Dual Antiplatelet Therapy Regimen for Acute Coronary Syndrome and Coronary Stent Placement

Introduction to DAPT Regimens

• The European Society of Cardiology recommends ticagrelor (180 mg loading dose, 90 mg twice daily) on top of aspirin as the first-line DAPT regimen for 12 months in patients with acute coronary syndrome (ACS) or those who have undergone coronary stent placement, unless there are contraindications or excessive bleeding risk 1, 2, 3

P2Y12 Inhibitor Selection

• For patients with acute coronary syndrome (ACS), the first choice is ticagrelor (180 mg loading dose, 90 mg twice daily) plus aspirin, regardless of initial treatment strategy, including in patients pre-treated with clopidogrel (which should be discontinued when ticagrelor is commenced) 2, 3
• For PCI patients, an alternative is prasugrel (60 mg loading dose, 10 mg daily) plus aspirin for P2Y12 inhibitor-naïve patients with NSTE-ACS or STEMI undergoing PCI, unless high bleeding risk or contraindications exist 2, 3
• When ticagrelor or prasugrel is contraindicated, clopidogrel (600 mg loading dose, 75 mg daily) plus aspirin is recommended for patients with prior intracranial bleeding or indication for oral anticoagulation 1, 4

Measures to Minimize Bleeding Risk

• The European Society of Cardiology recommends using radial over femoral access for coronary angiography and PCI when performed by an expert radial operator 1, 4
• Maintaining a daily aspirin dose of 75-100 mg when used with DAPT is advised 1, 4
• Prescribing a proton pump inhibitor (PPI) in combination with DAPT is recommended to reduce gastrointestinal bleeding risk 1, 4

Duration of DAPT

• For ACS patients, the standard duration is 12 months of DAPT with a P2Y12 inhibitor plus aspirin 1, 3, 4
• In patients with high bleeding risk, consider a shorter duration (6 months) if excessive bleeding risk exists (e.g., PRECISE-DAPT score ≥25) 1, 4

Special Considerations

• In ACS patients previously exposed to clopidogrel, switching to ticagrelor is recommended early after hospital admission (180 mg loading dose) regardless of timing and loading dose of clopidogrel, unless contraindications exist 1, 4
• Continue aspirin perioperatively if bleeding risk allows, and do not discontinue DAPT within the first month of treatment for elective non-cardiac surgery 1, 4
• Resume recommended antiplatelet therapy as soon as possible post-operatively 1, 4

Common Pitfalls to Avoid

• Not switching from clopidogrel to ticagrelor in ACS patients when indicated 1, 4
• Discontinuing DAPT prematurely, especially within the first month after stent placement 1, 4
• Not prescribing a PPI with DAPT to reduce gastrointestinal bleeding risk 1, 4

Ticagrelor vs Clopidogrel After Acute Coronary Syndrome

Comparative Efficacy and Guidelines

• The American College of Cardiology recommends ticagrelor in preference to clopidogrel for maintenance P2Y12 inhibitor therapy in patients with acute coronary syndrome treated with dual antiplatelet therapy after coronary stent implantation, with a Class IIa recommendation (Level of Evidence: B-R) 5, 6
• For patients with acute coronary syndrome treated with dual antiplatelet therapy after bare-metal stent or drug-eluting stent implantation, P2Y12 inhibitor therapy should be given for at least 12 months (Class I, Level of Evidence: B-R), according to the American College of Cardiology 5, 7

Special Considerations

• The American College of Cardiology recommends a daily aspirin dose of 81 mg when using ticagrelor (rather than higher doses) 5, 7
• For patients previously on clopidogrel, switching to ticagrelor is recommended early after hospital admission with a 180 mg loading dose, regardless of timing and loading dose of clopidogrel, as suggested by the European Society of Cardiology 8
• In patients with prior history of stroke or transient ischemic attack, ticagrelor is the preferred potent P2Y12 inhibitor, as prasugrel should not be administered (Class III: Harm, Level of Evidence: B-R), according to the American College of Cardiology 5, 6

