ABSTRACT
Treatment of patients with stable angina should be directed not only at controlling symptoms or identifying and treating coronary stenosis, but a complete evaluation of the patient is also mandatory, and should always include a correct diagnosis, investigation of possible associated conditions, gradation of the severity of ischemia, characterization of the risk profile and identification of possible contraindications for medical or invasive treatment (Table 1).1-3
Table 1 Evaluation of patients with stable angina
Correct diagnosis of angina Identify ischemia
Exclude other causes of angina
Characterization of risk profile Severity of ischemia
Ventricular function
Other (age, diabetes)
Identification of aggravating/precipitating causes Hypertension
Arrhythmias (atrial fibrillation, tachycardia)
Anemia
Identify possible contraindications for medical/revascularization treatment Bradycardia
Hypotension
Renal failure
Diagnosis of angina is based on the clinical symptoms, but other causes of chest pain must be ruled out and some evidence of ischemia must be demonstrated, especially in patients without typical symptoms and in the absence of a previous history of ischemic heart disease. A resting 12-lead electrocardiogram (ECG) may be normal in a significant proportion of cases, but may also reveal dynamic ST-segment changes in the presence of ischemia, particularly if there is an opportunity to obtain tracings with and without the presence of pain.6 An exercise stress test, with or without imaging techniques, is certainly more sensitive and specific for the diagnosis of ischemia, and is recommended in the initial evaluation of all patients with suspected stable angina.7,8 Coronary
angiography for diagnostic purposes should be reserved for high-risk patients and those without appropriate control of angina symptoms.1,3 Other causes of angina, such as aortic stenosis and hypertrophic cardiomyopathy, must be routinely excluded, as well as conditions that may precipitate or aggravate ischemia, including anemia, hypertension and arrhythmias, especially atrial fibrillation and tachycardia.1,3
The prognosis of patients with stable angina is variable, and risk stratification facilitates the selection of treatment options, in particular the need for coronary artery angiography and revascularization.1,3 The strongest predictor for outcome is ventricular function (left ventricular ejection fraction).9 However, other important information for appropriate risk stratification is derived from the clinical profile of the patient, including age, female gender, previous history of any cardiovascular disease, co-morbidity conditions, the severity of angina,10 the presence and severity of classical cardiovascular risk factors (smoking, diabetes, hypertension and hyperlipidemia)11,12 and ECG abnormalities (previous myocardial infarction, ST-segment depression) in the resting ECG.13 Response to stress testing has been given special attention, and some risk scores that consider the presence and severity of stress-induced ischemia have been developed, the most popular being that proposed by Duke University.14 Finally, the extent and severity of coronary artery disease are important independent indicators of long-term outcome; left main stem, three-vessel disease, and proximal, left-anterior, descending severe stenosis and its combinations have consistently been identified as the most important coronary lesions associated with the worst outcome.15 Although there is no well-defined and validated risk score, patients with stable angina can be categorized into three broad groups, with a low, intermediate or high risk of suffering cardiovascular events during long-term evolution.
