When should an angiogram be performed in a patient with Non-ST-Elevation Myocardial Infarction (NSTEMI)?

From the Guidelines

For patients with NSTEMI, an early invasive strategy with coronary angiography is recommended within 24 hours of presentation for high-risk patients, with immediate angiography (within 2 hours) indicated for very high-risk patients with ongoing ischemia, hemodynamic instability, or cardiogenic shock. The decision to perform angiography on NSTEMI patients should be based on their risk profile, with high-risk features including hemodynamic instability, refractory angina despite medical therapy, heart failure symptoms, life-threatening arrhythmias, dynamic ST-T wave changes, or an elevated GRACE risk score 1. According to the 2021 ESC guidelines, an immediate invasive strategy (<2 hours) is recommended in patients with very high-risk criteria, such as hemodynamic instability or cardiogenic shock, while an early invasive strategy within 24 hours is recommended in patients with high-risk criteria, such as diagnosis of NSTEMI or dynamic ST/T-segment changes 1.

The 2022 ACC/AHA/SCAI guideline also supports an invasive strategy with intent to proceed with revascularization in patients with NSTE-ACS who are at elevated risk of recurrent ischemic events and are appropriate candidates for revascularization, with a recommendation for emergency revascularization in patients with cardiogenic shock 1. The TIMACS study, although older, provides insight into the timing of angiography, suggesting that early intervention might prevent ischemic events, but the evidence base for a definitive recommendation on timing is weak 1.

In clinical practice, the timing of angiography should be individualized based on the patient's risk profile and clinical presentation. High-risk patients should undergo angiography within 2-24 hours, while intermediate-risk patients should undergo angiography within 24-72 hours. Before angiography, patients should receive dual antiplatelet therapy, anticoagulation, and high-intensity statin therapy to reduce recurrent ischemic events and improve outcomes 1.

Key considerations in the decision to perform angiography on NSTEMI patients include:

• Risk profile: high-risk features, such as hemodynamic instability or elevated GRACE risk score
• Clinical presentation: ongoing ischemia, refractory angina, or cardiogenic shock
• Timing: immediate angiography (within 2 hours) for very high-risk patients, early invasive strategy within 24 hours for high-risk patients
• Pre-procedural therapy: dual antiplatelet therapy, anticoagulation, and high-intensity statin therapy.

From the Research

Timing of Angiogram in NSTEMI

• The optimal timing of angiography in Non-ST-Elevation Myocardial Infarction (NSTEMI) is a matter of debate 2.
• The 2015 European Society of Cardiology NSTEMI guidelines recommend angiography within 24 hours in high-risk patients with NSTEMI 3.
• A study found that diagnosing NSTEMI patients in the pre-hospital phase or immediately upon hospital admission is feasible, and acute coronary angiography (CAG) may impact the mode of revascularization and is associated with earlier revascularization and shorter hospital stay 3.
• Another study suggested that patients who underwent percutaneous coronary intervention (PCI) between 90 minutes to 24 hours from presentation had better 1-year outcomes, but treatment selection bias makes causal inference concerning rapid revascularization and outcome unreliable 2.
• A real-world cohort study found that the early invasive strategy did not reduce the incidence of major adverse cardiac events (MACEs) and mortality within 30 days compared with the delayed invasive strategy in NSTEMI patients 4.

Patient Characteristics and Outcomes

• Patients with prior coronary artery bypass grafting (CABG) had a higher risk profile, but similar risk-adjusted in-hospital adverse outcomes compared with patients without prior CABG 5.
• Patients with NSTEMI and normal coronary arteries had a good long-term prognosis, and predictors of normal coronary arteries included female sex, age <55 years, and the absence of diabetes, previous antiplatelet treatment, or ST-segment depression 6.
• The timing of angiography and outcomes in patients with NSTEMI may vary depending on individual patient characteristics and risk factors 4, 5.

Clinical Considerations

• The decision to perform an angiogram in NSTEMI should be based on individual patient characteristics, risk factors, and clinical presentation 3, 2, 4, 5, 6.
• Further research is needed to determine the optimal timing of angiography in NSTEMI and to clarify the clinical benefits of acute CAG in NSTEMI patients 3, 2.