ACUTE MYOCARDIAL INFARCTION: DIAGNOSTIC DIFFICULTIES AND OUTCOME IN ADVANCED OLD AGE

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1 Age and Ageing 1987;1: J. J. DAY Research Registrar A. J. BAYS* Research Lecturer rssssffl 1^^' J. S. CHADRA Locum Consultant Geriatrician St Tydftl's Hospital, Merthyr Tydfll, Mid Glam. CF7 OSJ ACUTE MYOCARDIAL INFARCTION: DIAGNOSTIC DIFFICULTIES AND OUTCOME IN ADVANCED OLD AGE Summary The diagnostic features and outcome of acute myocardial infarction in 100 very elderly (aged 85 years or more) hospitalized patients are reviewed and compared with those in a group of younger elderly (aged 5-8 years). The diagnostic triad of chest pain, sequential ECG changes and raised cardiac enzymes was present in only 2 very elderly patients and in 27 the diagnosis was not initially suspected. Presenting symptoms were often atypical and characteristic ECG changes could not be demonstrated in 25 patients. Very elderly patients had a higher mortality during the first few days in hospital, despite no greater incidence of cardiac failure and similar infarct size to the younger patients. Subsequent in-hospital mortality was similar in both groups. A higher index of suspicion of myocardial infarction in acutely ill very elderly patients should lead to earlier diagnosis, more appropriate management and may improve immediate prognosis. INTRODUCTION Ischaemic heart disease is a major cause of morbidity and mortality in the elderly [ 1 ]. Acute myocardial infarction (AMI) in this age group is generally said to present more atypically [2, 3], to give rise to complications more frequently [] and to have a higher in-hospital mortality [5, ] than in younger patients. Some workers [7, 8], however, have failed to confirm these findings. The age range of the 'elderly' patients studied may clearly significantly affect the results obtained and the very elderly, aged over 85 years, have generally been poorly represented. Post-mortem studies have shown coronary atherosclerosis to be most extensive in this age group [9, 10], and electrocardiographic (ECG) evidence of ischaemic heart disease is present in nearly half [11]. Clinical suspicion of AMI in very elderly patients is often low [12] and little information is available concerning the most typical clinical features and prognosis of the condition in patients aged 85 years or over. We therefore report a series of very elderly, hospitalized patients with a discharge diagnosis of definite or probable myocardial infarction. Methods The patients were identified from a computer coding of discharge diagnoses and thorough review of medical discharge summaries of patients admitted between 197 and 1985 to acute geriatric medical Address correspondence to Dr A. J. Bayer.

2 20 AGE AND AGEING VOL. 1, NO. beds in the Cardiff area. Details of the methodology have been published previously [ 13]. One hundred very elderly patients, aged years (mean 88.2 years) were identified. There were 5 females and 35 males. All fulfilled the diagnostic criteria for definite or probable AMI of Rowley and Hampton [1]. Their presenting clinical features, past medical history, progress in hospital and final outcome were recorded. A comparative group was formed by using the next admission, of the same sex, aged between 5 and 8 years (mean 75.9 years) and also admitted with definite or probable AMI. The statistical method used for comparison was Yates' corrected chi squared test. RESULTS The typical diagnostic triad of AMI, of chest pain, sequential ECG changes and raised cardiac enzymes, was present in only 2 of the very elderly patients. In 27, of whom 10 were acutely confused, AMI was not initially considered as a possible diagnosis by the admitting medical officer and only became apparent following routine screening. The presenting symptoms of all 100 patients, together with those of the comparative group, are shown in the Table. Chest pain was reported by a minority, but, with shortness of breath, remained the commonest presentation. A previous history of angina (1 patients) or AMI (12 patients) had no influence on subsequent presentation. Acute confusion occurred in 22 very elderly patients (compared with six of the young elderly patients; P<0.01) and was often the sole presenting symptom. The five patients known to have an established dementing illness all had an exacerbation of their confusion associated with AMI. Clinical examination diagnosed heart failure in 2 patients and, of the 73 patients for whom a chest radiograph was available, 1 (5.2%) had evidence of pulmonary congestion. In the younger comparative group, clinical heart failure was found in Table. Presenting symptoms of acute myocardial infarction in 100 very elderly patients (aged 85 years or more) and a comparative group of younger elderly patients (aged 5 8 years): symptoms in the subgroup of patients without confusion are also shown Presenting symptoms Chest pain Shortness of breath Acute confusion Syncope Vomiting Sweating Weakness Stroke Giddiness Silent (symptomless) *P<0.05; 5-8 (n=100) All patients Age group (years) 85 + (n=100) 1*" 2 22 # * 17 17" 1» (n=9) 8 (72%) 1 (%) 13 (1%) 2 (2%) 2 (28%) 5 (5%) (%) 5(5%) 2(2%) Patients without acute txmfusion Age group (years) 85+ (n-78) 3 (%)»" 37 (7%) 10 (13%) 1 (18%) 11 (1%) 7(9%) (8%) 3(%) (5%)

