Outcomes of In-Hospital Cardiopulmonary Resuscitation in Morbidly Obese Patients.

OBJECTIVES: This study sought to assess the impact of morbid obesity on outcomes in patients with in-hospital cardiac arrest (IHCA). BACKGROUND: Obesity is associated with increased risk of out-of-hospital cardiac arrest; however, little is known about survival of morbidly obese patients with IHCA. METHODS: Using the Nationwide Inpatient Sample database from 2001 to 2008, we identified adult patients undergoing resuscitation for IHCA, including those with morbid obesity (body mass index ≥40 kg/m2) by using International Classification of Diseases 9th edition codes and clinical outcomes. Outcomes including in-hospital mortality, length of stay, and discharge dispositions were identified. Logistic regression model was used to examine the independent association of morbid obesity with mortality. RESULTS: Of 1,293,071 IHCA cases, 27,469 cases (2.1%) were morbidly obese. The overall mortality was significantly higher for the morbidly obese group than for the nonobese group experiencing in-hospital non-ventricular fibrillation (non-VF) (77% vs. 73%, respectively; p = 0.006) or VF (65% vs. 58%, respectively; p = 0.01) arrest particularly if cardiac arrest happened late (>7 days) after hospitalization. Discharge to home was significantly lower in the morbidly obese group (21% vs. 31%, respectively; p = 0.04). After we adjusted for baseline variables, morbid obesity remained an independent predictor of increased mortality. Other independent predictors of mortality were age and severe sepsis for non-VF and VF group and venous thromboembolism, cirrhosis, stroke, malignancy, and rheumatologic conditions for non-VF group. CONCLUSIONS: The overall mortality of morbidly obese patients after IHCA is worse than that for nonobese patients, especially if IHCA occurs after 7 days of hospitalization and survivors are more likely to be transferred to a skilled nursing facility.

Is defibrillation testing necessary?

With advancements in implantable cardioverter defibrillator (ICD) technology, the practice of performing defibrillation threshold (DFT) testing at the time of implantation has been questioned. With availability of biphasic waveforms, active cans, and high-output devices, opponents claim that DFT testing is no longer necessary. Clinical trials demonstrating the efficacy of ICDs in prevention of sudden cardiac death have, however, all used some form of defibrillation testing. This debate is fueled by the absence of data from randomized prospective trials evaluating the role of DFT testing in predicting clinical shock efficacy or survival. This review discusses both sides of the argument.

The effectiveness and cost effectiveness of public-access defibrillation.

Many sudden cardiac deaths are due to ventricular fibrillation (VF). The use of defibrillators in hospitals or by outpatient emergency medical services (EMS) personnel can save many cardiac-arrest victims. Automated external defibrillators (AEDs) permit defibrillation by trained first responders and laypersons. AEDs are available at most public venues, and vast sums of money are spent installing and maintaining these devices. AEDs have been evaluated in a variety of public and private settings. AEDs accurately identify malignant ventricular tachyarrhythmias and frequently result in successful defibrillation. Prompt application of an AED shows a greater number of patients in VF compared with initial rhythms documented by later-arriving EMS personnel. Survival is greatest when the AED is placed within 3 to 5 minutes of a witnessed collapse. Community-based studies show increased cardiac-arrest survival when first responders are equipped with AEDs rather than waiting for paramedics to defibrillate. Wide dissemination of AEDs throughout a community increases survival from cardiac arrest when the AED is used; however, the AEDs are utilized in a very small percentage of all out-of-hospital cardiac arrests. AEDs save very few lives in residential units such as private homes or apartment complexes. AEDs are cost effective at sites where there is a high density of both potential victims and resuscitators. Placement at golf courses, health clubs, and similar venues is not cost effective; however, the visible devices are good for public awareness of the problem of sudden cardiac death and provide reassurance to patrons.

Cost-effectiveness of therapeutic hypothermia after cardiac arrest.

