European society of cardiology guidelines classification scheme
Editor-In-Chief: C. Michael Gibson, M.S., M.D. 
The European Society of Cardiology (ESC) represents more than 50,000 cardiology professionals across Europe and the Mediterranean. Its mission is to reduce the impact of cardiovascular disease in Europe.
The ESC achieves a variety of scientific and educational activities including the coordination of clinical practice guidelines, education courses and initiatives, pan-European surveys on specific disease areas. It also organizes the ESC Annual Congress, which is the largest medical meeting in Europe.
The ESC is comprised of 3 Councils, 5 Associations, 19 Working Groups and 50 National Cardiac Societies. The administrative headquarters of the ESC, based at the European Heart House, is situated in the South of France, in the area of Sophia Antipolis that is between Nice and Cannes.
Classes of Recommendations
- Class I: Evidence and/or general agreement that a given diagnostic procedure or treatment is beneﬁcial, useful, and effective.
- Class II: Conﬂicting evidence and/or a divergence of opinion about the usefulness or efﬁcacy of the treatment or procedure.
- Class IIa: Weight of evidence or opinion is in favour of usefulness or efﬁcacy.
- Class IIb: Usefulness or efﬁcacy is less well established by evidence or opinion.
- Class III: Evidence or general agreement that the treatment or procedure is not useful or effective and, in some cases, may be harmful.
Level of Evidence
- Level of Evidence: A Data derived from multiple randomized clinical trials or meta-analyses.
- Level of Evidence: B Data derived from a single randomized clinical trial or large non-randomized studies.
- Level of Evidence: C Consensus of opinion of the experts and/or small studies, retrospective studies, and registries.