Survivors of out of hospital cardiac arrest: their prognosis, longevity and functional status

Resuscitation 35 (1997) 117 – 121

Survivors of out of hospital cardiac arrest: their prognosis, longevity and functional status ˚ sa Axelsson a, Lars Ekstro¨m a, Judith Reid Graves a, Johan Herlitz a,*, Angela Ba˚ng a, A a a Mikael Holmberg , Jonny Lindqvist , Katarina Sunnerhagen b, Stig Holmberg a b

a Di6ision of Cardiology, Sahlgrenska Uni6ersity Hospital, S-413 45 Go¨teborg, Sweden Di6ision of Rehabilitation Medicine, Sahlgrenska Uni6ersity Hospital, S-413 45 Go¨teborg, Sweden

Received 9 July 1996; received in revised form 18 April 1997; accepted 21 April 1997

Abstract This paper reports, consistent with Utstein Style definitions, 13 years experience observing out-of-hospital cardiac arrest survivors’ prognosis, longevity and functional status. We report for all patients, available outcome information for out-of-hospital cardiac arrest survivors in Go¨teborg Sweden between 1980 and 1993. Patients were followed for at least 1 year and some for over 14 years. From 1980 to 1993 Go¨teborg EMS treated 3754 out-of-hospital cardiac arrests. 9% (n= 324) were discharged from the hospital alive. Survivors’ median age was 67 and 21% (n = 67) were women. Mortality rate was: 21% (n= 61) at 1 year; 56% (n =78) by 5 years; and 82% (n=32) by 10 years following the arrest. During the first 3 years, 16% (n= 46) experienced another cardiac arrest, 19% (n=53) had an acute myocardial infarction and a total of 81% (n= 232) were rehospitalized for various conditions. 14% (n=40) returned to previous employment, and 74% (n= 229) had retired before their arrest occurred. Cerebral performance categories (CPC) scores were: At hospital discharge N=324; Data available for 320 — 1= 53% (n= 171), 2=21% (n =66), 3 =24% (n=77), 4=2% (n =6). One year post arrest N= 263; Data available for 212 — 1= 73% (n =156), 2=9% (n= 18), 3=17% (n=36), 4=1% (n= 2). Overall, 21% (n =61) of cardiac arrest survivors died during the first year, and an additional 16% (n=46) experienced another arrest. 73% of those patients who were still alive after 1 year returned to pre-arrest function. © 1997 Elsevier Science Ireland Ltd.

1. Introduction This is a population based, retrospective report of one community’s success resuscitating people outside the hospital. Attention focuses upon clinical survivor outcomes. A growing number of people survive an out-of-hospital cardiac arrest and live to be discharged from the hospital [1 – 5]. The goal with cardiocerebral resuscitation is to return people to a pre-arrest functional level for a sustained period of time. We examined survivor outcomes for prognosis, functional quality and duration. Our data supports the concept that community resuscitation efforts lend a

positive benefit to our society and our patients. Older medical literature reported a wide variety of patient outcomes but Utstein uniform reporting style allows for closer system and outcome comparisons [6,7]. Using Utstein style consistent terminology we depict survivor outcomes for 13 years in terms of post arrest prognosis, years lived and functional status. Our group previously characterized detailed prognosis for a subset within this study population [8].

2. Methods

2.1. Target area * Corresponding author. Tel.: + 46 31 601000; fax: + 46 31 826540. 0300-9572/97/$17.00 © 1997 Elsevier Science Ireland Ltd. All rights reserved. PII S 0 3 0 0 - 9 5 7 2 ( 9 7 ) 0 0 0 3 5 - X

The community of Go¨teborg has an area of 449 km2.

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2.2. Target population The community of Go¨teborg has 434 000 inhabitants.

2.3. Study population Between 1980 and 1993 there were 324 consecutive out-of-hospital cardiac arrest survivors in Go¨teborg.

2.4. Emergency medical ser6ice (EMS) organisation and equipment Go¨teborg has a single emergency telephone number and one in every three citizens is trained to: recognise an emergency; activate the EMS system; and perform cardiopulmonary resuscitation (CPR). Ambulances are dispatched from a single communication centre using a two-tiered response. For each suspected cardiac arrest, the closest basic life support (BLS) ambulance (equipped with semiautomatic defibrillators), is dispatched simultaneously with an advanced cardiac life support (ACLS) ambulance (when available). Eleven BLS units deployed throughout the area provided initial EMS response time intervals of: B 5 min for 50% of calls and B10 min for 97% of the calls. Two ACLS units operated round the clock. Advanced life support (ALS) units were staffed by nurses specially trained in resuscitation techniques including endotracheal intubation and administering intravenous (IV) medications. ALS nurses performed resuscitation using a standard protocol which included administering a combination of these ALS drugs: adrenaline, atropine, lidocaine, morphine, furosemide, and sodium bicarbonate. A detailed description of the Go¨teborg EMS system is available in a previous issue of this journal [2].

