Primary Risk of DAPT Non-Compliance After Coronary Stenting
The primary risk of non-compliance with DAPT is stent thrombosis, which carries a mortality rate of 20% to 45%, along with increased risk of myocardial infarction and other major adverse cardiac events. 1
Magnitude of Stent Thrombosis Risk
The risk of stent thrombosis increases dramatically when patients prematurely discontinue DAPT. 1 The timing and severity of this risk depends on the stent type:
- Bare-metal stents (BMS): Greatest risk occurs in the first 14 to 30 days after implantation 1
- Drug-eluting stents (DES): Risk extends beyond 30 days, with late stent thrombosis remaining a concern for at least 12 months 1
Clinical Outcomes Associated with Non-Compliance
Real-world registry data from the PARIS study demonstrates the severe consequences of DAPT disruption due to non-compliance 2:
- Non-compliant DAPT disruption occurred in 1.6% at 30 days, 6.5% at 12 months, and 9.1% at 2 years 2
- Non-compliance was associated with 73% increased risk of major adverse cardiac events (HR 1.73,95% CI 1.17-2.54) 2
- Nearly 3-fold increased risk of spontaneous myocardial infarction (HR 2.93,95% CI 1.85-4.65) 2
Comparison with Bleeding-Related Disruption
Importantly, the clinical impact differs based on the reason for DAPT cessation 2, 3:
- Non-compliance leads primarily to ischemic complications (MI, stent thrombosis) 2
- Bleeding-related disruption leads primarily to increased mortality (HR 1.93 for all-cause death) 2
- DAPT disruption increases major adverse cardiac events regardless of underlying bleeding risk 3
Critical Time Periods
The risk is not uniform throughout the post-PCI period 1:
- First 30 days after BMS: Highest risk period; minimum DAPT duration required 1
- First 12 months after DES: Consensus recommendation for DAPT to prevent late stent thrombosis 1
- Emergency surgery within 4 weeks of stenting: Associated with particularly high risk of stent thrombosis and death 1
Acute Coronary Syndrome Context
For patients who received stents during acute coronary syndrome, the consequences of non-compliance are even more severe 1:
- Minimum 12-month DAPT duration is mandatory regardless of stent type 1
- Early discontinuation in ACS patients should only occur for compelling bleeding-related reasons 1
Common Pitfall to Avoid
The most critical error is implanting coronary stents in patients unlikely to comply with DAPT 1. This is designated as a Class III: HARM recommendation, meaning PCI with stenting should not be performed if the patient cannot tolerate and comply with appropriate DAPT duration 1. Before stent implantation, interventional cardiologists must discuss with patients the need for DAPT, its duration, and assess the patient's ability to comply 1.