Patients who received percutaneous coronary intervention (PCI) should be treated with dual anti-platelet therapy (DAPT). DAPT significantly lowers the risk of the incidence of major adverse cardiac events (MACE). However, the risk factors for the incidence of MACE are unclear. We investigated the relationship between the incidence of MACE in PCI treated patients who underwent combined therapy by clopidogrel and aspirin, and patient background, present clinical history, lifestyle, and concomitant drugs. Between the MACE symptom group and non-MACE group, there were no significant differences in terms of patient background and lifestyle. In the MACE-symptom group, the percentage of treatments using concomitant drugs that inhibits cytochrom P450 (CYP)3A4 activity was significantly higher than in the non-MACE group (odds ratio 2.70). The present study also demonstrated that diabetes was an important risk factor (odds ratio 3.16, P = 0.001) of MACE symptoms. A significant positive correlation was found between diabetes and hypertension morbidity, and the administration ratio of concurrent drugs with CYP3A4 inhibition activity. The present study suggests that diabetes morbidity may be associated with MACE symptoms in antiplatelet therapy with DAPT.

Upper gastrointestinal symptoms, a common adverse effect of dabigatran, influence the continuation of medication. It has been speculated that this adverse effect can be reduced by changing the method of taking dabigatran: that is, to instruct patients to swallow dabigatran capsules whole with a glassful of water. However, there is no evidence to support this conclusion. Therefore, we changed our patient compliance instruction of dabigatran to the method mentioned above from September 2013 and investigated the effect of that change on the onset of adverse events and patient quality of life (QOL). Among 42 patients treated with dabigatran, 17 patients were categorized into the instruction change group and 25 were categorized into the no instruction change group. The Izumo scale was used to assess patient QOL. A total of 20 patients experienced side effects in the upper gastrointestinal tract (6 in the instruction change group, and 14 in the no instruction change group), and 18 patients in the lower gastrointestinal tract (3 in the instruction change group, and 15 in the no instruction change group). Izumo scale scores were significantly lower in the instruction change group than in the no instruction change group. Furthermore, in the no instruction change group, 5 patients showed a remarkable decrease in patient QOL by the adverse effects of gastrointestinal symptoms; however, in the instruction change group, this did not occur in any patients. The results indicate that patient QOL can be maintained by altering the method of taking dabigatran.