Background: SMI is the reduction of oxygen-rich condition in blood flow to the heart which happens in the absence of discomfort chest or other symptoms. Around 20 – 30% of all SMI are silent, only 5% of SMI in early treadmill-testing which signs adverse diagnosis.

Aim: To estimate and identify the prevalence risk factors of silent myocardial ischemia in anterior STEMI patients treated with primary PCI.

Patients and Methods: This prospective cross sectional observational study involved 50 patients from the attendants of the department of cardiology at Al Shiekh Zayed specialized Hospital diagnosed with anterior STEMI were classified into two subgroups, Group (A) included patients with TMT Positive, and Group (B) included patients with TMT Negative.

Results: our findings revealed that 14 patients (28%) had a positive treadmill test at 6 months follow up and 36 patients (72%) were negative. From the 14 patients with positive treadmill test, (78.6%) were males and (21.4%) were females. In patients with negative exercise treadmill test, mean age was (62.50 ± 4.01) years, 12 patients (85.7%) had DM (p value <0.001), 8 patients (57.1%) were hypertensives, 13 patients (92.9 %) had Dyslipidemia, 3 patients (21.4%) were Smokers, 3 patients (21.4%) were Obese, zero patients (0%) had no Family history for CAD.

Conclusion: Silent myocardial ischemia was detected in more than quarter of study population. This proves that CAD is a major risk factor for further and even silent myocardial ischemia. Older age, diabetes mellitus and dyslipidemia are risk factors for silent myocardial ischemia.