Appearance of T-wave inversions without raised serum enzyme activity in suspected acute myocardial infarction: clinical outcome in relation to subendocardial infarction

In 67 patients with a clinical history of suspected acute myocardial infarction (MI) who developed T-wave inversions in standard ECG and had normal serum aspartate aminotransferase activity (possible MI) the clinical outcome was compared with that in patients fulfilling criteria for subendocardial infarction. Patients with possible MI had a lower mortality (p = 0.02) and also a lower reinfarction rate (p = 0.14) during the first 2 years as compared with those with subendocardial MI. Although patients with subendocardial MI had more problems with chest pain in the acute phase, angina pectoris occurred more frequently in patients with possible MI during a longer follow-up period. Congestive heart failure occurred more frequently in patients with subendocardial MI during initial hospitalization, whereas treatment for heart failure appeared similar in the two groups during a longer follow-up time. We conclude that the clinical course in patients with possible MI, here defined as chest pain and appearance of T-wave inversions without elevation of serum enzyme activity, seems to differ from that in patients with subendocardial MI, particularly regarding long-term survival and incidence of angina pectoris.     

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.     

Prognostic value of echocardiographic evaluation of septal function in acute anteroseptal myocardial infarction.

To determine the clinical usefulness of echocardiography in patients with anteroseptal myocardial infarction, echocardiograms were performed within 24 hours of admission on 40 patients with acute transmural anteroseptal myocardial infarction. Twenty-one patients had normal septal motion and septal systolic thickening, and 19 patients had abnormalities of one or both of these measurements. Of the 21 patients who had normal septal motion and thickening, only five developed congestive heart failure, none developed bundle branch block, and none died. Of the 19 patients with abnormal septal motion and/or thickening, 17 developed congestive heart failure (p less than .001), seven developed bundle branch block (p less than .001), and six died (p less than .001). Therefore, (1) electrocardiographic evidence of septal infarction does not correlate with abnormalities of the portion of septum seen on echocardiogram, and (2) patients with anteroseptal myocardial infarction and abnormalities of the septum on echocardiogram have more complications and a higher in-hospital mortality rate. These patients may have more extensive myocardial infarction predisposing to pump failure and possibly involving the conduction system.     

Relationship between electrocardiographically estimated infarct size and morbidity during a two-year follow-up

In 587 patients with a first myocardial infarction (MI) the electrocardiographically (ECG) estimated infarct size was related to morbidity during a two-year follow-up. Patients with transmural MI (Q- or R-wave changes in standard ECG) were more often treated for heart failure and returned to work less frequently than patients with subendocardial MI (ST-T-wave changes only). There were trends indicating a higher reinfarction rate in patients with subendocardial MI, whereas angina pectoris was observed as frequently in both groups. In a subset of patients with anterior MI, infarct size was estimated from the total Q- and R-wave amplitude in 24 precordial leads 4 days after arrival in hospital. A positive relationship was observed between ECG-estimated infarct size and treatment for heart failure, and patients with smaller infarctions according to ECG criteria returned to work less frequently. A higher reinfarction rate was observed in patients with smaller infarctions. In patients with inferior MI there were mostly weaker correlations between ECG-estimated infarct size (Q- and R-wave changes in leads II, III, and a VF) and morbidity during the two-year follow-up.     

Nontransmural myocardial infarction: A comparison of hospital and late clinical course of patients with that of matched patients with transmural anterior and transmural inferior myocardial infarction

