest disparities in care quality.

OBJECTIVE

To assess institutional variation in risk-standardized complication rates (RSCRs) for CIED.

DESIGN

Cohort study.

SETTING

174 hospitals in Australia and New Zealand, 98 of which implanted at least 25 CIEDs during the study period.

PARTICIPANTS

81 304 patients older than 18 years (mean, 74.7 years [SD, 12.4]; 37.9% female) who received a new CIED (65 711 permanent pacemakers [PPMs] and 15 593 implantable cardioverter-defibrillators [ICDs]) in 2010 to 2015.

MEASUREMENTS

RSCRs and frequencies of major device-related complications during hospitalization or within 90 days of discharge.

RESULTS

Of the cohort, 6664 patients (8.2%) had a major complication. Although complication rates were higher for ICDs than PPMs (10.04% vs. 7.76%), 76.5% of all complications were attributable to PPMs (5098 vs. 1566 for ICDs). Among hospitals that implanted at least 25 CIEDs, the median RSCR was 8.1%; however, rates varied from 5.3% to 14.3%, with 22 hospitals identified as having RSCRs that differed significantly from the national average. Similar variation was observed when RSCRs for PPM implantation (n = 96 hospitals) (median RSCR, 7.6% [range, 5.4% to 12.9%]) were considered separately from those for ICD placement (n = 68 hospitals) (median RSCR, 9.7% [range, 6.2% to 16.9%]) and persisted when only elective procedures were assessed (n = 88 hospitals) (median RSCR, 7.4% [range, 4.7% to 13.0%]).

LIMITATION

Possible unmeasured confounding from the use of administrative data.

CONCLUSION

CIED complications are common and vary among hospitals, suggesting institutional variation in CIED care quality. Concerted clinical and policy interventions are needed to address CIED-related complications. These efforts should preferentially target PPMs, because most CIED complications are attributable to these devices.

PRIMARY FUNDING SOURCE

The Hospitals Contribution Fund Research Foundation.

Predicting Length of Stay and the Need for Postacute Care After Acute Myocardial Infarction to Improve Healthcare Efficiency

Background To improve value in the care of patients with acute myocardial infarction (MI), payment models increasingly hold providers accountable for costs. As such, providers need tools to predict length of stay (LOS) during hospitalization and the likelihood of needing postacute care facilities after discharge for acute MI patients. We developed models to estimate risk for prolonged LOS and postacute care for acute MI patients at time of hospital admission to facilitate coordinated care planning. Methods and Results We identified patients in the National Cardiovascular Data Registry ACTION registry (Acute Coronary Treatment and Intervention Outcomes Network) who were discharged alive after hospitalization for acute MI between July 1, 2008 and March 31, 2017. Within a 70% random sample (Training cohort) we developed hierarchical, proportional odds models to predict LOS and hierarchical logistic regression models to predict discharge to postacute care. Models were validated in the remaining 30%. Of 633 737 patients in the Training cohort, 16.8% had a prolonged LOS (≥7 days) and 7.8% were discharged to a postacute facility (extended care, a transitional care unit, or rehabilitation). Model discrimination was moderate in the validation dataset for predicting LOS (C statistic=0.640) and strong for predicting discharge to postacute care (C statistic=0.827). For both models, discrimination was similar in ST-segment-elevation MI and non-ST-segment-elevation MI subgroups and calibration was excellent. Conclusions These models developed in a national registry can be used at the time of initial hospitalization to predict LOS and discharge to postacute facilities. Prospective testing of these models is needed to establish how they can improve care coordination and lower costs.

Untapped potential of multicenter studies: a review of cardiovascular risk prediction models revealed inappropriate analyses and wide variation in reporting

BACKGROUND

Clinical prediction models are often constructed using multicenter databases. Such a data structure poses additional challenges for statistical analysis (clustered data) but offers opportunities for model generalizability to a broad range of centers. The purpose of this study was to describe properties, analysis, and reporting of multicenter studies in the Tufts PACE Clinical Prediction Model Registry and to illustrate consequences of common design and analyses choices.

