What is the recommended duration of Dual Antiplatelet Therapy (DAPT) after coronary artery stenting?

From the Guidelines

Dual antiplatelet therapy (DAPT) after coronary stenting should be continued for at least 6 months in patients with stable ischemic heart disease and at least 12 months in patients with acute coronary syndrome, with the option to extend beyond 12 months in patients who have tolerated DAPT without a bleeding complication and are not at high bleeding risk. The choice of P2Y12 inhibitor, including clopidogrel 75mg daily, ticagrelor 90mg twice daily, or prasugrel 10mg daily, depends on patient risk factors and clinical presentation 1. High bleeding risk patients may receive shorter DAPT durations (3-6 months), while those with high ischemic risk may benefit from extended therapy beyond 12 months. DAPT is crucial because it prevents stent thrombosis by inhibiting platelet aggregation through two complementary pathways: aspirin blocks thromboxane A2 production via COX-1 inhibition, while P2Y12 inhibitors block ADP-mediated platelet activation. Premature DAPT discontinuation significantly increases the risk of stent thrombosis, which carries high mortality rates, so patient education about adherence is essential.

Some key considerations for DAPT duration include:

• Stent type: bare metal stents generally require shorter DAPT durations (at least 1 month) compared to drug-eluting stents (6-12 months) 1
• Patient risk factors: high bleeding risk patients may require shorter DAPT durations, while those with high ischemic risk may benefit from extended therapy beyond 12 months 1
• Clinical presentation: acute coronary syndrome patients typically require longer DAPT durations regardless of stent type 1

The most recent guidelines recommend a minimum of 6 months of DAPT for patients with stable ischemic heart disease and at least 12 months for patients with acute coronary syndrome, with the option to extend beyond 12 months in select patients 1. It is essential to weigh the benefits and risks of DAPT duration for each patient, considering their individual risk factors and clinical presentation.

From the FDA Drug Label

The primary outcome measure was the composite of cardiovascular death, nonfatal MI, or nonfatal stroke in the UA/NSTEMI population. Patients were randomized to receive prasugrel (60 mg loading dose followed by 10 mg once daily) or clopidogrel (300 mg loading dose followed by 75 mg once daily), with administration and follow-up for a minimum of 6 months (actual median 14. 5 months). Patients also received aspirin (75 mg to 325 mg once daily).

DAPT after stenting involves the use of aspirugrel and aspiring. The study TRITON-TIMI 38 compared prasugrel to clopidogrel, each added to aspirin and other standard therapy, in patients with ACS who were to be managed with PCI.

• The treatment effect of prasugrel was apparent within the first few days, and persisted to the end of the study.
• Prasugrel reduced the occurrence of the primary composite endpoint compared to clopidogrel in both the UA/NSTEMI and STEMI populations.
• The study used a DAPT regimen with a minimum duration of 6 months 2.

From the Research

DAPT Duration After Stenting

• The optimal duration of dual antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI) is not well established, with guidelines recommending treatment for between 1 month after receiving a bare metal stent (BMS) and 6 to 12 months after PCI with a drug-eluting stent (DES) 3.
• For patients at high risk of bleeding, a shorter duration of DAPT (3-6 months) may be considered, while for those with a low risk of bleeding, prolonged DAPT may be considered 4.
• The risk of bleeding is a major consideration in determining the duration of DAPT, with factors such as age, body weight, diabetes, and prior bleeding influencing this risk 4.

Stent Type and DAPT Duration

• Drug-eluting stents (DESs) have been shown to reduce restenosis compared to bare metal stents (BMSs), but the optimal duration of DAPT after DES implantation is still unclear 5.
• Some studies have suggested that a shorter course of DAPT (less than 12 months) may be considered with second-generation or newer-generation DESs, which have a lower risk of stent thrombosis 5.
• A network meta-analysis found that all DESs reduced the risk of major adverse cardiovascular events (MACE) compared to BMSs, with Orsiro and Synergy stents showing a lower risk of stent thrombosis and repeated revascularization 6.

Perioperative DAPT Management

• For patients undergoing surgery after PCI, the management of DAPT is critical to balance the risk of stent thrombosis and bleeding complications 7.
• The recommendations for perioperative DAPT have changed with emerging evidence, with a mandatory interval of 1 year for elective surgery after DES implantation shortened to 6 months (3 months if surgery cannot be further delayed) 7.
• In emergent or urgent surgeries, proceeding to surgery with continued DAPT should be considered, while for intracranial procedures or other selected surgeries, cessation of DAPT with bridge therapy using short-acting, reversible intravenous antiplatelet agents may be contemplated 7.