Long-term survival after prehospital sudden cardiac death

Return to Work in Out-of-Hospital Cardiac Arrest Survivors

Background—

Data on long-term function of out-of-hospital cardiac arrest survivors are sparse. We examined return to work as a proxy of preserved function without major neurologic deficits in survivors.

Methods and Results—

In Denmark, out-of-hospital cardiac arrests have been systematically reported to the Danish Cardiac Arrest Register since 2001. During 2001–2011, we identified 4354 patients employed before arrest among 12 332 working-age patients (18–65 years), of whom 796 survived to day 30. Among 796 survivors (median age, 53 years [quartile 1–3, 46–59 years]; 81.5% men), 610 (76.6%) returned to work in a median time of 4 months [quartile 1–3, 1–19 months], with a median time of 3 years spent back at work. A total of 74.6% (N=455) remained employed without using sick leave during the first 6 months after returning to work. This latter proportion of survivors returning to work increased over time (66.1% in 2001–2005 versus 78.1% in 2006–2011; P =0.002). In multivariable Cox regression analysis, factors associated with return to work with ≥6 months of sustainable employment were as follows: (1) arrest during 2006–2011 versus 2001–2005, hazard ratio (HR), 1.38 (95% CI, 1.05–1.82); (2) male sex, HR, 1.48 (95% CI, 1.06–2.07); (3) age of 18 to 49 versus 50 to 65 years, HR, 1.32 (95% CI, 1.02–1.68); (4) bystander-witnessed arrest, HR, 1.79 (95% CI, 1.17–2.76); and (5) bystander cardiopulmonary resuscitation, HR, 1.38 (95% CI, 1.02–1.87).

Conclusions—

Of 30-day survivors employed before arrest, 76.6% returned to work. The percentage of survivors returning to work increased significantly, along with improved survival during 2001–2011, suggesting an increase in the proportion of survivors with preserved function over time.

Employment status 1 year after out-of-hospital cardiac arrest in comatose patients treated with therapeutic hypothermia

BACKGROUND

Therapeutic hypothermia for comatose survivors of out-of-hospital cardiac arrest (OHCA) has improved survival and neurologic outcome. This study focused on return to work 1 year after therapeutic hypothermia.

METHODS

From June 2004 to June 2009, patients between 18 and 65 years of age with OHCA, who were treated with hypothermia from two regions, representing one third of the national population, were identified from the Danish National Patient Registry, and from hospital and ambulance records. The patients' employment status was obtained from the Danish Ministry of Employment.

RESULTS

One hundred thirty-three comatose patients after OHCA treated with hypothermia were identified. One hundred and four (78%) patients were employed, or able to work, at the time of cardiac arrest. This particular group of patients showed significant lower in-hospital mortality compared to the group of patients who were not able to work before cardiac arrest; 13% vs. 48%, respectively (P < 0.001). The workable group had a lower Charlson comorbidity score (P = 0.004), a higher incidence of witnessed cardiac arrest (P = 0.004) and a higher incidence of shockable heart rhythm (P < 0.001). Eighty-seven patients (84%), who were able to work prior to cardiac arrest, survived, and 55 (65%) of these patients were employed or able to work at 1 year follow-up.

CONCLUSION

The majority of patients employed, or able to work prior to OHCA, had returned to work at one year follow-up. Predictors of return to work in comatose patients treated with hypothermia have to be identified in a larger-scale study.

Long-term survival after out-of-hospital cardiac arrest

OBJECTIVE

The purpose of this study was to assess the long-term survival after OHCA.

METHODS

All OHCA-calls where the Copenhagen Mobile Emergency Care Unit (MECU) was involved from 1994 to1998 are included in this study. Data were collected prospectively. Data on long-term survival was obtained from the Danish Causes of Death Registry and the Danish Civil Registration System. We conducted a search to find out whether patients were still alive on 31 January 2005.

