Use of implantable cardioverter defibrillators in Canadian and US survivors of out-of-hospital cardiac arrest

Breaking Barriers: Ensuring Gender Neutral Care on Short Term Surgical Missions

INTRODUCTION

Gender discrimination is prevalent worldwide in medical and surgical care. In the setting of short-term surgical missions (STSMs) conducted to address the global burden of surgical disease, patient selection raises ethical considerations regarding equitable distribution of limited clinical resources. The goal of this study was to examine if equitable distribution of operative care between male and female patients occurs in STSMs.

METHODS

The International Surgical Health Initiative (ISHI) is a US based nonprofit, nongovernmental organization. Records from surgical missions to Ghana (2014-2023) and Sierra Leone (2013-2023) were analyzed to evaluate for gender equity in inguinal hernia repairs, the most common procedure performed. A control group was created from a literature review inclusive of all studies of inguinal hernia repairs that included over 500 patients and patient gender.

RESULTS

The review of 26 studies, representing 3,239,043 patients, demonstrated a gender distribution of 13% female. In Sierra Leone 246 inguinal hernia repairs were performed between 2013 and 2023. 28 (11.4%) of the hernia repairs were in females, which was not significantly different from the control group (P = 0.45). In Ghana 150 inguinal hernia repairs were performed between 2014 and 2023. 12 (8%) of the hernia repairs were in females. This was not significantly different from the control group (P = 0.07).

CONCLUSIONS

This is the first study investigating the gender equity conducted within the context of humanitarian surgical outreach. Equitable patient selection is a paramount consideration in STSMs, particularly to address gender-related disparities in surgical care.

ICD Implantation Rates in Cardiac Arrest Survivors in Canada

Background

Patients resuscitated from out-of-hospital cardiac arrest (OHCA) are at high risk of recurrence, posing a substantial burden on healthcare systems. Despite the established benefit of implantable cardioverter defibrillator (ICD) therapy in many such patients, and recommendations by guidelines, few studies have described the proportion of OHCA patients who receive guideline-concordant care.

Methods

The Canadian Institute for Health Information Discharge Abstract Database dataset was used to identify OHCA patients admitted to hospitals across Canada, excluding Quebec. We analyzed all patients without a probable ischemic or bradycardia etiology of cardiac arrest, who survived to discharge, to estimate the ICD implantation rates in patients who were potentially eligible to have an ICD.

Results

Between 2013 and 2017, a total of 10,435 OHCA patients who were admitted to the hospital were captured in the database; 4486 (43%) survived to hospital discharge, and 2580 survivors (57.5%) were potentially eligible to receive an ICD. Among these potentially eligible patients, 757 (29.3%) received an ICD during their index admission or within 30 days after discharge from the hospital. The ICD implantation rate during index admission increased from 13.8% in 2013 to 19.6% in 2017 (P-value for time trend < 0.05). The rate of ICD implantations in potentially eligible patients was higher in urban than in rural settings (19.5% vs 11.1%) and in teaching vs community hospitals (34.7% vs 9.8%).

Conclusions

Although ICD implantation rates show an increasing trend among patients with OHCA who are likely eligible for secondary prevention, significant underutilization of ICDs persists in these patients.

A Commentary on the Effect of Targeted Temperature Management in Patients Resuscitated from Cardiac Arrest

The members of the International Liaison Committee on Resuscitation (ILCOR) Advanced Life Support Task Force have written a comprehensive summary of trials of the effectiveness of induced hypothermia (IH) or targeted temperature management (TTM) in comatose patients after cardiac arrest (CA). However, in-depth analysis of these studies is incomplete, especially since there was no significant difference in primary outcome between hypothermia versus normothermia in the recently reported TTM2 trial. We critically appraise trials of IH/TTM versus normothermia to characterize reasons for the lack of treatment effect, based on a previously published framework for what to consider when the primary outcome fails. We found a strong biologic rationale and external clinical evidence that IH treatment is beneficial. Recent TTM trials mainly included unselected patients with a high rate of bystander cardiopulmonary resuscitation. The treatment was not applied as intended, which led to a large delay in achievement of target temperature. While receiving intensive care, sedative drugs were likely used that might have led to increased neurologic damage as were antiplatelet drugs that could be associated with increased acute stent thrombosis in hypothermic patients. It is reasonable to still use or evaluate IH treatment in patients who are comatose after CA as there are multiple plausible reasons why IH compared to normothermia did not significantly improve neurologic outcome in the TTM trials.

