The BleeMACS (Bleeding complications in a Multicenter registry of patients discharged with diagnosis of Acute Coronary Syndrome) registry is an international observational database of bleeding outcomes for patients who are discharged with diagnosis of ACS and underwent Percutaneous Coronary Intervention (PCI), including myocardial infarction or unstable angina.

BleeMACS registry enrolls a total of more than 15,000 patients, including data from 16 hospitals in 11 countries: North America (Canada), South America (Brazil) Europe (Germany, Netherlands, Poland, Spain, Italy, Macedonia, Greece), and Asia (Japan and China).

The end-point of this study is to characterize patients at high risk of bleeding and to develop a risk score to accurately predict the risk of major bleeding within the first year after discharge from the hospital for an ACS.

In December 2014, given the actual need for rigorous multicenter clinical investigation to test the safety of antithrombotic and contemporary therapies in patients with acute coronary syndromes (ACS), Dr. Sergio Raposeiras-Roubín and Dr. Emad Abu-Assi launched the BleeMACS (Bleeding complications in a Multicenter registry of patients discharged with diagnosis of Acute Coronary Syndrome) project.

Antithrombotic medication is commonly used for secondary prevention in patients following an ACS. This therapy, along with the invasive strategies, has been proved as effective, although it increases the risk of bleeding, which may counteract its benefits.

A growing body of evidence has demonstrated that the risk of death in patients with ACS is affected not only by recurrent ischemic events but also by major bleeding. Bleeding complications is the downside of antithrombotic therapy, as they were consistently associated with short- and long-term mortality, in addition to increase the risk of new thrombotic events particularly due to temporary or permanent modification/suspension of antithrombotic therapy, which is especially relevant in the first year after an ACS.

At present, there are several risk scores for predicting bleeding at short-term (during the hospitalization stage and at 30 days). However, at medium and long-term (i.e., ≤ 1 year), there is no available predicting systems to help clinicians quantify the bleeding risk of their patients. How could physicians predict the risk of bleeding after hospital discharge for ACS?

The purpose of this project was focused on helping clinicians to estimate the patient's baseline risk of major bleeding within the first year following an ACS. The investigators aim to identify the independent predictors of major bleeding at 1-year in order to develop a user-friendly bleeding risk score. The scoring system that the investigators intended to design using the data from the present registry would help clinicians in the decision-making process by identifying the optimal antithrombotic strategy, focusing closer attention to the patients with high risk of bleeding.

Inclusion Criteria:

1. Consecutive patients discharged with diagnosis of an Acute Coronary Syndrome (ACS)
2. Undergoing percutaneous coronary intervention (PCI).
3. One year follow-up (except death)

Exclusion Criteria:

1. Patients who died during hospitalization.
2. Patients without coronary artery disease (basing on the definitions of criteria 2).
3. Patients who did not undergo PCI (simple balloon angioplasty, stent implantation and/or tromboaspiration).

Patients discharged with diagnosis of Acute Coronary Syndrome underwent percutaneous coronary intervention with at least 1 year of follow-up (except death)