[Coronary angiography in stable angina: friends and foes]

Preventive intervention presupposes a threat that can be averted at an acceptable cost; in patients with stable coronary artery disease, the threat of subsequent myocardial infarction and death is generally low, and proper management can usually control symptoms and improve prognosis substantially. In general, patients who have indications for coronary angiography are also potential candidates for revascularization. The relation of typical angina to prognosis is mediated by its relation to the extent of coronary disease; since the risk of coronary occlusion is not proportional to stenosis severity, it is not surprising that treating one or more stable tight lesions does not reduce the rates of subsequent major cardiac events. Clinical evaluation, ventricular function, response to stress testing, and the extent of coronary artery disease are the key pieces of information to stratify patient risk. In subjects without a markedly positive stress test, the ischemic burden is helpful in decision-making with respect to selecting initial therapy, and contributes to risk assessment. An initial invasive strategy without prior functional testing is rarely indicated, and may only be considered for patients with severe valve disease, serious arrhythmias or when therapy has failed to control symptoms satisfactorily, with a view to revascularization. In the absence of uncontrolled symptoms, patients are potentially eligible for coronary angiography if noninvasive tests reveal a substantial area of myocardium at risk. Coronary angiography should also be undertaken in patients with moderate to severe ischemia who do not have a significant reduction of the ischemic burden with therapy, given their worse prognosis. Because the treatment of asymptomatic patients cannot improve their symptoms, recommendations for coronary angiography in this subset are weaker and limited to risk stratification in subjects with high-risk criteria. Invasive procedures require a high likelihood of success and acceptable risk of morbidity and mortality and patients should be fully informed of the risks of the therapeutic modality individually. Regardless of the treatment modality used (early invasive vs selectively invasive), noninvasive imaging of the ischemic burden may assist in both decision-making for initial therapy and determining therapeutic efficacy related to long-term outcome.