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Pathologic findings in pre-hospital deaths due to coronary atherosclerosis
Pathologic Findings in Pre-Hospital Deaths due to Coronary Atherosclerosis
R. FOSTER SCOTT, MD TERESA S. BRIGGS, BS Albany,
New York
From the Department of Pathology, Albany Medical College, Albany, N. Y. This study was supported ‘in part by U. S. Public Health Service Grants HE-7155 and 2 TO1 GM-477. Manuscri’pt received June 3, 1971; revised manuscript received September 23, 1971, accepted October 29,
1971. Address for reprints: R. F. Scott, MD, Department of Pathology, Albany Medical College, Albany, N. Y. 12208.
782
On the basis of medicolegal autopsy series from large metropolitan cities, it has been thought that only 10 percent of patients dying suddenly from coronary atherosclerosis show histologic evidence of acute myocardial infarction. It has been inferred that these patients die before the tissue changes of a myocardial infarct can take place. This study characterizes the anatomic changes in the hearts of a group of patients dying suddenly of coronary atherosclerosis in Albany County, N. Y. Autopsy records and slides were reviewed from 150 men and 33 women who were pronounced dead on arrival, from coronary atherosclerosis, in Albany County hospitals. Histologic evidence of acute myocardial infarcts from 6 hours to 1 week old were found in 47 percent of the cases. When the witnessed final episode was 1 hour or less, 49 percent of the hearts had gross and histologic evidence of acute infarcts. The presence of large areas bf myocardial necrosis, often of days’ duration, apparently does not ensure hospitalization or necessarily interfere with normal activity. Approximately two thirds of the hearts with recent acute infarcts also had evidence of a previous myocardial infarct. Thus, the final myocardial insult in these patients was not the first.
The prehospital phase of clinically manifest acute myocardial infarction can be defined as that interval of time between the apparent onset of the event and the arrival of the patient in a hospital. As has been succinctly stated, the major complication of the pre-hospital phase of myocardial infarction is death.l Numerous epidemiologi+ and pathologic6-g studies of prehospital death due to coronary atherosclerosis have been reported. Most pathologic studies in the United States have emanated from large cities and have concluded that only about 10 percent of cases have histologic evidence of an acute myocardial infarct. It is inferred that the majority of victims died before there was time for histologic changes in the myocardium to develop. In this study we have characterized the pathologic findings at autopsy of persons who died in the pre-hospital phase of coronary atherosclerosis in Albany County, N. Y. We were particularly interested in those who apparently di’ed within 1 hour after the onset of their final episode of ill health. We wished to learn how many of those reported as dead on arrival at a hospital showed histologic evidence of recent myocardial infarction or coronary arterial thrombi. It was our impression that this was a much larger group than reported in older studies from large cities. In addition, we hoped to learn something concerning the possible mode of deathsudden arrhythmia, cardiogenic shock or cardiac rupture and tamponade.
The American
Journal
of CARDIOLOGY
PRE-HOSPITAL
Materials and Methods The material consisted of autopsy records and slides of persons pronounced dead on arrival as a result of coronary artery disease in Albany County hospitals from 1966 through 1970. The autopsies were performed by senior hospital pathologists, most of them on the staff of the Albany Medical College ; nearly all autopsies were performed in the Albany Medical Center Hos$ital, the main teaching hospital of the medical school. However, all were medicolegal autopsies, in the sense that they were ordered by the coroner on the advice of the coroner’s physician. Thus, the study is a retrospective one. It is not a study of the community type such as the Framingham study, and there was considerable selectivity of the patients undergoing autopsy. To put the autopsy findings in perspective, we determined the total number of deaths in and out of hospital attributed to coronary artery disease in Albany County in 1970. In the 5 years from 1966 to 1970 there were 183 autopsy cases (150 male, 33 female subjects) of pre-hospita1 deaths due to coronary atherosclerosis in Albany County. Five male and 3 female subjects were black. All had been pronounced dead in the emergency room of 1 of the 5 general hospitals in the county. The autopsy protocols and the microscopic slides of each case were reviewed. The anatomic features and all of the available pertinent clinical data were tabulated for each subject. The tables of raw data contained more than 3,000 entries which were summarized for this report. Each autopsy protocol was accompanied by 15 to 20 slides ; an average of 5 slides were obtained from the heart and coronary arteries. The clinical data for each case were derived primarily from the inquiries of the coroner’s physician and coroner. An autopsy is usually not ordered on someone pronounced dead on arrival at a hospital if the medical history is adequate to explain the patient’s death and there are no suspicious or unusual circumstances. The coroner’s physician and the coroner obtain from witnesses facts concerning the duration of the terminal episode and signs and reported symptoms during this episode. Evidence of prior cardiovascular and other