The hospital and long-term course of 67 patients with nontransmural myocardial infarction was compared with that of 66 patients with transmural anterior and 63 patients with transmural inferior infarction matched for age, sex, previous infarction and prior congestive heart failure. During their hospital stay, patients with nontransmural infarction had significantly less congestive heart failure and fewer intraventricular conduction defects than did patients with transmural anterior infarction; fewer atrial tachyarrhythmias and less sinus bradycardia and atrioventricular block than did patients with transmural inferior infarction; and an incidence of hypotension, pericarditis and ventricular irritability similar to that of patients in the other two groups. Patients with nontransmural infarction had a significantly lower coronary care unit mortality rate (9 percent) than that of patients with transmural anterior or transmural inferior infarction (20 and 19 percent, respectively). By 3 months, the mortality rate had risen to 14 percent in patients with nontransmural infarction, but was significantly higher (29 and 27 percent, respectively) in patients with transmural anterior or transmural inferior infarction. Angina was common in all three groups, occurring in more than 50 percent of patients during a mean follow-up period of 28.6 months after hospital discharge.In contrast, the incidence of subsequent myocardial infarction was significantly greater in patients with nontransmural myocardial infarction, occurring in 21 percent at 9 months compared with only 3 percent of patients with transmural anterior (p <0.01) and 2 percent of patients with transmural inferior (p <0.05) infarction. By 54 months, 57 percent of patients with nontransmural infarction had sustained a new infarction contrasted with only 12 percent of patients with transmural anterior (/p <0.001) and 22 percent of patients with transmural inferior (p <0.01) infarction. Late mortality increased in patients with nontransmural myocardial infarction and, although this group had a significantly better survival rate at 3 months, the overall late mortality of the three groups was comparable. The study suggests that nontransmural myocardial infarction is an unstable ischemic event associated with a great risk of later myocardial infarction and high late mortality rate. A more aggressive diagnostic and therapeutic approach may be warranted in patients with nontransmural myocardial infarction.     

Comparison of the natural history of new onset and exacerbated chronic ischemic heart disease. The Chest Pain Study Group

To compare the natural history of patients with new onset ischemic heart disease with that of patients with exacerbations of chronic ischemic heart disease, short- and long-term outcomes of 3,465 emergency room patients with acute ischemic heart disease at four community and three university hospitals were evaluated. Acute myocardial infarction was diagnosed in 598 (33%) of the 1,835 patients with a prior history of infarction or angina and 934 (57%) of the 1,630 without such a history (p less than 0.001). Patients with new onset ischemic heart disease with acute myocardial infarction were more likely than patients with infarction and exacerbated chronic ischemic heart disease to have Q wave infarction (57% versus 36%) and to receive thrombolytic therapy (11% versus 5%); they also had higher maximal creatine kinase levels (1,088 +/- 1,299 versus 733 +/- 906 U/liter) (p less than 0.0001 for all three). After adjustment for differences in clinical presentation and initial triage, patients with new onset ischemic heart disease with acute myocardial infarction were less likely than the comparison group to have congestive complications (odds ratio 0.63, 95% confidence interval 0.47 to 0.84, p less than 0.01) but not less likely to have arrhythmic, ischemic or overall complications. Among patients with angina without acute myocardial infarction, patients with new onset ischemic heart disease were less likely to have recurrent ischemic pain and congestive heart failure. In multivariate analysis of long-term follow-up data on 457 patients from one hospital, patients with new onset ischemic heart disease had better cardiovascular survival rates.(ABSTRACT TRUNCATED AT 250 WORDS)     

Survival after hospital discharge in matched populations with inferior or anterior myocardial infarction

Prognostic differences between patients with anterior or inferior myocardial infarction are often related to such variables as previous infarction or the size of the myocardial infarct. We examined the determinants of mortality in 997 hospital survivors of acute Q wave infarction (anterior in 449, inferior in 548) who, although not preselected, were well matched with respect to age, sex and prior infarction or congestive heart failure. Additionally, there was no significant difference in peak serum creatine kinase (CK) between the groups with anterior and inferior infarction (1,459 +/- 1,004 versus 1,357 +/- 1,036). Among the patients with anterior infarction who died during the 1 year follow-up period, 56% died in the first 60 days after hospital discharge compared with 18% of those without inferior infarction (p less than 0.01). Survival curves then became nearly identical at 3 months, and remained so until 1 year when the total mortality rate was 10% for the anterior and 7% for the inferior infarction group (p = NS). Variables associated with heart failure during the hospital phase were more prevalent in anterior infarction, but rales above the scapulae during the hospital stay (p less than 0.0001) and ventricular gallop at the time of discharge (p less than 0.0001) were the top two predictors of 1 year mortality by both univariate and multivariate analysis in inferior infarction. Age (p less than 0.0001) and peripheral edema (p less than 0.0001) were the strongest predictors of mortality in anterior infarction. Previous infarction, although just as common in the group with anterior infarction, was present at 1 year in 48% of nonsurvivors of the group with inferior infarction compared with only 19% of survivors (p less than 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)     