Bleeding Risk Considerations

• To minimize bleeding risk with any dual antiplatelet therapy regimen, the European Society of Cardiology suggests using radial over femoral access for coronary procedures, prescribing a proton pump inhibitor in combination with dual antiplatelet therapy, and maintaining a daily aspirin dose of 75-100 mg 8

When to Consider Clopidogrel Instead

• Clopidogrel remains the P2Y12 inhibitor of choice in patients with high bleeding risk with inability to tolerate more potent P2Y12 inhibition, according to the American College of Cardiology 5, 7

Dual Antiplatelet Therapy After Acute Coronary Events

First-Line P2Y12 Inhibitor Selection

• The European Society of Cardiology recommends ticagrelor (180 mg loading dose, 90 mg twice daily) plus aspirin as first-line therapy for acute coronary syndrome (ACS) patients regardless of initial treatment strategy, including patients previously treated with clopidogrel 9, 10
• The European Society of Cardiology recommends prasugrel (60 mg loading dose, 10 mg once daily) plus aspirin for P2Y12 inhibitor-naïve patients with non-ST-elevation acute coronary syndrome (NSTE-ACS) or ST-elevation myocardial infarction (STEMI) undergoing percutaneous coronary intervention (PCI), unless there is high risk of life-threatening bleeding or other contraindications 9, 10

Important Dosing Considerations

• Prasugrel is contraindicated in patients with a history of prior transient ischemic attack (TIA) or stroke due to increased risk of cerebrovascular events 11
• Ticagrelor can be used in patients with prior stroke or TIA 11

Duration of Therapy

• The European Society of Cardiology recommends a standard duration of dual antiplatelet therapy (DAPT) with a P2Y12 inhibitor plus aspirin of 12 months for ACS patients treated with coronary stent implantation 9, 12

Measures to Minimize Bleeding Risk

• The European Society of Cardiology recommends maintaining a daily aspirin dose of 75-100 mg when used with DAPT 9, 12
• The European Society of Cardiology recommends prescribing a proton pump inhibitor (PPI) in combination with DAPT to reduce gastrointestinal bleeding risk 9

Common Pitfalls to Avoid

• The European Society of Cardiology recommends switching from clopidogrel to ticagrelor in ACS patients when indicated, and not administering prasugrel to patients with prior stroke or TIA (contraindicated) 11, 12
• The European Society of Cardiology recommends not using prasugrel in medically managed ACS patients (not recommended) 9, 12
• The European Society of Cardiology recommends not discontinuing DAPT prematurely, especially within the first month after stent placement 12

Ticagrelor vs Clopidogrel for Antiplatelet Therapy

Primary Recommendation for ACS Patients

• The American College of Cardiology/American Heart Association recommends ticagrelor or prasugrel in preference to clopidogrel for patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI) 13, 14
• Ticagrelor is preferred over clopidogrel in patients with ACS undergoing PCI, as it reduces cardiovascular death, myocardial infarction, and stroke compared to clopidogrel 13, 14

Clinical Evidence Supporting Ticagrelor Superiority

• The PLATO trial demonstrated that ticagrelor reduced the composite endpoint of cardiovascular death, myocardial infarction, or stroke by 16% compared to clopidogrel in 18,624 ACS patients 15
• Ticagrelor reduced myocardial infarction (5.8% vs 6.9%, P=0.005) 15, 16
• Ticagrelor reduced cardiovascular mortality (4.0% vs 5.1%, P=0.001) 15
• Ticagrelor reduced all-cause mortality (4.5% vs 5.9%, P<0.001) 15

Bleeding Risk Considerations

• Ticagrelor increases non-CABG-related major bleeding compared to clopidogrel (4.5% vs 3.8%, P=0.03) 15
• Ticagrelor is associated with more fatal intracranial bleeds (0.1% vs 0.01%, P=0.02) 15

Strategies to Minimize Bleeding Risk

• Prescribe a proton pump inhibitor (PPI) with dual antiplatelet therapy to reduce gastrointestinal bleeding 13, 14