BACKGROUND: Therapeutic hypothermia can improve survival and neurological outcomes in cardiac arrest survivors, but its cost-effectiveness is uncertain. We sought to evaluate the cost-effectiveness of treating comatose cardiac arrest survivors with therapeutic hypothermia. METHODS AND RESULTS: A decision model was developed to capture costs and outcomes for patients with witnessed out-of-hospital ventricular fibrillation arrest who received conventional care or therapeutic hypothermia. The Hypothermia After Cardiac Arrest (HACA) trial inclusion criteria were assumed. Model inputs were determined from published data, cooling device companies, and consultation with resuscitation experts. Sensitivity analyses and Monte Carlo simulations were performed to identify influential variables and uncertainty in cost-effectiveness estimates. The main outcome measures were quality-adjusted survival after cardiac arrest, cost of hypothermia implementation, cost of posthospital discharge care, and incremental cost-effectiveness ratios. In our model, postarrest patients receiving therapeutic hypothermia gained an average of 0.66 quality-adjusted life years compared with conventional care, at an incremental cost of $31,254. This yielded an incremental cost-effectiveness ratio of $47,168 per quality-adjusted life year. Sensitivity analyses demonstrated that poor neurological outcome postcooling and costs associated with posthypothermia care (in-hospital and long term) were the most influential variables in the model. Even at extreme estimates for costs, the cost-effectiveness of hypothermia remained less than $100,000 per quality-adjusted life year. In 91% of 10,000 Monte Carlo simulations, the incremental cost-effectiveness ratio was less than $100,000 per quality-adjusted life year. CONCLUSIONS: In cardiac arrest survivors who meet HACA criteria, therapeutic hypothermia with a cooling blanket improves clinical outcomes with cost-effectiveness that is comparable to many economically acceptable health care interventions in the United States.

Life after a ventricular arrhythmia.

BACKGROUND: There are few data from community-based evaluations of outcomes after a life-threatening ventricular arrhythmia (LTVA). We evaluated patients' quality of life (QOL) and medical costs after hospitalization and treatment for their first episode of an LTVA. METHODS: We prospectively evaluated QOL by use of the Duke Activity Status Index (DASI), Medical Outcomes Study SF-36 mental health and vitality scales, the Cardiac Arrhythmia Suppression Trial (CAST) symptom scale, and resource use in patients discharged after a first episode of an LTVA in a managed care population of 2.4 million members. RESULTS: We enrolled 264 subjects with new cases of LTVA. Although functional status initially decreased compared with self-reports of pre-event functional status, both functional status and symptom levels improved significantly during the study period. These improvements were greater in patients receiving an implantable cardioverter defibrillator (ICD) than in patients receiving amiodarone. Ratings of mental health and vitality were not significantly different between the treatment groups and did not change significantly during follow-up. The total 2-year medical costs were higher for patients receiving an ICD than for patients receiving amiodarone, despite lower costs during the follow-up period for the patients receiving an ICD. CONCLUSIONS: New onset of an LTVA has a substantial negative initial impact on QOL. With therapy, most patients have improvements in their QOL and symptom level, possibly more so after treatment with an ICD. The costs of treating these patients are very high.

Trends in hospital treatment of ventricular arrhythmias among Medicare beneficiaries, 1985 to 1995.

BACKGROUND: Treatment options for patients with ventricular arrhythmias have undergone major changes in the last 2 decades. Trends in use of invasive procedures, clinical outcomes, and expenditures have not been well documented. METHODS: We used administrative databases of Medicare beneficiaries from 1985 to 1995 to identify patients hospitalized with ventricular arrhythmias. We created a longitudinal patient profile by linking the index admission with all earlier and subsequent admissions and with death records. RESULTS: Approximately 85,000 patients aged > or =65 years went to hospitals in the United States with ventricular arrhythmias each year, and about 20,000 lived to admission. From 1987 to 1995, the use of electrophysiology studies and implantable cardioverter defibrillators in patients who were hospitalized grew substantially, from 3% to 22% and from 1% to 13%, respectively. Hospital expenditures rose 8% per year, primarily because of the increased use of invasive procedures. Survival improved, particularly in the medium term, with 1-year survival rates increasing between 1987 and 1994 from 52.9% to 58.3%, or half a percentage point each year. CONCLUSION: Survival of patients who sustain a ventricular arrhythmia is poor, but improving. For patients who are admitted, more intensive treatment has been accompanied by increased hospital expenditures.

