Update your Knowledge with MKSAP 18 Q&A: Answer and Critique

Answer

D: Urgent angiography

Educational Objective

Treat a patient with a non–ST-elevation acute coronary syndrome with an early invasive strategy.

Critique

This patient should undergo urgent angiography. Patients with a non–ST-elevation acute coronary syndrome (NSTE-ACS) should undergo risk stratification before invasive treatment because the link between revascularization and clinical outcomes is less clear in these patients than in patients with ST-elevation myocardial infarction (STEMI). Risk stratification tools, such as the TIMI risk score, can be used to determine which patients with NSTE-ACS should be treated with an invasive strategy versus an ischemia-guided approach. An early invasive strategy benefits patients with high TIMI risk scores (5-7) and intermediate TIMI risk scores (3-4). This patient has a TIMI risk score of 5, as indicated by the presence of three traditional risk factors for coronary artery disease, aspirin use within the last week, age older than 65 years, two or more angina episodes in the past 24 hours, and significant ST-segment deviation on electrocardiogram. His score places him at high risk for death and cardiac ischemic events, and despite the absence of elevated cardiac biomarker levels, urgent coronary angiography is warranted.

Stress testing with adenosine nuclear stress testing or exercise stress electrocardiography could be considered for purposes of risk stratification if this patient declines an early invasive strategy. However, an invasive strategy has been shown to improve the composite clinical endpoint of death, recurrent myocardial infarction, and repeat hospitalization compared with an ischemia-guided approach in patients with NSTE-ACS.

In patients with suspected NSTE-ACS with a normal initial troponin level and inconclusive electrocardiographic findings, further diagnostic studies may be indicated. Coronary CT angiography is appropriate, and rest single-photon emission CT may be appropriate. However, in this patient with a high pretest probability of CAD, coronary CT angiography would only delay critical therapy.

Key Point

Patients with a non–ST-elevation acute coronary syndrome who have a high or intermediate TIMI risk score should be treated with an early invasive strategy.

Bibliogrpahy

Amsterdam EA, Wenger NK, Brindis RG, Casey DE Jr, Ganiats TG, Holmes DR Jr, et al; ACC/AHA Task Force Members. 2014 AHA/ACC guideline for the management of patients with non-ST-elevation acute coronary syndromes: executive summary: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. Circulation. 2014;130:2354-94. [PMID: 25249586] doi:10.1161/CIR.0000000000000133

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