Trend and Geographic Disparities in the Mortality Rates of Primary Systemic Vasculitis in the United States from 1999 to 2019: A Population-Based Study

The current data on rates and geographic distribution of vasculitis mortality are limited. We aimed to estimate the mortality rates of primary systemic vasculitis and its geographic distribution using recent population data in the United States. The mortality rates of vasculitis from 1999 to 2019 were obtained from the Center for Disease Control (CDC) Wonder Multiple Cause of Death (MCD). The age-adjusted rates per million for vasculitis as MCD and as an underlying cause of death (UCD) were calculated by state using demographics. A joinpoint regression analysis was applied to evaluate trends over time. The age-adjusted mortality rate of vasculitis as MCD was 4.077 (95% CI: 4.029-4.125) and as a UCD was 1.888 per million (95% CI: 1.855-1.921). Since 1999, mortality rates have progressively decreased. The age-adjusted mortality rate was higher in females than in males. The highest mortality rate for vasculitis as MCD was in White patients (4.371; 95% CI: 4.317-4.424). The northern states and areas with lower populations had higher mortality rates. We found a trend of progressive decreases in the mortality rates of vasculitis, as well as gender, racial, and geographic disparities. Further analyses are warranted to better understand the factors associated with these disparities in order to implement targeted public health interventions to decrease them.

Insufficient quality of public automated external defibrillator recordings in the greater Paris area, a descriptive study

BACKGROUND

Western countries report a significant increase in the proportion of patients who experience out-of-hospital cardiac arrests (OHCAs) and benefit from a public automated external defibrillator (pAED) before the arrival of rescue teams. However, recordings of devices recovered after resuscitation are of variable quality. Analysis of these data may inform decisions of whether to implement an internal defibrillator for survivors, and provide useful information about the performance of pAED algorithms and the actions of bystanders.

OBJECTIVE

To investigate the quality of the information recorded by pAEDs during OHCAs in the Paris area.

METHODS

pAED files used for some of the 8629 OHCAs that occurred in the greater Paris area between 1 January 2017 and 31 April 2019 on the day of the arrest were collected. The presence and accuracy of 23 factors required to interpret the recording was noted, including readability of the ECG, the presence of an impedance curve and the accuracy of the date and time. The recordings were analysed to assess the diagnostic and therapeutic performance of the pAEDs used.

RESULTS

A total of 258 patients with an OHCA received assistance from a pAED, and 182 recordings were recovered. The pAEDs were made by 12 different manufacturers. Data extraction required eight different transmission modes and 16 software programmes; recordings were of highly heterogeneous quality. Two per cent of the recordings were of such poor quality that they were not interpretable. Among the 98% remaining, only 43% included a thoracic impedance curve, 34% the intensity of the shocks delivered and 8% the patient name. The date and time were accurate in 68% and 48% of recordings, respectively. The pAEDs had 87.6% (95% CI 83.7% to 91.0%) sensitivity and 99.5% (99.5% to 99.5%) specificity for defibrillating shockable rhythms (positive predictive value 98.2% (96.4% to 99.0%), negative predictive value 96.4% (95.3% to 96.8%)). The absence of important variables prevented the analysis of approximately half of the inappropriate decisions made by pAEDs.

CONCLUSION

Collection of pAED recordings is a major challenge. Their analysis is compromised by heterogeneity and poor quality (incomplete maintenance records, patient details and logs). AED recordings are currently the most relevant resource to track pAED performance and bystander practices. The quality of these recordings needs to improve.

Standardized programming to reduce the burden of inappropriate therapies in implantable cardioverter defibrillators - Single centre follow up results

BACKGROUND

Current algorithms and device morphology templates have been proposed in current Implantable Cardioverter-Defibrillators (ICDs) to minimize inappropriate therapies (ITS), but this has not been completely successful.

AIM

Assess the impact of a deliberate strategy of using an atrial lead implant with standardized parameters; based on all current ICD discriminators and technologies, on the burden of ITS.

METHOD

A retrospective single-centre analysis of 250 patients with either dual chamber (DR) ICDs or biventricular ICDs (CRTDs) over a (41.9 ± 27.3) month period was performed. The incidence of ITS on all ICD and CRTD patients was chronicled after the implementation of standardized programming.

RESULTS

39 events of anti-tachycardial pacing (ATP) and/or shocks were identified in 20 patients (8% incidence rate among patients). The total number of individual therapies was 120, of which 34% were inappropriate ATP, and 36% were inappropriate shocks. 11 patients of the 250 patients received ITS (4.4%). Of the 20 patients, four had ICDs for primary prevention and 16 for a secondary prevention. All the episodes in the primary indication group were inappropriate, while seven patients (43%) of the secondary indication group experienced inappropriate therapies.

