An observational, retrospective, multicenter, blinded adjudication study to evaluate the clinical appropriateness of Percutaneous Coronary Intervention (PCI) indication and execution in patients with stable Coronary Artery Disease (CAD) and in patients with acute coronary syndrome without ST-segment elevation (NSTE-ACS) (ratio 4:1). Half of the included patients will be diabetic. Also the implementation of selected, key guideline recommendations will be examined.

At least 400 patients will be retrospectively selected among 22 Catheterization Laboratories in Italy in the region of Lombardia and Veneto.

This study will be conducted in compliance with Good Clinical Practices (GCP) including the Declaration of Helsinki and all applicable regulatory requirements.

A strategy based on early invasive coronary angiography followed by revascularization is the most effective treatment of patients with acute coronary syndrome, especially in those with ST-segment elevation (STE-ACS). In patients with acute coronary syndrome without ST-segment elevation (NSTE-ACS), an early invasive strategy is associated with a reduction in cardiac death and myocardial infarction in patients at higher risk. In stable coronary artery disease rather no data so convincing. The undeniable evolution of techniques of PCI has been accompanied by a parallel progress of medical therapy and also from increased awareness, both cardiologists and patients, the importance of the control of coronary risk factors.

European Society of Cardiology Guide give precise indications (but often ignored) on the use of PCI or coronary artery bypass grafting according to the extent of coronary artery disease and the site of injury . However, especially in patients with NSTE-ACS often we limit ourselves to dilate the culprit stenosis, leaving untreated other injuries that underlie large myocardial territory, that is, by configuring an incomplete revascularization framework. The calculation of the SYNTAX score residual (that is, what remains after percutaneous revascularization procedure) allows to objectively verify the incompleteness of PCI treatment, which correlates with the outcome in the patient's distance . Moreover, in case of equivocal stenosis, especially in patients with stable coronary disease, large should be the use of a functional assessment using the calculation of the Fractional Flow Reserve (FFR).

This could indicate that the increase of the number of invasive diagnostic tests does not increase the number of patients with coronary artery disease extended, in which is usually indicated a surgical revascularization. So to identify patients at higher risk, may be enough specific investigations and conducted selectively.

The purpose of the pilot study APACHE is to assess the appropriateness of indication and appropriateness of execution of a sample carried out PCI in patients with stable coronary artery disease and in patients with NSTE-ACS (in the ratio 4: 1). As such, the APACHE be considered a quality improvement initiative.

Retrospective observational study, multicenter. The study population will consist of 20 cases of PCI per center (then about 400 PCI in total) selected randomly within the center of the case studies in the previous approval of the study. Of these 16 will be patients with stable coronary artery disease (including 8 with diabetes mellitus in medical therapy) and 4 will be patients with NSTE-ACS (4: 1 ratio).

Patients with a history of coronary artery bypass are excluded. The series will consist of patients in whom the procedure was carried out in the previous year to a declaration of participation in the survey and in any case after the publication of the document. There have been no previous analysis of this type in Italy and is therefore not known what is the rate of inappropriateness for PCI procedures in stable patients. It is not possible therefore to perform a calculation of sample size. However, the investigators believes that for a pilot analysis, an initial sample of 400 PCI procedures, analytically considered, is sufficient to verify the magnitude of the problem in the Italian Catheterization Laboratories.

The investigators anticipate the participation of about 20 centers in total between Lombardia and Veneto italian regions. The study will have an approximate duration of about 2 years.

The data to be collected will be different in patients with nSTE - ACS compared to patients with stable coronary artery disease. As an initiative of quality improvement, and according to extensive international literature on the subject, will not be requested individual informed consent to selected patients but only the approval of the Ethics Committee of the Center Coordinator. Patient data will be de-identified and used only in the aggregate and all individual sensitive information (name, phone, address) will be erased.

Inclusion criteria:

• Age >= 18 yrs
• Stable Coronary Artery Disease(CAD)
• Unstable Angina or NSTEMI

Exclusion criteria :

• STEMI at presentation
• previous CABG

Twenty patients per center will be selected among those who underwent PCI in the last months, going backwards from the date of first Site visit.

Selection will be stratified for clinical presentation in two subgroups (stable CAD:NSTEACS = 4:1) and diabetes status (1:1) for each subgroups.