The main aim of this study will evaluate differences in serum levels of tryptase in study population. Will be selected a number of 350 patients hospitalized for coronary heart disease.

A series of scientific studies have evaluated the tryptase as a biomarker of coronary plaque instability, in the course of ischemic heart disease. Among these, the most recent and 'outcome' is better defined by Meixiang Xiang study, which has been conducted in 2011 on 270 patients. This study evaluated and compared the levels of tryptase in four populations:

1. acute myocardial infarction (31 subjects)
2. unstable angina (108 subjects)
3. stable angina (36 subjects)
4. coronary artery disease with coronary stenosis <50% (95 subjects). In this Chinese population the final evaluations have led to define the tryptase as a marker independent of instability of the atheromatous plaque.

In reference to the fact that there is still some correlation between tryptase and coronary plaque instability and clinical symptoms, we propose a verification study of the role of tryptase as a biomarker in acute coronary conditions by studying a large population of Italian subjects in the acute phase of pathology and follow up.

The work will be conducted on 4 patient population:

1. acute coronary syndrome with ST elevation on electrocardiogram;
2. acute coronary syndrome without ST elevation on electrocardiogram (acute myocardial infarction with ST-segment depression on electrocardiogram and unstable angina)
3. noncritical coronary artery disease with coronary stenosis <50%;
4. aortic aneurysms. Secondary endpoints will evaluate the role of tryptase in the event of major cardiovascular events.

Inclusion Criteria:

• male and female subjects aged 18 to 80 years
• patients with clinical manifestations have been discovered and documented symptoms of coronary heart disease
• all patients with these characteristics will necessarily have to sign the informed consent for inclusion in the study

Exclusion Criteria:

• patients with allergy symptoms in place (hives, uncontrolled asthma) autoimmune diseases, mastocytosis, hypereosinophilia, myelodysplastic syndrome, cancer, kidney failure
• those who deny consent to participate

Italian subjects in the acute phase of disease and follow up. The work will be on 4 patient populations:

1. sindrome coronary acute ST elevation on electrocardiogram
2. sindrome ACS without ST elevation on electrocardiogram (acute myocardial infarction with ST-segment depression on electrocardiogram and unstable angina)
3. malattia critical coronary artery stenosis <50%
4. aneurismi aorta.