Acute coronary syndrome (ACS) refers to a group of
symptoms that are attributed to obstruction of coronary arteries. In other
words, it is a term that includes heart attack and unstable angina (a condition
in which the heart doesn't get enough blood flow and oxygen).
There is a
specific type of heart attack, called non-ST elevation myocardial infarction,
which does not show the diagnostic elevation on the ECG suggestive of a heart
attack occurring. Acute coronary syndrome (ACS) is measured using a
Thrombolysis in Myocardial Infarction risk score (TIMI). It categorizes a
patient's percentage risk of all-cause mortality and new or recurring ischemic
Angiography is a non-invasive imaging procedure that
can be performed faster than the cardiac catheterization and with less
discomfort and speedy recovery.
The Coronary Computed Tomographic Angiography
(CCTA) uses advanced CT technology (computed tomography) with intravenous (IV)
contrast dye for obtaining three-dimensional high resolution pictures of blood
vessels and heart. CCTA is also known as multi-slice computed tomography
(MSCT), Cardiac CAT or Cardiac CT. Nowadays it is seen that emergency departments are
crowded by patients with possible acute coronary syndromes.
However, for most
of them the symptoms are ultimately found not to be of a heart disease. Although the coronary computed tomographic
angiography (CCTA) is known to have negative predicitive ability in the
identification of coronary diseases, its role in determining the safety of
discharging patients from the emergency department is not well proven.
Harold Litt and colleagues, in a study published in
New England Journal of Medicine 2012, assessed the effectiveness of CCTA for
safe discharge of patients with possible acute coronary syndromes. For the purpose of study, CCTA or traditional care
was randomly done on low-to-intermediate-risk patients with acute coronary
syndromes in 2:1 ratio.
involved 1370 patients aged above 30 years with a TIMI risk score of 0 to 2 and
signs and symptoms that warranted admission or testing.
patients were enrolled at the five study centers in the United States. Out of
1370 volunteers, 462 received traditional care while 908 received CCTA.
showed that in contrast to traditional care receiving group where 22.7 percent
were safely discharged, patients in CCTA group had higher percentage (49.6
percent) of being discharged safely from the emergency department.
short duration of hospital stay and greater coronary disease detection rate.
During the study no serious event was noted in either of the groups.
The study revealed the efficacy of CCTA in
detecting coronary syndromes in low-to-intermediate-risk patients and promoted
a speedy and safe discharge from the emergency department who would otherwise
was funded by the Commonwealth of Pennsylvania Department of Health and the
American College of Radiology Imaging Network Foundation. Reference:
CT Angiography for Safe Discharge of Patients
with Possible Acute Coronary Syndromes; Harold Litt et al; N Engl J Med 2012; 366:1393-1403