Invasive coronary revascularisation is better than conservative treatment in patients with acute coronary syndromes.

New advances in interventional cardiology and antithrombotic pharmacological treatment have modified the risk:benefit ratio of percutaneous interventions in acute coronary syndromes without ST segment elevation. In general terms, invasive strategies have two main limitations. The first stems from the fact that the severity of a coronary stenosis is not an index of the likelihood of the development of clinical instability or future cardiovascular events. It is now well known that the main pathophysiological mechanism of acute coronary syndromes is destabilisation of the atherosclerotic plaque, which leads to fissuring and the consequent exposure of the subendothelium matrix. The critical factors determining the clinical manifestations and prognosis of these syndromes are the duration and degree of the reduction in coronary flow caused by thrombosis (and its variable associations with superimposed vasoconstriction), the coexistence of collateral flows, and the microvascular embolisation of platelet aggregates and atherothrombotic material. Given the lack of suitable instruments for evaluating the degree of plaque vulnerability and predicting its prothrombotic response, angiographic data alone are insuYcient. The second and more practical limitation concerns the complications of percutaneous revascularisation: in addition to severe complications such as dissection, vascular damage and consequent platelet activation, percutaneous interventions contribute towards the onset of adverse events caused by the occlusion of collateral vessels and the embolisation of atherothrombotic material with varying degrees of microvascular deterioration. Recent studies have found a correlation between the incidence of myocardial necrosis (as indicated by post-intervention enzyme release) and that of long term mortality.