Report summary. Acidity problem only?

Hi Sir, My father is 73 yrs old. He is diabetic from past 30 years, and bp from past 20 years. Recently he was facing heartburn issue while doing morning or evening walk. And once in day time he faced similar problem, while resting. We consulted general doctor and they told it could be because of gas problem or  heart attack symptom. They gave antacid syrup and suggested for ecg, echo, treadmill test. Ecg is good. Echo is good. After seeing treadmill test report, doctor was confused and suggested for second opinion and also gave ecosprin along with antacid for 15 days. Now he didn't face heart burn issue in past weeks, so should we consider it as gas/ acidity problem only? Attached are reports for your reference. Thanks in advance.