disease is obtained from relatives and friends. If the decedent is reported to have consulted a physician within the previous year, that physician is questioned by the coroner’s physician. When no relatives or friends capable of providing a medical history can be located immediately after death, an autopsy is ordered, even though a history of previous coronary artery disease may exist but cannot be discovered. Autopsies are ordered even in the presence of a history of coronary artery disease if any of the circumstances of death are thought to be unusual. Such circumstances would include death occurring while driving a motor vehicle or after an accident or, occasionally, at work. In 1970, autopsies were performed in approximately 10 percent of the cases of pre-hospital deaths in Albany County which were attributed to coronary atherosclerosis. Pre-hospital deaths from were divided into 2 groups:
coronary
atherosclerosis
those in which the final event appeared to last no more than 1 hour, and all others. If the death was unwitnessed, the case was not
VOLUME
29. JUNE
1972
DEATHS AND MYOCARDIAL
INFARCTION
included in the first group. In 101 of 150 men and in 18 of 33 women, there was a final episode, usually described as “collapse,” lasting 1 hour or less before death. Only 15 of the 101 men who died within 1 hour had an available history of feeling ill for 1 day to 1 week before the final episode. In many instances the decedents were said by informants to have had a “cold.” Five of the 101 men and 1 of the 33 women had seen a physician within 3 weeks of death, but in no instance had a diagnosis of coronary artery disease been made. The activities immediately preceding death suggest that the 101 men who died apparently within 1 hour had no premonition of death or refused to recognize significant symptoms. Thirty-four were at their usual work, 18 were driving a motor vehicle, 10 were away from home and engaged in miscellaneous activities ranging from jogging to attending a Christmas party. Of the 35 stricken at home, only 4 were reported to have been at home because they thought they were ill. The histologic criterion for an acute myocardial infarct was the presence of foci of polymorphonuclear leukocytes amid necrotic myocardial fibers with or without macrophages. The presence alone of apparently necrotic myocardial fibers as suggested by nuclear changes or smudging of the fibers was not accepted as sufficient evidence to warrant a diagnosis of acute infarction. The criteria for the diagnosis of a healing myocardial infarct were variable amounts of granulamacrophages containing pigment and tion tissue, chronic inflammatory cells. The criterion for an old or healed myocardial infarct was the presence of dense areas of collagen in the myocardium. The stains used were hematoxylin and eosin ; no myocardial studies with special stains were performed. The areas of infarction (old, healing or new) had to be at least 1 cm in diameter; the vast majority were 2 cm or more in diameter. Vital statistics from the New York State Department of Health and medical records in the 5 general hospitals in Albany County were examined for the year 1970 to determine the number of patients diagnosed as having cardiovascular disease who were dead on arrival, or had died in the emergency room or after hospital admission. According to the 1970 census, Albany County had 285,618 residents, of whom 135,378 were male and 150,240 female; 15,472 of the population were black, and 1,321 were of other racial groups. In 1970 there were 3,172 deaths in the county. The records from all autopsies performed by medicolegal pathology services for Albany County in 1970 were examined in order to put the findings in further perspective.
Results Anatomic data: Forty-seven percent of the 183 autopsy subjects (Table I) had recent myocardial infarcts manifested by foci 1 cm or larger of necrotic myocardial cells surrounded by polymorphonuclear leukocytes with or without macrophages. The location of these infarcts was as follows: anterior 40 percent, posterior 22 percent, septal 20 percent, other 18 percent. Eleven hearts showed aneurysmal dilatation at the site of old in-
783
SCOTT AND BRIGGS
TABLE
I
TABLE
Anatomic Data for All Subjects Pronounced Dead on Arrival from Coronary Atherosclerosis Who Subsequently Underwent Autopsy: Albany County, N. Y., 1966-1970
II
Detailed Data on Combinations of Myocardial Infarcts Coronary Thrombi in. Entire Series: Albany County, N. Y. 1966-1970
Duration of Final Episode Unknown or More than 1 Hour or Less 1 Hour (no.) (no.)
Total Series
(no.)
Total Acute MI Healing MI Old MI No Ml Recent thrombi
in coronary artery Ruptured heart Aneurysm or aneurysmal dilatation Enlarged heart* Lungs
1,001-l ) 500 g >1,500 g
M
F
M
F
M
F
150
33 17 0 12
101
11
50 16 64 29
17 8 0 6 7
49 23 12 27 7
16 9 0 6 4
13 0
49 5
6 0
22 0
7 0
73 28 81 36
71 5 11
0
70
13
7 49
0 3
4 21
0 10
59 62 24
25 4 3
48 36 12
14 1 1
11 26 12
11 3 2
28 49 70
12 12 7
16 36 46
5 5 5
13 13 24
7 7 2
18
5
10
2
8
3
Liver
<1,600 g 1,601-2,000 g >2,000 g Pleural or abdominal effusion
* Greater than 450 and 400 g for male and female respectively. Ml = myocardial infarction.
Total autopsies Acute Ml Acute alone Acute and healing Acute and old Acute, old and healing Total healing Ml Healing alone Healing and old Total old Ml Old alone No recent infarct No infarct
M
F
150
33 17 8 0 9
73 20 7 38 8 28 5 8 81 27
0 0 0 0 12 3
77 36
16 11
* Categories contain duplicated
TABLE
Coronary Arterial Thrombi Present (no. of subjects)” M
F
71 36 13 3 16 4 12 3 2 33
13 7 3 0 4 0 0 0 0 5
11 35 19
1 7 4
counts.