RESULTS

Resuscitation was indicated and attempted in 1095 cases and 95 patients (8.7%) survived to discharge. Of these 75% had an initial rhythm of VF, 13% had asystole, 10% had PEA and 2% were unknown. Survival was 87% after one year and survival after 10 years was 46% with a significantly lower survival for patients over 60 years.

CONCLUSION

Long-term survival after out-of-hospital cardiac arrest in a physician-staffed emergency system was comparable to survival after myocardial infarction with 46% being alive after ten years.

The epidemiology of out-of-hospital 'sudden' cardiac arrest

It is difficult to assemble data from an out-of-hospital cardiac arrest since there is often lack of objective information. The true incidence of sudden cardiac death out-of-hospital is not known since far from all of these patients are attended by emergency medical services. The incidence of out-of-hospital cardiac arrest increases with age and is more common among men. Among patients who die, the probability of having a fatal event outside hospital decreases with age; i. e. younger patients tend to more often die unexpectedly and outside hospital. Among the different initial arrhythmias, ventricular fibrillation is the most common among patients with cardiac aetiology. The true distribution of initial arrhythmias is not known since several minutes most often elapse between collapse and rhythm assessment. Most patients with out-of-hospital cardiac arrest have a cardiac aetiology. Out-of-hospital cardiac arrests most frequently occur in the patient's home, but the prognosis is shown to be better when they occur in a public place. Witnessed arrest, ventricular fibrillation as initial arrhythmia and cardiopulmonary resuscitation are important predictors for immediate survival. In the long-term perspective, cardiac arrest in connection with acute myocardial infarction, high left ventricular ejection fraction, moderate age, absence of other heart failure signs and no history of myocardial infarction promotes better prognosis. Still there is much to learn about time trends, the influence of patient characteristics, comorbidity and hospital treatment among patients with prehospital cardiac arrest.

Long-term mortality among patients discharged alive after out-of-hospital cardiac arrest does not differ markedly compared with that of myocardial infarct patients without out-of-hospital cardiac arrest

The aim of our research was to study the long-term prognosis among patients discharged alive after an out-of-hospital cardiac arrest (OHCA) in comparison with patients discharged alive after acute myocardial infarction (AMI) without OHCA, and also to study the long-term influence of AMI in connection with OHCA. Our research was conducted in the municipality of Göteborg. We retrospectively studied patients discharged from hospital 1990-91 after an OHCA of cardiac aetiology and patients discharged after an AMI without prehospital cardiac arrest. During 1980-98, we studied all patients discharged alive after OHCA of cardiac aetiology, divided into groups of precipitating AMI and no AMI. The study includes 48 patients discharged alive after an OHCA 1990-91, 30 (62%) of whom had a simultaneous AMI and 1425 patients with an AMI without OHCA. Compared with AMI survivors, survivors of an OHCA of cardiac origin were younger but had more frequently a history of congestive heart failure. Their mortality rate during the subsequent 5 years was 46%, compared with 40% among survivors of an AMI (NS). The 5-year mortality rate among patients with an OHCA precipitated by an AMI was 40%. When correcting for differences at baseline, the adjusted risk ratio for death among patients with an OHCA of cardiac origin was 1.2 (95% CI 0.8-1.8) compared with patients with an uncomplicated AMI. During 1980-98, 215 patients were judged as having an OHCA precipitated by an AMI and 115 patients had an OHCA of cardiac aetiology but no simultaneous AMI. Five-year mortality was 54% and 50% respectively (NS). It is concluded that survivors of an OHCA of cardiac origin differed from survivors of an uncomplicated AMI in that they were younger and more frequently had a history of cardiovascular disease. Their 5-year mortality after discharge was similar to that of survivors of an AMI without a prehospital cardiac arrest, even after adjusting for differences at baseline.

In-hospital versus out-of-hospital presentation of life-threatening ventricular arrhythmias predicts survival: results from the AVID Registry. Antiarrhythmics Versus Implantable Defibrillators

OBJECTIVES

This study describes the outcomes of patients from the Antiarrhythmics Versus Implantable Defibrillators (AVID) Study Registry to determine how the location of ventricular arrhythmia presentation influences survival.

