The incidence and pattern of angina prior to acute myocardial infarction: A study of 577 cases

In order to determine the incidence and pattern of angina as a premonitory symptom of acute myocardial infarction, 577 consecutive patients with acute myocardial infarction were questioned shortly after hospital admission about the presence and pattern of chest pain prior to onset of infarction, with particular emphasis on the month prior to infarction. Two hundred and seventy-six patients (48 per cent) had no angina before infarction (Group I), whereas 301 (52 per cent) did. One hundred and seventy-nine patients (31 per cent) had a history of chronic angina, and of these, 75 had no change in the pattern of angina prior to infarction (Group II) while 104 noticed worsening of their symptoms in the month prior to infarction (Group III). One hundred and twenty-two patients (21 per cent) had new onset angina in the month prior to infarction (Group IV). The number of patients with unstable angina prior to infarction (Groups III and IV) was therefore 226 or 39 per cent of the total series. In patients with unstable angina, the increase in severity of symptoms or the development of new onset angina occurred within a period of 1 week or less in 69 per cent. Patients with a history of previous infarction or chronic angina had a higher incidence of unstable angina prior to infarction than patients without such a history (p < 0.05). Patients with prior angina (Groups II, III, and IV) had a higher incidence of subendocardial infarction than patients without angina (p < 0.05). The hospital mortality rate in the four groups did not differ significantly.     

Clinical and angiographic features and prognostic significance of early postinfarction angina with and without electrocardiographic signs of transient ischemia

PURPOSE: The goal of the study was to characterize the clinical and angiographic characteristics and the prognostic significance of early postinfarction angina associated or unassociated with ST-T changes. PATIENTS AND METHODS: Four hundred forty-nine consecutive patients surviving an acute myocardial infarction and catheterized before hospital discharge were included. They were closely monitored in the coronary care unit and a 12-lead electrocardiogram (ECG) was promptly obtained before the administration of nitroglycerin whenever chest pain suggestive of ischemia occurred. Complete follow-up information was obtained for all patients a mean of 14 +/- 8 months after the qualifying infarction. RESULTS: Early postinfarction angina occurred in 164 patients. Transient ST-T changes were documented during pain in 79 patients and were absent in 85. Compared with patients without postinfarction angina, patients with angina without ST-T changes were older and had a more frequent past history of angina (42% versus 28%, p = 0.01). They also more often had a non-Q-wave myocardial infarction with lower peak creatine kinase blood level elevation. At angiography, patients with angina had more extensive coronary artery disease (1.9 +/- 0.8 diseased vessels per patient versus 1.6 +/- 0.8, p less than 0.05) and more left ventricular segments at jeopardy by a significant coronary artery stenosis (1.5 +/- 1.1 versus 1.2 +/- 1.1, p less than 0.05). The presence of ST-T changes during chest pain was associated with a further increase in the severity of coronary artery disease (2.1 +/- 0.8 diseased vessels per patient, p less than 0.05) and with a less well-developed collateral circulation (18% versus 34% of patients, p = 0.01) that was more often compromised by a coronary artery stenosis (22% versus 8% of patients, p = 0.008). In-hospital infarct extension occurred in 2% of patients without angina, 3.5% of patients with angina without ECG changes, and 28% of patients with angina and ST-T changes (p less than 0.01). The 2-year survival was similar in the first two groups (90% and 96%), and poorer (83%, p = 0.02) in patients with ST-T changes. Survival rates without myocardial infarction were respectively 80%, 78%, and 67% (p less than 0.004). CONCLUSION: A gradient in the severity of coronary artery disease and in the extent of myocardium at jeopardy exists from patients with no postinfarction angina to patients with angina and to patients with angina accompanied by ECG signs of ischemia. The presence of ST-T changes during pain indicates a much less favorable clinical outcome.     

