This prospective observational study will evaluate and compare the sensitivity and specificity of the Modified TIMI, HEART and SACS Scores for accurately predicting the presence and absence of obstructive coronary artery disease (OCAD) as diagnosed during coronary angiography in the cardiac catheterization suite. In addition, we plan to determine if a variant of SACS, HEART, TIMI, or a hybrid score resulting from combining formulas from two or all three scores yields a new tool that exceeds the predictive performance of all three current models for determining the absence or presence of OCAD.

HISTORY: The Simple Acute Coronary Syndrome (SACS) Score was developed in 2009 by Cardiac Catheterization staff after noting what appeared to be an unacceptable volume of patients presenting with low Modified TIMI Scores (0-2) who were found to have severe Obstructive Coronary Artery Disease (OCAD). The SACS Scoring formula was derived by observing correlations in an estimated 12,000 cases between patients' SYMPTOMS, ECG FINDINGS, CAD RISK FACTOR PROFILES, TROPONIN VALUES and the degree of OCAD discovered during coronary angiography.

The primary objective of the SACS Score is to identify patients who are at high risk for OCAD, with the intent that they will receive diagnostic and interventional measures prior to the occurence of Acute Myocardial Infarction (AMI) or other Major Adverse Coronary Event (MACE).

In a small pilot study conducted in 2009 at St Joseph's Hospital in Tampa, Florida, the SACS Score demonstrated a trend of reliability superior to the Modified TIMI Score for accurately predicting the absence or presence of OCAD. Because the sample size was deemed to be not statistically significant (n=42), the study team concluded that the "SACS Score demonstrates a promising trend, but additional data needs to be collected and analyzed before any definitive conclusions can be drawn."

Since the advent of the St Joseph's study, another ACS / MACE predictive tool, the HEART Score, was introduced by Backus and Six et al of the Netherlands. The HEART Score has been scientifically validated by several studies with results published most recently in the International Journal of Cardiology (2013). Furthermore the studies demonstrated that HEART is superior to the Modified TIMI and GRACE Scores for accurately predicting the probability of MACE.

It is interesting to note that the HEART Score closely resembles SACS, with differences in the scoring formula for ECG findings and the patient's age. Our hypothesis is both scores will demonstrate superior predictability of OCAD, but a hybrid combination of the HEART and SACS formulas may produce a scoring tool that will exceed all three in sensitivity and specificity for predicting the presence or absence of OCAD.

STUDY END POINT for all patients is CARDIAC CATHETERIZATION: The findings obtained during CORONARY ANGIOGRAPHY, and the need for immediate intervention, as dictated by the Interventional Cardiologist.

DATA TO BE COLLECTED: Patient symptoms, history, CAD risk factor profile, 12 Lead ECG findings, Lab results (Troponin, electrolytes, BUN/Creatinine, BNP), and all other data fields necessary to calculate a complete Modified TIMI, HEART and SACS score, Cardiac Cath Lab findings (description of coronary angiography for each vessel) and any Coronary Artery Interventions performed or recommended (PCI, CABG). . A STANDARDIZED DATA COLLECTION FORM has been developed and will be utilized for all patients.

REGRESSION ANALYSIS will result from 126 data points collected from each patient encounter. Relationships between score values and the degree of obstructive CAD present will be established, along with p values and sensitivity / specificity for each scoring system. Recommendations for modifications to currently existing scores, and/or proposals for development of a hybrid scoring system will result from the analysis of this data.

Inclusion Criteria:

• Any patient presenting to the Cardiac Catheterization Lab during the study period.

Exclusion Criteria:

• Patients who refuse / wish to not be included in the study,
• Patients with Wolff-Parkinson-White syndrome with visible Delta waves on the ECG.
• Patients with Renal Failure and abnormally elevated Creatinine >2.0
• Patients with Potassium values >6.0

All patients selected in this study will be patients who are having URGENT (Group 1) or NON-URGENT (Group 2) cardiac catheterization performed:

Group 1: All (100%) of STEMI / Non-STEMI patients presenting for cardiac catheterization during the study period, with a minumum number of 25 STEMI and 25 NSTEMI patients to be included.

Group 2: Non-urgent cardiac catheterization patients will be randomly selected, with consents obtained, PRIOR TO elective cardiac catheterization.