BACKGROUND

Most studies of cardiac arrest report outcome following out-of-hospital resuscitation. In contrast, there are minimal data on long-term outcome following in-hospital cardiac arrest.

METHODS

The AVID Study was a multicenter, randomized comparison of drug and defibrillator strategies to treat life-threatening ventricular arrhythmias. A Registry was maintained of all patients with sustained ventricular arrhythmias at each study site. The present study includes patients who had AVID-eligible arrhythmias, both randomized and not randomized. Patients with in-hospital and out-of-hospital presentations are compared. Data on long-term mortality were obtained through the National Death Index.

RESULTS

The unadjusted mortality rates at one- and two-year follow-ups were 23% and 31.1% for patients with in-hospital presentations, and 10.5% and 16.8% for those with out-of-hospital presentations (p < 0.001), respectively. The adjusted mortality rates at one- and two-year follow-ups were 14.8% and 20.9% for patients with in-hospital presentations, and 8.4% and 14.1% for those with out-of-hospital presentations (p < 0.001), respectively. The adjusted long-term relative risk for in-hospital versus out-of-hospital presentation was 1.6 (95% confidence interval [CI] 1.3-1.9).

CONCLUSIONS

Compared with patients with out-of-hospital presentations of life-threatening ventricular arrhythmias not due to a reversible cause, patients with in-hospital presentations have a worse long-term prognosis. Because location of ventricular arrhythmia presentation is an independent predictor of long-term outcome, it should be considered as an element of risk stratification and when planning clinical trials.

The new ABCs: Airway, Breathing, and Court injunctions

Jusqu’à quel point la loi s’est-elle immiscée dans la pratique médicale? Les tribunaux peuvent-ils nous «obliger» à réanimer des patients lorsque nous jugeons l’intervention inutile? M. A.S., un homme âgé de 79 ans arrive difficilement à parler et à avaler à la suite de plusieurs AVC. Il a subi une trachéostomie et il ne peut exprimer ses propres souhaits. En 1998, lorsqu’il fut admis dans un hôpital de réadaptation, ses médecins rédigèrent un ordre de ne pas réanimer. Par la suite, comme l’ont rapporté les journaux, l’épouse de M. A.S. obtint une injonction «obligeant» le personnel de l’hôpital à administrer la réanimation dans le cas d’un arrêt cardiaque. Cette cause bien connue est présentement en litige devant les tribunaux du Manitoba. Qui a le dernier mot lorsque les médecins et les patients sont en désaccord? Quelles leçons doivent en tirer les médecins d’urgence? Le présent article discute des questions éthiques entourant la réanimation.

Secondary prevention of sudden death: the Dutch Study, the Antiarrhythmics Versus Implantable Defibrillator Trial, the Cardiac Arrest Study Hamburg, and the Canadian Implantable Defibrillator Study

Although indisputably effective in the prevention of sudden death, use of implantable cardioverter defibrillator (ICD) therapy may not necessarily affect all-cause mortality, as most patients at risk also present with severely depressed left ventricular dysfunction. Correction of the sudden death risk in these patients creates a new clinical condition in need of a careful assessment. Should all-cause mortality be affected by the expected reduction in sudden death rate associated with ICD therapy, issues of critical importance, such as the time extent of life prolongation and the associated quality of life, still remain to established. To investigate the potential benefit of ICD therapy compared with antiarrhythmic drug treatment, 4 prospective studies--the Dutch trial, the Antiarrhythmics Versus Implantable Defibrillators (AVID) study, the Cardiac Arrest Study Hamburg (CASH), and the Canadian Implantable Defibrillator Study (CIDS)--have been conducted in which patients with documented sustained ventricular arrhythmia were randomized to 1 of these 2 treatment strategies. The enrollment criteria differed in these 4 studies: (1) in the Dutch trial, they included cardiac arrest secondary to a ventricular arrhythmia, old (> 4 weeks) myocardial infarction, and inducible ventricular arrhythmia; (2) in AVID and CIDS, ventricular fibrillation or poorly tolerated ventricular tachycardia; and (3) in CASH, cardiac arrest secondary to a ventricular arrhythmia regardless of the underlying disease. With regard to the antiarrhythmic drugs, the Dutch trial tested class I and III agents, whereas AVID and CIDS compared ICD therapy with class III agents (mostly amiodarone). In CASH, 3 drug subgroups were investigated: propafenone, amiodarone, and metoprolol. All trials used all-cause mortality as the primary endpoint. Data from these trials provide support for ICD as a therapy superior to antiarrhythmic drugs in prolonging survival in patients meeting the entry criteria. This review briefly summarizes the methods, results, limitations, and clinical implications of these 4 studies.