Comparative predictive value of ST-segment depression or angina during early and repeat postinfarction exercise tests

To determine the relative value of electrocardiographic (ECG) ST-segment depression alone compared to angina alone for predicting multivessel coronary artery disease during early and repeat postinfarction exercise tests, we evaluated 93 postmyocardial infarction patients with modified treadmill exercise tests prior to hospital discharge (mean 14 +/- 2 days), and 36 of these 93 patients with repeat exercise tests at six weeks following infarction. It was concluded that angina alone or angina irrespective of the presence of ST-segment depression are better predictors of multivessel coronary artery disease than ECG ST-segment depression alone, and the persistence of ischemic abnormalities during repeat treadmill exercise tests following infarction is useful for confirming the presence of multivessel coronary artery disease.     

Prognostic significance of transient myocardial ischaemia after first acute myocardial infarction: five year follow up study.

OBJECTIVE--To assess the five year prognostic significance of transient myocardial ischaemia on ambulatory monitoring after a first acute myocardial infarction, and to compare the diagnostic and long term prognostic value of ambulatory ST segment monitoring, maximal exercise testing, and echocardiography in patients with documented ischaemic heart disease. DESIGN--Prospective study. SETTING--Cardiology department of a teaching hospital. PATIENTS--123 consecutive men aged under 70 who were able to perform predischarge maximal exercise testing. INTERVENTIONS--Echocardiography two days before discharge (left ventricular ejection fraction), maximal bicycle ergometric testing one day before discharge (ST segment depression, angina, blood pressure, heart rate), and ambulatory ST segment monitoring (transient myocardial ischaemia) started at hospital discharge a mean of 11 (SD 5) days after infarction. MAIN OUTCOME MEASURES--Relation of ambulatory ST segment depression, exercise test variables, and left ventricular ejection fraction to subsequent objective (cardiac death or myocardial infarction) or subjective (need for coronary revascularisation) events. RESULTS--23 of the 123 patients had episodes of transient ST segment depression, of which 98% were silent. Over a mean of 5 (range 4 to 6) years of follow up, patients with ambulatory ischaemia were no more likely to have objective end points than patients without ischaemic episodes. If, however, subjective events were included an association between transient ST segment depression and an adverse long term outcome was found (Kaplan-Meier analysis; P = 0.004). The presence of exercise induced angina identified a similar proportion of patients with a poor prognosis (Kaplan-Meier analysis; P < 0.004). Both exertional angina and ambulatory ST segment depression had high specificity but poor sensitivity. The presence of exercise induced ST segment depression was of no value in predicting combined cardiac events. Indeed, patients without exertional ST segment depression were at increased risk of future objective end points (Kaplan-Meier analysis; P < 0.0045). These findings may be explained in part by a higher prevalence of left ventricular dysfunction in patients without ischaemic changes in the exercise electrocardiogram (P < 0.05). CONCLUSION--There seem to be limited reasons to perform ambulatory ST segment monitoring in survivors of a first myocardial infarction who can perform exercise tests before discharge. Patients at high risk of future myocardial infarction or death from cardiac causes are not identified. Ambulatory monitoring and exertional angina distinguish a small subset of patients who will develop severe angina pectoris demanding coronary revascularisation during follow up. Patients without exercise induced ST segment depression comprise a high risk subgroup in terms of subsequent objective end points. The role of ambulatory ST segment monitoring performed in unselected patients immediately after infarction when risk is maximal remains to be clarified.     

Significance and treatment of nocturnal angina preceding myocardial infarction.

The presence of nocturnal angina and congestive heart failure within the month prior to admission was evaluated in the 174 patients with acute myocardial infarction. Heart size was evaluated radiographically at the time of admission. Twenty-three patients (13 per cent) experienced nocturnal angina. The incidence of nocturnal angina was significantly higher in those with anterior myocardial infarction (p less than 0.005) and subendocardial infarction (p less than 0.02) when compared with patients with inferior MI. Congestive heart failure was more common prior to admission in those with nocturnal angina (9/23) as opposed to those without (3/141) (p less than 0.001). Cardiomegaly was seen in 9/23 patients with nocturnal angina and 22/141 without (p less than 0.02). We conclude that the presence of nocturnal angina in those who develop MI increases the likelihood that the infarction will be either anterior or subendocardial rather than inferior. The association of nocturnal angina and congestive heart failure to anterior myocardial infarction is probably due to more severe and probably significant left coronary artery disease.     