Clinical aspects of ACE inhibition in patients with acute myocardial infarction

Summary The purpose of the present article was to review the current evidence on the use of angiotensin-converting enzyme (ACE) inhibitors in acute myocardial infarction (MI). This article is based on published information as well as on our personal experience derived from an extensive analysis of the SMILE study. All the randomized trials have been included irrespective of the primary endpoint, and the results are presented in terms of either hemodynamic or clinical benefit. Short- and long-term treatment with ACE inhibitors in patients with acute MI results in a significant reduction in mortality, which is more evident in high risk patients (i.e., patients with left ventricular dysfunction, congestive heart failure on admission, or anterior myocardial infarction). Development and progression of congestive heart failure after myocardial infarction was significantly reduced by ACE inhibition, which also reduced the rate of reinfarction, the need for revascularization procedures, as well as the occurrence of ventricular arrhythmias, probably through a mechanism involving some drug-dependent effects. In conclusion, the available data strongly support a wide benefit associated with the use of ACE inhibitors in patients with high-risk acute MI.     

Myocardial infarction in young adults: Risk factors and natural history

The risk factors and clinical course of 165 patients under 40 years of age (mean age 35) having an initial myocardial infarction (MI) (Group I) were compared to 100 patients over 40 (mean age 50) (Group II). Six risk factors were analyzed: smoking 20 pack-years, hyperlipidemia, hypertension, family history of ischemic disease, diabetes mellitus, and obesity. Only two patients in Group I and six patients in Group II had no risk factors, but the mean number of risk factors in Group I (3) differed from Group II (2) (p< 0.05). Group I had only 18% of patients without either obesity, hyperlipidemia, hypertension, or diabetes mellitus as risk factors while Group II had 41 patients with similar findings (p< 0.001). Group I had hyperlipidemia, obesity, and family history more commonly than did Group II while hypertension was more frequent in the older patients. A prior history of angina was present in nearly half of Group I and II but physical exertion just prior to MI was more common in Group I (32%) than in Group II (20%) (p < 0.05). Death at the time of MI was more frequent in Group II (p < 0.001) but congestive failure occurred in 17% of both groups. On follow-up, 45% of both groups had no complications, and the rates of subsequent MI and angina pectoris were similar in both groups. However, late death was less frequent in Group I than in Group II. Patients under 40 with myocardial infarction have more risk factors than those over 40 which may play some role in pathophysiology of young myocardial infarction. Physical exertion at the time of myocardial infarction is more common in younger patients. The complication rate is similar in both young and older myocardial infarction patients but the mortality rate, both early and late, is lower in young myocardial infarction patients.     

Prognostic significance of mitral regurgitation in acute myocardial infarction. The MILIS Study Group

To define the frequency, natural history and clinical correlates of the murmur of mitral regurgitation (MR) detected after myocardial infarction, clinical data from 849 patients with documented acute myocardial infarction were analyzed. A murmur suggestive of MR was present on admission in 76 patients (9%). Patients with MR on admission were older and more apt to be female and nonwhite. They also had a significantly greater frequency of prior infarction and signs and symptoms of congestive heart failure. There was no difference in the location (anterior or inferior) of infarction. Patients with MR on admission had a 36% mortality compared to 16% for those who developed MR later in the hospitalization and 15% for those without MR by auscultation (p less than 0.001). Correction for differences in baseline variables indicated that the presence of MR on admission did not contribute independently to mortality. Thus, the murmur of MR derives its prognostic significance from integration of multiple clinical, radiographic and electrocardiographic characteristics.     

Does angina the week before protect against first myocardial infarction in elderly patients?