CONCLUSIONS

The burden of ITS in the population of patients receiving ICDs was 4.4% in the presence of atrial leads. The proposed rationalized programming criteria seems an effective strategy to minimize the burden of inappropriate therapies and will require further validation.

Selection bias, interventions and outcomes for survivors of cardiac arrest

OBJECTIVE

Cardiac catheterisation and implantable cardioverter defibrillator (ICD) insertion are increasingly common following cardiac arrest survival. However, much of the evidence for the benefit is observational, leaving open the possibility that biased patient selection confounds the association between these invasive procedures and improved outcome. We evaluated the likelihood of selection bias in the association between cardiac catheterisation or ICD placement and outcome by measuring long-term outcomes overall and in a cause-specific approach that separated cardiac mortality from non-cardiac mortality.

METHODS

We performed a multivariable survival analysis of a clinical cohort between 2005 and 2013, with follow-up through 2015. We included patients who had out-of-hospital or inhospital cardiac arrest that survived to discharge, and evaluated the association between cardiac catheterisation or ICD insertion and all-cause, cardiovascular and non-cardiovascular mortality.

RESULTS

Among 678 patients who survived cardiac arrest, we observed lower all-cause mortality among patients who underwent cardiac catheterisation (adjusted HR (aHR) 0.40; P<0.01) or ICD insertion (aHR 0.55; P<0.01). However, cause-specific analysis showed that the benefits of cardiac catheterisation and ICD insertion resulted from reduced non-cardiac causes of death (cardiac catheterisation: aHR 0.24, P<0.01; ICD: aHR 0.58, P<0.01), while reduced cardiac cause of death was not associated with cardiac catheterisation (cardiac catheterisation: aHR 0.75, P=0.33).

CONCLUSIONS

There is evidence of selection bias in the secondary prevention survival benefit attributable to cardiac catheterisation for patients who survive cardiac arrest. Observational studies that consider its effects on all-cause mortality likely overestimate the potential benefit of this procedure.

Implantable Cardioverter Defibrillator Implantation Rates After Out of Hospital Cardiac Arrest: Are the Rates Guideline-Concordant?

BACKGROUND

Clinical practice guidelines recommend implantable cardioverter defibrillators (ICDs) for the secondary prevention of sudden death after a cardiac arrest not from a reversible cause, but "real world" implantation rates are not well described.

METHODS

Adults with out of hospital cardiac arrest attended by Emergency Medical Services are captured in the Toronto Regional RescuNET database. We analyzed those who survived to hospital discharge and collected data on age, sex, initial rhythm, ST-elevation myocardial infarction (STEMI) on presenting electrocardiogram (ECG), in-hospital revascularization, neurologic status (Modified Rankin Scale [MRS]) at discharge, and admission hospital type. To estimate 'indicated' ICD implantation rates, "likely ICD-eligible" patients were defined as having an initial shockable rhythm, no STEMI on presenting ECG, no revascularization, and good neurologic status (MRS 0-3). "Not likely ICD-eligible" patients were defined as having a STEMI on presenting ECG, revascularization, or poor neurologic status (MRS 4-5).

RESULTS

In the 1238 adults (2011-2014) analyzed, the overall ICD implantation rate was 23.9%. Two hundred fifty-six patients were "likely ICD-eligible," of whom 146 (57.0%) received an ICD. The implantation rate for "not likely ICD-eligible" patients was 16.7% (112 of 670). ICD eligibility could not be determined for 312 patients, of whom 38 (12.2%) received an ICD. Admission to a hospital with ICD implantation facilities was associated with a higher probability of ICD implantation (odds ratio, 2.85; 95% confidence interval, 1.40-5.82).

CONCLUSIONS

Postcardiac arrest ICD implantation rates in eligible patients are lower than expected. Implementation strategies to monitor guideline adherence after out of hospital cardiac arrest are warranted.

Implantable cardioverter defibrillator and survival after out-of-hospital cardiac arrest due to acute myocardial infarction in Denmark in the years 2001-2012, a nationwide study

AIM

The purpose of this study was to describe the implantation of implantable cardioverter defibrillator after out-of-hospital cardiac arrest caused by myocardial infarction in Denmark 2001-2012 and subsequent survival.

METHODS

The Danish Cardiac Arrest Registry was used to identify patients ⩾18 years surviving to discharge without prior implantable cardioverter defibrillator. Information on cardioverter defibrillator implantation was obtained from the National Patient Registry.