Use of ankle brachial pressure index to predict cardiovascular events and death: a cohort study

OBJECTIVE

To determine whether a low ankle brachial pressure index is associated with an increased risk of cardiovascular events and death, and whether the prediction of such events could be improved by including this index.

DESIGN

Cohort study.

SETTING

11 practices in Edinburgh, Scotland.

SUBJECTS

1592 men and women aged 55-74 years selected at random from the age-sex registers of 11 general practices and followed up for 5 years.

MAIN OUTCOME MEASURES

Incidence of fatal and non-fatal cardiovascular events and all cause mortality.

RESULTS

At baseline 90 (5.7%) of subjects had an ankle brachial pressure index < or = 0.7, 288 (18.2%) had an index < or = 0.9, and 566 (35.6%) < or = 1.0. After five years subjects with an index < or = 0.9 at baseline had an increased risk of non-fatal myocardial infarction (relative risk 1.38, 95% confidence interval 0.88 to 2.16), stroke (1.98, 1.05 to 3.77), cardiovascular death (1.85, 1.15 to 2.97), and all cause mortality (1.58, 1.14 to 2.18) after adjustment for age, sex, coronary disease, and diabetes at baseline. The ability to predict subsequent events was greatly increased by combining the index with other risk factors--for example, hypertensive smokers with normal cholesterol concentrations had a positive predictive value of 25.0%, increasing to 43.8% in subjects with a low index and decreasing to 15.6% in those with a normal index.

CONCLUSION

The ankle brachial pressure index is a good predictor of subsequent cardiovascular events, and improves on predictions by conventional risk factors alone. It is simple and accurate and could be included in routine screening of cardiovascular status.

Myocardial dysfunction after successful resuscitation from cardiac arrest

OBJECTIVE

To investigate the functional and metabolic changes in the myocardium after successful resuscitation from cardiac arrest.

DESIGN

Prospective, randomized, sham-controlled study.

SETTING

Animal laboratory at a university center.

SUBJECTS

Domestic pigs.

INTERVENTIONS

Electric induction of ventricular fibrillation by alternating current delivered to the right ventricular endocardium through a pacing electrode. Electric defibrillation was attempted after an interval of 12 mins of ventricular fibrillation, which included 4 mins of untreated ventricular fibrillation and 8 mins of precordial compression in 13 animals, seven of which were successfully resuscitated. Seven additional animals were randomized to serve as "sham" controls, in which cardiac arrest was not induced.