2.5. Functional outcomes To estimate neurologic outcome we used the five point cerebral performance categories (CPCs) classifications. Categories were defined with accepted classifications [6]. No patients discharged alive had CPC scores of 5. 1. Normal, or slight neurological deficits 2. Moderate, or mild neurological deficits 3. Severe neurological deficits 4. Chronic vegetative state 5. Brain death

2.6. Data collection Cerebral performance categories (CPC) scores were obtained from medical records and scored by CPC

level when patients were discharged from the hospital. CPC scores were collected by a single research nurse then confirmed by one cardiologist. The research nurse abstracted CPC scores reported at the 1 year follow up examination, as well as recorded additional cardiac arrests and hospitalisations. (Last CPC data reported for those who died before 1 year was their hospital discharge score.)

2.7. Longe6ity outcomes All deaths are recorded in a Swedish National Death Archive, or tracked directly through hospital patient addresses by researchers. The national data base made possible 100% follow up for all patients in terms of survival and years of life lived post arrest. 3. Results The emergency medical system (EMS) treated 3754 out-of-hospital cardiac arrests during the inclusion period. Of these 22% (n= 807) were hospitalised alive and 9% (n= 324) lived to be discharged from the hospital. Table 1 describes the survivors’ clinical history. The median age was 67 and 21% (n= 67) were female. Nearly half the patients had experienced a previous acute myocardial infarction and one third had a history of congestive heart failure. About half of the survivors were smokers at the time of their arrest.

Table 1 Patient charachteristics N =324

No.

Age (years) Median Mean9S.D. Range

67 64 9 15 0 – 89

Total 324

Gender (4)a Male Female

(%) 79 21

253 67

Previous medical history Cardiac arrest (2) Myocardial infarction Angina pectoris (2) Diabetes mellitus (2) Hypertension (2) Congestive heart failure (2) Bronchial asthma (2) Stroke (2) Smoking (78) Alcoholism (20)

(%) 5 45 44 8 25 30 7 9 52 6

17 146 143 27 81 97 23 30 128 17

a

Parenthesis denotes missing information.

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Table 2 Factors at resuscitation N = 324

No.

Arrest cause Cardiac origin Surgical/accident/trauma Obstructive pulmonary disease Drug abuse Other

(%) 92 3 2 0.9 2

299 10 6 3 6

Initial arrythmia (6)a Ventricular tachycardia Ventricular fibrillation Asystole Pulseless electrical activity Other

3 82 8 6 0.6

10 262 26 18 2

Witnessed arrest (47)a 94 261 Bystander CPR initiated (4)a 30 95 Collapse to defibrillation time interval (min) (53)a for 221 patients Median 6 Mean 9 S.D. 69 3 Range 0–25 a

Denotes patients with missing information.

Table 2 shows most survivors’ arrests were from cardiac aetiology. Ventricular fibrillation/ventricular tachycardia (VF/VT) appeared as the initial recorded ECG rhythms for 85% (n =272) of these patients. Asystole or pulseless electrical activity (PEA) was the initial arrhythmia for 14% (n = 44) recorded by the EMS responders. Surprisingly, 70% (n = 225) of the survivors had no CPR before EMS arrival. Mortality the first year after hospital discharge was 21% (n =61); after 5 years it was 56% (n =78) and by 10 years 82% had died. Follow up revealed 16% (n =46) rearrested and 19% (n = 53) had a subsequent acute myocardial infarction. Table 3 depicts readmission rates to the hospital. In

Fig. 1. Distribution of patients according to CPC score at discharge.

all 81% (n=232) of the survivors were re-admitted to the hospital. Returning to work has been used to indicate survivors’ ability to function [9]. In our population 74% (n=229) retired prior to their cardiac arrest. We found 14% (n=40) returned to some type of work. For younger patients B 63 years old 34% (n =35) returned to work. Fig. 1 illustrates patients’ CPC-scores at discharge. About half of the patients were discharged with a CPC score of 1 (normal, or near normal function), and about one quarter had scores of 3 or 4. Fig. 2 and Table 4, show how CPC scores improved between discharge and 1 year post discharge, thus among patients who had CPC of 2 at discharge, 77% improved to CPC score of 1 one year later. Among patients having CPC score 3, at discharge 25% improved to CPC score 2 and 4% to CPC score 1 one year later.

