Present classifications of
bleeding events used in antithrombotic and/or antiplatelet clinical trials are based on the criteria developed by the Thrombolysis In
Myocardial Infarction (TIMI) and Global Use of Strategies to Open Coronary Arteries (GUSTO) groups. Introduced more than a decade ago, the 2 classifications used the criteria to better categorize hemorrhagic events after
therapy with
thrombolytic agents. Recent advances in interventional cardiology, resulting in a domination of percutaneous intracoronary procedures over systemic drug-induced thrombolysis, have substantially changed the clinical characteristics and magnitude of
bleeding complications. Moreover, disturbances of the coagulation cascade, as well as platelet inhibition caused directly by antithrombotic and
antiplatelet agents, share very specific and well-recognized clinical features not reflected in the existing classifications.
Bleeding events after
aspirin or
clopidogrel, and especially those after more delicate antiplatelet regimens with
dipyridamole used in patients after
ischemic stroke or
transient ischemic attack, are impossible to classify by the present guidelines, other than categorically triaging them altogether to the "minor" category. Uniting entirely different
bleeding events as "minor" under-rates their importance and diminishes affiliated risks, creating an illusion that they do not require monitoring and/or changes in antiplatelet or antithrombotic regimens. In reality, such unrecognized and unreported mild complications may transform into more serious bleeds or lead to noncompliance. Unauthorized withdrawal from
antiplatelet agents in turn causes rebound platelet activation and higher risk for secondary vascular events. In conclusion, a new classification of
bleeding events is introduced (the BleedScore), based on a point accumulation depending on the severity of
hemorrhage, which is believed to be more suitable for the assessment of modern, more delicate antithrombotic and antiplatelet
therapies, particularly for their realistic assessment in clinical trials.