MEASUREMENTS AND MAIN RESULTS

Left ventricular pressure-volume relationships utilizing the conductance method were obtained in conjunction with conventional hemodynamic and metabolic measurements at baseline and during a 6-hr interval after successful cardiac resuscitation. Progressive and striking increases in left ventricular volumes were observed after successful cardiac resuscitation. The end-diastolic volume increased from a prearrest level of 89 +/- 21 mL to a maximum of 154 +/- 53 mL (p<.05) at 360 mins after successful resuscitation. The time-coincident end-systolic volume increased from 54 +/- 21 to 126 +/- 54 mL (p<.05), such that the ejection fraction was reduced from 0.41 +/- 0.10 to 0.20 +/- 0.07 ( p<.05). Ventricular dilation was associated with marked reductions in stroke volume and ventricular work. However, compensatory increases in heart rate maintained cardiac output at levels that sustained adequate systemic oxygen delivery. The slope of the end-systolic pressure-volume relationships progressively decreased from 5.04 +/- 1.88 to 2.00 +/- 0.57 mm Hg/mL (p<.05) at 360 mins after successful resuscitation. The volume intercept at left ventricular pressure of 100 mm Hg increased from 43 +/- 19 to 94 +/- 51 mL (p=.03). Both the decrease in the slope and the increase in the volume intercept were characteristic of progressive impairment in contractile function. The rate of left ventricular pressure decrease was unchanged. Accordingly, no substantial changes in lusitropic properties were identified. Despite large increases in end-diastolic volume, the end-diastolic pressure remained unchanged.

CONCLUSION

Postresuscitation myocardial dysfunction in this animal model was characterized by impaired contractile function, decreased work capability, and ventricular dilation.

Exercise testing and training of patients with malignant ventricular arrhythmias

Malignant ventricular arrhythmias account for a significant number of deaths annually. Improved therapies have increased survival for this patient population. These patients, however, remain at high risk due to their history of sudden cardiac death and the preponderance of poor ventricular function in this population. This high risk status may have excluded them from participation in cardiac rehabilitation programs or from undergoing exercise testing in some medical centers. Although the risk of complications, especially arrhythmias, is quite real, the experience in some centers has indicated that it is manageable. This experience and some guidelines for exercise testing and training of patients with malignant ventricular arrhythmias are reviewed in this paper.

Results of cardiopulmonary resuscitation in a cardiology hospital

The authors analysed a series of 557 consecutive patients who suffered cardiorespiratory arrest at the Dante Pazzanese Institute of Cardiology (DPIC) during a period of 5 years in order to examine factors predicting successful resuscitation and long-term survival. Cardiopulmonary resuscitation (CPR) maneuvers were tried in 536 patients, with the following results: 284 patients (53%) died immediately, another 102 (19%) died within the first 24 h after the cardiac arrest and 150 patients (28%) survived more than 24 h. Among these, 65 (12.1%) died in the first month after cardiac arrest and other 29 (5.4%) died after that period. There were 43 late survivors (8%). Thirteen patients (2.4%) were lost to follow-up. After 9 years, the accumulative life expectancy was 8.7%. Coronary heart disease, cardiomyopathy and valvular heart disease were the most frequent underlying diseases. None of the 49 patients with cyanotic congenital heart disease survived. The heart arrest was mostly caused by heart failure (55.8%) and primary arrhythmia (17.2%) in the whole group, whereas the survivor group showed primary arrhythmia in 81.7% and heart failure in 7.3%. In those patients where the initial mechanism of cardiac arrest was ventricular fibrillation, 33.2% survived more than 1 month, while among those on ventricular asystole, only 3.4% survived more than 1 month.

Time-dependent risk of and predictors for cardiac arrest recurrence in survivors of out-of-hospital cardiac arrest with chronic coronary artery disease