"Silent" myocardial ischemia during and after exercise testing in patients with coronary artery disease

Although many patients with coronary artery disease (CAD) have a positive exercise test without pain, the frequency and significance of this "silent" ischemia is unclear. Therefore, we studied 122 consecutive clinically stable patients with angiographically defined CAD (greater than 75 per cent luminal stenosis) and a positive exercise test. Seventy-eight patients had pain or anginal equivalent during or after a positive exercise test; 44 did not, including 32 (26 per cent) with no symptoms at all. Patients were evaluated as to age, sex, prior myocardial infarction, congestive failure, hypertension, diabetes mellitus, and digoxin or propranolol therapy--in addition to anginal symptoms before, during, or after the exercise itself. Extent of CAD, presence of collaterals, and left ventricular ejection fraction were also determined. All exercise tests were evaluated for evidence of ST-T abnormalities or prior infarction on the control ECG as well as peak heart rate during exercise and post-exercise degree of ST segment depression. There were no significant differences between patients with and without exercise-induced pain in regard to any of the clinical and angiographic features noted above, demonstrating that "silent" myocardial ischemia during or after exercise testing is not uncommon and is not readily attributable to any obvious clinical or catheterization findings. Further studies are necessary to determine if patients with evidence of "silent" myocardial ischemia are especially prone to sudden death.     

Silent left ventricular dysfunction during routine activity after thrombolytic therapy for acute myocardial infarction

To investigate prospectively the occurrence and significance of postinfarction transient left ventricular dysfunction, 33 ambulatory patients who underwent thrombolytic therapy after myocardial infarction were monitored continuously for 187 +/- 56 min during normal activity with a radionuclide left ventricular function detector at the time of hospital discharge. Twelve patients demonstrated 19 episodes of transient left ventricular dysfunction (greater than 0.05 decrease in ejection fraction, lasting greater than or equal to 1 min), with no change in heart rate. Only two episodes in one patient were associated with chest pain and electrocardiographic changes. The baseline ejection fraction was 0.52 +/- 0.12 in patients with transient left ventricular dysfunction and 0.51 +/- 0.13 in patients without dysfunction (p = NS). At follow-up study (19.2 +/- 5.4 months), cardiac events (unstable angina, myocardial infarction or death) occurred in 8 of 12 patients with but in only 3 of 21 patients without transient left ventricular dysfunction (p less than 0.01). During submaximal supine bicycle exercise, only two patients demonstrated a decrease in ejection fraction greater than or equal to 0.05 at peak exercise; neither had a subsequent cardiac event. These data suggest that transient episodes of silent left ventricular dysfunction at hospital discharge in patients treated with thrombolysis after myocardial infarction are common and associated with a poor outcome. Continuous left ventricular function monitoring during normal activity may provide prognostic information not available from submaximal exercise test results.     

Exercise testing early after myocardial infarction: Predictive value for subsequent unstable angina and death

Recently, modified treadmill exercise testing before hospital discharge has been reported to be safe in patients after uncomplicated myocardial infarction. Accordingly, the frequency of treadmill exercise-induced abnormalities and their prognostic value were evaluated in 130 patients with uncomplicated myocardlal infarction. Seventy-eight patients (60 percent) had one or more treadmill exercise-induced abnormalities; 42 had S-T segment depression, 35 had angina and 17 had an inadequate blood pressure response. During the mean follow-up period of 11 months, 27 patients experienced unstable angina, 12 had a recurrent myocardlal infarction and 10 died of cardiac causes. Compared with patients with no exercise-induced abnormality, patients with S-T segment depression, angina pectoris or an inadequate blood pressure response had a significantly greater (p < 0.001) incidence of all cardiac events during the follow-up period. Furthermore, unstable angina pectoris was significantly more frequent (p <0.005) in patients with S-T segment depression or angina pectoris. Finally, when the patients with ischemic treadmill abnormalities were combined with the patients exhibiting an inadequate blood pressure response, they had a statistically greater (p < 0.005) incidence of cardiac death than that of patients with no treadmill abnormalities. Therefore, these three abnormalities during modified treadmill exercise testing before hospital discharge identify patients with uncomplicated myocardial infarction who are at risk for a future cardiac event.     

