Bleeding After DAPT Found to Be an Independent Predictor of Cardiovascular Events

In patients with coronary artery disease, advances in dual antiplatelet therapy (DAPT) have improved clinical outcomes through the reduction of ischemic and thrombotic events, with the caveat of an increased risk of bleeding. In East Asian populations, specifically, relatively high platelet reactivity is commonly seen in response to clopidogrel treatment; however, this relatively high on-treatment platelet reactivity does not appear to increase the risk of ischemic events, an occurrence that has rarely been investigated.

A recent study examined this phenomenon by use of the National Health Insurance Research Database (NHIRD) of Taiwan to estimate the incidence of clinical events such as bleeding, myocardial infarction, and all-cause mortality in patients with acute myocardial infarction (AMI) and chronic coronary syndrome (CCS) who received DAPT after coronary stenting.

The study authors enrolled patients into 2 respective groups: AMI (n = 15,391) and CCS (n = 19,724). Bleeding endpoints were defined as Bleeding Academic Research Consortium (BARC) types 2, 3, and 5. Type 2 is categorized as bleeding that requires medical intervention that does not fit the criteria of the other 2 types; type 3 is bleeding that requires a blood transfusion or intravenous vasoactive agents, cardiac tamponade, intracranial hemorrhage, or intraocular bleeding; and type 5 is bleeding that is the principle diagnosis of admission with mortality within 7 days.

One-year outcomes found that the incidence rate of BARC type 3 bleeding was higher in patients with AMI compared with patients with CCS (0.22 vs. 0.13 per 100 person-months; HR 1.64; 95% CI, 1.39–1.93; P < .01), while the incidence rate of BARC type 2 bleeding was numerically higher in the CCS patients than in the AMI patients, despite the lack of statistical significance (1.32 vs. 1.4 per 100 person-months; HR 0.94; 95% CI, 0.89–1.0; P = .06). BARC type 5 bleeding risk was comparable between the 2 groups at 1 year after the index procedure (0.03 vs. 0.02 per 100 person-months; HR 1.21; 95% CI, 0.78–1.86; P = .4).

Additionally, the AMI group had a significantly higher incidence rate of all-cause death (0.49 vs. 0.32 per 100 person-months; HR 1.55; 95% CI, 1.39–1.73; P < .01). The incidence rates of overall stroke (0.17 vs. 0.16 per 100 patient-months; HR 1.06; 95% CI, 0.9–1.25; P = .49), ischemic (0.15 vs. 0.15 per 100 person-months; HR 1.05; 95% CI, 0.88–1.25; P = .6), and hemorrhagic subtypes of stroke (0.01 vs. 0.01 per 100 person-months; HR 0.83; 95% CI, 0.45–1.54; P = .56) were comparable between the 2 groups, the authors found.

After bleeding occurred, 44.7% of the AMI patients and 36.5% of the CCS patients continued DAPT; 48.6% of the AMI patients and 59.4% of the CCS patients received single antiplatelet therapy; and 6.7% of the AMI patients and 4.1% of the CCS patients discontinued antiplatelet therapy altogether.

Study investigators used propensity score weighting to compare outcomes at 1 year after bleeding onset. Their findings demonstrated that bleeding was associated with a higher risk of stroke (0.29 vs. 0.17 per 100 patient-months; HR 1.7; 95% CI, 1.17–2.48; P = .01), especially ischemic stroke (0.22 vs. 0.13 per 100 patient-months; HR 1.71; 95% CI, 1.11–2.63; P = .02), and a trend toward a higher risk of myocardial infarction (0.34 vs. 0.25 per 100 patient-months; HR 1.38; 95% CI, 0.99–1.91; P = .06) in the AMI group compared with the CCS group. All-cause death at 1 year after the initial bleeding was comparable between the 2 groups after propensity score weighting (1.1 vs. 1.04 per 100 patient-month; HR 1.06; 95% CI, 0.89–1.26; P = .52).

Overall, the authors found that bleeding indicated an independent prediction of myocardial infarction, stroke, and death in East Asian patients who were receiving DAPT after a percutaneous coronary intervention.

Reference

Tung YC, See LC, Chang SH, et al. Impact of bleeding during dual antiplatelet therapy in patients with coronary artery disease. Sci Rep. Published online December 7, 2020. doi: 10.1038/s41598-020-78400-4