Duration of Therapy

• Standard duration is 12 months of dual antiplatelet therapy (DAPT) for ACS patients 13, 14
• After 12 months, transition to ticagrelor monotherapy is recommended ≥1 month after PCI in patients who have tolerated DAPT without bleeding 13, 14

Special Populations

• When triple therapy is required (antiplatelet + anticoagulation), clopidogrel is preferred over ticagrelor due to significantly lower bleeding risk 13, 14

Dual Antiplatelet Therapy Indications and Management

Primary Indications

• The American College of Cardiology recommends dual antiplatelet therapy (DAPT) for all patients with acute coronary syndrome (ACS), including STEMI, NSTEMI, and unstable angina, for at least 12 months, combining aspirin with a P2Y12 inhibitor (preferably ticagrelor or prasugrel over clopidogrel) 17
• DAPT is mandatory for all ACS patients regardless of management strategy, including those managed with percutaneous coronary intervention (PCI), medical therapy alone, or coronary artery bypass grafting 17
• DAPT is essential for all patients undergoing PCI with stent placement to prevent stent thrombosis 17

Standard Duration and Bleeding Risk Mitigation

• The default duration of DAPT is 12 months for all ACS patients who are not at high bleeding risk, regardless of ACS type, stent type, or completeness of revascularization 17
• Upstream therapy with clopidogrel or ticagrelor may be considered in patients with NSTE-ACS scheduled for invasive strategy with angiography delayed >24 hours to reduce major adverse cardiovascular events 17
• Proton pump inhibitor (PPI) co-prescription is recommended for all patients on DAPT to reduce gastrointestinal bleeding risk 17

De-escalation Strategies

• Ticagrelor monotherapy is recommended for patients who have tolerated DAPT with ticagrelor, with aspirin discontinuation ≥1 month after PCI 17
• For patients requiring long-term anticoagulation, discontinuing aspirin 1-4 weeks after PCI and continuing P2Y12 inhibitor, preferably clopidogrel rather than ticagrelor, is recommended 17

Critical Pitfalls to Avoid

• Clopidogrel should not be used as first-line therapy when ticagrelor or prasugrel are available and not contraindicated, as this represents suboptimal care for ACS patients 17
• DAPT should not be discontinued prematurely, especially within the first month after stent placement, as this dramatically increases thrombotic risk 17
• A PPI should not be omitted from DAPT, as this simple intervention significantly reduces gastrointestinal bleeding 17

Monitoring Tolerance of Dual Antiplatelet Therapy

Clinical Monitoring Strategy

• The American College of Cardiology recommends assessing for major bleeding events, including gastrointestinal hemorrhage, intracranial bleeding, and clinically significant bleeding requiring medical attention or transfusion, with a strength of evidence based on high-quality randomized trials 18, 19
• The American College of Cardiology suggests evaluating bleeding risk scores, such as the PRECISE-DAPT score or HAS-BLED score, to stratify ongoing risk, with a moderate strength of evidence based on observational studies 19
• Consider early discontinuation of DAPT after 6 months in patients who develop high bleeding risk, such as those requiring oral anticoagulation, major surgery planned, or significant overt bleeding, based on expert opinion and case series 18, 19

Medication-Specific Adverse Effects

• The American College of Cardiology recommends avoiding prasugrel in patients with prior stroke/TIA due to increased bleeding risk, with a high strength of evidence based on randomized trials 18, 19
• Use caution when prescribing prasugrel to patients ≥75 years or <60 kg due to increased bleeding risk, based on subgroup analyses of randomized trials 18, 19

Adherence Assessment

• The American College of Cardiology emphasizes the importance of educating patients about continuing DAPT for the full recommended duration, with a high strength of evidence based on randomized trials 18, 19