Table 3 Rehospitalization (missing information in 39 patients) Reason for rehospitalization %b

Mean 9S.D.**

Median***

Myocardial infarction Chest pain, other cause Arrhythmia Congestive heart failure Heart investigation Other cause Totala

2 910 4 914 19 5 69 21 296 75 9 193 899187

9 10 8 22 6 25 30

14 20 13 15 20 58 81

a

Refers to rehospitalisation regardless of cause. Percentage of patients being rehospitalised. ** Mean number of days for rehospitalization among all patients. ***Median number of days for rehospitalization among patients being rehospitalized.

b

Fig. 2. Distribution of patients according to CPC score 1 year after discharge.

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Table 4 Mortality and recovery during first year in relation to CPC score at discharge (%) CPC score at discharge

1 2 3 4

(n= 171)a (n=66) (n=77) (n=6)

Dead

13 32 28 33

Worseningb

Equalb

3

2

1

0 0 0 0

2 0 0 0

0.8 5 0 0

98 18 70 100

Improvementb 1

2

3

0 77 25 0

0 0 4 0

0 0 0 0

a

Number of patients discharged from hospital. Denotes units in CPC score and represents percentage of patients who had deteriorated, remained unchanged or had improved in CPC score 1 year after discharge in relation to CPC-score at discharge.

b

4. Discussion This report provides an extended view of post arrest neurological function, length of survival and prognosis for people resuscitated within a single community-based emergency medical system [7]. The Go¨teborg EMS system has several advantages for compiling all out-ofhospital cardiac arrest patient information. Out-of hospital patient data can be matched to complete hospital treatment records, and follow up medical examinations as well as death dates confirmed by a national registry. We observed that 21% (n =61) died during first year; 56% (n =78) expired by 5 years and 82% (n = 32) were dead within 10 years of their arrest. Our information is similar to previous observations about long term follow up for survivors of cardiac arrest [10,11]. CPC scores were our measure for functional status and they provide only a rough but consistent measurement [6]. The retrospective study design limited this study in that it allowed no pre-arrest CPC information. About half the patients displayed no disabling sequelae at the time of hospital discharge. By 1 year post arrest about three quarters of the CPC scores improved to near normal neurological function. A surprisingly large number, 14% (n =44), of patients who lived to hospital discharge displayed initial EMS ECG rhythms of asystole or pulse-less electrical activity (PEA). Long term follow up studies for these patients are scarce in the medical literature. Our small sample size offers hope for treating these patients aggressively with advanced cardiac life support interventions, but no significant conclusions can be drawn from this limited data set. 16% (n=46) of patients had another cardiac arrest during a mean follow up of 3 years. Previous studies cite between 8 and 32% of patients rearrest [10 – 13]. A minority 13% (n =43) underwent coronary artery bypass grafting or received an internal convertor defibrillator (ICD) [9,12]. About half (n = 174) of the patients received prophylactic beta-blockers [8]. This data suggests we may have reduced risk for recurrent cardiac arrest through post arrest interventions.

A significant number of patients required additional hospital stays. Other researchers reported similar increased hospital admissions for survivors [11,14]. This is not surprising since survivors medical histories often cite past acute myocardial infarction, angina pectoris, congestive heart failure, hypertension or diabetes (72%). Grossvasser et al. found that only one of 31 survivors were back to work 3 years after their arrest [15]. Earnest et al. reported for consecutive out-of-hospital cardiac arrest survivors, 38% were without significant neurological detriment when discharged from the hospital [16]. Roine et al. found 50% of out of hospital cardiac arrest survivors had normal neurological function 1 year following their arrest [17]. In a previous study we administered the mini-mental state exam to 32 survivors aged 75 or less, an average of 25.5 months post arrest [18]. Approximately a third (n = 17) showed abnormal cognitive function [19]. Survivors complained of more social problems than before their arrest. Patients attributed these problems to altered routine social contacts and activities.

5. Implications We found most out-of-hospital cardiac arrest survivors still alive after 1 year, and most had died within 10 years. Patients were often rehospitalized in the years following their initial event and a few had a subsequent arrest. A large proportion of patients had CPC scores indicating functional problems when discharged, but these functional problems decreased 1 year later. The majority of cardiac arrest survivors returned to normal or near normal functional levels within a year and then continued to live for many years. An effective community emergency cardiac care system produces survivors with minimal neurological deficits.

