A 65-Year-Old's Ongoing Exercise Limitation
A 65-year-old woman was seen in her physician's office six months ago with exertional chest pain of four months duration, limiting her ability to play tennis, a sport she had enjoyed for many years. She has a history of smoking one pack of cigarettes daily for 20 years but had stopped smoking 25 years ago. She has a history of Type 2 diabetes mellitus diagnosed eight years ago, which was being treated with a diabetic diet and with metformin 1,000 mg daily. She was also treated with ramipril 10 mg twice daily and a low sodium diet for a blood pressure of 150/78 mm Hg. She has no history of dyslipidemia or obesity and no family history of coronary artery disease.
Her blood pressure was 138/74 mm Hg, and her pulse 86 beats per minute and regular. Her body mass index was 25 kg/m2. Her physical examination was entirely normal except for a fourth heart sound heard at her cardiac apex. The complete blood count and urinalysis were normal. The fasting blood sugar was 99 mg/dL. The hemoglobin A1c was 6.9%. A comprehensive metabolic panel was normal. The estimated glomerular filtration rate was 80 ml/minute/1.73 m2. The fasting serum total cholesterol was 192 mg/dL, the serum low-density lipoprotein (LDL) cholesterol was 110 mg/dL, the serum high-density lipoprotein cholesterol was 56 mg/dL, and the sreum triglycerides was 130 mg/dL. The ankle-brachial index was 1.1 in both lower extremities. The electrocardiogram and 2-dimensional echocardiogram were normal.
An exercise treadmill stress test was performed using the Bruce protocol. The patient stopped exercise after 6 minutes because she developed her typical chest pain. The systolic blood pressure rise after exercise was 20 mm Hg. The maximal heart rate achieved was 148 beats per minute. The electrocardiogram at peak exercise showed 2 mm of downsloping ischemic ST-segment depression in leads II, III and aVF that resolved four minutes after recovery. A diagnosis of ischemic heart disease was established, and she was started on metoprolol tartrate 50 mg twice a day, isosorbide mononitrate 40 mg twice daily with seven hours between doses, sublingual nitrogycerin 0.3 mg prn for chest pain, aspirin 81 mg daily, a low cholesterol, low saturated fat diet, rosuvastatin 20 mg daily, and advised to walk 60 minutes daily.
She was seen by her physician one month later with minimal improvement in her exertional chest pain and was interested in coronary revascularization to improve her symptoms. Her blood pressure was 130/70 mm Hg, and her pulse was 78 beats per minute. Her serum LDL cholesterol was reduced to 68 mg/dl. She had been using prn sublingual nitroglycerin daily. She was referred for coronary angiography to evaluate the extent of her coronary artery disease. Coronary angiography showed 80% obstructive disease of the distal right coronary artery and 90% obstruction of the second obtuse marginal artery that were not amenable to revascularization and 40% non-obstructive coronary artery disease in the mid left anterior and left circumflex arteries. A decision was made to medically manage her chronic stable angina pectoris. Metoprolol was increased to 100 mg twice a day, and diltiazem 90 mg three times daily was added to her anti-anginal regimen.
Three weeks later, she states that her exertional chest pain has improved markedly but complains that her exertional chest pain is limiting her from playing tennis or performing other activities she wants to. Her sublingual nitroglycerin consumption has decreased to two to three times a week. Her blood pressure is 120/60 mm Hg. Her electrocardiogram shows sinus bradycardia with a ventricular rate of 58 beats per minute and no abnormalities with a normal QT interval.
What should be recommended at this time to manage her ongoing exercise limitation?