III
Historical Data for all Subjects Pronounced Dead on Arrival from Coronary Atherosclerosis Who Subsequently Underwent Autopsy: Albany County, N. Y., 19664970
Duration of Final Episode
subjects,
farcts. Five hearts had ruptured through areas of recent infarction. Slightly less than 50 percent of the hearts were hypertrophied (more than 450 g in a man and 400 g in a woman). The data on lung weight suggest that most subjects did not die with massive pulmonary edema ; only 27 subjects in the total series had a lung weight of more than 1,500 g. The values for liver weight were considerably greater than normal. Histologically, few of the livers showed evidence of chronic passive congestion or fatty metamorphosis. The increased weight appeared to be caused primarily by acute congestion. The anatomic data in subjects whose final episode lasted less than 1 hour, and in those in whom the duration of the final episode was unknown or appeared to last more than 1 hour are compared in Table I. The only significant difference between the 2 groups (chi square test, P <0.05) is the greater number with no myocardial infarcts in the group of subjects who apparently died within 1 hour of the onset of their final symptoms.
784
Acute, Healing and Old Infarcts (no. of subjects)*
and
Unknown or Greater than 1 Hour or less 1 Hour
Total Series
no. of patients Age (yr> <40 4150 51-60 >61 Average Weight Overweight* Normal Underweight Activity during final episode At work At home Driving car Miscellaneous Unknown History of heart disease History of seeing a doctor Recent illness
M
F
M
F
M
F
150
33
101
17
49
16
15 35 50 50 55
1 6 10 16 59
11 24 32 34 55
1 4 7 5 55
4 11 18 16
0 2 3 11
97 30 17
17 16 0
71 14 11
8 9 0
26 16 6
9 7 0
38 61 18 17 16 15 9 18
3 19 0 3 8 6 3 2
34 35 18 10 4 10 5 15
3 10 0 3 1 3 1 2
4 26 0 7 12 5 4 3
0 9 0 0 7 3 2 0
* Weight criteria from Metropolitan
Life Insurance
The American
Journal
Co.
of CARDIOLOGY
PRE-HOSPITAL
Table II gives data concerning combinations of myocardial infarcts and recent coronary arterial thrombi. Many of the acute infarcts were found in hearts that also showed either healing or old myocardial infarcts. Of the 93 (of the total of 183) hearts showing no recent infarcts, 42 had recent coronary artery thrombi ; of the 47 hearts showing no infarcts, 23 had thrombi. Historical data. The average age of the 150 men was 55 years, and that of the 33 women, 59 (Table III). Fifteen men were 40 years of age or less. Almost two thirds of the men and half of the women were overweight according to weight tables of New York Metropolitan Life Insurance Company. Table III presents the historical data of the 101 men and 17 women who died within 1 hour or less. Table IV lists the cause of death as determined by the 281 medicolegal autopsies performed in Albany County in 1970. In previous years the total number of autopsies was smaller, but the proportion of causes of death (motor vehicle accident, TABLE
TABLE
DEATHS AND MYOCARDIAL
INFARCTION
IV
Diagnoses
in 281 Medicolegal
Autopsies
of Out-of-Hospital
Deaths: Albany County, N. Y., 1970 Diagnosis
Percent
Nonviolent deaths Coronary artery disease Cerebrovascular accident Cardiomyopathy and myocarditis Other Violent deaths Motor vehicle accidents Homicide, suicide Other
53 23 3 2 25 47 26 8 13
coronary artery disease, and so on) was not significantly different. Table V presents the number of men and women in Albany County dying of coronary artery disease whose deaths were categorized as pre-hospital deaths, deaths in the emergency room, or deaths after hospital admission.
V
Number and Percentage of Pre-Hospital, Albany County, N. Y., 1970
Emergency
Room and Hospital
Deaths Due to Coronary
Artery
Disease:
Age 00 Deaths
25-39
40-49
50-59 A.
60-69
70-79
80-89
90+
Total
Male Subjects
Pre-hospital no. % Emergency
3 0.5
21 3.2
51 7.8
104 15.8
79 12.0
52 7.9
15 2.3
325 49.5
no. % Hospital
1 0.2
2 0.3
7 1.0
7 1.0
6 0.9
3 0.5
1 0.2
27 4.1
no. % Total
2 0.3
12 1.8
46 7.0
86 13.1
106 16.1
44 6.7
9 1.4
305 46.4
no. %
6 0.9
35 5.3
104 15.8
197 29.9
191 29.1
99 15.1
25 3.8
657 100
33 5.9
314 56.3
room
B.