Clinical correlates of coronary cineangiography in young males with myocardial infarction.

Thirty-eight men who suffered acute transmural myocardial infarction before age 40, and after recovery were New York Heart Association functional Class I or II, were studied by noninvasive means and by coronary angiography in order to determine whether these nonivasive studies could predict the presence of significant coronary artery disease remote from that felt to be responsible for the previous myocardial infarction. Patients were divided into two groups on the basis of the absence (Group I) or presence (Group II) of obstructive disease in a major coronary artery supplying myocardium remote from the prior myocardial infarction. There were 21 patients in Group I and 17 patients in Group II. They did not differ with respect to age, abnormalities of lipid or glucose metabolism, family history, history of hypertension or cigarette use, presence of obesity, or infarct localization. Ten of 17 patients in Group II had angina pectoris; only 3/21 patients in Group I had angina pectoris (p less than 0.01). All 12 patients tested in Group II had a positive maximal exercise tolerance test; only 1/17 patients tested in Group I was similarly positive (p less than 0.001). The absence of angina pectoris and the presence of a negative maximal exercise tolerance test is strong evidence against the pressure of significant CAD remote from that responsible for the prior myocardial infarction.     

Holter-detected myocardial ischemia. Impact for prognosis and decision making after acute myocardial infarction

BACKGROUND: Aim of the study was to evaluate the prognostic and decision making value of Holter detected myocardial ischemia after acute myocardial infarction in comparison with clinically detected postinfarction angina and exercise test. METHODS: To this aim the patients consecutively admitted to our coronary care unit with acute myocardial infarction during one year were retrospectively evaluated. One hundred and eighty-nine patients (age 70+/-11 years, 137 male and 51 female) had a 24 hour Holter monitoring. One-year follow up of these patients was obtained. RESULTS: Myocardial ischemia was detected by Holter monitoring in 21 patients (11%), 4 with and 17 without angina. Symptom limited exercise test was obtained before discharge in 116 patients (62%): 45% were positive, 42% non-diagnostic and 13 negative for myocardial ischemia. Post infarction angina was present in 15 patients (9%). Patients with Holter detected myocardial ischemia were older (73+/-10 vs 66+/-11 years, p<0.05) and had higher prevalence of both angina and positive exercise test (p<0.01). One-year follow up was obtained in 186 patients. Holter detected myocardial ischemia positive predictive value for death or reinfarction was 15%, negative predictive value was 90%, similar to the absence of angina (90%) and the absence of positive exercise test (93%). Angina and exercise test identified 62% of patients with Holter detected myocardial ischemia. Residual myocardial ischemia was exclusively observed by Holter monitoring in 4% of the population, particularly in 1 patients with and 7 without exercise test. CONCLUSIONS: The additive contribution of Holter detected myocardial ischemia in the prognosis and decision making of post infarction patients is rather scanty.     

Surgical versus non-surgical management of patients soon after acute myocardial infarction.

