A 65-year-old female has recently moved to your city and is in your clinic today to establish care with a cardiologist. She has a past medical history of vasospastic angina with non-occlusive coronary artery disease that was diagnosed two and half years ago and she was started on medical therapy. Her other past medical history is significant for hypertension and hyperlipidemia. She is a past smoker and has a 10-pack year smoking history. Her family history is significant for hypertension and diabetes.
At present the patient does not have any symptoms of chest pain, shortness of breath, dizziness, palpitations, pedal edema, orthopnea or PND. In the past, she was having symptoms of chest pain that was unrelated to exertion almost on a daily basis. Her last angina event was about two years ago. Her previous cardiologist had started her on metoprolol tartrate 25 mg twice a day, amlodipine 10 mg daily, isosorbide mononitrate 120 mg daily, Aspirin 81 mg daily and Atorvastatin 40 mg daily. She has been religiously taking her medications, exercises for about 30 minutes every day and eats a healthy diet.
On physical examination, her heart rate is 62 beats/min, regular rhythm and blood pressure is 108/62 mm Hg. Her cardiovascular examination is unremarkable. She had her fasting lipid profile done and it shows a total cholesterol of 120 mg/dl, HDL of 54 mg/dl and LDL of 48 mg/dl. EKG done today shows normal sinus rhythm and there are non-specific ST-T wave changes in the anterior leads and this is unchanged from her previous ekg tracing. The results of an echocardiogram done two years ago shows the ejection fraction to be in the range of 60-65%, with trace mitral regurgitation and normal diastolic function.
The correct answer is: C. Consider discontinuing isosorbide mononitrate
The patient is known to have non-obstructive coronary artery disease with vasospastic angina and is currently symptom free. The patient was started on appropriate therapy for vasospastic angina. Calcium channel blockers have been recommended as first line drugs with or without nitrates and were appropriately started at the time of her medical diagnosis as per the 2012 ACC/AHA guidelines.1 However, more recent evidence suggests that chronic nitrate therapy does not afford any clinical benefit.2 In fact, there is potential for harm with the use of nitrates in this group of patients as observed in the above study. Therefore this patient can be considered for discontinuing isosorbide mononitrate and observed off this medication. There has been no change in the patient's clinical condition and therefore echocardiogram is not indicated at this time.
Takahashi et al.2 in their study have evaluated the long-term prognostic value of using nitrates in patients with vasospastic angina. In this multicenter study of 1429 patients, 49% of the patients were taking nitrates in addition to calcium channel blockers and the remainders of the patients were taking calcium channel blockers. The hazard ratio for MACE on propensity-matched analysis (cardiac death, myocardial infarction, hospitalization for heart failure, angina or ICD shock) was 1.28 (95% CI 0.72 – 2.28). Further, they observed that there is increased risk for adverse events when the patient was taking more than one type of nitrate drug. There is potential benefit with the use of nicorandil, however this conclusion did not meet statistical significance and moreover this drug has not been approved in the United States.
References
- Fihn SD, Gardin JM, Abrams J et al. 2012 ACCF/AHA/ACP/AATS/PCNA/SCAI/STS Guideline for the diagnosis and management of patients with stable ischemic heart disease: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines, and the American College of Physicians, American Association for Thoracic Surgery, Preventive Cardiovascular Nurses Association, Society for Cardiovascular Angiography and Interventions, and Society of Thoracic Surgeons. J Am Coll Cardiol 2012;60:e44-e164.
- Takahashi J, Nihei T, Takagi Y et al. Prognostic impact of chronic nitrate therapy in patients with vasospastic angina: multicentre registry study of the Japanese coronary spasm association. Eur Heart J 2015;36:228-37.
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