Effect of risk stratification on cost-effectiveness of the implantable cardioverter defibrillator.

BACKGROUND: Implantable cardioverter defibrillators (ICDs) effectively prevent sudden cardiac death, but selection of appropriate patients for implantation is complex. We evaluated whether risk stratification based on risk of sudden cardiac death alone was sufficient to predict the effectiveness and cost-effectiveness of the ICD. METHODS: We developed a Markov model to evaluate the cost-effectiveness of ICD implantation compared with empiric amiodarone treatment. The model incorporated mortality rates from sudden and nonsudden cardiac death, noncardiac death and costs for each treatment strategy. We based our model inputs on data from randomized clinical trials, registries, and meta-analyses. We assumed that the ICD reduced total mortality rates by 25%, relative to use of amiodarone. RESULTS: The relationship between cost-effectiveness of the ICD and the total annual cardiac mortality rate is U-shaped; cost-effectiveness becomes unfavorable at both low and high total cardiac mortality rates. If the annual total cardiac mortality rate is 12%, the cost-effectiveness of the ICD varies from $36,000 per quality-adjusted life-year (QALY) gained when the ratio of sudden cardiac death to nonsudden cardiac death is 4 to $116,000 per QALY gained when the ratio is 0.25. CONCLUSIONS: The cost-effectiveness of ICD use relative to amiodarone depends on total cardiac mortality rates as well as the ratio of sudden to nonsudden cardiac death. Studies of candidate diagnostic tests for risk stratification should distinguish patients who die suddenly from those who die nonsuddenly, not just patients who die suddenly from those who live.

Effect of clinical risk stratification on cost-effectiveness of the implantable cardioverter-defibrillator: the Canadian implantable defibrillator study.

BACKGROUND: Three randomized clinical trials showed that implantable cardioverter-defibrillators (ICDs) reduce the risk of death in survivors of ventricular tachyarrhythmias, but the cost per year of life gained is high. A substudy of the Canadian Implantable Defibrillator Study (CIDS) showed that 3 clinical factors, age >/=70 years, left ventricular ejection fraction /=2 of 3 risk factors. Incremental cost-effectiveness of ICD therapy was computed as the ratio of the difference in mean cost to the difference in life expectancy between the 2 groups. Over 6.3 years, the mean cost per patient in the ICD group was Canadian (C) $87 715 versus $38 600 in the amiodarone group (C$1 approximately US$0.67). Life expectancy for the ICD group was 4.58 years versus 4.35 years for amiodarone, for an incremental cost-effectiveness of ICD therapy of C$213 543 per life-year gained. The cost per life-year gained in patients with >/=2 factors was C$65 195, compared with C$916 659 with <2 risk factors. CONCLUSIONS: The cost-effectiveness of ICD therapy varies by patient risk factor status. The use of ICD therapy in patients who have >/=2 risk factors of age >/=70 years, left ventricular ejection fraction

Automated external defibrillators in long-term care facilities are cost-effective.

OBJECTIVE: To assess the cost per life saved of equipping long-term care facilities (LTCFs) with automated external defibrillators (AEDs). METHODS: Outcomes for cardiac arrests within LTCFs were retrieved for 1994 to 1997 from a comprehensive out-of-hospital cardiac arrest registry in a mid-sized U.S. city. The total expense for all LTCFs to obtain and maintain AEDs and to educate and maintain staff skill was estimated for a theoretical four-year period. The cost per life saved to the time of hospital discharge was calculated based on an estimated survival rate of 25% of patients found in ventricular fibrillation (VF) with placement of AEDs in LTCFs. A sensitivity analysis that varied survival rates and costs was conducted. RESULTS: Over four years, there were 160 actual arrests in 43 LTCFs, with a hospital discharge survival rate of 2/160. Twenty of 160 presented to emergency medical services in VF. Training costs for four years were $1,225 per AED. Purchase and maintenance expenses for one AED over four years were $3,941. Placing AEDs in LTCFs would cost $87,837 per life saved if 25% of patients found in VF survived to hospital discharge. Sensitivity analysis using survival rates of 5%, 15%, and 35% established the cost per life saved at $439,184, $146,395, and $62,741, respectively. When costs were calculated at one-half and twice the estimated expense, the cost per life saved was $43,918 and $175,674, respectively. CONCLUSION: Placing AEDs in LTCFs is cost-effective at $87,837 per life saved, if a hospital discharge survival rate of 25% of patients in VF can be achieved.

