Beta blockers are considered first-line therapy status post myocardial infarction because they reduce blood pressure and heart rate so the onset of exercised-induced ischemia can be delayed or avoided. A newer generation beta blocker may be the answer although with any newer drug there may be cost considerations. However, some patients are unable to tolerate beta blockers (including because of sexual dysfunction).  The next option would be a calcium channel blocker or a long-acting nitrate for symptom relief.  PDE5 inhibitors may be contradicted with nitrates because of the potential of serious hypotension. Talk to your cardiologist so a medical management plan can be determined that is best for you. Good luck.