Is there an indication for coronary angiography in patients under 60 years of age with no or minimal angina pectoris after a first myocardial infarction?

Association between fibrinogen level and the severity of coronary stenosis in 418 male patients with myocardial infarction younger than 35 years old

Fibrinogen (Fib) is a useful marker for predicting the severity of coronary artery disease (CAD) in adult population. However, whether Fib can be a predictor for the presence and severity of CAD in very young MI patients (≤35 years old) remains to be determined. A total of 418 males from 61,863 patients with MI who were under 35 years old were sequentially recruited in our study. The patients were divided into two main groups and three subgroups according to coronary angiograph and Gensini score (GS) system: no coronary artery stenosis (group A), the results of the coronary artery stenosis (group B); low GS, intermediate GS and high GS. Data indicated that Fib, body mass index, current smoking, white blood cell count (WBCC) and GS were significantly higher in group B than those in group A (all P < 0.01). Moreover, there were significant differences in Fib, mean age, diabetes mellitus, family history of CAD, WBCC, left ventricular ejection fraction, and GS between high GS and low GS subgroups (all P < 0.01). A positive correlation between Fib levels and GS was found (r = 0.242, p < 0.001). Receiver operating characteristics curve analysis demonstrated that the best cut-off level of Fib predicting the severity of coronary stenosis was 3.475g/L (sensitivity 64%; specificity 70%) and the area under the curve was 0.656. Fib was also independently associated with high GS (OR=2.173, 95%CI 1.011–4.670, P = 0.047) after adjusting for potential confounders. In conclusion, Fib is significantly related to the presence and severity of coronary stenosis in male patients with MI under 35 years old.

Myocardial infarction in young adults: angiographic characterization, risk factors and prognosis (Coronary Artery Surgery Study Registry)

OBJECTIVES

This study examined the angiographic characteristics, coronary risk factors and prognosis in young men and women with a history of myocardial infarction compared with that in older patients.

BACKGROUND

There are few data regarding myocardial infarction in young adults. It is undetermined whether the development of myocardial infarction at a young age represents a form of coronary heart disease with an adverse prognosis.

METHODS

Of the 8,839 patients with a history of myocardial infarction in the Coronary Artery Surgery Study (CASS), there were 294 men < or = 35 years old and 210 women < or = 45 years old. Coronary anatomy, baseline characteristics and prognosis were compared in younger and older patients.

RESULTS

Young men and women more often had angiographically normal coronary arteries, nonobstructive disease < 70% stenosis and single-vessel disease than older patients (p < 0.0001). Current smoking was more frequent in young patients (p < 0.0001). Hypertension and diabetes were more frequent in both older men and women, whereas a positive family history of premature coronary disease was significantly more prevalent only in young men. The survival rate at 7 years was improved for young men compared with that in older men (84% vs. 75%, p = 0.0094) and for young women compared with that in older women (90% vs. 77%, p = 0.0004). When multivariate analysis was applied to the data, the survival advantage for young patients remained after adjustment.

CONCLUSIONS

Young patients with a myocardial infarction have a favorable prognosis compared with that in older patients.

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.

Risk stratification in survivors of acute myocardial infarction: routine cardiac catheterization and angiography is a reasonable approach in most patients