Female Subjects
Pre-hospital no. % Emergency no. % Hospital no. % Total no. %
VOLUME
1 0.2
2 0.4
21 3.8
45 8.1
96 17.2
116 20.7
0 0
1 0.2
1 0.2
4 0.7
3 0.5
1 0.2
0 0
0 0
1 0.2
10 1.8
36 6.4
105 18.8
70 12.5
12 2.2
234 41.9
1 2
4 0.7
32 5.7
85 15.2
204 36.6
187 33.6
45 8.0
558 100
room
29, JUNE
1972
10 1.8
785
SCOTT AND BRIGGS
Of the 3,172 deaths in 1970 in Albany County, 1,215 were reported to have been due either directly or in part to coronary artery disease. Of these, approximately 50 percent were pre-hospital deaths. Discussion
Histologic evidence of acute myocardial infarction was found in approximately half of the patients considered to have died before hospital admission from coronary atherosclerosis and studied at autopsy by the medicolegal service in Albany County from 1966 to 1970. By conventional histologic criteria, these infarcts were 6 hours to 1 week old, even in patients whose apparent final witnessed episode of ill health lasted no more than 1 hour. However, grouping of patients by final symptoms lasting 1 hour or less, or more than 1 hour on the basis of interview data is difficult in a retrospective study. It is possible that some patients classified as having severe symptoms for 1 hour or less also had minor symptoms of coronary artery disease for a longer period. The autopsy population in this study is a highly selected one. Although drawn from a large population dying of coronary atherosclerosis, most of the autopsy patients apparently died within 1 hour, and few had an available history of previous coronary artery disease. A high proportion died while driving a motor vehicle, or at their regular work. Since the coroner seldom ordered autopsies on persons whom he judged to have chronic coronary artery disease, the study is possibly biased in favor of the subject without previous symptoms. This makes the presence of histologically well established acute myocardial infarction in such a group more surprising, and suggests at least 2 possibilities. Some of these people may have had symptoms referrable to acute myocardial infarction which they either misinterpreted or ignored. A second possibility is that the acute infarction was silent. Regardless of the explanation, the findings suggest that in a substantial portion of those who died prehospital deaths from coronary arterial atherosclerosis, the presence of a major pathologic process in the myocardium of at least 6 hours’ duration does not ensure that the patient will be hospitalized, or even that it will interfere with normal activity. The frequency of acute infarcts and coronary arterial thrombi in persons who died suddenly from coronary atherosclerosis is much higher in this series than in previous studies reported from larger metropolitan areas.6s7 However, the number is similar to that found in a recent series reported by Titus et al.1° The differences could be due to a changing pattern of the disease in the last
766
decade, but a more likely reason is that the previously reported autopsy series dealt with population groups different from this series or the recent series from Rochester County in Minnesota.lO In addition to the differences in general populations, there may be differences in selection of cases for autopsy in different localities, which may influence the pathologic findings. The very brief final episode of ill health of most persons in our series probably explains the differences in such findings as place and activity during the onset of final symptoms, and history of recent medical care, compared to the series of Kuller et a1.,2 in which the time interval for sudden death was 24 hours. In our study most subjects died within 1 hour. Thus, it is not surprising, for instance, that a higher proportion of persons in our series had their final episode while at work or while driving a car, and comparatively few of the subjects were at home. Mechanism of sudden death: There is considerable indirect evidence suggesting that arrhythmias are the immediate cause of pre-hospital deaths from coronary artery disease.ll The anatomic findings (specifically the infrequency of massive pulmonary edema) further support this view, and indicate that a minority of the patients in the study died of “pump failure,” Eighty-four of the patients had a lung weight of less than 1,000 g, and only 27 had a lung weight of more than 1,500 g. Only 23 of the patients in the entire series had a pleural or abdominal effusion of 50 ml or more, an observation that suggests that not many of the patients in this study had a chronically failing heart. Anatomically it was clear that the final episode, with a histologically visible acute myocardial infarct, was not the first time many of these patients had had myocardial damage. In the total series, 62 of the 90 patients who died with an acute myocardial infarct also had old or healing myocardial infarcts. However, these old and healing infarcts had obviously not resulted in sudden death when they occurred and, furthermore, had not induced congestive failure, although many of the hearts with old infarcts were found to be enlarged. Our study suggests that further characterization of the hearts of patients dying suddenly from coronary atherosclerosis should be performed. We are at present carrying out investigations of the conduction system and of the precise locations of coronary arterial thrombi and acute myocardial infarcts (when they exist) in such patients. Acknowledgment We thank Mr. V. Logrillo, Office of Biostatistics, New York State Department of Health, for his help in compiling some of the data in this study.
The American
Journal
of
CARDIOLOGY
PRE-HOSPITAL
DEATHS AND MYOCARDIAL
INFARCTION
References 1. Bondurant S: Problems of the pm-hospital phase of acute myocardial infarction. Amer J Cardiol 24:612-616, 1969 2. Kuller L, Lilienfield A, Fisher R: Epidemiologic study of sudden deaths due to arteriosclerotic heart disease. Circulation 34:1056-1068, 1966 3. Kannel WB, Dawber TR, McNamara PM: Detection of the coronary-prone adult: the Framingham Study. J Iowa Med’Soc 56:26-34, 1966 4. Hackett TP, Cassem NH: Factors contributing to the delay in responding to the signs and symptoms of acute myocardial infarction. Amer J Cardiol 24651658, 1969 5. Anderson TW, LeRiche WH, Mackay JS: Sudden death and ischemic heart diseas-rrelation with hardness of water supply. New Eng J Med 280:805-807,1969 6. Weinberg SB, Helpem M: Circumstances related to sudden, unexpected death Bn coronary heart disease. In, Work and the Heart (Rosenbaum FF, Belknap EL ed). New York, Hoeber, 1959, p 288-292
VOLUME 29, JUNE 1972
7. Adelson L, Hoffman W: Sudden death from coronary disease: related to lethal mechanism arising independently of vascular occlusion or myocardial damage. JAMA 176:129-135, 1961 8. Rabson SM, Helpern M: Sudden and unexpected natural death. 2. Coronary artery sclerosis. Amer Heart J 35: 635-642, 1948 9. Spain DM, Bradess VA: The relationship of coronary thrombosis to coronary atherosclerosis and sischemic heart d,isease (a necropsy study), covering a ‘period of 25 years. Amer J Med Sci 240:701-710, 1960 10. Titus JL, Oxman HA, Nobrega FT, et ah Sudden unexpected death as the initial manifestation of ischemic heart disease. Clinical and pathologic observations. Amer J Cardiol 26662663, 1970 11. Side1 VS, Acton J, Lown B: Models for the evaluation of prehospital coronary care. Amer J Card&l 24674-688, 1969
787
R. FOSTER SCOTT, MD TERESA S. BRIGGS, BS Albany,
New York
From the Department of Pathology, Albany Medical College, Albany, N. Y. This study was supported ‘in part by U. S. Public Health Service Grants HE-7155 and 2 TO1 GM-477. Manuscri’pt received June 3, 1971; revised manuscript received September 23, 1971, accepted October 29,