Mortality rates for coronary artery disease are greater in elderly patients. Although prodromal angina occurring shortly before an acute myocardial infarction (MI) has protective effects against ischemia, this effect has not been well documented in older patients. This study investigated whether angina 1 week before a first MI provides protection in this group of patients. A total of 290 consecutive elderly (>64 years old, n = 143) and adult patients (<65 years old, n = 147) with a first MI were examined to assess the effect of preceding angina on the short- and long-term prognosis. Elderly patients with a history of prodromal angina were less likely than those without angina to experience in-hospital death, heart failure, or the combined end point of in-hospital death and heart failure (6% vs 20.4%, p = 0.02; 10% vs 23.7%, p = 0.07; 14% vs 32.3%, p = 0.01, respectively). Left ventricular function was more frequently depressed (ejection fraction <40%) in elderly patients without (44.8%) than with (26%, p = 0.04) preinfarction angina, and the incidence of arrhythmias (complete heart block and ventricular fibrillation) was greater in the former group (16.1% vs 4%, p = 0.03). Multivariate analysis confirmed that the presence of preinfarction angina was an independent predictor of in-hospital death and heart failure in older patients (odds ratio 0.28, p = 0.009). The occurrence of angina 1 week before a first MI may confer protection against in-hospital adverse outcomes, and may preserve left ventricular function in older patients.     

Correlation of heart size with clinical and hemodynamic findings in patients with coronary artery disease.

The clinical, hemodynamic, and angiographic findings were correlated with the heart size in 207 patients with proved coronary artery disease. Cardiomegaly was noted in 34 patients and normal heart size in 173. In these two groups, the patients' age range, duration of disease, and history of myocardial infarction were similar. There was no statistical difference in incidence of shortness of breath, hypertension, left ventricular hypertrophy, or abnormal glucose tolerance. Patients with cardiomegaly had a significantly higher incidence of congestive heart failure (26 per cent) as compared to patients with normal heart size (2.9 per cent) (P less than 0.001). Patients with enlarged heart presented a high incidence of anterior wall or multiple myocardial infarction (73 per cent) (P less than 0.001). The cardiomegaly group had a high incidence of elevated end-diastolic volumes, elevated end-diastolic pressures, and diminished ejection fractions when compared to patients with normal heart size (P less than 0.01). Double and triple coronary artery disease was more frequent in patients with cardiomegaly and total coronary score was also higher in this group (P less than 0.005). Asynergy was present in 55 per cent of patients with normal heart size but in 82 per cent of those with enlarged hearts (P less than 0.01). The group of patients with cardiomegaly and documented congestive heart failure had ejection fractions less than 0.30. Cardiac catheterization is probably not advisable in these patients in the absence of associated significant mitral regurgitation, ventricular septal defect, or ventricular aneurysm.     

Prognostic value of dipyridamole thallium-201 imaging in elderly patients.

The prognostic value of intravenous dipyridamole myocardial perfusion imaging has not been studied in a large series of elderly patients. Patients greater than or equal to 70 years of age with known or suspected coronary artery disease were evaluated to determine the predictive value of intravenous dipyridamole thallium-201 imaging for subsequent cardiac death or nonfatal myocardial infarction. Of the 348 patients, 207 were symptomatic and 141 were asymptomatic; 52% of the asymptomatic group had documented coronary artery disease. During 23 +/- 15 months of follow-up, there were 52 cardiac deaths, 24 nonfatal myocardial infarctions and 42 revascularization procedures (percutaneous transluminal coronary angioplasty in 20; coronary artery bypass surgery in 22). Clinical univariate predictors of a cardiac event included previous myocardial infarction, congestive heart failure symptoms, hypercholesterolemia and diabetes (all p less than 0.05). The presence of a fixed, reversible or combined thallium-201 defect was significantly associated with the occurrence of cardiac death or myocardial infarction during follow-up (p less than 0.05). Cardiac death or nonfatal myocardial infarction occurred in only 7 (5%) of 150 patients with a normal dipyridamole thallium-201 study (p less than 0.001). Stepwise logistic regression analysis of clinical and radionuclide variables revealed that an abnormal (reversible or fixed) dipyridamole thallium-201 study was the single best predictor of cardiac events (relative risk 7.2, p less than 0.001). As has been demonstrated in younger patients, previous myocardial infarction (relative risk 1.8, p less than 0.001) and symptoms of congestive heart failure at presentation (relative risk 1.6, p = 0.02) were also significant independent clinical predictors of cardiac death or myocardial infarction.(ABSTRACT TRUNCATED AT 250 WORDS)     

