Hello, 
Thanks for the query to H.C.M. Forum. 
Since last year you got 
heart attack & now taking blood thinners. 
Now you are having 
chest pain ,but you haven't mentioned the side of chest pain ?
Heart burn ,you yourself judges ,if you are right then  take treatment . 
In my opinion this pain may be,
1 
Esophagitis due to tension and stress of old disease . Blood thinners also causes gastritis . 
Simultaneously many factors may be the reason of heart burn or esophagitis. 
2 May be due to heart  pain ,if this pain is  on the left side and radiates to left shoulder or chin ( left side).
In my opinion please consult a physician and get his opinion for  both heart and gastritis. 
Since one year passed ( of previous heart attack) so 
angiography  may help to locate the disease in coronary arteries or its branches. 
Upper endoscopy will confirm any disease in stomach or  esophagus. 
Good luck. 
Dr. HET