RESULTS

We identified 974 myocardial infarction-out-of-hospital cardiac arrest patients surviving to hospital discharge, 130 of these patients (13%) had a cardioverter defibrillator implanted early (⩽40 days post-out-of-hospital cardiac arrest), 58 patients (6%) had late implantable cardioverter defibrillator (41-365 days post-out-of-hospital cardiac arrest). Odds of implantable cardioverter defibrillator implantation within one year were higher in patients receiving cardiopulmonary resuscitation (odds ratio (OR)_CPR: 1.99, confidence interval (CI): 1.23-3.22, p=0.01), and Charlson Comorbidity Index level 1, (OR_CCI1: 2.10, CI:1.25-3.49, p<0.01). Odds of a late implantable cardioverter defibrillator was higher in patients undergoing percutaneous coronary intervention (PCI) (OR_PCI: 3.67, CI: 1.35-9.97, p=0. 01). An early, but not late implantable cardioverter defibrillator was associated with increased survival (event time ratio_{Early ICD}: 1.45, CI: 1.11-1.90, p=0.01). Chronic heart failure, higher age groups, Charlson Comorbidity Index levels 1 to ⩾3 and male sex were associated with lower survival. Highest income was associated with higher survival.

CONCLUSION

Cardioverter defibrillator implantation rates in patients surviving an myocardial infarction-out-of-hospital cardiac arrest increased from 14% to 19% over the period. Of the total patient population, 13% had implantation earlier than recommended by guidelines, presumably as primary prevention of sudden cardiac death. Acute PCI and arrest later in the study period (increase one year) were predictors of late cardioverter defibrillator implantation. Early cardioverter defibrillator implantation was significantly associated with a long-term survival benefit, later implantation was not.

Effect of gender on outcome of out of hospital cardiac arrest in the Resuscitation Outcomes Consortium

INTRODUCTION

This study examined the relationship between gender and outcomes of non-traumatic out-of-hospital cardiac arrest (OHCA).

METHODS

All eligible, consecutive, non-traumatic Emergency Medical Services (EMS) treated OHCA patients in the Resuscitation Outcomes Consortium between December 2005 and May 2007. Patient age was analyzed as a continuous variable and stratified in two age cohorts: 15-45 and >55 years of age (yoa). Unadjusted and adjusted (based on Utstein characteristics) chi square tests and logistic regression models were employed to examine the relationship between gender, age, and survival outcomes.

RESULTS

This study enrolled 14,690 patients: of which 36.4% were women with a mean age of 68.3 and 63.6% of them men with a mean age of 64.2. Women survived to hospital discharge less often than men (6.4% vs. 9.1%, p<0.001); the unadjusted OR was 0.69, 95%CI: 0.60, 0.77 whereas when adjusted for all Utstein predictors the difference was not significant (OR: 1.16, 95%CI: 0.98, 1.36, p=0.07). The adjusted survival rate for younger women (15-45 yoa) was 11.1% vs. 9.8% for younger men (OR: 1.66, 95%CI: 1.04, 2.64, p=0.03) but no difference in discharge rates was observed in the >55 cohort (OR: 0.94, 95%CI: 0.78, 1.15, p=0.57).

CONCLUSIONS

Women who suffer OHCAs have lower rates of survival and have unfavourable Utstein predictors. When survival is adjusted for these predictors survival is similar between men and women except in younger women suggesting that age modifies the association of gender and survival from OHCA; a result that supports a protective hormonal effect among premenopausal women.

Current status of primary prevention of sudden cardiac death with implantable cardioverter defibrillator in patients with chronic heart failure--a report from the CHART-2 Study

BACKGROUND

The current status of primary prevention of sudden cardiac death (SCD) with implantable cardioverter defibrillator (ICD) in patients with heart failure with reduced ejection fraction remains to be fully elucidated in Japan.

METHODS AND RESULTS

In the chronic heart failure (CHF) cohort study, the CHART-2 Study, we enrolled 2,778 consecutive patients with NYHA class II-III. According to the Japanese Circulation Society guideline of prophylactic ICD, we divided them into 3 groups: group A, class I indication; B, class IIa; and C, no indication. During the (median) 3.2-year follow-up, 79 fatal arrhythmic events (FAE), defined as composite of sudden cardiac/arrhythmic death, ventricular tachycardia/fibrillation and appropriate ICD therapy, occurred. In the groups A, B and C, the prevalence of FAE was 16.1%, 8.9% and 1.9%, respectively; the use of prophylactic ICD among those with FAE, however, was only 44%, 9% and 6%, respectively. In the groups A and B combined, chronic atrial fibrillation (cAF) and left ventricular end-diastolic dimension (LVDd) ≥ 65 mm were independent predictors of FAE, and, when combined, their prognostic impact was highly significant (hazard ratio, 7.01; P<0.001).