Abnormal Q waves on the admission electrocardiogram of patients with first acute myocardial infarction: Prognostic implications

Background: Q waves developed in the subacute and persisting into the chronic phase of myocardial infarction (MI) usually signify myocardial necrosis. However, the mechanism and significance of Q waves that appear very early in the course of acute MI (<6 h from onset of symptoms), especially if accompanied by ST elevation, are probably different. Hypothesis: This study assesses the prognostic implications of abnormal Q waves on admission in 2,370 patients with first acute MI treated with thrombolytic therapy <6 h of onset of symptoms. Results: Patients with abnormal Q waves in ≥2 leads with ST-segment elevation (n = 923) were older than patients without early Q waves (n = 1,447) (60.6 ±11.9 vs. 58.8 ±11.9 years, respectively; p = 0.0003), and had a greater incidence of hypertension (34.3 vs. 30.5% p = 0.05) and anterior MI (60.6 vs. 41.1 % p<0.0001). Time from onset of symptoms to therapy was longer in patients with Q waves upon admission (208 ± 196 vs. 183 ± 230 min; p = 0.01). Peak serum creatine kinase (2235 ± 1544 vs. 1622 ± 1536 IU; p<0.0001), prevalence of heart failure during hospitalization (13.8 vs. 7.0%, p<0.0002), hospital mortality (8.0 vs. 4.6% p = 0.02), and cardiac mortality (6.6 vs. 4.5%, p = 0.11) were higher in patients with anterior MI and with abnormal Q waves than in those without abnormal Q waves upon admission. There was no difference in peak creatine kinase, prevalence of heart failure, in-hospital mortality, and cardiac mortality between patients with and without abnormal Q waves in inferior MI. Multivariate regression analysis confirmed that mortality is independently associated with presence of Q waves on admission (odds ratio 1.61; 95% CI 1.04–2.49; p = 0.04 for all patients; odds ratio 1.65; 95% CI 0.97–2.83; p=0.09 for anterior wall MI. Conclusion: Abnormal Q waves on the admission electrocardiogram (ECG) are associated with higher peak creatine kinase, higher prevalence of heart failure, and increased mortality in patients with anterior MI. Abnormal Q waves on the admission ECG of patients with inferior MI are not associated with adverse prognosis.     

Is preinfarction angina associated with better outcome after myocardial infarction?

BACKGROUND. In a clinical setting of acute myocardial infarction (MI), short-lasting and transient anginal pain, preceding the development of acute MI, is regarded as a symptom representing ischaemic preconditioning. Some experimental and clinical data suggested that preinfarction angina may favourably influence the course of acute MI. AIM. We sought to examine the hypothesis that preinfarction angina occurring within 24 hours prior to the onset of acute MI favourably influences the outcome. METHODS. The study group consisted of 331 patients who were admitted to our hospital due to acute MI with ST segment elevation with a symptom duration <12 hours and received thrombolysis. Preinfarction angina within 24 hours prior to MI was present in 80 patients whereas the remaining 251 patients had no chest pain preceding acute MI. The course of the in-hospital phase of MI (mean 15 days) was analysed. RESULTS. In patients with preinfarction angina the in-hospital complication rate was significantly lower than in patients without angina preceding acute MI (p<0.001). Patients without preinfarction angina more frequently developed heart failure (p<0.001) or died (p<0.01) in hospital. Patients with preinfarction angina had significantly less extensive MI and had reperfusion symptoms more frequently. Multivariate analysis showed that there were three factors which independently favourably influenced survival: preinfarction angina (p=0.01), age < or =65 years (p=0.04) and duration of chest pain during acute MI < or =3h (p=0.03). Of the analysed group, 73 patients died in hospital. The independent variables predicting death included prior MI (p=0.04), history of diabetes (p=0.02), acute left bundle branch block (p=0.01) and age >65 years (p=0.03). Non-fatal re-infarction complicated the in-hospital course of MI in 27 patients. The independent variables which predicted this complication included age >65 years (p=0.03) and hypercholesterolemia (p=0.04). CONCLUSIONS. Patients with preinfarction angina, occurring within 24 hours of acute MI, have better in-hospital outcome and less extensive myocardial injury than patients without antecedent angina. These results may be attributed to the protective effects of ischaemic preconditioning.     