METHODS

Fifty randomly selected studies that are included in the Tufts registry as multicenter and published after 2000 underwent full-text screening. Simulated examples illustrate some key concepts relevant to multicenter prediction research.

RESULTS

Multicenter studies differed widely in the number of participating centers (range 2 to 5473). Thirty-nine of 50 studies ignored the multicenter nature of data in the statistical analysis. In the others, clustering was resolved by developing the model on only one center, using mixed effects or stratified regression, or by using center-level characteristics as predictors. Twenty-three of 50 studies did not describe the clinical settings or type of centers from which data was obtained. Four of 50 studies discussed neither generalizability nor external validity of the developed model.

CONCLUSIONS

Regression methods and validation strategies tailored to multicenter studies are underutilized. Reporting on generalizability and potential external validity of the model lacks transparency. Hence, multicenter prediction research has untapped potential.

REGISTRATION

This review was not registered.

A risk score model for predicting intraprocedural cardiac injury during implantable cardioverter defibrillator implantation: Insights from the National Cardiovascular Data Registry

BACKGROUND

Individual risk factors of intraprocedural cardiac injury (cardiac perforation and tamponade) during implantable cardioverter defibrillator (ICD) placement have been documented. However, the prognostic impact of their coexistence has not been explored.

OBJECTIVE

To develop a risk score model to identify patients at risk for intraprocedural cardiac injury.

METHODS

We identified 438 679 patients from National Cardiovascular Data Registry (NCDR)-ICD who underwent de novo ICD implantation between 2010 and 2015, split randomly into a derivation cohort (n = 220 000) and a validation cohort (n = 218 679). The generalized estimating equations (GEEs) analysis with quasilikelihood under the independence model criterion goodness-of-fit statistics were used to identify the predictors of intraprocedural cardiac injury and a risk scoring model was developed. Model discrimination was assessed by receiver-operator characteristic curve and C-statistic.

RESULTS

The risk of intraprocedural cardiac injury in the overall cohort was 0.13%. GEE analysis yielded seven variables (points in parentheses) that were strongly associated with intraprocedural cardiac injury: age, greater than 75 years (1), female gender (1), body mass index, less than 18.5 kg/m ² (1), hypertension (1), chronic lung disease (1), left bundle branch block (1), and continued warfarin use (1). Only prior history of coronary artery bypass grafting (CABG) (-1) was associated with reduced risk. A risk scoring system was developed that had good discrimination with a C-statistic of 0.72. The risk of intraprocedural cardiac injury increased with the increase in risk score from low risk (0.03%) to high risk (1.37%).

CONCLUSION

A practical risk score model can stratify patients into high- and low-risk groups for cardiac perforation or tamponade before undergoing ICD implantation.

Is Time From Last Hospitalization for Heart Failure to Placement of a Primary Prevention Implantable Cardioverter-Defibrillator Associated With Patient Outcomes?

BACKGROUND

Landmark studies have demonstrated the safety and efficacy of implantable cardioverter-defibrillators (ICDs) in selected stable ambulatory patients with heart failure (HF) with a reduced ejection fraction receiving optimal medical therapy. It is not known whether a recent hospitalization for HF before ICD placement is associated with subsequent outcomes.

METHODS

A post hoc analysis was performed of Medicare beneficiaries enrolled in the National Cardiovascular Data Registry's ICD Registry with a known diagnosis of HF and an ejection fraction ≤35% underdoing a new ICD placement for primary prevention. Patients were grouped based on the timing of ICD placement from the last hospitalization for HF. The association between timing of ICD placement and outcomes was assessed by using multivariable logistic regression models.

