What are the effects of using both aspirin and clopidogrel (Plavix) for ischemic heart disease?

From the Guidelines

Dual antiplatelet therapy with aspirin and clopidogrel is recommended for patients with ischemic heart disease, particularly following acute coronary syndrome or coronary stent placement, as it reduces the risk of major cardiovascular events and stent thrombosis, despite a slight increase in bleeding risk. The typical regimen consists of low-dose aspirin (81-100 mg daily) combined with clopidogrel (75 mg daily) 1. For patients undergoing percutaneous coronary intervention (PCI) with stent placement, a loading dose of clopidogrel (300-600 mg) is usually given, followed by the daily maintenance dose. The duration of DAPT depends on the specific clinical scenario: 12 months is standard after acute coronary syndrome, while patients with stable coronary disease receiving drug-eluting stents typically require 6-12 months of therapy 1.

Some key points to consider when using dual antiplatelet therapy include:

• The combination of clopidogrel and aspirin has been shown to reduce the risk of major cardiovascular events, including myocardial infarction, stroke, and vascular death, in patients with acute coronary syndrome 1.
• The use of dual antiplatelet therapy is not routinely recommended for patients with prior ischemic stroke due to the risk of bleeding 1.
• Patients with prior gastrointestinal bleeding are at highest risk for recurrent bleeding on antiplatelet therapy, and the use of proton pump inhibitors (PPIs) may be beneficial in reducing this risk 1.
• The concomitant use of PPIs and thienopyridines, such as clopidogrel, may reduce the antiplatelet effects of clopidogrel, although the clinical significance of this interaction is not established 1.

Overall, the benefits of dual antiplatelet therapy with aspirin and clopidogrel in patients with ischemic heart disease outweigh the risks, and this combination therapy should be used in accordance with current guidelines and patient-specific factors.

From the FDA Drug Label

Clopidogrel tablets are indicated to reduce the rate of myocardial infarction (MI) and stroke in patients with non–ST-segment elevation ACS (unstable angina [UA]/non–ST-elevation myocardial infarction [NSTEMI]), including patients who are to be managed medically and those who are to be managed with coronary revascularization Clopidogrel tablets should be administered in conjunction with aspirin.

Clopidogrel tablets are indicated to reduce the rate of myocardial infarction and stroke in patients with acute ST-elevation myocardial infarction (STEMI) who are to be managed medically. Clopidogrel tablets should be administered in conjunction with aspirin.

The use of both aspirin and clopidogrel is indicated for patients with ischemic heart disease, specifically those with:

• Acute Coronary Syndrome (ACS)
• Recent MI
• Recent Stroke
• Established Peripheral Arterial Disease

This combination is recommended to reduce the rate of myocardial infarction and stroke in these patients 2.

From the Research

Ischemic Heart Disease Treatment

Using both aspirin and clopidogrel for ischemic heart disease is a common practice, and several studies have investigated the efficacy and safety of this treatment approach.

• Dual antiplatelet therapy (DAPT) with aspirin and clopidogrel is recommended for at least 6 and 12 months following percutaneous coronary intervention with drug-eluting stents among patients with stable ischemic heart disease and acute coronary syndrome, respectively 3.
• A systematic review and network meta-analysis found that DAPT with aspirin and clopidogrel for 12 months was compared with 4 major strategies: high-potency, high- to low-potency, low-dose, and short-duration DAPT, and the results showed that high- to low-potency DAPT and aspirin+prasugrel containing DAPT for 12 months had a significantly lower incidence of major adverse cardiovascular events at 1 year 4.
• Another study found that dual antiplatelet therapy with clopidogrel and aspirin has been considered the gold standard for reducing cardiovascular events in patients with acute coronary syndrome undergoing percutaneous coronary intervention, but the use of clopidogrel has limitations, including variable patient response 5.

Duration of Dual Antiplatelet Therapy

The duration of DAPT is an important consideration in the treatment of ischemic heart disease.

• A systematic review and meta-analysis found that short-term (3-6 months) DAPT had a lower major bleeding rate compared to standard-term (12 months) DAPT, but a higher repeat revascularization rate 6.
• A study found that decisions surrounding the duration of DAPT after revascularization should include clinical judgment, assessment of the risk of bleeding and ischemic events, and time after revascularization 3.

Alternative Antiplatelet Agents

Several alternative antiplatelet agents have been developed, including prasugrel and ticagrelor.

• A study found that prasugrel and ticagrelor containing DAPT for 12 months had significantly higher rates of major bleeding compared to DAPT with aspirin and clopidogrel for 12 months 4.
• Another study found that prasugrel is an oral thienopyridine with greater potency and less antiplatelet variability than clopidogrel, and ticagrelor is another oral antiplatelet agent that has shown greater platelet inhibition than clopidogrel 5.