1971. Address for reprints: R. F. Scott, MD, Department of Pathology, Albany Medical College, Albany, N. Y. 12208.
782
On the basis of medicolegal autopsy series from large metropolitan cities, it has been thought that only 10 percent of patients dying suddenly from coronary atherosclerosis show histologic evidence of acute myocardial infarction. It has been inferred that these patients die before the tissue changes of a myocardial infarct can take place. This study characterizes the anatomic changes in the hearts of a group of patients dying suddenly of coronary atherosclerosis in Albany County, N. Y. Autopsy records and slides were reviewed from 150 men and 33 women who were pronounced dead on arrival, from coronary atherosclerosis, in Albany County hospitals. Histologic evidence of acute myocardial infarcts from 6 hours to 1 week old were found in 47 percent of the cases. When the witnessed final episode was 1 hour or less, 49 percent of the hearts had gross and histologic evidence of acute infarcts. The presence of large areas bf myocardial necrosis, often of days’ duration, apparently does not ensure hospitalization or necessarily interfere with normal activity. Approximately two thirds of the hearts with recent acute infarcts also had evidence of a previous myocardial infarct. Thus, the final myocardial insult in these patients was not the first.
The prehospital phase of clinically manifest acute myocardial infarction can be defined as that interval of time between the apparent onset of the event and the arrival of the patient in a hospital. As has been succinctly stated, the major complication of the pre-hospital phase of myocardial infarction is death.l Numerous epidemiologi+ and pathologic6-g studies of prehospital death due to coronary atherosclerosis have been reported. Most pathologic studies in the United States have emanated from large cities and have concluded that only about 10 percent of cases have histologic evidence of an acute myocardial infarct. It is inferred that the majority of victims died before there was time for histologic changes in the myocardium to develop. In this study we have characterized the pathologic findings at autopsy of persons who died in the pre-hospital phase of coronary atherosclerosis in Albany County, N. Y. We were particularly interested in those who apparently di’ed within 1 hour after the onset of their final episode of ill health. We wished to learn how many of those reported as dead on arrival at a hospital showed histologic evidence of recent myocardial infarction or coronary arterial thrombi. It was our impression that this was a much larger group than reported in older studies from large cities. In addition, we hoped to learn something concerning the possible mode of deathsudden arrhythmia, cardiogenic shock or cardiac rupture and tamponade.
The American
Journal
of CARDIOLOGY
PRE-HOSPITAL
Materials and Methods The material consisted of autopsy records and slides of persons pronounced dead on arrival as a result of coronary artery disease in Albany County hospitals from 1966 through 1970. The autopsies were performed by senior hospital pathologists, most of them on the staff of the Albany Medical College ; nearly all autopsies were performed in the Albany Medical Center Hos$ital, the main teaching hospital of the medical school. However, all were medicolegal autopsies, in the sense that they were ordered by the coroner on the advice of the coroner’s physician. Thus, the study is a retrospective one. It is not a study of the community type such as the Framingham study, and there was considerable selectivity of the patients undergoing autopsy. To put the autopsy findings in perspective, we determined the total number of deaths in and out of hospital attributed to coronary artery disease in Albany County in 1970. In the 5 years from 1966 to 1970 there were 183 autopsy cases (150 male, 33 female subjects) of pre-hospita1 deaths due to coronary atherosclerosis in Albany County. Five male and 3 female subjects were black. All had been pronounced dead in the emergency room of 1 of the 5 general hospitals in the county. The autopsy protocols and the microscopic slides of each case were reviewed. The anatomic features and all of the available pertinent clinical data were tabulated for each subject. The tables of raw data contained more than 3,000 entries which were summarized for this report. Each autopsy protocol was accompanied by 15 to 20 slides ; an average of 5 slides were obtained from the heart and coronary arteries. The clinical data for each case were derived primarily from the inquiries of the coroner’s physician and coroner. An autopsy is usually not ordered on someone pronounced dead on arrival at a hospital if the medical history is adequate to explain the patient’s death and there are no suspicious or unusual circumstances. The coroner’s physician and the coroner obtain from witnesses facts concerning the duration of the terminal episode and signs and reported symptoms during this episode. Evidence of prior cardiovascular and other disease is obtained from relatives and friends. If the decedent is reported to have consulted a physician within the previous year, that physician is questioned by the coroner’s physician. When no relatives or friends capable of providing a medical history can be located immediately after death, an autopsy is ordered, even though a history of previous coronary artery disease may exist but cannot be discovered. Autopsies are ordered even in the presence of a history of coronary artery disease if any of the circumstances of death are thought to be unusual. Such circumstances would include death occurring while driving a motor vehicle or after an accident or, occasionally, at work. In 1970, autopsies were performed in approximately 10 percent of the cases of pre-hospital deaths in Albany County which were attributed to coronary atherosclerosis. Pre-hospital deaths from were divided into 2 groups:
coronary
atherosclerosis
those in which the final event appeared to last no more than 1 hour, and all others. If the death was unwitnessed, the case was not
VOLUME
29. JUNE
1972
DEATHS AND MYOCARDIAL
INFARCTION
included in the first group. In 101 of 150 men and in 18 of 33 women, there was a final episode, usually described as “collapse,” lasting 1 hour or less before death. Only 15 of the 101 men who died within 1 hour had an available history of feeling ill for 1 day to 1 week before the final episode. In many instances the decedents were said by informants to have had a “cold.” Five of the 101 men and 1 of the 33 women had seen a physician within 3 weeks of death, but in no instance had a diagnosis of coronary artery disease been made. The activities immediately preceding death suggest that the 101 men who died apparently within 1 hour had no premonition of death or refused to recognize significant symptoms. Thirty-four were at their usual work, 18 were driving a motor vehicle, 10 were away from home and engaged in miscellaneous activities ranging from jogging to attending a Christmas party. Of the 35 stricken at home, only 4 were reported to have been at home because they thought they were ill. The histologic criterion for an acute myocardial infarct was the presence of foci of polymorphonuclear leukocytes amid necrotic myocardial fibers with or without macrophages. The presence alone of apparently necrotic myocardial fibers as suggested by nuclear changes or smudging of the fibers was not accepted as sufficient evidence to warrant a diagnosis of acute infarction. The criteria for the diagnosis of a healing myocardial infarct were variable amounts of granulamacrophages containing pigment and tion tissue, chronic inflammatory cells. The criterion for an old or healed myocardial infarct was the presence of dense areas of collagen in the myocardium. The stains used were hematoxylin and eosin ; no myocardial studies with special stains were performed. The areas of infarction (old, healing or new) had to be at least 1 cm in diameter; the vast majority were 2 cm or more in diameter. Vital statistics from the New York State Department of Health and medical records in the 5 general hospitals in Albany County were examined for the year 1970 to determine the number of patients diagnosed as having cardiovascular disease who were dead on arrival, or had died in the emergency room or after hospital admission. According to the 1970 census, Albany County had 285,618 residents, of whom 135,378 were male and 150,240 female; 15,472 of the population were black, and 1,321 were of other racial groups. In 1970 there were 3,172 deaths in the county. The records from all autopsies performed by medicolegal pathology services for Albany County in 1970 were examined in order to put the findings in further perspective.
Results Anatomic data: Forty-seven percent of the 183 autopsy subjects (Table I) had recent myocardial infarcts manifested by foci 1 cm or larger of necrotic myocardial cells surrounded by polymorphonuclear leukocytes with or without macrophages. The location of these infarcts was as follows: anterior 40 percent, posterior 22 percent, septal 20 percent, other 18 percent. Eleven hearts showed aneurysmal dilatation at the site of old in-
783
SCOTT AND BRIGGS
TABLE
I
TABLE
Anatomic Data for All Subjects Pronounced Dead on Arrival from Coronary Atherosclerosis Who Subsequently Underwent Autopsy: Albany County, N. Y., 1966-1970
II
Detailed Data on Combinations of Myocardial Infarcts Coronary Thrombi in. Entire Series: Albany County, N. Y. 1966-1970
Duration of Final Episode Unknown or More than 1 Hour or Less 1 Hour (no.) (no.)
Total Series
(no.)
Total Acute MI Healing MI Old MI No Ml Recent thrombi
in coronary artery Ruptured heart Aneurysm or aneurysmal dilatation Enlarged heart* Lungs
1,001-l ) 500 g >1,500 g
M
F
M
F
M
F
150
33 17 0 12
101
11
50 16 64 29
17 8 0 6 7
49 23 12 27 7
16 9 0 6 4
13 0
49 5
6 0
22 0
7 0
73 28 81 36
71 5 11
0
70
13
7 49
0 3
4 21
0 10
59 62 24
25 4 3
48 36 12
14 1 1
11 26 12
11 3 2
28 49 70
12 12 7
16 36 46
5 5 5
13 13 24
7 7 2
18
5
10
2
8
3
Liver
<1,600 g 1,601-2,000 g >2,000 g Pleural or abdominal effusion
* Greater than 450 and 400 g for male and female respectively. Ml = myocardial infarction.
Total autopsies Acute Ml Acute alone Acute and healing Acute and old Acute, old and healing Total healing Ml Healing alone Healing and old Total old Ml Old alone No recent infarct No infarct
M
F
150
33 17 8 0 9
73 20 7 38 8 28 5 8 81 27
0 0 0 0 12 3
77 36
16 11
* Categories contain duplicated
TABLE
Coronary Arterial Thrombi Present (no. of subjects)” M
F
71 36 13 3 16 4 12 3 2 33
13 7 3 0 4 0 0 0 0 5
11 35 19
1 7 4
counts.
III
Historical Data for all Subjects Pronounced Dead on Arrival from Coronary Atherosclerosis Who Subsequently Underwent Autopsy: Albany County, N. Y., 19664970
Duration of Final Episode
subjects,
farcts. Five hearts had ruptured through areas of recent infarction. Slightly less than 50 percent of the hearts were hypertrophied (more than 450 g in a man and 400 g in a woman). The data on lung weight suggest that most subjects did not die with massive pulmonary edema ; only 27 subjects in the total series had a lung weight of more than 1,500 g. The values for liver weight were considerably greater than normal. Histologically, few of the livers showed evidence of chronic passive congestion or fatty metamorphosis. The increased weight appeared to be caused primarily by acute congestion. The anatomic data in subjects whose final episode lasted less than 1 hour, and in those in whom the duration of the final episode was unknown or appeared to last more than 1 hour are compared in Table I. The only significant difference between the 2 groups (chi square test, P <0.05) is the greater number with no myocardial infarcts in the group of subjects who apparently died within 1 hour of the onset of their final symptoms.