RESULTS

The final analytic cohort included 81 180 patients undergoing initial ICD placement for primary prevention who were currently hospitalized for HF (n=11 563, 14%), hospitalized for HF within 3 months (n=6252, 8%), or hospitalized for HF >3 months previously or had no previous hospitalizations for HF (n=63 365, 78%). Patients currently or recently hospitalized for HF had a higher unadjusted composite periprocedural complication rate (2.60% versus 1.71% versus 1.25%, P<0.001). After adjusting for potential confounders, patients currently hospitalized for HF were at higher risk for death (odds ratio, 2.25; 95% CI, 2.02-2.52; P <0.001) and all-cause readmission (odds ratio, 1.89; 95% CI, 1.79-1.99; P <0.001) at 90 days.

CONCLUSION

Older patients currently or recently hospitalized for HF undergoing initial ICD placement for primary prevention experienced a higher rate of periprocedural complications and were at increased risk of death in comparison with those receiving an ICD without recent HF hospitalization. Additional prospective, real-world, pragmatic, comparative effectiveness studies should be conducted to define the optimal timing of ICD placement.

Quality and Safety in Health Care, Part XLIII: Selected Outcome Studies From the Implantable Cardioverter Defibrillator Registry

To compare outcome results from different institutions in a registry, it is necessary to have a way to take into account differences in the risk characteristics of the patients. This model has been constructed for the Implantable Cardioverter Defibrillator (ICD) Registry, and the most important variables have been identified. In another study, it has also been found that many of these patients have comorbidities, and the mortality rate 60 months after a replacement ICD was 41.2%. In a third study, it was determined that for individuals at least 65 years of age, 60 months after ICD placement, 50.9% of the recipients used hospice services or were dead.

Reasons for and predictors of acute hospitalization versus elective outpatient implantable cardioverter-defibrillator implantation and subsequent differential clinical outcomes

BACKGROUND

Implantable cardioverter-defibrillator (ICD) implantation is often an elective outpatient procedure, but previous studies have shown that approximately 30% are performed during acute hospitalizations.

PURPOSE

This study aims to identify predictors of acute hospitalization versus elective outpatient ICD implantation and evaluate differential clinical outcomes.

METHODS

We studied 327 first-time ICD recipients between 2011 and 2015. All patients receiving a primary prevention ICD were optimized on guideline directed medical therapy (GDMT) prior to consideration for device implantation. Using multivariate logistic regression, we examined predictors of ICD implantation during acute hospitalization. Cox proportional hazard regression was used adjusting for patient characteristics to examine associations with clinical outcomes including complications, device therapy, heart failure re-admission, and death.

RESULTS

Of all patients, 132 (40.3%) underwent ICD implantation during acute hospitalization, most frequently performed for secondary prevention (n = 76, 57.6%). The most common reason for acute hospitalization ICD implantation in primary prevention patients was an indication for pacing (n = 20, 35.7%). In multivariable adjusted models, secondary prevention indication, non-single chamber device, NYHA class IV symptoms, lower diastolic blood pressure, higher BUN, and lower hemoglobin were significant predictors of ICD implantation during an acute hospitalization. In univariate analysis, acute hospitalization ICD implantation was associated with a higher risk of heart failure re-admission (HR = 1.6, 95% CI 1.1-2.4) and mortality (HR = 3.0, 95% CI 1.1-8.0) but no difference in risk of ICD therapy (HR = 1.4, 95% CI 0.9-2.3) or adverse events (HR = 1.1, 95% CI 0.6-2.1). After multivariable adjustment for potential confounders, all outcomes were no different between acute hospitalization versus elective outpatient ICD recipients.

CONCLUSIONS

Among first-time ICD recipients, specific clinical characteristics predicted acute hospitalization ICD implantation. After adjustment for potential confounders, acute hospitalization ICD implantation was not associated with increased risk of morbidity or mortality.

Long-term complications, reoperations and survival following cardioverter-defibrillator implant

OBJECTIVE

Implantable cardioverter-defibrillators (ICDs) reduce risk of death in select populations, but are also associated with harms. We aimed to characterise long-term complications and reoperation rate.