CONCLUSIONS

Primary prevention of SCD with ICD in CHF patients is validated but is still underused in Japan, and the combination of cAF and LVDd ≥ 65 mm may be a useful indication of prophylactic ICD implantation.

Ventricular arrhythmias in patients with heart failure secondary to reduced ejection fraction: a current perspective

PURPOSE OF REVIEW

To review the management of ventricular arrhythmias in patients with heart failure secondary to reduced ejection fraction (HFrEF).

RECENT FINDINGS

Recurrent ventricular arrhythmias and automatic implantable cardioverter defibrillator (AICD) shocks are responsible for significant mortality and morbidity in patients with HFrEF. Antiarrhythmic drugs and catheter ablation are the main treatment options. Frequent premature ventricular contractions (PVCs; >10,000-20,000/24-h period) are being recognized as a cause of cardiomyopathy and suboptimal response to cardiac resynchronization therapy (CRT). Patients with ventricular assist devices (VADs) have frequent ventricular tachyarrhythmias resulting in increased morbidity and mortality. Such patients may need continuation of active ICD therapy and adjunctive catheter ablation.

SUMMARY

There is a pressing need to develop new antiarrhythmic drugs to treat patients with recurrent AICD shocks. The effectiveness of catheter ablation as first-line therapy for preventing ventricular arrhythmias and recurrent AICD shocks needs to be directly compared with amiodarone. Ventricular tachyarrhythmias are common in CRT patients and patients with VADs. Frequent PVCs may result in a reversible form of HFrEF.

Living with an implantable cardiac defibrillator: a model of chronic uncertainty

Over the last two decades, the number of patients receiving implantable cardiac defibrillators (ICDs) for the prevention of sudden cardiac death has grown significantly. This growth is largely the result of broadened indication for ICD use because of the success of trials demonstrating efficacy. Early ICD indication centered on secondary prevention, which then advanced to primary prevention in high-risk patients. Nurses delivering care to these patients not only manage this complex technology but also patients' uncertainty about their survival and related psychosocial adjustment to receiving an ICD. To inform practice, theoretical models such as Mishel's (1988) uncertainty in illness model provide insight into such acute phases of illness. This article proposes expansion of the uncertainty in illness model to advance knowledge in this field for nurses caring for patients with ICD.

Use and long-term outcomes of implantable cardioverter-defibrillators, 1990 to 2009

BACKGROUND

Automated implantable cardioverter-defibrillators (ICDs) have become standard therapy for patients at high risk for sudden cardiac death. Linked data allow examination of trends in use and long-term survival after ICD implantation in an adult population.

METHODS

Linked state-wide person-based data on hospital admissions and deaths from 1980 to 2009 were used to identify incident cases of ICD implantation. Population rates were calculated using census data. Kaplan-Meier techniques were used to describe cumulative survival. Cox regression models were used to determine the factors associated with the outcomes.

RESULTS

Between 1988 and 2009, 1593 devices were implanted in patients in Western Australia, rising from 2 in 1988 to 245 in 2009; standardized population rates rose from 0.8 in 100000 in 1995 to 14.9 in 100000 in 2009. Mean age rose from 52.6 (SD 11.6) to 64.1 (11.4) years. Ventricular tachycardia (23%), cardiomyopathy (18%), and heart failure (16%) were the most frequent principal diagnoses. Ischemic heart disease was present in 49% of patients. Five-year cumulative survival was 0.74 (SE 0.01), and at 10 years, 0.53 (SE 0.03); median survival was 11.3 years. Readmission within a year, older age, heart failure, device complications, and chronic ischemic heart disease were associated with poorer survival.

CONCLUSIONS

Implantable cardioverter-defibrillator use in adults at risk for sudden cardiac death has grown rapidly. Readmission within 12 months of discharge is associated with worse medium and long-term mortality. Survival for most patients younger than 65 years exceeds 10 years and 5 years for those aged ≥75 years.

Do major cardiovascular outcomes in patients with stable ischemic heart disease in the clinical outcomes utilizing revascularization and aggressive drug evaluation trial differ by healthcare system?

BACKGROUND

The Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation (COURAGE) trial enrolled patients from 3 distinct healthcare systems (HCSs) in North America. The primary aim of this study was to determine whether there is a treatment difference in cardiovascular outcomes by HCS.