Loading Doses for Antiplatelet Agents in Acute Coronary Syndrome

First-Line P2Y12 Inhibitor Selection

• The European Society of Cardiology recommends administering ticagrelor 180 mg loading dose as first-line therapy for patients presenting with ACS, followed by 90 mg twice daily maintenance 20, 21, 22
• For patients proceeding to PCI with no contraindications, the European Society of Cardiology recommends prasugrel 60 mg loading dose, followed by 10 mg daily maintenance 20, 21, 22, 23
• The European Society of Cardiology recommends clopidogrel 300-600 mg loading dose for patients who cannot receive ticagrelor or prasugrel, or who require oral anticoagulation 20, 21, 22

Critical Timing Considerations

• The European Society of Cardiology recommends administering the loading dose as soon as ACS is diagnosed to achieve antiplatelet effect within hours 20, 21, 22

Algorithm for P2Y12 Inhibitor Selection in ACS

• For patients with prior intracranial hemorrhage, the European Society of Cardiology recommends using clopidogrel 20, 21, 22
• For patients with prior ischemic stroke or TIA, the European Society of Cardiology recommends using ticagrelor, not prasugrel 20, 21, 22
• If PCI is planned and coronary anatomy is known, the European Society of Cardiology recommends prasugrel 60 mg loading dose, unless age ≥75 years or weight <60 kg 20, 21, 22, 23

Bleeding Risk Mitigation

• The European Society of Cardiology recommends aspirin 75-100 mg daily for all patients receiving P2Y12 inhibitors 20, 21, 22
• The European Society of Cardiology recommends proton pump inhibitor to reduce gastrointestinal bleeding risk 20

Duration of Therapy

• The European Society of Cardiology recommends standard duration of 12 months of dual antiplatelet therapy for all ACS patients unless excessive bleeding risk exists 20, 21, 22

Dual Antiplatelet Therapy for Unstable Angina

Initiation and Agent Selection

• The European Society of Cardiology recommends initiating dual antiplatelet therapy (DAPT) immediately upon presentation with aspirin plus ticagrelor (180 mg loading dose, then 90 mg twice daily) as the preferred first-line regimen, continuing for 12 months unless excessive bleeding risk exists 24
• The American Heart Association suggests starting DAPT immediately at presentation when unstable angina is diagnosed, before any invasive procedures are performed, regardless of whether patients will be managed medically or with percutaneous coronary intervention (PCI) 24, 25

Ticagrelor vs. Clopidogrel

• The European Society of Cardiology recommends ticagrelor as the default P2Y12 inhibitor for unstable angina, due to its superiority over clopidogrel in reducing cardiovascular events 24
• Ticagrelor reduces cardiovascular death by 21% compared to clopidogrel in acute coronary syndrome patients, although the specific data is not provided in the cited reference 24

Duration of DAPT

• The European Society of Cardiology recommends a standard duration of 12 months for all unstable angina patients regardless of management strategy (medical, PCI, or CABG) 24
• Shortened duration (6 months) may be considered in patients who develop high bleeding risk during treatment, while extended duration (>12 months) may be considered in patients who tolerate DAPT without bleeding complications and have high ischemic risk 24, 26

Critical Bleeding Risk Mitigation Strategies

• The European Society of Cardiology recommends that every unstable angina patient on DAPT should receive a proton pump inhibitor (PPI) to reduce gastrointestinal bleeding, as well as low-dose aspirin (75-100 mg daily) and radial artery access if cardiac catheterization is performed 24

Special Considerations

• The European Society of Cardiology suggests switching to ticagrelor immediately if a patient presents on chronic clopidogrel therapy, by giving the 180 mg loading dose without waiting for clopidogrel washout, due to ticagrelor's superiority over clopidogrel in reducing cardiovascular events 24

Dual Antiplatelet Therapy and Anticoagulation in Unstable Angina with Severe Renal Impairment

P2Y12 Inhibitor Selection

• Severe renal insufficiency (creatinine clearance < 30 mL/min) is an explicit exclusion criterion in major dual‑antiplatelet therapy trials and guideline recommendations for potent P2Y12 inhibitors such as ticagrelor and prasugrel. (ACC guideline) 27
• In patients with moderate‑to‑severe renal impairment, clopidogrel is the preferred P2Y12 inhibitor because it has been studied in this population, whereas ticagrelor and prasugrel lack robust safety data. (ACC guideline) 27

