Association of Mortality with Antiplatelet Treatment in Patients with Stent Placement or Angioplasty: A Population-Based Nested Case-Control Study

Abstract

Purpose: Antiplatelet drugs are essential in patients with cardiovascular disease who undergo stent placement. We hypothesized that risks of mortality would differ according to adherence to antiplatelet agents, number of antiplatelet agents, and antiplatelet regimens in patients undergoing stent placement or angioplasty.

Materials and methods: Between 2002 and 2013, we initially enrolled 8671 subjects who underwent stent placement or angioplasty in the National Health Insurance Service-National Sample Cohort in Korea. Using the International Classification of Diseases, 10th revision, the incidence of all-cause death, including cardiovascular disease, cerebrovascular disease, and cancer, was defined. Using a nested case-control study design, controls were matched to cases at a ratio of 4:1, and a total of 5415 subjects were eligible for this study.

Results: During a median follow-up period of 3.51 years, the incidence rate of all-cause death was 40 per 1000 person-years. We found that adherence to antiplatelet monotherapy significantly decreased risk of death by cerebro-cardiovascular disease, compared with discontinuation of antiplatelets [adjusted odds ratio (OR) 0.62, 95% confidence interval (CI) (0.41-0.96)]. Compared with dual antiplatelet therapy (DAPT), aspirin and clopidogrel monotherapy significantly reduced death by cerebro-cardiovascular disease [adjusted OR 0.65, 95% CI (0.44-0.95) and adjusted OR 0.58, 95% CI (0.35-0.96), respectively]. There was no significant difference of mortality between aspirin monotherapy and clopidogrel monotherapy.

Conclusion: Our study demonstrated that adherence to antiplatelet therapy and antiplatelet monotherapy, compared with DAPT, in patients with stent placement or angioplasty may have a beneficial effect on mortality in cerebro-cardiovascular disease.

Keywords: Antiplatelet; mortality; stent.

Fig. 1. Flowchart of the study participants. NHIS, National Health Insurance Service; NOAC, non-vitamin K antagonist oral anticoagulants.

Fig. 2. Nested case-control study design. (A) Medication patterns for 6 months from 6 months before index data. (B) Medication patterns for 9 months from 3 months before index date.

Fig. 3. Patterns of antiplatelet treatment for the 2-year follow-up period after stent placement.