METHODS

We assessed the rate, cumulative incidence and predictors of long-term reoperation and survival using a prospective, multicentre registry serving British Columbia in Canada, a universal single payer healthcare system with 4.5 million residents. 3410 patients (mean 63.3 years, 81.7% male) with new primary (n=1854) or secondary prevention (n=1556) ICD implant from 2003 to 2012 were followed for a median of 34 months (single chamber n=1069, dual chamber n=1905, biventricular n=436). Independent predictors of adverse outcomes were defined using Cox regression models.

RESULTS

The overall reoperation rate was 12.0% per patient-year, and less for single vs dual vs biventricular ICDs (9.1% vs 12.5% vs 17.8% per patient-year, respectively). The Kaplan-Meier complication estimates (excluding generator end of life) at 1, 3 and 5 years were respectively: single chamber 10.2%, 16.2% and 21.6%; dual 11.7%, 19.1% and 27.4% and biventricular 15.9%, 22.2% and 24.7%. Cardiac resynchronisation therapy had the highest rate of early lead complications, but lower long-term need for upgrade. Device complexity, age and atrial fibrillation were key determinants of complications. Overall mortality at 1, 3 and 5 years was 5.4%, 17.4% and 32.7%, respectively. In younger patients, observed 5-year survival approached the expected survival in the general population (relative survival ratio=0.96 (0.90-0.98)). With increasing age, observed survival steadily declined relative to expected.

CONCLUSIONS

In a prospective registry capturing all procedures, complication and reoperation rates following de novo ICD implantation were high. Shared decision making must carefully consider these factors.

Healthcare Utilization and Expenditures Associated With Appropriate and Inappropriate Implantable Defibrillator Shocks

Background—

In patients with implantable cardioverter–defibrillators, healthcare utilization (HCU) and expenditures related to shocks have not been quantified.

Methods and Results—

We performed a retrospective cohort study of patients with implantable cardioverter–defibrillators identified from commercial and Medicare supplemental claims databases linked to adjudicated shock events from remote monitoring data. A shock event was defined as ≥1 spontaneous shocks delivered by an implanted device. Shock-related HCU was ascertained from inpatient and outpatient claims within 7 days following a shock event. Shock events were adjudicated and classified as inappropriate or appropriate, and HCU and expenditures, stratified by shock type, were quantified. Of 10 266 linked patients, 963 (9.4%) patients (61.3±13.6 years; 81% male) had 1885 shock events (56% appropriate, 38% inappropriate, and 6% indeterminate). Of these events, 867 (46%) had shock-related HCU (14% inpatient and 32% outpatient). After shocks, inpatient cardiovascular procedures were common, including echocardiography (59%), electrophysiology study or ablation (34%), stress testing (16%), and lead revision (11%). Cardiac catheterization was common (71% and 51%), but percutaneous coronary intervention was low (6.5% and 5.0%) after appropriate and inappropriate shocks. Expenditures related to appropriate and inappropriate shocks were not significantly different.

Conclusions—

After implantable cardioverter–defibrillator shock, related HCU was common, with 1 in 3 shock events followed by outpatient HCU and 1 in 7 followed by hospitalization. Use of invasive cardiovascular procedures was substantial, even after inappropriate shocks, which comprised 38% of all shocks. Implantable cardioverter–defibrillator shocks seem to trigger a cascade of health care. Strategies to reduce shocks could result in cost savings.

The impact of co-morbidity burden on appropriate implantable cardioverter defibrillator therapy and all-cause mortality: insight from Danish nationwide clinical registers

AIMS

In a nationwide cohort of primary (PP-ICD) and secondary prevention (SP-ICD) implantable cardioverter defibrillator (ICD) patients, we aimed to investigate the association between co-morbidity burden and risk of appropriate ICD therapy and mortality.