Comparison of left ventricular function and infarct size in patients with and without persistently positive technetium-99m pyrophosphate myocardial scintigrams after myocardial infarction: analysis of 357 patients

One hundred nine patients with persistently positive technetium-99m pyrophosphate (Tc-99m-PPi) myocardial scintigrams 6 months after acute myocardial infarction (MI) (Group A) and 185 patients without such persistently positive scintigrams (Group B) were compared with regard to enzymatically determined infarct size, early and late measurements of left ventricular (LV) function determined by radionuclide ventriculography, and preceding clinical course during the 6 months after MI. The CK-MB-determined infarct size index in Group A (17.4 +/- 10.6 g-Eq/m2) did not differ significantly from that in Group B (16.0 +/- 14.6 g-Eq/m2). Similarly, myocardial infarct areas in the 2 groups, determined by planimetry of acute Tc-99m-PPi scintigrams in those patients with well-localized 3+ or 4+ anterior pyrophosphate uptake, were not significantly different (35.7 +/- 13.4 vs 34.4 +/- 13.1 cm2, respectively). However, patients in Group A had significantly lower LV ejection fractions than those in Group B, both within 18 hours of the onset of MI (0.42 +/- 0.14 vs 0.49 +/- 0.14, p less than 0.01) and at 3 months after MI, both at rest (0.42 +/- 0.14 vs 0.51 +/- 0.14, p less than 0.01) and at maximal symptom-limited supine bicycle exercise (0.44 +/- 0.17 vs 0.51 +/- 0.17, p less than 0.01). Peak exercise levels achieved in the 2 groups were not significantly different. Furthermore, patients in Group A demonstrated a greater incidence of congestive heart failure during the initial hospital admission (41 vs 24%; p less than 0.01) and a greater requirement for digoxin (p less than 0.05) and furosemide (p less than 0.01) after discharge.(ABSTRACT TRUNCATED AT 250 WORDS)     

The influence of angina the week before a first myocardial infarction on short and medium-term prognosis

INTRODUCTION AND OBJECTIVES: The implications of early angina on the prognosis of myocardial infarction are controversial. The aim of this study was to assess the effect of angina one week before the first myocardial infarction on short and medium-term prognosis. PATIENTS AND METHOD: A total of 290 consecutive patients (107 with previous angina and 183 without it) with the first myocardial infarction were studied to determine the effect of preceding angina on short and medium-term prognosis. Further criteria for inclusion were no previous history of angina > 1 week before the first myocardial infarction, and no evidence of prior structural cardiopathy. The end points studied were death and congestive heart failure in the acute phase of myocardial infarction and during the follow-up. RESULTS: Patients with a history of prodromal angina were less likely to experience in-hospital death, heart failure or combined end-point (3.7 vs 11.5%; 4.6 vs 15.8%; 7.5 vs 21.3%) (p = 0.002). There was also a difference between groups in the follow-up (4.1 vs 13.2%; p = 0.03). Multivariate analysis confirmed that the presence of preinfarction angina was an independent predictor of death and heart failure in the acute phase of myocardial infarction as well as in the follow-up. CONCLUSIONS: The occurrence of angina one week before the first myocardial infarction protects against death and heart failure in the acute phase of myocardial infarction as well as in the medium follow-up.     

Clinical predictors of angina following myocardial infarction.