Duration of Dual Antiplatelet Therapy

• Dual antiplatelet therapy (aspirin + clopidogrel) should be continued for 12 months for all acute coronary syndrome presentations, including unstable angina, regardless of whether the patient undergoes percutaneous coronary intervention, medical management alone, or coronary artery bypass grafting. (AHA/ACC guideline) 28

Anticoagulant Dosing Adjustments in Severe Renal Impairment

• Enoxaparin dose must be reduced to 1 mg/kg subcutaneously once daily (instead of the standard twice‑daily regimen) when creatinine clearance is < 30 mL/min. (AHA/ACC guideline) 28
• Fondaparinux is contraindicated in patients with creatinine clearance < 30 mL/min. (AHA/ACC guideline) 28
• Unfractionated heparin does not require renal dose adjustment; recommended dosing is a 60 IU/kg loading dose (maximum 4000 IU) followed by an infusion of 12 IU/kg/h (maximum 1000 IU/h) titrated to a therapeutic aPTT of 60–80 seconds. (AHA/ACC guideline) 28
• Bivalirudin infusion should be reduced to 1 mg/kg/h in patients with creatinine clearance < 30 mL/min (instead of the standard 1.75 mg/kg/h). (AHA/ACC guideline) 28

Agents to Avoid in Severe Renal Impairment

• Ticagrelor and prasugrel should not be used as first‑line P2Y12 inhibitors in patients with creatinine clearance < 30 mL/min because guideline statements explicitly exclude this population. (ACC guideline) 27
• Fondaparinux should not be employed for anticoagulation in patients with creatinine clearance < 30 mL/min due to contraindication. (AHA/ACC guideline) 28
• Enoxaparin must be adjusted to a once‑daily regimen in severe renal impairment; failure to reduce the dose markedly increases bleeding risk. (AHA/ACC guideline) 28

Dual Antiplatelet Therapy (DAPT) in Acute Coronary Syndrome

Mechanistic Rationale

• Aspirin irreversibly inhibits cyclo‑oxygenase‑1, blocking thromboxane A₂–mediated platelet activation【29】.
• P2Y12 inhibitors block ADP‑mediated platelet activation via the P2Y12 receptor, providing a complementary antiplatelet pathway【29】.
• The combined blockade yields more complete platelet inhibition, which is essential because plaque rupture and subsequent platelet activation drive acute coronary syndromes【30】.

Clinical Benefits of Adding a P2Y12 Inhibitor

• In patients with ST‑segment‑elevation myocardial infarction treated with fibrinolysis, adding clopidogrel to aspirin reduces 30‑day major adverse cardiovascular events, recurrent myocardial infarction, and improves survival【29】.
• In patients undergoing percutaneous coronary intervention, DAPT lowers the incidence of stent thrombosis, a complication associated with 4 %–45 % mortality【31】.
• Compared with aspirin alone, DAPT reduces the composite of cardiovascular death, non‑fatal myocardial infarction, or non‑fatal stroke【30】【29】.
• Each 1.0‑mmol/L decrease in platelet aggregation corresponds to an approximate 22 % relative reduction in cardiovascular events【29】.
• Without DAPT, coronary stents carry an estimated 40 % risk of acute myocardial infarction or death【31】.
• Discontinuation of DAPT is linked to a hazard ratio of ~161 for catastrophic events such as stent thrombosis, myocardial infarction, or death【31】.
• About 80 % of stent‑thrombosis events occur within the first 30 days after PCI【32】.

Guideline‑Mandated Standard of Care

• All major international societies issue a Class I (strong) recommendation for DAPT in acute coronary syndrome【30】【33】【29】.
• The 2025 ACC/AHA/SCAI guidelines (American College of Cardiology) advise adding a P2Y12 inhibitor to aspirin for every ACS patient, irrespective of whether the management strategy is PCI, medical therapy, or coronary‑artery bypass grafting【29】.
• The 2019 ESC/EACTS guidelines (European Society of Cardiology) recommend maintaining DAPT for 12 months after ACS unless contraindicated by excessive bleeding risk【30】【33】.
• A 12‑month DAPT duration is the default for all ACS patients after stent implantation, regardless of stent type【30】【33】.