784
Acute, Healing and Old Infarcts (no. of subjects)*
and
Unknown or Greater than 1 Hour or less 1 Hour
Total Series
no. of patients Age (yr> <40 4150 51-60 >61 Average Weight Overweight* Normal Underweight Activity during final episode At work At home Driving car Miscellaneous Unknown History of heart disease History of seeing a doctor Recent illness
M
F
M
F
M
F
150
33
101
17
49
16
15 35 50 50 55
1 6 10 16 59
11 24 32 34 55
1 4 7 5 55
4 11 18 16
0 2 3 11
97 30 17
17 16 0
71 14 11
8 9 0
26 16 6
9 7 0
38 61 18 17 16 15 9 18
3 19 0 3 8 6 3 2
34 35 18 10 4 10 5 15
3 10 0 3 1 3 1 2
4 26 0 7 12 5 4 3
0 9 0 0 7 3 2 0
* Weight criteria from Metropolitan
Life Insurance
The American
Journal
Co.
of CARDIOLOGY
PRE-HOSPITAL
Table II gives data concerning combinations of myocardial infarcts and recent coronary arterial thrombi. Many of the acute infarcts were found in hearts that also showed either healing or old myocardial infarcts. Of the 93 (of the total of 183) hearts showing no recent infarcts, 42 had recent coronary artery thrombi ; of the 47 hearts showing no infarcts, 23 had thrombi. Historical data. The average age of the 150 men was 55 years, and that of the 33 women, 59 (Table III). Fifteen men were 40 years of age or less. Almost two thirds of the men and half of the women were overweight according to weight tables of New York Metropolitan Life Insurance Company. Table III presents the historical data of the 101 men and 17 women who died within 1 hour or less. Table IV lists the cause of death as determined by the 281 medicolegal autopsies performed in Albany County in 1970. In previous years the total number of autopsies was smaller, but the proportion of causes of death (motor vehicle accident, TABLE
TABLE
DEATHS AND MYOCARDIAL
INFARCTION
IV
Diagnoses
in 281 Medicolegal
Autopsies
of Out-of-Hospital
Deaths: Albany County, N. Y., 1970 Diagnosis
Percent
Nonviolent deaths Coronary artery disease Cerebrovascular accident Cardiomyopathy and myocarditis Other Violent deaths Motor vehicle accidents Homicide, suicide Other
53 23 3 2 25 47 26 8 13
coronary artery disease, and so on) was not significantly different. Table V presents the number of men and women in Albany County dying of coronary artery disease whose deaths were categorized as pre-hospital deaths, deaths in the emergency room, or deaths after hospital admission.
V
Number and Percentage of Pre-Hospital, Albany County, N. Y., 1970
Emergency
Room and Hospital
Deaths Due to Coronary
Artery
Disease:
Age 00 Deaths
25-39
40-49
50-59 A.
60-69
70-79
80-89
90+
Total
Male Subjects
Pre-hospital no. % Emergency
3 0.5
21 3.2
51 7.8
104 15.8
79 12.0
52 7.9
15 2.3
325 49.5
no. % Hospital
1 0.2
2 0.3
7 1.0
7 1.0
6 0.9
3 0.5
1 0.2
27 4.1
no. % Total
2 0.3
12 1.8
46 7.0
86 13.1
106 16.1
44 6.7
9 1.4
305 46.4
no. %
6 0.9
35 5.3
104 15.8
197 29.9
191 29.1
99 15.1
25 3.8
657 100
33 5.9
314 56.3
room
B.