One hundred one consecutive patients with chronic coronary artery disease who had survived out-of-hospital cardiac arrest in the absence of acute myocardial infarction underwent electrophysiologic evaluation and were followed prospectively. Ventricular tachyarrhythmias were inducible in 76 patients (75%) in the control state and were suppressed by antiarrhythmic drugs or surgery in 32 of the 76 patients (42%). During a mean follow-up of 27 months, cardiac arrest recurred in 21 patients: in two of the 25 patients in whom ventricular tachyarrhythmias were not inducible in the control state, three of the 32 in whom inducible ventricular tachyarrhythmias were suppressed after treatment, and 16 of the 44 in whom inducible ventricular tachyarrhythmias could not be suppressed after treatment. Actuarial rate of cardiac arrest recurrence was 11.2% during the first 6 months of follow-up ("high-risk early phase") and then decreased to less than 4% in each subsequent 6-month period. Multivariate Cox proportional hazards analysis identified an ejection fraction less than 35% (p = 0.0013) and persistent inducibility of ventricular tachyarrhythmias (p = 0.0025) as independent predictors of cardiac arrest recurrence for the entire follow-up period. Separate analysis of variables within and after the first 6 months showed that an ejection fraction less than 35% was the strongest predictor for early phase recurrence (p = 0.0078) but had only marginally significant predictive value for late phase recurrence (p = 0.0516). Persistent inducibility of ventricular tachyarrhythmias had no significant predictive value for early phase recurrence (p = 0.1382) but was the strongest predictor for late phase recurrence (p = 0.0061). These data suggest that, in patients with chronic coronary artery disease who survive out-of-hospital cardiac arrest, poor ejection fraction and persistent inducibility of ventricular tachyarrhythmias have a different predictive influence on early and late phase recurrence. Time-dependent risk factor analysis may have great clinical relevance in assessing an individual's changing risk over time.

Experience with a mobile coronary care unit in Brisbane

We examined the performance of a hospital-based mobile coronary care unit staffed by emergency physicians, coronary care nurses, and ambulance personnel in a metropolitan setting (Brisbane, Australia). Our unit attended 2,260 calls during 18 months of operation. Standard dispatched ambulances arrived first to 78% of the 2,260 calls. Ten percent of these calls were to patients who had died or had arrested; 45% of these patients were found in ventricular fibrillation and 10% were discharged alive from the hospital. Survival was related to the performance of CPR before the arrival of the unit and to the finding of ventricular fibrillation. As the success of our unit was clearly inferior to that reported from centers where the first-responders are licensed to defibrillate, its operations have ceased and regular ambulance crews are being taught to recognize and treat patients with ventricular fibrillation.

Coronary artery bypass grafting in patients with ventricular fibrillation

The role of coronary artery revascularization in the management of survivors of cardiac arrest remains controversial. Patients with sustained monomorphic ventricular tachycardia rarely respond to revascularization, but the response of patients with ventricular fibrillation as their basic arrhythmia has not been characterized. Coronary artery bypass grafting was performed in 8 patients with a history of cardiac arrest known to be caused by ventricular fibrillation without preceding sustained monomorphic ventricular tachycardia. All patients had critical double-vessel or triple-vessel coronary artery disease, and 7 of 8 had wall motion abnormalities from a prior myocardial infarction. After successful operation, 5 patients had no spontaneous arrhythmias and no inducible arrhythmias at a postoperative electrophysiological study. Three patients, however, had spontaneous, recurrent episodes of ventricular fibrillation unassociated with recurrent ischemia. Clinical factors were not useful predictors of response. The effect of coronary artery revascularization in patients with ventricular fibrillation is unpredictable, and full postoperative electrophysiological evaluation is necessary to judge the success of the procedure.

Risk factor profiles of patients with sudden cardiac death and death from other cardiac causes: a report from the Coronary Artery Surgery Study (CASS)

Identification of patients at risk of sudden death is essential if optimal preventive treatment strategies are to be developed. In the Coronary Artery Surgery Study (CASS) Registry, 19,946 patients were analyzed to characterize baseline clinical, hemodynamic and angiographic features of patients dying from sudden cardiac death and to compare them with features of patients dying from other cardiac causes, of those dying from noncardiac causes and of survivors. Of the 11,843 medically treated patients, 1,621 died during a mean follow-up period of 5.0 years: death was sudden in 557 (34%), nonsudden but cardiac in 813 (50%) and noncardiac in 251 (16%). In 8,103 surgically treated patients, 824 deaths occurred during a mean follow-up period of 5.1 years: death was sudden in 204 (25%), nonsudden but cardiac in 390 (47%) and noncardiac in 230 (28%). In general, the patients (both medically and surgically treated) who died of cardiac causes, either suddenly or nonsuddenly, were similar to each other but significantly different from patients who either survived or died of noncardiac causes. Although patients with an increased risk of any type of cardiac death could be identified, there were no measures of angiographic or hemodynamic characteristics that were significantly different between patients with sudden cardiac death and those with nonsudden cardiac death. Identification of patients at high risk for sudden cardiac death will require approaches in addition to clinical, angiographic and hemodynamic assessment, such as electrophysiologic assessment or monitoring techniques to identify triggering mechanisms.