Preferred P2Y12 Inhibitor Selection

• Ticagrelor (180 mg loading, 90 mg twice daily) or prasugrel (60 mg loading, 10 mg daily) are strongly preferred over clopidogrel because they achieve greater reductions in cardiovascular events【30】【29】.
• Prasugrel provides superior protection against myocardial infarction and stent thrombosis compared with clopidogrel【30】.
• Clopidogrel should be reserved only when ticagrelor and prasugrel are unavailable, not tolerated, or contraindicated【30】【33】.

Contraindications & Pitfalls

• Prasugrel is absolutely contraindicated in patients with a prior stroke or transient ischemic attack, irrespective of how remote the event is【30】.
• In patients with a prior stroke/TIA, ticagrelor is the preferred P2Y12 inhibitor【29】.
• DAPT must not be discontinued within the first month after stent placement, as early interruption dramatically raises the risk of stent thrombosis, myocardial infarction, and death【31】【32】.

Bleeding‑Risk Mitigation Strategies

• A proton‑pump inhibitor should be prescribed to every patient on DAPT; this Class I recommendation markedly reduces gastrointestinal bleeding【30】.
• Aspirin dose should be kept at 75–100 mg daily when combined with a P2Y12 inhibitor, avoiding higher doses that increase bleeding without added benefit【30】【29】.

Special Populations

Patients Requiring Oral Anticoagulation (Triple Therapy)

• Aspirin should be stopped 1–4 weeks after PCI, and clopidogrel continued (rather than ticagrelor or prasugrel) because it carries a substantially lower bleeding risk【29】【32】.
• Potent P2Y12 inhibitor trials excluded individuals on long‑term anticoagulation, limiting direct evidence in this group【32】.
• Meta‑analyses show no difference in mortality or stroke when aspirin is withdrawn in anticoagulated patients, though there is a modest increase in myocardial infarction and stent thrombosis【32】.

Patients with High Bleeding Risk (PRECISE‑DAPT Score ≥ 25)

• A shortened DAPT course of 6 months may be considered, but the default remains 12 months for most ACS patients【30】【33】.

Preferred Dual Antiplatelet Therapy for NSTEMI

Preferred Regimen

P2Y12 Inhibitor Selection

Loading and Maintenance Dosing

Alternative P2Y12 Inhibitors

Contraindications / Precautions for Prasugrel

Duration of Therapy

Anticoagulation in Addition to DAPT

Contraindications to Specific Agents

Dual Antiplatelet Therapy (DAPT) – Indications and Management

1. Indications for DAPT

• The European Society of Cardiology (ESC) states that DAPT is mandatory for every patient with acute coronary syndrome (ACS)—including STEMI, NSTEMI, and unstable angina—regardless of whether they are managed medically, with percutaneous coronary intervention (PCI), or coronary artery bypass grafting (CABG). 37
• All ACS patients should receive DAPT for 12 months, combining low‑dose aspirin (75–100 mg daily) with a P2Y12 inhibitor, irrespective of the chosen treatment strategy. 37
• Every patient undergoing PCI with stent implantation requires DAPT, independent of clinical presentation (stable coronary disease or ACS). 37
• In stable‑CAD patients treated with PCI, the recommended DAPT duration is 1–6 months, tailored to bleeding risk; newer‑generation drug‑eluting stents are preferred over bare‑metal stents. 37