METHODS AND RESULTS

The study population included 968 patients from the US Department of Veterans Affairs (VA), 386 from the US non-VA, and 931 from Canada with different comorbidities and prognoses. The primary outcome was all-cause mortality or nonfatal myocardial infarction (MI) during the median 4.6-year follow-up. Baseline demographics were similar between percutaneous coronary intervention and optimal medical therapy treatment groups within each HCS. After follow-up, the primary end point of total mortality and nonfatal MI was not statistically significant between percutaneous coronary intervention and optimal medical therapy, regardless of HCS: VA, 22.3% versus 21.9% (hazard ratio, 1.05; 95% CI, 0.80-1.38; P=0.95); US non-VA, 15.8% versus 21.8% (hazard ratio, 0.70; 95% CI, 0.43-1.12; P=0.24); Canadian HCS, 17.3% versus 13.5% (hazard ratio, 1.30; 95% CI, 0.93-1.83; P=0.17). The interaction between HCSs and treatment was not statistically significant. Long-term mortality was significantly higher in the VA system as a result of significantly greater comorbidity and worse left ventricular function.

CONCLUSIONS

In the COURAGE trial, addition of percutaneous coronary intervention to optimal medical therapy did not improve 5-year survival or reduce MI or other major adverse cardiovascular events regardless of whether patients were Canadian or American or US veterans or non-veterans. Outcome differences were largely explained by differences in baseline characteristics known to affect long-term prognosis.

In-hospital mortality in 13,263 survivors of out-of-hospital cardiac arrest in Canada

BACKGROUND

There is a substantial mortality rate in patients admitted alive after out-of-hospital cardiac arrest. The primary objective of our study was to examine trends in in-hospital survival in out-of-hospital cardiac arrest survivors in Canada between 1994 and 2004. The secondary objective was to examine predictors of in-hospital survival in these patients.

METHODS

Data on hospital admissions from April 1, 1994, to March 31, 2004, were obtained from the Health Person-oriented Information Database, maintained by Statistics Canada. We included all patients with a primary diagnosis of cardiac arrest who survived to hospital admission. We assessed survival to hospital discharge in all patients admitted alive.

RESULTS

In Canada, 13,263 patients survived community arrest between 1994 and 2004. The annual incidence of hospital admission after out-of-hospital cardiac arrest decreased by 33%, from 5.37 per 100,000 in 1994 to 3.63 per 100,000 in 2004 (P < .0001 for trend). Subsequently, 5,045 patients (38.03%) survived to hospital discharge. The survival rate did not change during the duration of the study. Invasive coronary artery disease management was associated with a greatly increased chance of survival (odds ratio 21.98, 95% CI 17.62-27.42). Also male gender, heart failure, and acute myocardial ischemia were independent positive predictors of survival to hospital discharge; greater age and comorbidities were negative predictors of survival. Finally, there were significant interprovincial variations in survival rates.

CONCLUSIONS

Our study, the largest of its kind, has 4 main findings. Firstly, between 1993 and 2004, there was a significant and steady decline in admission rates after community cardiac arrest. Second, there was no change in the in-hospital survival rates. Thirdly, invasive management of coronary artery disease was associated with a greatly improved chance of survival, and finally, there were important regional variations in survival rates.

Low referral pattern for implantable defibrillator therapy in a tertiary hospital: referral physician survey and Monte Carlo simulation

Although implantable cardioverter defibrillator (ICD) therapy is the standard of care for prevention of sudden cardiac death (SCD), its underutilization is a clinical concern. We performed a retrospective study on patients who underwent cardiac catheterization at a tertiary medical center to identify those who were eligible for ICD therapy as per the guidelines and those who actually received it as a part of treatment. Surprisingly, only 4.4% of eligible patients received ICD for SCD prevention. Assuming that the major cause of this underutilization of ICD therapy was low referral, we performed a structured survey among the referring physicians to assess specialists' availability, primary care physicians' role in ICD referral, patient management concerns, familiarity with ICD guidelines, and economics of ICD implantation. Physician response rate of the survey was 51% (35/68). Survey results showed that the common reasons for underreferral included nonavailability of electrophysiologists (34%), poor quality of life of patients (25.7%), patients not being on optimal therapy (25.7%), and low awareness (22.85%). Subsequently, a Monte Carlo simulation was used to assess a hypothetical survival of the study cohort, which showed that in an "ideal scenario" of ICD implantation, the mortality in the study cohort was decreased by 6.9% and 12.3% at 2- and 5-year follow-up, respectively. This study highlights the underutilization of ICDs and the referring physicians' approach to this therapy.

