Abnormal ecg and borderline positive tmt

Hi..im 26 years old i have anxiety symptoms couple a months ago i had episodes of sinus tachycardia had an ecg done at the time of episode which showed sinus tachycardia and st an t wave depression in ii,iii & avf..done further ecg's which showed similiar st and t wave abnormality (st and t wave depression in ii,iii and avf).. 2d echo was normal. Doctor advised me to have a tmt done which came out borderline positive with less likelyhood of signficant CAD prior starting the test baseline resting ecg showed similiar st and t depression in ii iii and avf METS was 8.8 at stage 3 bp was 150/80 normal hr response, good exercise tolerance,no arrythmias. HR achieved: 187,max bp:150/80,total exercise time:7.14min. I felt no chest discomfort and pain during exercise. Is angiogram needed? And what's causing these st and t changes