Noninvasive risk assessment in survivors of AMI can effectively subdivide patients into groups with differing risk profiles after hospital discharge, but some patients at risk for late death or recurrent AMI may be incorrectly identified; data from cardiac catheterization and angiography provide complementary and generally more powerful prognostic information. Many patients may derive particular benefit from early cardiac catheterization and angiography, including: (1) patients with AMI complicated by recurrent myocardial ischemia, congestive heart failure, and/or complex ventricular arrhythmias; (2) patients with abnormal or inconclusive results of noninvasive testing or those patients unable to perform an exercise test; (3) patients with abnormal left ventricular global systolic function and those with increased left ventricular end-systolic volume; (4) "young" patients (younger than 50 years of age?); (5) older patients (older than 65 to 70 years of age?); (6) patients with non-Q wave AMI; and (7) patients who are receiving thrombolytic therapy. Performance of early cardiac catheterization and angiography in virtually all survivors of AMI, with selective use of appropriate noninvasive tests, may provide a more efficacious means of risk assessment after AMI; if all tests are performed judiciously, the cost of such an approach need not be excessive. A combination of invasive and selected noninvasive tests probably provides optimal information. The risks to the routine performance of diagnostic cardiac catheterization and angiography in all survivors of AMI are: (1) adequate care and attention may not be paid to proper performance of the procedure(s) and to detailed and proper analyses of the data; (2) the need for additional noninvasive testing in selected patients may be ignored; and most importantly, (3) premature or unnecessary revascularization procedures may be performed subsequently. For optimal patient care, the clinician must obtain all necessary data, avoid unnecessary and repetitive tests, know the accuracy of individual tests at his or her own facility, interpret all data in proper context, and then counsel patients objectively about available management strategies. With this approach, all patients who might appropriately benefit from coronary artery revascularization will be correctly identified, and patients who are truly at very low risk (minimal residual coronary artery disease and preserved left ventricular function particularly if associated with a patent infarct-related artery) may be similarly identified and managed appropriately with elimination of unnecessary additional testing and pharmacologic therapy. Finally, whatever approach to risk stratification one chooses for an individual patient, the importance of and the need to correct and/or ameliorate risk factors for coronary artery disease must be recognized and undertaken.

A decision scheme for coronary angiography after acute myocardial infarction

It is important to select patients in the convalescent phase of acute myocardial infarction in whom knowledge of coronary anatomy may identify those potentially suitable for intervention aimed at improving prognosis. However, differing guidelines have been proposed, and by applying some of these guidelines to our large database of patients after acute myocardial infarction, several problem areas were identified. These include lack of considering patients with resting ischemia beyond day 5 of hospitalization, management of patients with reduced ventricular function or patients not exercise tested, and the role of coronary angiography in the elderly. Based on this experience and further analysis in 1,848 patients surviving beyond day 5 of hospitalization, a modified decision scheme for coronary angiography was developed and then tested in a second population (n = 780). In the new scheme, patients over 75 years of age are considered individually. Those under 75 years of age with severe resting ischemia in the hospital at any time beyond the first 24 hours (18% mortality between day 6 and year 1), and hospital survivors with a history of previous myocardial infarction and clinical or radiographic signs of left ventricular failure in the hospital (25% 1-year mortality after discharge), are recommended for coronary angiography. Among the remaining patients, some will perform an exercise test, and those with an ischemic response or poor workload (11% 1-year mortality) are also assigned to coronary angiography. When an exercise test is not performed, a resting radionuclide left ventricular ejection fraction is recommended, and coronary angiography is considered if the value lies between 0.20 and 0.44 (12% 1-year mortality). This relatively simple scheme does not make general recommendations in the elderly, considers patients with in-hospital left ventricular failure or reduced left ventricular function or both, and approaches the problem of patients who do not perform an exercise test. This general approach would avoid early coronary angiography in patients with an average 1-year mortality risk after discharge of 3% and recommend coronary angiography in those at increased risk (average mortality rate, 16%) who make up about 55% of this population under 75 years of age.

Does beta adrenergic blockade influence the prognostic implications of post-myocardial infarction exercise testing?

The influence of beta blockade on the ability of ST depression, during pre-discharge exercise testing, to predict coronary anatomy and subsequent complications was studied in 300 consecutive post-infarct patients, 125 of whom underwent cardiac catheterisation. At the time of exercise 62 patients were taking a beta blocker. The exercise test had a higher sensitivity in predicting multivessel disease in patients who were not taking beta blockers than in patients who were (95% v 76%). beta Blockade did not, however, influence the ability of the test to identify patients at risk of subsequent cardiac events (sensitivity 84% and 85% respectively). These results suggest that it is not necessary to stop treatment with beta blockers before predischarge exercise testing of patients who have had an acute myocardial infarction.