Acknowledgements We appreciate aggressive resuscitation skills of fire-

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fighters, paramedics, emergency nurses and dispatchers from Go¨teborg’s Ra¨ddningstja¨nst, who helped return these people to live among us. This study was supported by grants from the Swedish Heart and Lung Foundation.

References [1] Cobb LA, Werner JA, Trobaugh GB. Sudden cardiac death I. A decade’s experience with out-of-hospital resuscitation. Mod Concepts Cardiovasc Dis 1980;49:31–6. ˚ , Ba˚ng A, [2] Ekstro¨m L, Herlitz J, Wennerblom B, Axelsson A Holmberg S. Survival after cardiac arrest outside hospital over a 12-year period in Go¨teborg. Resuscitation 1994;27:181–7. [3] Eisenberg MS, Cummins Ro, Damon S, Larsen MP, Hearne TR. Survival rates from out-of-hospital cardiac arrest: a tale of 29 cities. Ann Emerg Med 1990;19:238–43. [4] Westal RE, Reissman S, Doering G. Out-of-hosptial cardiac arrests: an 8-year New York City experience. Am J Emerg Med 1996;14:364 – 8. [5] Rainer TH, Gordon MW, Robertson CE, Cusack S. Evaluation of outcome following cardiac arrest in patients presenting to two Scottish emergency departments. Resuscitation 1995;29:33 – 9. [6] Cummins RO, Chamberlain DA, Abramson NS, et al. Recommended guidelines for uniform reporting of data from out-of-hospital cardiac arrest: The Utstein style: a statement for health professionals from a task force of the American Heart Association, the European Resuscitation Council, the Heart and Stroke Foundation of Canada, and the Australian Resuscitation Council. Circulation 1991;84:960–75. [7] Cobb L, Weaver WD, Fahrenbruch C, Hallstrom A, Copass M. Community-based interventions for sudden cardiac death: impact, limitations and changes. Circulation 1992;85(I):I98–I102. ˚ , Ba˚ng A, [8] Herlitz J, Ekstro¨m L, Wennerblom B, Axelsson A Holmberg S. Prognosis among survivors of prehospital cardiac

.

121

arrest. Ann Emerg Med 1995;25:58 – 63. [9] Kalbfleisch K, Lehmann M, Steinman R, et al. Reemployment following implantation of the automatic cardioverter defibrillator. Am J Cardiol 1989;64:199 – 202. [10] Goldstein S, Landis JR, Leighton R, et al. Predictive survival models for resuscitated victims of out-of-hospital cardiac arrest with coronary heart disease. Circulation 1985;71:873 – 80. [11] Kimman GP, Ivens EMA, Hartman JAM, Hart HN, Simoons ML. Long-term survival after successful out-of-hospital resuscitation.. Resuscitation 1994;28:227 – 32. [12] Kelly P, Ruskin JN, Vlahakes GJ, Buckley MJ, Freeman CS, Garan H. Surgical coronary revascularization in survivors of prehospital cardiac arrest: Its effect on inducible ventricular arrhythmias and long-term survival. J Am Coll Cardiol 1990;15(2):267– 73. [13] The Cascade Investigators: Harboview Medical Center, University of Washington Medical Center, University of Washington, Seattle, Washington. Randomized anti-arrhythmic drug therapy in survivors of cardiac arrest (the CASCADE study). Am J Cardiol 1993;72:280 – 7. [14] Maynard Ch for the Cascade Investigators: Harboview Medical Center. University of Washington Medical Center, University of Washington, Seattle, Washington. Rehospitalization in surviving patients of out-of-hospital ventricular fibrillation (the CASCADE study). Am J Cardiol 1993;72:1295 – 1300. [15] Grossvater S, Cohen M, Costef H. Rehabilitation outcome after anoxic brain damage. Arch Phys Med Rehabil 1989;70:186–8. [16] Earnest MP, Breckinridge JC, Yarnell PR, Oliva PB. Quality of survival after out-of-hospital cardiac arrest: Predictive values of early neurological evaluation. Neurology 1979;29:56 – 60. [17] Roine RO, Kajaste S, Kaste M. Neuropsychological sequela of cardiac arrest. JAMA 1993;269:237 – 42. [18] Folstein MF, Folstein SE, McHugh PR. ‘‘Mini-mental state.’’ A practical method for grading the cognitive state of patients for the clinician. J Psychiatr Res 1975;12(3):189– 98. [19] Sunnerhagen K, Johansson O, Herlitz J, Grimby G. Life after cardiac arrest: a retrospective study. Resuscitation 1996;31:135– 40.