Prehospital discharge defibrillation testing in ICD recipients: a prospective study based on cost analysis.

Prehospital discharge defibrillation testing is often performed to verify the function of newly implanted cardioverter defibrillators (ICDs). To determine whether elimination of predischarge testing could reduce costs without placing patients at additional risk, 31 patients were randomized in this prospective clinical evaluation to either receive or not receive a predischarge ICD defibrillation test. Expenses associated with postimplant care was the primary endpoint. All patients underwent induction of ventricular fibrillation after 6 months to evaluate ICD function. The groups were well matched in terms of patient characteristics, initial lead implant parameters, and defibrillation thresholds. Elimination of prehospital discharge testing resulted in a savings of $1,800/patient after 6 months, with no difference between groups in terms of ICD complication rates or unanticipated hospital admissions. Further studies are needed to better define the most appropriate time to assess defibrillation thresholds in the first year after implantation.

Impact of the implantable cardioverter-defibrillator on rehospitalizations.

UNLABELLED: Patients who survive out-of-hospital ventricular tachycardia or ventricular fibrillation are at risk of sudden cardiac death and often return to hospital after initial discharge. The frequency and duration of readmittance to hospital are not well known. Thus, the purpose of this study was to evaluate the impact of the implantable cardioverter defibrillator on frequency and duration of hospitalizations. METHODS: Between 1989 and 1993, 38 consecutive patients who had drug-refractory ventricular tachyarrhythmias were selected for the study. A total of 38 patients were implanted with the implantable cardioverter-defibrillator in accordance with the guidelines of the European Society of Cardiology. This analysis includes 35 of the 38 patients (92%). All hospitalizations which occurred one year before and one year after were studied. Clinical information for all patients was obtained by consulting medical records and by interviewing personal general practitioners. RESULTS: The annual number of hospitalizations before and after implantation of the implantable cardioverter-defibrillator was, respectively, 3.28 +/- 2.38 hospitalizations/ patient/year and 0.88 +/- 1.23 hospitalizations/patient/year (P < 0.05). Before implantation of the implantable cardioverter-defibrillator, patients were hospitalized a mean of 32.94 +/- 24.18 days/patient/year and after, 9.31 +/- 32.14 days/patient/year (P < 0.05). The number of hospitalizations for cardiac reasons decreased by 90%. Before implantation, the most frequent cause was ventricular tachyarrhythmia (47 hospitalizations for ventricular tachycardia and eight for ventricular fibrillation), while after implantation, it was as a result of the shock from the implantable cardioverter-defibrillator (11 hospitalizations). The number of hospitalizations for non-cardiac reasons were similar in the two time periods. Of the 35 patients, 26 (74%) had at least one appropriate successful ventricular tachycardia interrupted by the implantable cardioverter-defibrillator, while 17 patients (49%) had their ventricular fibrillation terminated. There is a significant difference in the rate of hospitalizations to intensive care units (ICU) between the two periods. Before implantation, 30% of hospital days were spent in the ICU, with 3% after. CONCLUSIONS: This study documents that the implantable cardioverter-defibrillator not only reduces the frequency and duration of hospital stays, but reduces admissions to the more expensive units in hospital. Taking into account the reduction in hospitalizations, the payback period for the implantation of an implantable cardioverter-defibrillator is 19 months.