A comparative study of uncertainty, optimism and anxiety in patients receiving their first implantable defibrillator for primary or secondary prevention of sudden cardiac death

BACKGROUND

Increasingly, patients are receiving implantable cardioverter defibrillators (ICDs) for prevention of sudden cardiac death. ICDs are implanted for primary prevention (patients at risk for ventricular arrhythmia [PP]) and secondary prevention (patients who have had/survived a sustained ventricular arrhythmia or cardiac arrest [SP]). Few prospective studies have examined psychosocial factors associated with these patients.

OBJECTIVES

To determine if patients receiving their first ICD for PP versus SP differed in uncertainty, anxiety, and optimism, before, 1 week, and 1 month after implant.

DESIGN

Prospective, descriptive, correlational pilot.

PARTICIPANTS AND SETTING

Fifteen PP and 15 SP patients receiving their first ICD were enrolled. Mean ages (+/- SD) were 65.7+/-11.3 and 67.9+/-7.7 respectively.

METHODS

Mishel's Uncertainty in Illness Scale (MUIS-C), State-Trait Anxiety Inventory (STAI) and the Life Orientation Test (LOT-R) were taken pre-implant, at the first post-implant visit, and at 1 month. Measures were compared using Student't-tests and ANOVA.

RESULTS

Pre-implant, both groups had moderately high MUIS-C scores (mean+/-SD; PP=67.67+/-13.36; SP=70.27+/-6.80; t=0.67; t(df)=28; p=0.507). LOT-R scores were 15.67+/-3.8 for PP and 16.47+/-3.6 for SP; t=0.59; t(df)=28; p=0.557. Pre-implant state anxiety scores were (mean PP=37.40+/-10.0, SP=37.73+/-13.6; t=0.076; t(df)=28; p=0.940). At 1-month PP patients had significantly lower uncertainty scores than the SP group (mean 62.33+/-4.17 versus 67.87+/-4.61; t=3.45; t(df)=28; p=0.002). A main effect for time, between pre-implant and 1-month, was found for uncertainty (F(2,56)=3.26; p<0.05) and state anxiety (F(2,56)=3.61, p<0.05), where both groups showed lower scores.

CONCLUSION

This study identified moderately high uncertainty in PP and SP patients prior to receiving their ICD. Though uncertainty was high, both groups reported an optimistic disposition and normal anxiety. At 1-month, SP patients had higher uncertainty scores than PP patients. This post-intervention uncertainty among patients who experienced an arrhythmic event warrants attention from nurses caring for ICD patients. Interventions to ameliorate uncertainty should be tailored to consider ICD indication.

Evaluating sex differences in population-based utilization of implantable cardioverter-defibrillators: role of cardiac conditions and noncardiac comorbidities

BACKGROUND

The influence of age and comorbidities on sex-specific implantable cardioverter-defibrillator (ICD) use for primary or secondary prevention is undefined.

OBJECTIVE

The purpose of this study was to investigate the influence of age and comorbidities on sex-specific ICD use.

METHODS

Sex disparities and sex-specific trends in ICD implantation according to indication in patients with cardiac arrest (1998-2007) in Ontario, Canada, were examined. Use of ICDs for primary prevention in patients with myocardial infarction (2002-2007) or heart failure (2005-2007) also was examined.

RESULTS

Among 9,246 eligible secondary prevention patients (age 66.3 +/- 14.3 years; 3,577 women [39%]) with cardiac arrest, men were more likely to undergo ICD implantation, with an age-, comorbidity-, and arrhythmia-adjusted hazard ratio (HR) of 1.92 (95% confidence interval [CI]: 1.66-2.23). Among 105,516 patients with myocardial infarction (age 68.3 +/- 12.7 years; 42,987 women [41%]), men were threefold more likely to undergo ICD implantation, with an adjusted HR of 3.00 (95% CI: 2.53-3.55). Among 61,160 patients with heart failure (age 76.2 +/- 12.0 years; 31,575 women [52%]), ICD implantation was more likely in men, with an adjusted HR of 3.01 (95% CI: 2.59-3.50). The odds of ICD implant for secondary prevention increased over time by 21% (95% CI: 13%-30%) in women and by 6% (95% CI: 2%-11%) in men, but rates of ICD use in men for primary prevention indications were persistently higher.

CONCLUSION

Men were more likely to undergo defibrillator implant than were women for primary and secondary prevention. Age and comorbidities did not account for the observed sex differences. Although sex differences in secondary prevention are declining over time, disparities in primary prevention persist.