Plasminogen activator inhibitor in plasma: risk factor for recurrent myocardial infarction

Measurements of haemostatic function and metabolic and angiographic indices of risk were included in a prospective cohort study of variables predictive of recurrences within 3 years in 109 unselected men with a first myocardial infarction (MI) before the age of 45. In the course of follow-up, 16 patients had at least one reinfarction (fatal recurrences in 9 and nonfatal in 7) and 1 died suddenly. High plasma concentrations of the fast-acting plasminogen activator inhibitor were independently related to reinfarction along with dyslipoproteinaemia involving VLDL and HDL, poor left ventricular performance, and multiple-vessel coronary artery disease. Besides being independently associated with reinfarction in the present population, high triglyceride levels were possibly connected with a predisposition to thrombosis through a coexisting high level of plasminogen activator inhibitor. The data indicate that reduced fibrinolytic capacity due to increased plasma levels of the plasminogen activator inhibitor predisposes to reinfarction in a complex interplay with atherogenic factors, multiple coronary lesions, and compromised left ventricular function.

Accurate detection of triple vessel disease in patients with exercise induced ST segment depression after infarction

The severity of coronary artery disease is an important determinant of prognosis after acute myocardial infarction. The ability of a symptom limited exercise test to predict the presence of triple vessel disease was assessed in 221 patients three weeks after infarction. Coronary angiography was performed in patients with exercise induced ST segment depression. The presence of ST segment depression alone was poorly indicative of triple vessel disease; however, some specific features of ST segment changes on exercise were of predictive value. Downsloping ST segment configuration alone or horizontal ST segment depression associated with an early onset and a late recovery time after exercise correctly identified 30 (90%) of 33 patients with triple vessel disease whereas it incorrectly identified only 6 (15%) of 39 patients with single and double vessel disease. An abnormal blood pressure response was also predictive. In patients with ST segment depression after infarction triple vessel disease can be detected accurately by a combination of the electrocardiographic and haemodynamic variables attained on exercise.

Post-infarction exercise testing in patients under 55 years. Relation between ischaemic abnormalities and the extent of coronary artery disease

Previous studies have suggested that the early post-infarction exercise test is useful in predicting the extent of coronary artery disease. The results of a heart rate limited exercise test three weeks after infarction and a symptom limited exercise test six weeks after infarction obtained by both standard lead electrocardiograms and 16 lead precordial maps were compared in 100 consecutive survivors of acute myocardial infarction under 55 years of age. Exercise tests were defined as being positive on the basis of angina, ST segment depression greater than or equal to 1 mm in any electrocardiogram lead, or exertional hypotension. Multivessel disease, that is two or three vessel disease, was present in 60 patients, and three vessel disease in 22 patients. The sensitivity, specificity, and predictive value for multivessel disease of the three week test were 38%, 83%, and 76% respectively; and results for the six week test were 55%, 75%, and 77% respectively. Only 32% of patients with three vessel disease were identified at the three week test, and 59% at the six week test. Significantly more patients with multivessel and three vessel disease were identified by the symptom limited six week test. Precordial mapping offered no advantages over the standard 12 lead electrocardiogram in either the identification of patients with multivessel disease or the prediction of the distribution of coronary artery disease. Angina pectoris during the exercise test at six weeks was the single most useful predictor of multivessel disease. Multivessel disease was found in 27 (87%) of the 31 patients with angina with or without ST depression during the test at six weeks compared with 33 (48%) of the 69 patients who did not have angina during the test at six weeks. Exercise testing in the early post-infarction period in patients under 55 years of age is of limited value in predicting the extent of coronary artery disease. It is, therefore, unreasonable to use such exercise tests to select patients for coronary arteriography after myocardial infarction. None the less angina pectoris occurring during a symptom limited exercise test six weeks after infarction is a strong predictor of multivessel disease, and coronary arteriography is recommended in these patients.