Acute coronary syndrome
Classification
Unstable angina
Unstable angina is defined as "precordial pain at rest, which may precede a myocardial infarction".[1]
Myocardial infarction
A myocardial infarction is defined as "gross necrosis of the myocardium, as a result of interruption of the blood supply to the area".[2]
Diagnosis
Clinical practice guidelines jointly written by multiple expert groups anchor the diagnosis on troponin blood assays obtained within 6 hours and again within 8-12 hours of a patient arriving for medical care.[3][4]
The Acute Cardiac Ischemia Time-Insensitive Predictive Instrument (ACI-TIPI), a clinical prediction rule, can help diagnose patients with chest pain and has been shown to improve medical care in a randomized controlled trial.[5][6]
The ACI-TIPI was studied up through 1993 before troponin assays were widely available and thus does not incorporate the troponin. However, the ACI-TIPI should retain its ability to use the medical history and the EKG to decide who should be observed for serial troponin levels. It is unclear why this role is not recognized by the ACC/AHA guidelines. One reason may be that the ACI-TIPI is patented.[7][8]
Treatment
Clinical practice guidelines address the treatment of unstable angina and non-ST-elevation myocardial infarction.[3][4]
Patients with ST-segment changes, a TIMI risk score of 3 or more, elevated myocardial enzymes, and elderly patients may be most likely to benefit from invasive management according to the TACTICS randomized controlled trial.[9]
Non ST-segment elevation myocardial infarction (NSTEMI)
Among patients with NSTEMI, elderly patients may receive the most benefit from invasive treatment.[10]
ST-segment elevation myocardial infarction (STEMI)
Prognosis
The Thrombolysis in Myocardial Infarction (TIMI) Risk Score is a clinical prediction rule that can predict the likelihood of morbidity in patients with unstable angina or NSTEMI.[11] The TIMI risk score is scored as one point for each of the following:
- Age 65 years or older
- At least 3 risk factors for coronary artery disease (family history or coronary heart disease, hypertension, hypercholesterolemia, diabetes, current smoking)
- Prior coronary stenosis of 50% or more
- ST-segment deviation on electrocardiogram at presentation
- At least 2 anginal events in prior 24 hours
- Use of aspirin in prior 7 days
- Elevated serum cardiac markers
The GRACE Risk Score and the Platelet Glycoprotein IIb/IIIa in Unstable Angina: Receptor Suppression Using Integrilin Therapy (PURSUIT) risk model can also help predict which patients will have complications.
References
- ↑ National Library of Medicine. Unstable angina. Retrieved on 2007-10-28.
- ↑ National Library of Medicine. Myocardial infarction. Retrieved on 2007-10-28.
- ↑ 3.0 3.1 Anderson JL, Adams CD, Antman EM, et al (2007). "ACC/AHA 2007 guidelines for the management of patients with unstable angina/non-ST-Elevation myocardial infarction: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to Revise the 2002 Guidelines for the Management of Patients With Unstable Angina/Non-ST-Elevation Myocardial Infarction) developed in collaboration with the American College of Emergency Physicians, the Society for Cardiovascular Angiography and Interventions, and the Society of Thoracic Surgeons endorsed by the American Association of Cardiovascular and Pulmonary Rehabilitation and the Society for Academic Emergency Medicine". J. Am. Coll. Cardiol. 50 (7): e1–e157. DOI:10.1016/j.jacc.2007.02.01. PMID 17692738. Research Blogging.
- ↑ 4.0 4.1 Braunwald E, Antman EM, Beasley JW, et al (2002). "ACC/AHA 2002 guideline update for the management of patients with unstable angina and non-ST-segment elevation myocardial infarction--summary article: a report of the American College of Cardiology/American Heart Association task force on practice guidelines (Committee on the Management of Patients With Unstable Angina)". J. Am. Coll. Cardiol. 40 (7): 1366–74. PMID 12383588. [e]
- ↑ Selker HP, Beshansky JR, Griffith JL, et al (1998). "Use of the acute cardiac ischemia time-insensitive predictive instrument (ACI-TIPI) to assist with triage of patients with chest pain or other symptoms suggestive of acute cardiac ischemia. A multicenter, controlled clinical trial". Ann. Intern. Med. 129 (11): 845–55. PMID 9867725. [e] Online calculator at InfoRetriever
- ↑ Selker HP, Griffith JL, D'Agostino RB (1991). "A tool for judging coronary care unit admission appropriateness, valid for both real-time and retrospective use. A time-insensitive predictive instrument (TIPI) for acute cardiac ischemia: a multicenter study". Med Care 29 (7): 610–27. PMID 2072767. [e]
- ↑ Selker HP et al.. Continuous monitoring using a predictive instrument. Retrieved on 2007-11-29.
- ↑ Selker HP et al.. Continuous monitoring using a predictive instrument. Retrieved on 2007-11-29.
- ↑ Cannon CP, Weintraub WS, Demopoulos LA, et al (2001). "Comparison of early invasive and conservative strategies in patients with unstable coronary syndromes treated with the glycoprotein IIb/IIIa inhibitor tirofiban". N. Engl. J. Med. 344 (25): 1879-87. PMID 11419424. [e]
- ↑ Bach RG, Cannon CP, Weintraub WS, et al (2004). "The effect of routine, early invasive management on outcome for elderly patients with non-ST-segment elevation acute coronary syndromes". Ann. Intern. Med. 141 (3): 186-95. PMID 15289215. [e]
- ↑ Antman EM, Cohen M, Bernink PJ, et al (2000). "The TIMI risk score for unstable angina/non-ST elevation MI: A method for prognostication and therapeutic decision making". JAMA 284 (7): 835–42. PMID 10938172. [e] printable card