A 60-year-old man comes to the physician due to nighttime chest pain. The patient was diagnosed with extensive coronary artery disease a year ago and was offered coronary artery bypass grafting surgery. He refused surgery and instead opted for medical management. Since the medical therapy was started, the patient's symptoms have improved. He has angina during the daytime only after moderate to severe exertion. However, the patient still has been waking up 3-4 times per week in the middle of the night with substernal chest pain, which usually resolves spontaneously in 7-8 minutes but sometimes requires nitroglycerin. His other medical problems include difficult-to-control hypertension, hyperlipidemia, and peripheral vascular disease. The patient has smoked cigarettes for 35 years and quit 5 years ago. His medications include aspirin, metoprolol, isosorbide mononitrate, amlodipine, lisinopril, rosuvastatin, and nitroglycerin as needed. He takes all his medications during the morning hours.
His blood pressure is 150/82 mm Hg, pulse is 62/min and regular, and respirations are 14/min. The patient is obese with large neck circumference and a BMI of 34 kg/m². Chest is clear to auscultation. There is no peripheral edema. The remainder of the examination is normal.
An electrocardiogram (ECG) performed in the office shows normal sinus rhythm with nonspecific T wave changes. His most recent echocardiogram showed a left ventricular ejection fraction of 60%. During exercise single photon emission computed tomography (SPECT) performed a month ago, the patient exercised for 8 minutes and reached 85% of age-predicted maximal predicted heart rate. He stopped due to fatigue and mild chest discomfort. Stress SPECT images showed a moderately extensive inferior wall reversible defect.
Which of the following is the most appropriate next step in management of this patient?

Question

Quizplus · Accepted Answer

11ec193a_9746_31a2_853d_611efaf1500e_MD0002_00 This patient's nocturnal angina in the setting of obesity, large neck circumference, and difficult-to-treat hypertension (HTN) is suggestive of obstructive sleep apnea (OSA). OSA is associated with cardiovascular diseases, including coronary artery disease. Studies have shown higher OSA incidence in patients with resistant HTN, even in the absence of classic OSA symptoms (eg, excessive daytime sleepiness, snoring, witnessed apneas). All obese patients with nocturnal angina, nocturnal cardiac arrhythmias, or difficult-to-control HTN should be evaluated for OSA with full nighttime polysomnography and electrocardiogram (ECG) monitoring to document possible ischemia and/or arrhythmias. Treatment of OSA with positive airway pressure may reduce blood pressure, cardiovascular events, and mortality. (Choices A and C) Adjusting this patient's medications without first excluding OSA would not be the most appropriate next step. This patient's resting heart rate is about 60/min, and OSA increases the risk for nocturnal bradycardia, which could contribute to angina; therefore, increasing the β-blockade could exacerbate this patient's symptoms. Adding isosorbide mononitrate in the evening may not provide much relief of this patient's angina due to medication tolerance. Ranolazine, a late sodium channel blocker, is used in patients who have failed all other antianginal therapies. (Choice B) Esophageal disease may present with nocturnal cough and substernal burning. However, this patient's extensive coronary artery disease history with known angina, reversible myocardial wall defects on stress imaging, and resistant HTN make esophageal disease a less likely cause of his pain. (Choice D) Pulmonary function tests are useful in evaluating for restrictive and obstructive lung diseases but not for OSA. Educational objective: Obese patients with difficult-to-treat hypertension, nocturnal arrhythmias, or nocturnal angina should undergo evaluation for obstructive sleep apnea using overnight polysomnography with electrocardiogram (ECG) monitoring. __________ References: Role of obstructive sleep apnea in cardiovascular disease (http://www.ncbi.nlm.nih.gov/pubmed/21993356) Obstructive sleep apnea syndrome and cardiovascular diseases (http://www.ncbi.nlm.nih.gov/pubmed/21455862)

A 60-Year-Old Man Comes to the Physician Due to Nighttime