Of 510 patients admitted to hospital with acute myocardial infarction, 34 had coronary artery bypass grafting before discharge (6-43 days (median 20) after infarction). The patients who were given grafts generally had a smaller infarction with less functional impairment than the 476 patients who were not. The outcome of coronary artery bypass grafting was investigated in a retrospective matched pair study. Patients were matched on the basis of the presence of postinfarction angina, left ventricular ejection fraction, location of the infarction, peak creatine kinase activity, Killip clinical class, and severity of coronary disease with 34 patients who were given medical treatment only. At one year follow up fewer of the operated patients had symptoms than did the matched non-operated patients. Survival at one year in the operated and non-operated groups respectively was 94% vs 91%; angina within one year occurred in 3% vs 68%; congestive heart failure in 3% vs 6%; and 0% vs 32% were referred for later bypass grafting or coronary angioplasty. It is concluded that coronary artery bypass grafting can be performed safely soon after myocardial infarction provided that left ventricular function is not seriously compromised. Such treatment is more effective than medical treatment for relief of angina during the first year after infarction.     

Surgical versus non-surgical management of patients soon after acute myocardial infarction

Of 510 patients admitted to hospital with acute myocardial infarction, 34 had coronary artery bypass grafting before discharge (6-43 days (median 20) after infarction). The patients who were given grafts generally had a smaller infarction with less functional impairment than the 476 patients who were not. The outcome of coronary artery bypass grafting was investigated in a retrospective matched pair study. Patients were matched on the basis of the presence of postinfarction angina, left ventricular ejection fraction, location of the infarction, peak creatine kinase activity, Killip clinical class, and severity of coronary disease with 34 patients who were given medical treatment only. At one year follow up fewer of the operated patients had symptoms than did the matched non-operated patients. Survival at one year in the operated and non-operated groups respectively was 94% vs 91%; angina within one year occurred in 3% vs 68%; congestive heart failure in 3% vs 6%; and 0% vs 32% were referred for later bypass grafting or coronary angioplasty. It is concluded that coronary artery bypass grafting can be performed safely soon after myocardial infarction provided that left ventricular function is not seriously compromised. Such treatment is more effective than medical treatment for relief of angina during the first year after infarction.     

The short- and long-term prognosis of patients with transmural and nontransmural myocardial infarctio

To compare the long-term prognosis in patients surviving transmural with patients surviving nontransmural myocardial infarctions, the records of 188 consecutive patients with clinical histories and enzyme elevations consistent with acute infarction were reviewed. According to standard electrocardiographic criteria the patients were divided into two groups: 148 with transmural myocardial infarction (group 1) and 40 with nontransmural myocardial infarction (group 2). Of the patients who survived hospitalization, follow-up data were obtained on 119 of 124 patients in group 1 and 36 of 37 patients in group 2 at a mean follow-up period of 36 months. In group 2, the patients had a high incidence of sudden death after discharge (33 per cent in group 2 versus 15 per cent in group 1, p < 0.02) as well as a significantly higher incidence of death from all cardiac causes (41.6 per cent in group 2 versus 24.3 per cent in group 1, p < 0.05). Furthermore, the patients in group 2 still alive at the end of the follow-up period had an increased incidence of angina pectoris and of recurrent infarction. The data suggest that patients with nontransmural myocardial infarction carry a particularly guarded prognosis.     

Clinical characteristics of patients with variant angina complicated by myocardial infarction or death within 1 month

Of 132 consecutive patients hospitalized during a 5 year period because of active variant angina, 18 died or had a myocardial infarction within 1 month. In 4 patients an episode of pain and S-T elevation unrelieved by calcium antagonist drugs and intravenous nitroglycerin persisted for more than 1 hour, inducing cardiogenic shock and death before the appearance of Q waves and elevated serum enzyme levels. In the other 14 patients myocardial infarction developed in the electrocardiographic leads in which S-T elevation had occurred during attacks of variant angina.Clinical features were not helpful in distinguishing the 18 patients with complications from the other 114. Angina at rest had been present for less than 1 month in 7 of the 18 patients with infarction compared with 31 of 114 in the other group (probability [p] not significant [NS]). Before infarction the artery presumed to be perfusing the involved territory contained a fixed stenosis of 70 percent or more of luminal diameter in 8 of the 14 patients with complications who had coronary arteriograms compared with 50 of 112 in the other group (p = NS). In 13 of the 18 patients, complications occurred in spite of large doses of calcium antagonist drugs. In 11 of these 13, attacks of variant angina were monitored for 3 to 17 days both before and during treatment. All 11 had fewer attacks with treatment and 5 had no attacks. Daily attacks per patient decreased from 4.6 ± 4.3 to 0.5 ± 0.7 (mean ± standard deviation) (p < 0.01). It is concluded that in variant angina of recent onset myocardial infarction occurs frequently and unpredictably. Myocardial infarction may occur in the absence of severe fixed lesions and in spite of apparent clinical improvement with administration of calcium antagonist drugs.     