METHODS AND RESULTS

We identified all patients >18 years, implanted with first-time PP-ICD (n = 1873) or SP-ICD (n = 2461) in Denmark from 2007 to 2012. Co-morbidity was identified in administrative registers of hospitalization and drug prescription from pharmacies. Co-morbidity burden was defined as the number of pre-existing non-ICD indication-related co-morbidities including atrial fibrillation, diabetes, chronic obstructive pulmonary disease, chronic renal disease, liver disease, cancer, chronic psychiatric disease, and peripheral and/or cerebrovascular disease, and divided into four groups (co-morbidity burden 0, 1, 2, and ≥3). Through Cox models, we assessed the impact of co-morbidity burden on appropriate ICD therapy and mortality. Increasing co-morbidity burden was not associated with increased risk of appropriate therapy, irrespective of implant indication [all hazard ratios (HRs) 1.0-1.4, P = NS]. Using no co-morbidities as reference, increasing co-morbidity burden was associated with increased mortality risk in PP-ICD patients (co-morbidity burden 1, HR 2.1; comorbidity burden 2, HR 3.7; co-morbidity burden ≥3, HR 6.6) (all P < 0.001) and SP-ICD patients (co-morbidity burden 1, HR 2.2; co-morbidity burden 2, HR 3.8; co-morbidity burden ≥3, HR 5.8). With increasing co-morbidity burden, an increasing frequency of patients died without having utilized their device, with 72% PP-ICD and 45% SP-ICD patients with co-morbidity burden ≥3 dying without prior appropriate ICD therapy.

CONCLUSION

Increasing co-morbidity burden was not associated with increased risk of appropriate ICD therapy. With increasing co-morbidity burden, mortality increased, and a higher proportion of patients died, without ever having utilized their device.

Measuring quality in electrophysiology

The evolving healthcare environment demands optimally measured quality of care. Performance measures are increasingly being used for quality improvement, public reporting, and reimbursement determinations. The National Quality Forum has created rigorous criteria for the evaluation of potential performance measures across medical fields. The Heart Rhythm Society has championed the development of four separate electrophysiology (EP)-specific performance measures: implantable cardioverter defibrillator complication rate, cardiac tamponade and/or pericardiocentesis following atrial fibrillation ablation, infection within 180 days of a cardiac implantable electronic device implantation, replacement, or revision, and in-person evaluation following a cardiac implantable electronic device implantation. National registries serve a key role in developing performance measures and facilitating quality improvement, particularly as they provide improved granularity and accuracy of data compared with administrative claims data. All performance measures demand continued reassessment as technology and performance gaps change and as unintended consequences may arise.

Impact of early complications on outcomes in patients with implantable cardioverter-defibrillator for primary prevention

BACKGROUND

The lifesaving benefit of implantable cardioverter-defibrillators (ICDs) has been demonstrated. Their use has increased considerably in the past decade, but related complications have become a major concern.

OBJECTIVE

The purpose of this study was to assess the incidence and effect on outcomes of early (≤30 days) complications after ICD implantation for primary prevention in a large French population.

METHODS

We analyzed data from 5539 patients from the multicenter French DAI-PP (Défibrillateur Automatique Implantable-Prévention Primaire) registry (2002-2012) who had coronary artery disease or dilated cardiomyopathy and were implanted with an ICD for primary prevention.

RESULTS

Overall, early complications occurred in 707 patients (13.5%), mainly related to lead dislodgment or hematoma (57%). Independent factors associated with occurrence of early complications were severe renal impairment (odds ratio [OR] 1.66, 95% confidence interval [CI] 1.17-2.37, P = .02), age ≥75 years (OR 1.01, 95% CI 1.00-1.02, P = .03), cardiac resynchronization therapy (OR 1.58, 95% CI 1.16-2.17, P = .01), and anticoagulant therapy (OR 1.28, 95% CI 1.02-1.61, P = .03). During a mean ± SD follow-up of 3.1 ± 2.3 years, 824 (15.8%) patients experienced ≥1 late complication (>30 days), and 782 (14.9%) patients died. After adjustment, early complications remained associated with occurrence of late complications (OR 2.15, 95% CI 1.73-2.66, P < .0001) and mortality (OR 1.70, 95% CI 1.34-2.17, P = .003).

