In this patient with ongoing stable angina pectoris and a low-risk exercise stress test result (that is, a Duke treadmill score of +6), initiation of a long-acting nitrate such as isosorbide mononitrate is recommended by current guidelines. β-Blockers and nitrates improve functional capacity, delay onset of exercise-induced myocardial ischemia, and decrease the frequency and severity of anginal episodes. Most patients with stable angina will require combination therapy with these two classes of drugs to achieve effective control of anginal symptoms. Although this patient is at low risk, initiation of medical therapy is also appropriate in patients who are at intermediate risk and high risk based on clinical risk factors, symptom burden, and/or stress testing results. Those patients with intermediate-risk stress test findings (Duke treadmill score of −10 to +4) and high-risk stress testing findings (Duke treadmill score of less than −11) have a 1% to 3% cardiovascular mortality per year and a 3% or higher cardiovascular mortality rate per year, respectively.

Calcium channel blockers, such as diltiazem, are second-line therapy in patients with stable angina pectoris who are intolerant of β-blockers or who have continued symptoms on β-blockers and nitrates. This patient is tolerating his β-blocker well and is not yet taking a nitrate for his angina. Therefore, diltiazem is not indicated at this time.

Because of the invasive nature of coronary angiography and the inherent risks of vascular complications, it should be reserved for patients with lifestyle-limiting angina despite optimal medical therapy or high-risk criteria on noninvasive stress testing such as significant ST-segment depression at a low work load, ST-segment elevation, or hypotension.

Pharmacologic nuclear stress testing is not indicated in this patient owing to the presence of stable symptoms, lack of optimal medical therapy, and low-risk findings on exercise stress testing.