الفهرس 
ACUTE CORONARY SYNDROMESOnly 14 pages are availabe for public view
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Abstract
T
he management of patients with an acute coronary syndrome (ACS) requires accurate risk stratification to guide appropriate therapy.
The Thrombolysis in Myocardial Infarction (TIMI) Risk Score for stratification of patients with non- ST-segment-elevation myocardial infarction (MI) was derived from the population of the TIMI 11B trial (Antman et al., 2000).
The score is calculated as the sum of seven presenting characteristics, and has been validated in subsequent trial populations (Cannon et al., 2001). However, there is only one small study (n¼245) evaluating the usefulness of the TIMI risk score in stratifying unselected patients with possible ACS, outside of trial or registry settings (Bartholomew et al., 2004).
When originally developed, the TIMI risk score was correlated with clinical end points, such as death, myocardial infarction, or urgent revascularization (Anteman et al., 2000).
Our study aims to determine whether the TIMI risk score correlate with the angiographic extent and severity of coronary artery disease in patient with acute coronary syndrome. So our study results shows the score has a broader usefulness in that it can be used to predict angiographic findings as well, and use it as indicator for the clinical end point or outcome.
Our prospective study was done from December 2008-to July 2009. TIMI risk score was applied for (75) unselected cases of acute coronary syndrome were admitted in 6 October hospital cardiac care unit (CCU) and introduced to Ain Shams University. Although the TIMI risk score was not developed in a population including STEMI, investigators from the global registry of acute coronary events (GRACE) have shown that risk factors for subsequent major events are similar for STEMI and NSTEMI (Granger et al., 2003).
Our study include patients with ST elevation myocardial infarction, non ST elevation myocardial infarction and patients with unstable angina(inclusive criteria).We exclude patients who had coronary artery bypass graft (CABG) or Percutaneous coronary intervention (PCI) in previous 6 months (exclusive criteria).
In our study the seven TIMI criteria have a significant predictive value in a cohort and significant CAD was found in 63 patients (84%). 24 patients (32%) have significant one-vessel disease, 23 (30.67%) have significant two-vessel disease, 16 (20.33%) have significant three-vessel CAD, and 3 (4%) have significant left main disease. Study results are summarized in Table (21). The Patients with TIMI score 0 to 2 have a greater likelihood of normal or non-significant CAD than patients with TIMI score 3 to 4, whereas patients with TIMI score 3 to 4 have a greater likelihood of normal or non-significant CAD than those with TIMI score 5 to 7.
Significant 3-vessel disease or left main disease was more likely to be found in patients with TIMI score 5 to 7 than in patients with TIMI score 3 to 4, and in patients with TIMI score 0 to 2 not found (p=0.022)
Normal or non significant CAD was not found in patients with TIMI score ≥5. Significant 3-vessel or left main disease was not found in patients with TIMI score 0 to 2. So in our study we found that, there is a significant correlation between the increase of TIMI SCORE and increase the severity and extent of coronary angiography result in patient with acute coronary syndrome (p = 0.000).
In this study, the predictive value of the established TIMI risk score was examined. This analysis was performed in an unselected cohort of patients admitted to with acute coronary syndrome. There was a clear correlation between TIMI risk score and the result of the coronary angiography. This agree with the study done by Santiago Garcia et al. (2004) to 2,624 patients. Also our data support the use of the TIMI risk score in unselected patients in clinical practice, and confirm the findings of Bartholomew et al. (2004).
This agree with the study which done by Soiza, et al. (2005). Which include 869 cases of possible ACS. Also support the study of Pollack et al. (2006) which found that The TIMI risk score may be a useful tool for risk stratification of ED patients with chest pain syndrome.
Our study agree with the study of Benjamin et al. (2010). Which found that in addition to risk stratifying ED patients with chest pain at the initial ED evaluation, the TIMI score can also predict the 1-year cardiovascular events in this patient, 2819 patients are included in this study. But in this study Patients with ST-segment elevation myocardial infarction (acute myocardial infarction) were excluded.
In our study we have 4 patients,(36%) of patients with TIMI score (0_2) with significant coronary lesions,(2 of them single vessel disease), (2 with two vessel disease), so patients with low risk not exclude the presence of significant coronary lesion.
The most attractive aspect of the TIMI risk score is that it can be estimated at the bedside with easy-to obtain clinical, laboratory, and electrocardiographic parameters. Estimating the coronary anatomy before angiography is performed could be useful when deciding on diagnostic and therapeutic interventions.
Cardiologists and surgeons are concerned about adverse outcomes among CABG patients who were given clopidogrel in the preoperative period (Khot et al., 2002). In this regard, the TIMI risk score could be used in clinical practice to predict the likelihood of a patient having coronary anatomy amenable to CABG
Limitations
3 or more major risk factors may probably adversely affected by the poor performance of hypercholesterolaemia and family history. it might be explained by the protective effect of statins, also We only coded a patient as having a positive family history , and this may have led to under-reporting of this factor. (Is more than one episode of chest pain within the 24 hours prior to admission). Although this was also our intention, we found numerous ‘grey cases’. (prior coronary stenosis ≥50%), this factor depend on history not coronary angiography, this may led to under-reporting of this factor.
In our study we have 4 patients, (36%) of patients with TIMI score (0_2) with significant coronary lesions, so patients with low TIMI risk score not exclude the presence of significant coronary lesion.
By arbitrarily creating 3 TIMI score categories, we avoided multiple comparisons among small groups of patients. Finally, these results apply to the population of patients referred for angiography from this data set, but may not apply to the entire population of patients with ACS.
Conclusions: In patients with ACS who are referred for cardiac catheterization, the TIMI risk scores correlated with the angiographic severity and extent of CAD. With each increase in the TIMI risk score category, there is an increase not only in the percentage of adverse clinical outcomes, but also in the likelihood of finding 3-vessel or left main disease. So, it is a successful risk stratification score for all patients presented with ACS. The score we have can be used to predict the likelihood of bypass surgery before coronary angiography and may assist the clinician to tailor preoperative medical therapy, but should not be used alone to exclude the presence of significant lesion at low TIMI risk score.