CONCLUSION

Early complications are common after ICD implantation for primary prevention, occurring in 1 in 7 patients, and are associated with an increased risk of late complications and overall mortality. Further studies are needed to investigate the underlying mechanisms of such associations.

Implantable cardioverter-defibrillator harm in young patients with inherited arrhythmia syndromes: A systematic review and meta-analysis of inappropriate shocks and complications

BACKGROUND

Implantable cardioverter-defibrillators (ICDs) are implanted with the intention to prolong life in selected patients with inherited arrhythmia syndromes, but ICD implantation is also associated with inappropriate shocks and complications.

OBJECTIVE

We aimed to quantify the rate of inappropriate shocks and other ICD-related complications to be able to weigh benefit and harm in these patients.

METHODS

We performed a systematic review and meta-analysis of inappropriate shock and/or other ICD-related complication rates, including ICD-related mortality, in patients with inherited arrhythmia syndromes, that is, arrhythmogenic right ventricular cardiomyopathy/dysplasia, Brugada syndrome, catecholaminergic polymorphic ventricular tachycardia, hypertrophic cardiomyopathy, dilated cardiomyopathy due to a mutation in the lamin A/C gene, long QT syndrome, and short QT syndrome. We searched MEDLINE and EMBASE from inception to May 30, 2014.

RESULTS

Of 2471 unique citations, 63 studies comprising 4916 patients with inherited arrhythmia syndromes (mean age of 39 ± 15 years) were included. Inappropriate shocks occurred in 20% of patients (crude annual rate of 4.7% per year), with a significantly higher rate in studies published before 2008 (6.1% per year vs 4.1% per year). Moreover, 22% experienced ICD-related complications (4.4% per year) and there was a 0.5% ICD-related mortality (0.08% per year).

CONCLUSION

ICD implantation carries a significant risk of inappropriate shocks and inhospital and postdischarge complications in relatively young patients with inherited arrhythmia syndromes. These data can be used to better inform patients and physicians about the expected risk of adverse ICD events and thereby facilitate shared decision making.

A systematic review of ICD complications in randomised controlled trials versus registries: is our 'real-world' data an underestimation?

Implantable cardioverter defibrillator (ICD) implantation carries a significant risk of complications, however published estimates appear inconsistent. We aimed to present a contemporary systematic review using meta-analysis methods of ICD complications in randomised controlled trials (RCTs) and compare it to recent data from the largest international ICD registry, the US National Cardiovascular Data Registry (NCDR).

PubMed was searched for any RCTs involving ICD implantation published 1999–2013; 18 were identified for analysis including 6433 patients, mean follow-up 3 months–5.6 years. Exclusion criteria were studies of children, hypertrophic cardiomyopathy, congenital heart disease, resynchronisation therapy and generator changes.

Total pooled complication rate from the RCTs (excluding inappropriate shocks) was 9.1%, including displacement 3.1%, pneumothorax 1.1% and haematoma 1.2%. Infection rate was 1.5%.There were no predictors of complications but longer follow-up showed a trend to higher complication rates (p=0.07). In contrast, data from the NCDR ICD, reporting on 356 515 implants (2006–2010) showed a statistically significant threefold lower total major complication rate of 3.08% with lead displacement 1.02%, haematoma 0.86% and pneumothorax 0.44%.

The overall ICD complication rate in our meta-analysis is 9.1% over 16 months. The ICD complication reported in the NCDR ICD registry is significantly lower despite a similar population. This may reflect under-reporting of complications in registries. Reporting of ICD complications in RCTs and registries is very variable and there is a need to standardise classification of complications internationally.

