The aspirin cardiovascular/gastrointestinal risk calculator - a tool to aid clinicians in practice

Background Assessment of both GI and CV risks vs. the benefits of low-dose aspirin for individual patients can be difficult in clinical practice. Aim To develop a tool to estimate CV and GI risks to facilitate the clinical decision-making process. Methods We constructed risk-ratio estimations and determined the incidence of CV events and upper GI complications according to the presence of different risk factors. For upper GI complications we assumed a baseline incidence of 1 case/1000-persons-year, a twofold increased risk with low-dose aspirin, and estimated a 60% GI risk reduction with proton pump inhibitors (PPI) co-therapy and a 60% risk reduction with H. pylori eradication in patients with a history of peptic ulcer. Results The calculator can be found at http://www.asariskcalculator.com. In patients with low CV risk the number of GI complications induced by low-dose aspirin may be greater than the number of CV events prevented. In patients with high CV risk, low-dose aspirin is recommended, but the number of GI complications induced may still overcome the CV events saved. The use of PPI reduces the number of complication events induced by low-dose aspirin, but the number of CV events saved may still be offset by the number of GI complications induced in patients at very high GI risk. Conclusions There are many clinical situations where the number of potential upper GI complications induced by low-dose aspirin may exceed the number of potentially prevented CV events. A risk calculator should guide physicians in choosing appropriate therapy and maximise the aspirin benefit.