Should the elderly be resuscitated following out-of-hospital cardiac arrest?

PURPOSE

Elderly and younger patients who were successfully resuscitated and hospitalized following out-of-hospital cardiac arrest were studied to determine if there was a significant difference in hospital course and long-term survival between the two groups.

PATIENTS AND METHODS

The study consisted of 214 consecutive patients, divided into two age groups: elderly (more than 70 years, n = 112) and younger (less than 70 years, n = 102). Hospital charts and paramedic run data were retrospectively reviewed for each patient and findings were compared between the two age groups.

RESULTS

Prior to cardiac arrest, 47 of 112 (42 percent) elderly patients had a history of heart failure, compared with 19 of 102 (18 percent) younger patients, and were more commonly taking digitalis (51 percent versus 29 percent) and diuretics (47 percent versus 26 percent). Younger patients, however, more often had an acute myocardial infarction at the time of the cardiac arrest (33 percent versus 16 percent). At the time of cardiac arrest, 83 percent of younger patients demonstrated ventricular fibrillation, compared with 71 percent of the elderly. In contrast, electromechanical dissociation was five times more common in the elderly patients. Although hospital deaths were more common in the elderly (71 percent versus 53 percent), the length of hospitalization and stay in intensive care units were not significantly different between the age groups. The number of neurologic deaths was similar in both age groups, as were residual neurologic impairments. Only five elderly patients and six younger patients required placement in extended-care facilities. Calculated long-term survival curves demonstrated similar survival in both age groups, with approximately 65 percent of hospital survivors alive at 24 months after hospital discharge.

CONCLUSION

Resuscitation of elderly patients in whom out-of-hospital cardiac arrest occurs is reasonable and appropriate, according to the findings of this study. Even though elderly patients are more likely than younger patients to die during hospitalization, the hospital stay of the elderly is not longer, the elderly do not have more residual neurologic impairments, and survival after hospital discharge is similar to that in younger patients.

Brain resuscitation

Optimal neurological outcome after cardiac arrest requires careful attention to the details of both intracranial and extracranial homeostasis. A high index of suspicion regarding the potential causes and complications of cardiac arrest facilitates discovery and treatment of problems before they adversely impact upon neurological outcome. The future is bright for resuscitation research since our fundamental understanding of cerebral ischemia and its consequences has dramatically improved. This knowledge can hopefully be transferred to clinical useful modes of therapy.

Electrophysiologic study in the management of cardiac arrest survivors: a critical review

This review discusses the value and limitations of EPS in the management of cardiac arrest survivors. Uncertainties associated with EPS include a lack of consensus with respect to stimulation protocol, end points for VT suppression during drug testing, significance of induced polymorphic VT or VF, and timing of EPS after myocardial infarction. Despite methodologic shortcomings in most clinical studies, a useful body of knowledge has emerged. In cardiac arrest survivors, incidence of inducible sustained VT ranged from 35% to 75%. Where induced VT (sustained or nonsustained) was successfully suppressed, recurrent arrhythmic events occurred in 0% to 33% of patients over a 1- to 5-year follow-up period. Failed regimens correlated with a high risk of arrhythmic recurrence. EPS also helps to select patients for the implantable defibrillator or electrocardiac surgery. In conclusion, EPS appears empirically useful in the management of cardiac arrest survivors with coronary artery disease; its value in other disease entities is uncertain.