Safety of Outpatient Implantation of the Implantable Cardioverter-defibrillator

INTRODUCTION AND OBJECTIVES

Strategies are needed to reduce health care costs and improve patient care. The objective of our study was to analyze the safety of outpatient implantation of cardioverter-defibrillators.

METHODS

A retrospective study was conducted in 401 consecutive patients who received an implantable cardioverter-defibrillator between 2007 and 2012. The rate of intervention-related complications was compared between 232 patients (58%) whose implantation was performed in the outpatient setting and 169 patients (42%) whose intervention was performed in the inpatient setting.

RESULTS

The mean age (standard deviation) of the patients was 62 (14) years; 336 (84%) were male. Outpatients had lower left ventricular ejection fraction and a higher percentage had an indication for primary prevention of sudden death, compared to inpatients. Only 21 outpatients (9%) required subsequent hospitalization. The rate of complications until the third month postimplantation was similar for outpatients (6.0%) and inpatients (5.3%); P = .763. In multivariate analysis, only previous anticoagulant therapy was related to the presence of complications (odds ratio = 3.2; 95% confidence interval, 1.4-7.4; P < .01), mainly due to an increased rate of pocket hematomas. Each outpatient implantation saved approximately €735.

CONCLUSIONS

Outpatient implantation of implantable cardioverter-defibrillators is safe and reduces costs. Close observation is recommended for patients receiving chronic anticoagulation therapy due to an increased risk of complications.

Value: a framework for radiation oncology

In the current health care system, high costs without proportional improvements in quality or outcome have prompted widespread calls for change in how we deliver and pay for care. Value-based health care delivery models have been proposed. Multiple impediments exist to achieving value, including misaligned patient and provider incentives, information asymmetries, convoluted and opaque cost structures, and cultural attitudes toward cancer treatment. Radiation oncology as a specialty has recently become a focus of the value discussion. Escalating costs secondary to rapidly evolving technologies, safety breaches, and variable, nonstandardized structures and processes of delivering care have garnered attention. In response, we present a framework for the value discussion in radiation oncology and identify approaches for attaining value, including economic and structural models, process improvements, outcome measurement, and cost assessment.

Survival after primary prevention implantable cardioverter-defibrillator placement among patients with chronic kidney disease

BACKGROUND

Guidelines recommend that implantable cardioverter-defibrillator (ICD) candidates have an estimated longevity of ≥1 year. Longevity can be affected by chronic kidney disease (CKD).

METHODS AND RESULTS

Using the National Cardiovascular Data Registry ICD registry linked with the Social Security Death Master File, we assessed the rate of death after primary prevention ICD placement between January 1, 2006, and December 31, 2007, according to CKD stage. Using Cox models, we identified factors associated with death among patients with CKD. Compared with patients without CKD (n=26,056), those with CKD (n=21,226) were older, less commonly men, more often white, and more frequently had comorbid illness. Compared with patients without CKD, patients with a glomerular filtration rate 30 to 60, glomerular filtration rate <30, and end-stage renal disease on dialysis had a higher risk of death after ICD placement (hazard ratio, 2.08; 95% confidence interval, 1.99-2.18; P<0.0001; hazard ratio, 4.20; 95% confidence interval, 3.92-4.50; P<0.0001; and hazard ratio, 4.80; 95% confidence interval, 4.46-5.17; P<0.0001, respectively). Corresponding 1-year death rates were 4.4%, 9.1%, 20.2%, and 22.4%. Among patients with CKD, factors associated with increased risk of death included CKD severity, age >65 years, heart failure symptoms, diabetes mellitus, lung disease, serum sodium <140 mEq/L, atrial fibrillation or flutter, and a lower ejection fraction.

CONCLUSIONS

The risk of death after primary prevention ICD placement is proportional to CKD severity. Among patients with CKD, several factors are prognostically significant and could inform clinical decision making on primary prevention ICD candidacy.