Non-ST-Elevation Acute Coronary Syndromes

Publication Date: September 22, 2014

Key Points

Key Points

ACS has evolved as a useful operational term that refers to a spectrum of conditions compatible with acute myocardial ischemia and/or infarction which are usually due to an abrupt reduction in coronary blood flow (Figure 1).
  • A key branch point is ST elevation or new left bundle-branch block on the ECG, which are considerations for immediate coronary angiography to determine if there is an indication for reperfusion therapy to open a likely completely occluded coronary artery.
The hallmark of ACS is the sudden imbalance between myocardial oxygen supply and demand, which is usually the result of coronary artery obstruction.
  • The imbalance may also be caused by other conditions, including excessive myocardial oxygen demand in the setting of a stable flow-limiting lesion; acute coronary insufficiency due to other causes (e.g., vasospastic [Prinzmetal] angina, coronary embolism, coronary arteritis); noncoronary causes of myocardial oxygen supply-demand mismatch (e.g., hypotension, severe anemia, hypertension, tachycardia, hypertrophic cardiomyopathy, severe aortic stenosis); nonischemic myocardial injury (e.g., myocarditis, cardiac contusion, cardiotoxic drugs); and multifactorial causes that are not mutually exclusive (e.g., stress [Takotsubo] cardiomyopathy, pulmonary embolism, severe HF, sepsis).
The absence of persistent ST elevation is suggestive of NSTE-ACS (except in patients with true posterior MI). NSTE-ACS can be further subdivided on the basis of cardiac biomarkers of necrosis (e.g., cardiac troponin).
  • If cardiac biomarkers are elevated and the clinical context is appropriate, the patient is considered to have NSTEMI. Otherwise, the patient is deemed to have UA.
  • ST depression, transient ST elevation, and/or prominent T-wave inversions may be present but are not required for a diagnosis of NSTEMI.
  • Abnormalities on the ECG and elevated troponins in isolation are insufficient to make the diagnosis of ACS but must be interpreted in the appropriate clinical context.

Diagnosis

...gnosis...

...Coronary SyndromesThe top half of the...


...GRACE Risk Model NomogramHaving trouble vie...


...e 1. TIMI Risk Scorea for NSTE-ACS...


...2. Clinical Assessment and Initial Evaluatio...


...ble 3. ED or Outpatient Facility Pre...


...le 4. Prognosis—Early Risk Strati...


...le 5. Cardiac Biomarkers and the Univers...


Treatment

...reatment...

...ndard Medical TherapiesHaving trouble...


...ble 7. Inhibitors of the Renin-Ang...


...8. Initial Antiplatelet/Anticoagulant T...


...ble 9. Early Invasive and Ischemia-Guided Strat...


...gorithm for Management of Patients With Defin...


...ble 10. Risk Stratification Before...


...dial RevascularizationHaving troub...


...of Urgent CABG in Patients With NSTE-ACS in Re...


Table 13. Discharge From the ED or Chest Pain Un...


...rs Associated With Appropriate Selection o...


...e 15. Dosing of Parenteral Anticoagulants Dur...


...16. Late Hospital Care, Hospital Discharg...


...le 17. Quality of Care and Outcomes for ACS...


...e 18. Special Patient GroupsHaving trouble...