Cost-benefit analysis of primary prevention of sudden cardiac death with an implantable cardioverter defibrillator versus amiodarone in Canada

BACKGROUND

Clinical trials have shown that implantable cardioverter defibrillators are effective in primary prevention of sudden cardiac death (SCD) in patients with high risk profiles.

OBJECTIVES

To conduct a cost-benefit assessment of prevention of sudden cardiac death with an implantable cardioverter defibrillator (ICD) vs. amiodarone from the Canadian health-care system perspective.

METHODS

A simulation model that estimates the patient's course following an implantation with an ICD or initiation of amiodarone treatment was created. A thousand pairs of patients with identical characteristics in each treatment group, with similar demographic profiles as observed in the Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT) were simulated. Based on the simulated individual patient characteristics, the model estimated the timing of severe arrhythmic events and deaths due to other causes and implemented the consequences at the time of the events. Patients might die at the time of severe arrhythmia (sudden cardiac death) or survive and become secondary prevention cases and be exposed to a higher risk of severe arrhythmia for the following 6 months. The rates of arrhythmia and death due to other causes were assumed to be the same, whereas the cases of fatality from severe arrhythmia differed between treatments. During the course of the simulation, the clinical (i.e., deaths) and economic outcomes were tallied for both treatment groups. All model parameters were obtained from the literature. The primary data source for clinical inputs was the published results of the SCD-HeFT trial which investigated the impact of ICDs on patients' survival in primary prevention of sudden cardiac deaths compared to amiodarone and conventional therapy. The value of a statistical life (CND$ 5.8 million) was obtained from an analysis previously performed by Health Canada. The direct medical costs and monetary value of lives saved were estimated over 5 years. Sensitivity analyses on key parameters were carried out. The most important study limitation was using two different sources to derive the age dependent clinical risks. This issue was resolved by calibrating the derived risks to account for the population differences.

RESULTS

The model predicted that the overall mortality would be reduced by 19.1% (7.1% absolute reduction) with ICD compared to amiodarone over 5 years. The incremental benefit with ICD was estimated at CND$526,700 and additional cost at CND$28,300, which translated into a 0.05 cost: benefit ratio--around 1: 20 return of investment.

CONCLUSION

In Canada, ICDs are a worthwhile alternative to amiodarone in the primary prevention of sudden cardiac death.

Fatal complications of pacemaker and implantable cardioverter-defibrillator implantation: medical malpractice?

OBJECTIVES

Pacemaker implantation has become a routine procedure in modern cardiology, and implantable cardioverter-defibrillators are implanted with rising frequency. Although fatal complications are relatively rare, they may give rise to malpractice lawsuits against medical personnel. The objective was to identify fatal complications after pacemaker and implantable cardioverter-defibrillators implantation and to evaluate the legal consequences in alleged malpractice cases.

METHODS

Retrospective analysis of all 27,730 autopsy cases performed at the Institute of Legal Medicine, Hamburg, Germany, between January 1983 and June 2007. Study cases were identified using the keywords 'cardiac death', 'malpractice', 'complications', 'pacemaker' and 'implantable cardioverter-defibrillator'.

RESULTS

Eleven pacemaker-related and four implantable cardioverter-defibrillator-related fatalities where lawsuits had been filed were identified. A causal connection between the procedure and fatal outcome was confirmed by autopsy in six cases. Malpractice or violation of the rules of good medical practice could be excluded in all cases. All inquiries were abandoned.

CONCLUSION

Fatal complications after pacemaker and implantable cardioverter-defibrillator implantation attributable to medical malpractice are extremely rare. The study illustrates the importance of a medico-legal autopsy in alleged fatal malpractice cases.

Trends in hospitalization for the implantation of cardioverter-defibrillators in the United States, 1990-2005

Implantable cardioverter-defibrillators were first approved for use in the United States in 1985. Their efficacy in improving the survival of patients at risk for sudden cardiac death has been shown, and the number of patients eligible for ICDs has increased. Using data from the National Hospital Discharge Survey (NHDS), hospitalizations for the implantation of ICDs were identified and age- and gender-specific rates and trends in hospitalizations for ICDs during the period from 1990 to 2005 were estimated. From 1990 to 2005, the estimated number of hospitalizations for the implantation of ICDs increased from 5,600 to >108,000 for the total United States population, and the estimated annual rate of hospitalizations for the implantation of ICDs increased 10-fold. The rate of ICD procedures was substantially greater in men than women, and the rate increased significantly with age, although there was no increase in ICD use in patients aged >or=75 years. In conclusion, as the list of clinical indications and insurance coverage for ICD use expand, continued surveillance to monitor trends in the use of ICDs is warranted.