Prognostic value of low-level exercise testing in patients with myocardial infarction

The prognostic value of low-level exercise testing (EXT) before hospital discharge was assessed in 111 patients with uncomplicated acute myocardial infarction (AMI). Of 111 patients, 94 were followed for 1 year after AMI to find that 22 carried a poor prognosis: reduction in duration of EXT (6 patients), postinfarction angina (2 patients), congestive heart failure (3 patients), coronary bypass graft surgery (7 patients) and reinfarction (4 patients). The prognosis was poor in 3.7% of 54 patients who tolerated exercise for 721 seconds or longer (4.2 METs) and 50% of 40 patients tolerating it no longer than 720 sec (p less than 0.0001). Of 22 patients who turned out to be carriers of a poor prognosis, 12 (54.5%) had an ST segment change during EXT, but 10 of the 12 patients were asymptomatic. Our results suggest that reduction in duration of exercise and asymptomatic ST segment changes during EXT provide important clues to establishing the short-term prognosis of AMI.     

First myocardial infarction in patients under 60 years old: the role of exercise tests and symptoms in deciding whom to catheterise.

OBJECTIVE--To determine the role of exercise tests and assessment of angina in the detection of potentially threatening disease in young patients with infarcts. DESIGN--Elective readmission of patients at a mean (SD) of 60 (30) days after acute myocardial infarction for assessment of angina, treadmill exercise tests, and cardiac catheterisation. SETTING--Cardiology department of a teaching hospital. PATIENTS--186 consecutive survivors, aged under 60 years and discharged from the coronary care unit after a first myocardial infarction. MAIN OUTCOME MEASURES--Coronary arteriography, presence of angina, result of exercise tests, and referral for revascularisation. RESULTS--31% of patients had either two vessel disease (with proximal left anterior descending involvement), three vessel disease, or left main stem disease. 49% of all patients had angina. Of the 173 patients who had an exercise test 34% had 1 mm and 24% had 2 mm of exercise induced ST depression. Thirty percent had no angina and a negative exercise test: after a mean (SD) follow up of 16 (4) months none of this symptom free sub-group had died, had experienced a further myocardial infarction, or had been referred for revascularisation. 79% of patients with either two vessel disease (with proximal left anterior descending involvement), three vessel disease, or left main stem disease had either angina or a 1 mm ST depression during the exercise test. CONCLUSION--Patients without cardiac pain after myocardial infarction and without ST changes during an exercise do not need arteriography.     

Post-infarction stenocardia (clinical and prognostic significance)

The impact of postinfarction angina pectoris on the course of myocardial infarction (MI) was studied in the hospital setting in 359 patients who had sustained large MI, 247 of them being followed for a year after their discharge. In the group of patients with postinfarction angina pectoris, the course of the disease was found to be more severe in hospital and during a year-follow-up after MI. They more frequently developed acute and chronic heart failure, rhythm and conduction disturbances, recurrent MI. A statistic relationship was not established between the development of postinfarction angina and late fatality. Postinfarction angina was demonstrated to increase a risk for an unfavorable course of a postinfarction period. No significant difference was found in the prognostic significance of the time angina occurred following MI.     

