[Diagnosis of restenosis]

Transluminal coronary angioplasty (TCA) has become a well established technique of coronary revascularisation. The medium-term results are however limited by the risk of restenosis. This restenosis occurs in the 6 months following angioplasty, above all between the 1st and 3rd month. The restenosis rate after balloon angioplasty is about 40% and about 20% after implantation of a stent, at least in short lesions. Some factors related to the underlying disease (diabetes), the clinical status and the date of TCA (unstable angina) or the type of lesion (chronic occlusion, stenosis of venous grafts) are associated with a high risk of restenosis. The occurrence of angina in the 6 months after TCA may be due to restenosis but also to incomplete revascularisation or the progression of non-significant lesions. This explains the low predictive value of angina for the diagnosis of restenosis. In asymptomatic patients, the diagnosis depends on non-invasive tests. The positive and negative predictive values of exercise stress testing are low (about 50% and 75%, respectively). Nevertheless, stress testing remains useful for assessing the functional capacity of patients, to confirm the absence of symptoms and to document silent ischaemia. The sensitivity of stress Thallium scintigraphy, associated or not with dipyridamole, is higher. Stress echocardiography, currently under evaluation, would seem to be as useful as Thallium scintigraphy for the diagnosis of restenosis.