Female Subjects
Pre-hospital no. % Emergency no. % Hospital no. % Total no. %
VOLUME
1 0.2
2 0.4
21 3.8
45 8.1
96 17.2
116 20.7
0 0
1 0.2
1 0.2
4 0.7
3 0.5
1 0.2
0 0
0 0
1 0.2
10 1.8
36 6.4
105 18.8
70 12.5
12 2.2
234 41.9
1 2
4 0.7
32 5.7
85 15.2
204 36.6
187 33.6
45 8.0
558 100
room
29, JUNE
1972
10 1.8
785
SCOTT AND BRIGGS
Of the 3,172 deaths in 1970 in Albany County, 1,215 were reported to have been due either directly or in part to coronary artery disease. Of these, approximately 50 percent were pre-hospital deaths. Discussion
Histologic evidence of acute myocardial infarction was found in approximately half of the patients considered to have died before hospital admission from coronary atherosclerosis and studied at autopsy by the medicolegal service in Albany County from 1966 to 1970. By conventional histologic criteria, these infarcts were 6 hours to 1 week old, even in patients whose apparent final witnessed episode of ill health lasted no more than 1 hour. However, grouping of patients by final symptoms lasting 1 hour or less, or more than 1 hour on the basis of interview data is difficult in a retrospective study. It is possible that some patients classified as having severe symptoms for 1 hour or less also had minor symptoms of coronary artery disease for a longer period. The autopsy population in this study is a highly selected one. Although drawn from a large population dying of coronary atherosclerosis, most of the autopsy patients apparently died within 1 hour, and few had an available history of previous coronary artery disease. A high proportion died while driving a motor vehicle, or at their regular work. Since the coroner seldom ordered autopsies on persons whom he judged to have chronic coronary artery disease, the study is possibly biased in favor of the subject without previous symptoms. This makes the presence of histologically well established acute myocardial infarction in such a group more surprising, and suggests at least 2 possibilities. Some of these people may have had symptoms referrable to acute myocardial infarction which they either misinterpreted or ignored. A second possibility is that the acute infarction was silent. Regardless of the explanation, the findings suggest that in a substantial portion of those who died prehospital deaths from coronary arterial atherosclerosis, the presence of a major pathologic process in the myocardium of at least 6 hours’ duration does not ensure that the patient will be hospitalized, or even that it will interfere with normal activity. The frequency of acute infarcts and coronary arterial thrombi in persons who died suddenly from coronary atherosclerosis is much higher in this series than in previous studies reported from larger metropolitan areas.6s7 However, the number is similar to that found in a recent series reported by Titus et al.1° The differences could be due to a changing pattern of the disease in the last
766
decade, but a more likely reason is that the previously reported autopsy series dealt with population groups different from this series or the recent series from Rochester County in Minnesota.lO In addition to the differences in general populations, there may be differences in selection of cases for autopsy in different localities, which may influence the pathologic findings. The very brief final episode of ill health of most persons in our series probably explains the differences in such findings as place and activity during the onset of final symptoms, and history of recent medical care, compared to the series of Kuller et a1.,2 in which the time interval for sudden death was 24 hours. In our study most subjects died within 1 hour. Thus, it is not surprising, for instance, that a higher proportion of persons in our series had their final episode while at work or while driving a car, and comparatively few of the subjects were at home. Mechanism of sudden death: There is considerable indirect evidence suggesting that arrhythmias are the immediate cause of pre-hospital deaths from coronary artery disease.ll The anatomic findings (specifically the infrequency of massive pulmonary edema) further support this view, and indicate that a minority of the patients in the study died of “pump failure,” Eighty-four of the patients had a lung weight of less than 1,000 g, and only 27 had a lung weight of more than 1,500 g. Only 23 of the patients in the entire series had a pleural or abdominal effusion of 50 ml or more, an observation that suggests that not many of the patients in this study had a chronically failing heart. Anatomically it was clear that the final episode, with a histologically visible acute myocardial infarct, was not the first time many of these patients had had myocardial damage. In the total series, 62 of the 90 patients who died with an acute myocardial infarct also had old or healing myocardial infarcts. However, these old and healing infarcts had obviously not resulted in sudden death when they occurred and, furthermore, had not induced congestive failure, although many of the hearts with old infarcts were found to be enlarged. Our study suggests that further characterization of the hearts of patients dying suddenly from coronary atherosclerosis should be performed. We are at present carrying out investigations of the conduction system and of the precise locations of coronary arterial thrombi and acute myocardial infarcts (when they exist) in such patients. Acknowledgment We thank Mr. V. Logrillo, Office of Biostatistics, New York State Department of Health, for his help in compiling some of the data in this study.
The American
Journal
of
CARDIOLOGY
PRE-HOSPITAL
DEATHS AND MYOCARDIAL
INFARCTION
References 1. Bondurant S: Problems of the pm-hospital phase of acute myocardial infarction. Amer J Cardiol 24:612-616, 1969 2. Kuller L, Lilienfield A, Fisher R: Epidemiologic study of sudden deaths due to arteriosclerotic heart disease. Circulation 34:1056-1068, 1966 3. Kannel WB, Dawber TR, McNamara PM: Detection of the coronary-prone adult: the Framingham Study. J Iowa Med’Soc 56:26-34, 1966 4. Hackett TP, Cassem NH: Factors contributing to the delay in responding to the signs and symptoms of acute myocardial infarction. Amer J Cardiol 24651658, 1969 5. Anderson TW, LeRiche WH, Mackay JS: Sudden death and ischemic heart diseas-rrelation with hardness of water supply. New Eng J Med 280:805-807,1969 6. Weinberg SB, Helpem M: Circumstances related to sudden, unexpected death Bn coronary heart disease. In, Work and the Heart (Rosenbaum FF, Belknap EL ed). New York, Hoeber, 1959, p 288-292
VOLUME 29, JUNE 1972
7. Adelson L, Hoffman W: Sudden death from coronary disease: related to lethal mechanism arising independently of vascular occlusion or myocardial damage. JAMA 176:129-135, 1961 8. Rabson SM, Helpern M: Sudden and unexpected natural death. 2. Coronary artery sclerosis. Amer Heart J 35: 635-642, 1948 9. Spain DM, Bradess VA: The relationship of coronary thrombosis to coronary atherosclerosis and sischemic heart d,isease (a necropsy study), covering a ‘period of 25 years. Amer J Med Sci 240:701-710, 1960 10. Titus JL, Oxman HA, Nobrega FT, et ah Sudden unexpected death as the initial manifestation of ischemic heart disease. Clinical and pathologic observations. Amer J Cardiol 26662663, 1970 11. Side1 VS, Acton J, Lown B: Models for the evaluation of prehospital coronary care. Amer J Card&l 24674-688, 1969
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