Blockage due to thrombus in Acute Myocardial Infarction (AMI) causes complete ischemia and necrosis in areas supplied by blocked arteries. Rapid revascularization with Percutaneous Coronary Intervention (PCI) will decrease myocardial damage. The left ventricle function is an important outcome during PCI. A semi-quantitative assessment of the regional left ventricular contractile function can be obtained through the assessment of the Wall Motion Score Index (WMSI). The time between angina and PCI is most important, since the time lag represents the total ischemic time, so it needs to be reduced to the shortest possible to increase the clinical outcome. This study aimed to know the correlation between WMSI changes between patients who were treated with PCI with shorter total ischemic time compare with longer total ischemic time. This was a cohort prospective study conducted in Sanglah Hospital, Denpasar, Bali, during November 2017 until January 2018. This study included 32 AMI patients who are treated with PCI. WMSI was measured using transthoracic echocardiography before and 72 hours after PCI. From ROC curve analysis, the time cutoff point between angina and PCI action was 313 minutes with 75% sensitivity and 54% specificity and there were 2 groups consist of group with the time integral between angina and PCI less than 313 minute (early group) and group with the time integral between angina and PCI more than equal to 313 minute (late group). By using the Wilcoxon sign rank pair test, there was significant WMSI changes in both early and late groups before and 72 hours after PCI, with the early group showed better improvement compared to the late group. Meanwhile, Wilcoxon Mann Whitney U test result showed that there was no significant difference in WMSI changes in the early group compared to the late group. These result showed the importance of PCI in improving myocardial contractility even in patients who underwent PCI later than 5 hours after the onset of chest pain.