Prognosis of ventricular arrhythmias in relation to sudden cardiac death: therapeutic implications

The hypothesis that ventricular arrhythmias represent an independent predictor of sudden cardiac death was examined by analyzing the published data. The frequency and complexity of ventricular arrhythmias increase progressively both with age and severity of heart disease, but no age- or disease-related norms have been established for clinical guidance. Simple and complex arrhythmias, including short runs of ventricular tachycardia, do not increase risk of sudden cardiac death in subjects without heart disease or with heart disease and normal myocardial function. Progression of nonsustained into sustained ventricular tachycardia in such individuals is rare. Simple and complex ventricular arrhythmias are not strong independent predictors of sudden death in survivors of myocardial infarction. In these, the overall incidence of sudden cardiac death averages 3.5 to 5% during the first year, but is about 15 to 20% per year in patients with severely impaired ventricular function. The results of this survey suggest that in patients with well preserved ventricular function, prophylactic use of antiarrhythmic drugs is not indicated, and that treatment of asymptomatic or mildly symptomatic ventricular arrhythmias is not likely to reduce the incidence of sudden cardiac death.

The effect of medical and surgical treatment on subsequent sudden cardiac death in patients with coronary artery disease: a report from the Coronary Artery Surgery Study

The effect of medical and surgical treatment on subsequent sudden cardiac death was assessed in 13,476 patients in the Coronary Artery Surgery Study registry who had significant coronary artery disease, operable vessels, and no significant valvular disease. (Patients were assigned to medical or surgical therapy on the basis of clinical judgment and not according to a randomization scheme; therefore, biases associated with unknown variables could not be evaluated.) Sudden cardiac death occurred in 452 patients (3.4%) during a mean follow-up of 4.6 years. Five year survival free of sudden death for medically treated patients was 94 +/- 0.3%, and that for surgically treated patients was 98 +/- 0.2% (p less than .0001). Twelve baseline clinical, electrocardiographic, and angiographic variables were significantly different between patients alive at the last follow-up and those suffering sudden death. Data on these variables were available for 11,508 patients. Sudden death occurred in 257 (4.9%) of 5258 medically treated and 101 (1.6%) of 6250 surgically treated patients. In a high-risk patient subset with three-vessel disease and history of congestive heart failure, 91% of surgically treated patients had not suffered sudden death compared with 69% of medically treated patients. After Cox survival analysis was used to correct for baseline variables, surgical treatment had an independent effect on sudden death (p less than .0001). This reduction was most pronounced in high-risk patients.

Long-term follow-up of survivors of prehospital sudden cardiac death treated with coronary bypass surgery

Although coronary artery bypass surgery is beneficial to patients with severe coronary artery disease, its role in preventing the recurrence of prehospital cardiac arrest in patients is not clear. In this article, we report on the long-term follow-up of 49 survivors of prehospital coronary arrest who had coronary artery bypass surgery. Prior to their prehospital cardiac arrest, 14% of the patients had a history of unstable angina. Coronary angiograms obtained after prehospital cardiac arrest showed that 71% of the patients had three-vessel coronary artery disease and 6% had single-vessel disease. The mean left ventricular ejection fraction was 45%. There were four postoperative deaths; three were caused by pump failure, and one was caused by refractory ventricular arrhythmias. After a maximum follow-up period of 102 months (mean of 55.4 months), there were seven cardiac deaths; five of the patients died of recurrent ventricular fibrillation, and two patients' deaths were related to refractory heart failure. Actuarial analyses of the 49 patients showed that the probability of survival at 6 months, 1 year, 2 years, 3 years, and 5 years was 92%, 92%, 89%, 82%, and 72%, respectively. After surgery, 35 of the 45 patients who were discharged from the hospital were asymptomatic, and 23 of the 32 patients who were employed when their prehospital cardiac arrest occurred returned to their employment. We concluded that coronary artery bypass surgery is beneficial to certain survivors of prehospital sudden death. After surgery, most patients are asymptomatic and capable of returning to their employment and the recurrence of prehospital sudden death is low.