Unstable angina: Relationship of clinical presentation,coronary artery pathology,and clinical outcome

Patients with unstable angina are heterogeneous with respect to presentation, coronary artery morphology, and clinical outcome. Subclassification of these patients based on clinical history has been proposed as a means of identifying individuals at increased cardiac risk. We applied such a classification system to 129 patients discharged from a coronary care unit with a diagnosis of acute myocardial ischemia. Patients were then assessed for cardiac events (recurrent angina requiring revascularization, myocardial infarction, death) 12 months following hospital discharge. Patients were classified as recent onset unstable angina preinfarction (n = 42), crescendo unstable angina preinfarction (n = 48), and unstable angina postinfarction (n = 39). Within each of these groups, the patients were further subclassified based on the occurrence of angina on effort, at rest, or both. No attempt was made to subset patients taking antiischemic drugs at the time of clinical presentation to the physician. Coronary angiographic pathology (morphology and number of vessels involved) was similar in the subgroups, but coronary artery thrombus was statistically more likely to be found in patients with crescendo rest angina preinfarction or with frequent anginal episodes at rest postinfarction. Mortality was significantly higher for patients with unstable angina postinfarction (7.7%) than preinfarction (1.1%). No statistical differences were noted between the subgroups with respect to the occurrence of myocardial infarction or recurrent unstable angina requiring revascularization. These data suggest that subclassification of unstable angina patients based on clinical characteristics at presentation is not useful to predict subsequent myocardial infarction or recurrent angina requiring revascularization. However, as one might expect, patients with recurrent angina postinfarction have a higher mortality rate than patients with unstable angina preinfarction, and patients with recurrent rest angina, either pre- or postinfarction, are more likely to have intracoronary thrombus than patients with new onset angina or crescendo effort angina; however, the presence of thrombus did not predict a poor clinical outcome.     

Results of aortocoronary bypass operations. Follow-up in 343 patients.

Three hundred and forty-three patients who had aortocoronary bypass graft operations for disabling angina were followed up for from 6 months to 5 years (average 2 years). 80 per cent had multiple grafts and 20 per cent had additional endarterectomy. The overall mortality within one month of operation was 5 per cent, and in those who had vein graft procedures only was 4 per cent. 11 per cent had a postoperative myocardial infarction (6% perioperative) and there were 3 per cent late deaths. At 3 years 90 per cent are surviving. 80 per cent are asymptomatic without treatment. The mean angina grade was 0.3 at the latest follow-up, compared with 2.5 before operation; maximum exercise tolerance was also significantly improved (P less than 0.001). When angina recurred, it did so in 80 per cent of the cases within 12 months of operation and was usually attributable to inadequate revascularisation. Ventricular function as assessed by preoperative ventriculography was the factor most clearly related to survival rate and the early excellent results of coronary bypass operations seem to be maintained up to 5 years. It is, therefore, reasonable to continue to advise operation if only for relief of angina.     

Predictors of spontaneous predischarge ischemia following acute myocardial infarction.

To determine if the occurrence and the consequences of spontaneous predischarge postinfarction ischemia could be predicted early after hospital admission, a consecutive series of patients with acute myocardial infarction was studied and followed for 3 years. No patient was treated by thrombolysis. Spontaneous predischarge ischemia was defined as angina that occurred at rest before hospital discharge, at least 3 days after the acute event, and that was accompanied by electrocardiographic changes, but not by an increase in cardiac enzymes. Patients who died within the first 3 days were excluded from analysis. Among the 943 patients who survived at least 3 days, 165 (17.5%) had spontaneous ischemia before discharge. They had a higher 1-year post-hospital mortality (16 vs. 10%), but did not have significantly higher total 3-year mortality rates. Four independent, early available variables predictive of the occurrence of spontaneous ischemia were selected from a stepwise logistic discriminant analysis: history of angina before infarction, non-Q-wave infarct, absence of smoking, and higher age. Among the 165 patients with spontaneous ischemia, 3 independent variables predictive of 3-year mortality were selected stepwise: left ventricular function score, history of previous infarction, and absence of smoking.