For patients with unstable angina/non-ST elevation myocardial infarction. There are two treatment strategies.
The first is the interventional strategy of performing coronary angiography to see if patient requires bypass surgery or a angioplasty/stent for an acute blockage.
The second strategy is the conservative strategy. This consists of treating the patient only with medical therapy and not performing a coronary angiogram unless the patient has an abnormal noninvasive test such as an exercise stress test.
We first determine the patient’s short term risk of death or nonfatal MI using one of the risk estimators.
The short term risk of death or nonfatal myocardial infarction in unstable angina/non-ST elevation myocardial infarction can be estimated using the GRACE risk score calculator available online at:
A chart representing the risk is available in the 2011 AHA Unstable Angina/non-ST elevation myocardial infarction updated guidelines (Table 7, p e442) available at: https://circ.ahajournals.org/content/123/18/e426.full.pdf.
Patients at high risk are then best managed by the invasive strategy and patients at low risk can be managed by the conservative (noninvasive) strategy. The following recommendations are from the 2011 AHA UA/NSTEMI guidelines above.
The invasive initial treatment strategy (meaning coronary angiography and medical therapy) is preferred for:
Recurrent angina or ischemia at rest or with low level of activity despite intensive medical therapy
Elevated cardiac biomarkers (TnT or TnI)
New or presumably new ST segment depression
Signs or symptoms of heart failure or new or worsening mitral regurgitation
High risk findings from noninvasive testing
Sustained Ventricular tachycardia
PCI within six months
High risk score (e.g. TIMI, Grace)
Reduced left ventricular function (LVEF less than 40%)
The conservative initial treatment strategy (meaning medical therapy without coronary angiography) is preferred for
Low risk score (e.g. TIMI , GRACE)
Patient or physician preference in the absence of high risk features (basically means intermediate risk as defined by Table 7 p e442 in the 2011 Guidelines).