3 DAY ET AL.: ACUTE MYOCARDIAL INFARCTION , 3 0 o Days after admhsion Figure. Hospital survival (%) of 100 very elderly patients aged 85 years or more ( elderly patients aged 5-8 years ( ) following acute myocardial infarction. -)and 100 young 57%, and, of the 71 with an available radiograph, 8 (7.%) had radiological evidence of pulmonary congestion. Characteristic sequential ECG changes were demonstrated in only 75 very elderly patients, either because conduction defects or previous myocardial damage made interpretation impossible, or because of the patient's early death. Significant hypotension (a systolic blood pressure of 90 mmhg or less) on admission was found in 11 very elderly patients, nine of whom died; in the comparative group all 10 patients with significant hypotension died. There was no difference between the two groups in mean systolic or diastolic blood pressure, peak creatine phosphokinase (CPK) or peak aspartate transaminase (AST). The average length of hospital stay of the very elderly patients was 12.8± 12. days (range 0-72 days), which was not significantly different from that of the younger patients in the comparative group ( ; range 0-2 days). However, only 51 of the very elderly patients survived to be discharged alive, compared to 1 in the comparative group. As shown in the Figure, this difference arose from the greater number of deaths (P<0.01) during the first days of their admission. Subsequent in-hospital mortality was similar in both groups. DISCUSSION Our findings confirm that the diagnosis of AMI in the very elderly admitted to hospital can be difficult and is often delayed. Atypical presentation was common,

4 22 AGE AND AGEING VOL. 1, NO. with chest pain or dyspnoea reported by only a minority of patients. The greater numbers of confused patients do not adequately explain the reduction in more typical symptomatology since their exclusion had little influence on the frequency of other reported symptoms. Acute confusion is a frequent feature of illness in the elderly and may arise from a complex interaction of organic factors and psychosocial changes [15]. Interestingly, the greater susceptibility to acute confusion of the very elderly in the present study was in spite of no greater haemodynamic changes than in the younger elderly, as evidenced by similar mean blood pressures and frequency of clinical and radiological evidence of cardiac failure. Cardiac failure as a complication of AMI in the geriatric population is reported as having a variable incidence [8], but is more frequent than in the young [1, 17]. The finding of no greater clinical cardiac failure and radiological evidence of pulmonary congestion in the very elderly, together with the observation that the infarct size, as indicated by peak CPK and AST, was similar in both elderly groups, would suggest that the function of the heart, in response to acute infarction in advanced old age is certainly no worse than in the young elderly. Undue pessimism about the outcome of AMI in the very elderly would therefore seem unjustified. The present study, however, identified a particularly high mortality during the first few days of hospitalization, although subsequent mortality was similar to that of the younger elderly patients. A higher incidence of dysrhythmias or cardiac rupture could explain this, suggesting that the very old might particularly benefit from close monitoring initially. This is contrary to most current coronary care unit practice. Furthermore, the failure to diagnose suspected AMI on admission in over a quarter of the patients may have led to inappropriate nursing and therapeutic regimens. A higher index of suspicion'of possible AMI in acutely ill, very elderly patients should lead to earlier diagnosis, more appropriate management and may improve the immediate prognosis. REFERENCES 1. Caird FI, Kennedy RD. Epidemiology of heart disease in old age. In: Caird FI, Dall JLC, Kennedy RD, eds. Cardiology in old age. New York and London: Plenum Press, 197; Pathy MS. Clinical presentation of myocardial infarction in the elderly. BrHeart J 1%7;29: "Librach G, SchadelM, Seltzer M, Hart A, YellinN. The initial manifestations of acute myocardial infarction. Geriatrics 197;31:1-.. Semple T, Williams BO. Coronary care for the elderly. In: Caird Fl, Dall JLC, Kennedy RD, eds. Cardiology in old age. New York and London: Plenum Press 197; Williams BO, Begg TB, Semple T, McGuinness JB. The elderly in a coronary unit. BrMedJ 197^: Latting CA, Silverman ME. Acute myocardial infarction in hospitalised patients over age 70. Am HeartJ 1980;100: Chaturvedi NC, Shivalingappa G, Shanks B, et al. Myocardial infarction in the elderly. Lancet 1972;i: Berman ND. Geriatric cardiology. Tunbridge Wells, Kent: Castle House Publications 1980, Waller BF, Roberts-WC. Cardiovascular disease in the very elderly: analysis of 0 necropsy patients aged 90 years or over. AmJCardiol : Jonsson A, Agnarsson BA, Hallgrimsson J. Coronary atherosclerosis and myocardial infarction in nonagenarians; a retrospective autopsy study. Age Ageing 1985;1:

5 DAY ET AL.: ACUTE MYOCARDIAL INFARCTION Rajala S, Kaltiala K, Haavisto M, Manila K. Prevalence of ECGfindingsin very old people. Eur Heart J 198;5: Wroblewski M, Mikulowski P, Steen B. Symptoms of myocardial infarction in old age; clinical case, retrospective and prospective studies. Age Ageing 198;15: Bayer AJ, ChadhaJS, FaragRR, PathyMSJ. Changing presentation of myocardial infarction with increasing old age. J Am Geriatr Soc 198;3: Rowley JM, Hampton JR. Diagnostic criteria for myocardial infarction. Br J Hosp Med 1981,2: Lipowski ZJ. Transient cognitive disorders (delirium, acute confusional states) in the elderly. Am J Psychiatry 1983,10: Applegate WB, Graves S, Collins T, Zwaag RV, Akins D. Acute myocardial infarction in elderly patients. South MedJ 198;77: MacDonald JB, Baillie J, Williams BO, Ballantyne D. Coronary care in the elderly. Age Ageing 1983;12: Date accepted 1 January 1987