Mortality After Events Occurring Beyond 1 Year Post-Stenting

Study Questions:

What is the prognosis of cardiovascular and bleeding events occurring beyond 1 year after coronary stenting?

Methods:

This was a secondary analysis derived from data from the DAPT (Dual Antiplatelet Therapy) study, a multicenter trial involving 220 US and international clinical sites from 11 countries. Individuals who underwent coronary stenting and completed 12 months of thienopyridine plus aspirin therapy without ischemic or bleeding events remained on an aspirin regimen and were randomized to continued thienopyridine therapy versus placebo for 18 additional months. Individuals were then followed up for 3 additional months while receiving aspirin therapy alone. Ischemic events (myocardial infarction not related to stent thrombosis, stent thrombosis, and ischemic stroke) and bleeding events (Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Arteries [GUSTO] classification moderate or severe bleeding) were assessed. The main outcome measures were ischemic events, bleeding events, and death at 21 months after randomization (33 months after coronary stenting).

Results:

A total of 25,682 individuals ages >18 years with an indication for coronary stenting were enrolled, and 11,648 (mean age, 61.3 years; 25.1% female) were randomized. After randomization, 478 individuals (4.1%) had 502 ischemic events (306 with myocardial infarction, 113 with stent thrombosis, and 83 with ischemic stroke), and 232 individuals (2.0%) had 235 bleeding events (155 with moderate and 80 with severe bleeding). Among individuals with ischemic events, 52 (10.9%) died. The annualized mortality rate after an ischemic event was 27.2 (95% confidence interval [CI], 20.3-35.7) per 100 person-years. The cumulative incidence of death after an ischemic event among the total randomized study population was 0.5% (0.3% with myocardial infarction, 0.1% with stent thrombosis, and 0.1% with ischemic stroke). Among individuals with bleeding events, 41 (17.7%) died. The annualized mortality rate after a bleeding event was 21.5 (95% CI, 15.4-29.1) per 100 person-years. The cumulative incidence of death after a bleeding event among the total randomized study population was 0.3% (0.1% with moderate and 0.2% with severe bleeding).

Conclusions:

The authors concluded that among patients treated with DAPT for at least 1 year after coronary stenting, ischemic events were more frequent than bleeding events, and both events were associated with a high risk of mortality.

Perspective:

This post hoc analysis from the DAPT study reports that among treatment-adherent patients who were event free for 1 year after coronary stenting, ischemic and bleeding events occurring between 12 and 33 months were associated with a high risk of mortality. Given these findings, it is evident that we need to individualize therapy based on patient characteristics to avoid late ischemic and bleeding events after coronary stenting, and carefully consider the risk versus benefits of prolonged DAPT. Furthermore, although bleeding events were less frequent than ischemic events according to prespecified classifications, they were associated with a twofold higher risk of death, and may become even more pertinent in the era of more widespread use of potent P2Y12 inhibitors.


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