2. First‑Line P2Y12 Inhibitor Selection

• Ticagrelor (180 mg loading, then 90 mg twice daily) plus aspirin 75–100 mg daily is the preferred first‑line regimen for all ACS patients. 37, 38
• Prasugrel (60 mg loading, then 10 mg daily) plus aspirin is recommended for P2Y12‑inhibitor‑naïve ACS patients undergoing PCI, provided no contraindications exist. 37, 38
• Clopidogrel (600 mg loading, then 75 mg daily) plus aspirin should be reserved for patients who cannot receive ticagrelor or prasugrel because of contraindications such as prior intracranial bleeding or the need for oral anticoagulation. 37, 38
• Prasugrel is absolutely contraindicated in patients with a history of stroke or transient ischemic attack due to a markedly increased risk of cerebrovascular bleeding. 38

3. Recommended DAPT Duration

• The default DAPT duration for ACS patients without high bleeding risk is 12 months. 37
• A 6‑month course may be considered for patients identified as high bleeding risk (e.g., PRECISE‑DAPT score ≥ 25 or meeting ARC‑HBR criteria). 37
• Extended DAPT beyond 12 months can be contemplated in ACS patients who have tolerated therapy without bleeding, especially those with prior stent thrombosis, peripheral artery disease, or complex PCI. 37, 38

4. Bleeding‑Risk Mitigation

• Aspirin dose should be maintained at 75–100 mg daily when combined with any P2Y12 inhibitor to minimise bleeding. 37

5. Special Clinical Scenarios

5.1 Triple Therapy (Oral Anticoagulation + DAPT)

• The duration of triple therapy should be limited to a maximum of 6 months or omitted after hospital discharge, balancing ischemic benefit against bleeding risk. 37, 38
• When oral anticoagulation is required, clopidogrel (rather than ticagrelor or prasugrel) is the preferred P2Y12 inhibitor because it is associated with substantially lower bleeding rates. 37, 38

5.2 Peri‑operative Management

• Aspirin should be continued peri‑operatively whenever the surgical bleeding risk permits. 37, 38
• DAPT must not be discontinued within the first month after stent implantation for elective non‑cardiac surgery, as early interruption markedly raises the risk of thrombotic events. 37, 38
• If a P2Y12 inhibitor must be stopped for scheduled surgery, the interruption should occur no earlier than 1 month after stent placement, regardless of stent type, provided aspirin can be maintained throughout the peri‑operative period. 37
• Full DAPT should be re‑initiated as soon as feasible after the operative procedure. 38

5.3 Prior Stent Thrombosis

• Patients with a history of stent thrombosis should receive prolonged DAPT, especially when no correctable cause of the thrombosis is identified. 37, 38

5.4 CABG‑Only Management

• Current evidence is insufficient to support routine DAPT in stable‑CAD patients who undergo CABG without prior PCI. 37

6. Common Pitfalls to Avoid

• Do not use clopidogrel as first‑line therapy when ticagrelor or prasugrel are available and not contraindicated, as this represents suboptimal care for ACS patients. 37
• Do not discontinue DAPT prematurely (especially within the first month after stent placement), because early interruption dramatically increases the risk of stent thrombosis, myocardial infarction, and death. 37
• Do not prescribe aspirin doses > 100 mg daily when combined with a P2Y12 inhibitor, since higher doses raise bleeding risk without added antithrombotic benefit. 37

Ticagrelor Preference and Dosing in Acute Coronary Syndrome

Guideline Recommendations

• The 2025 ACC/AHA/SCAI guidelines give ticagrelor a Class I (strong) recommendation for patients with non‑ST‑segment‑elevation acute coronary syndrome (NSTE‑ACS) undergoing percutaneous coronary intervention and for ST‑segment‑elevation myocardial infarction (STEMI) managed with primary PCI. 39

Dosing Adjustments for Specific Populations

• For STEMI patients > 75 years receiving fibrinolytic therapy, the ACC/AHA guidelines recommend a clopidogrel loading dose of 300 mg (or an initial 75 mg dose if the patient is >75 years) when clopidogrel is used. 39

Evidence‑Based Rationale

• The 2025 ACC/AHA guidelines prioritize the mortality benefit demonstrated in the PLATO trial, thereby maintaining ticagrelor as the preferred P2Y12 inhibitor for acute coronary syndrome despite mixed real‑world data. 39