To determine if angina following myocardial infarction could be predicted before hospital discharge we prospectively evaluated 219 consecutive patients admitted to the coronary care unit with acute myocardial infarction. Of the 166 who survived to one year, angina was present before infarction in 53 per cent and after infarction in 61 per cent. Angina did not recur postinfarction in 26 per cent of the patients who had angina before infarction. However, in 47 per cent of those without previous angina it developed postinfarction. Although postinfarction angina correlated with the presence of angina before infarction (p < 0.0005), it did not correlate significantly with age, sex, site of infarction, Killip class on admission nor the presence of a previous infarction.To improve our ability to predict angina after infarction we performed exercise tests to 5 metabolic equivalents (METS), or 70 per cent of age-predicted maximal heart rate, before hospital discharge on all patients less than 70 years old who were without chest pain within four days or without overt heart failure. Of the 105 patients exercised, 31 (86 per cent) of the 36 with positive tests had angina during the subsequent year compared to only 25 (36 per cent) of the 69 with negative tests (p < 0.001). Postinfarction angina occurred in 96 per cent (23 of 24) of the patients who had both angina before infarction and a positive test, but in only 26 per cent (10 of 39) of the patients with neither finding (p < 0.001).We conclude that the presence of angina prior to infarction and a positive limited exercise test performed before hospital discharge are predictive of angina following infarction. Myocardial infarction abolishes angina in a quarter of the patients, but angina develops postinfarction in nearly half of the patients who did not have angina previously.     

Prognostic value of a persistently positive technetium-99m stannous pyrophosphate myocardial scintigram after myocardial infarction.

Technetium-99m stannous pyrophosphate myocardial scintigrams were obtained in 138 clinically stable patients 32.7 +/- 47.3 weeks (range 6 to 260) after acute myocardial infarction. Of the 138 patients, 74 (54 percent) had a persistently positive scintigram. Patients with such a scintigram were more likely to have severe angina pectoris, compensated congestive heart failure, anterior location of acute myocardial infarction, Q waves and S-T segment elevation in the electrocardiograms, cardiomegaly, left ventricular dyssynergy (dyskinesia or global dyssynergy), and an ejection fraction of less than 50 percent. During a follow-up period of 11.6 +/- 6.9 months after scintigraphy, 42 percent of the patients with a persistently positive scintigram had either a cardiac death, a nonfatal myocardial infarction, unstable angina pectoris or decompensated congestive heart failure compared with 13 percent of the patients with a negative scintigram (P less than 0.001). Of the 14 patients with cardiac death, 13 (93 percent) had a persistently positive scintigram. A persistently positive scintigram not only was the best single predictor of cardiac death and combined end points, but also added significantly to the predictive ability of the other clinical variables, including age, location of acute myocardial infarct, clinical status, electrocardiographic findings, and chest X-ray findings. It is concluded that technetium-99m stannous pyrophosphate myocardial scintigraphy has prognostic value in patients after acute myocardial infarction.     

Myocardial infarction in young patients: an analysis by age subsets

We examined, in age subsets, 2643 patients with acute myocardial infarction. Clinical features and 1 year morbidity and mortality were compared in 203 young patients (less than 45 years), 1671 patients 46 to 70 years old, and 769 elderly patients (greater than 70 years). Ninety-two percent of young patients were men, and a family history of premature coronary artery disease was more common in young patients (41% compared with 28% of middle-aged and 12% of elderly patients). More young patients were currently smoking cigarettes (82% compared with 56% of middle-aged and 24% of elderly patients), and only 8% of young patients had never smoked. Previous myocardial infarction and history of angina pectoris or congestive heart failure were less common (p less than .001) in the young patients than in middle-aged and elderly patients. In-hospital mortality was only 2.5% for young patients, compared with 9.0% in middle-aged and 21.4% in elderly patients (both p less than .001). Postdischarge 1 year mortality was also strikingly low in young patients, at 2.6% compared with 10.3% in middle-aged and 24.4% in elderly patients. The incidence of reinfarction during the 1 year of follow-up was similar in all subsets. The statistical significance of 65 variables as predictors of 1 year mortality and reinfarction was tested and the following found to be significant (p less than .05): hospital discharge on antiarrhythmic drugs, digoxin, or diuretics; history of previous myocardial infarction or congestive heart failure; chest x-ray findings of heart failure; low ejection fraction; and atrial fibrillation. Thus, young patients entering the hospital have an excellent 1 year prognosis, but those with prior infarction in whom there are selected abnormal findings at hospital discharge comprise a subgroup that may benefit from early aggressive management.