Nifedipine is the Best Single-Drug Strategy for Long-Term Management
For this patient with documented coronary artery spasm (positive ergonovine test) and normal coronary arteries who desires single-drug therapy, nifedipine (a calcium channel blocker) is the definitive first-line treatment. Calcium channel blockers are the cornerstone of vasospastic angina management, with nifedipine specifically recommended at doses of 60-120 mg daily 1.
Why Calcium Channel Blockers Are First-Line
Calcium channel blockers directly prevent coronary artery spasm by inhibiting calcium influx in vascular smooth muscle, making them the most pathophysiologically appropriate choice for vasospastic angina 1, 2.
High-dose monotherapy with nifedipine (60-120 mg/day) achieves symptom control in approximately 90% of patients with coronary vasospasm, though complete resolution occurs in only 38% with monotherapy alone 2.
The prognosis is excellent with calcium channel blocker therapy, with 5-year survival rates of 89-97% in patients with normal or near-normal coronary arteries like this patient 1, 2.
Why the Other Options Are Incorrect
Carvedilol (Beta-Blocker) - Contraindicated
Beta-blockers are explicitly contraindicated in vasospastic angina because they leave α-mediated vasoconstriction unopposed by β-mediated vasodilation, potentially precipitating or worsening coronary spasm 1, 2.
The ACC/AHA guidelines specifically state that beta-blockers have "theoretical adverse potential" and their clinical effect is "controversial" in coronary spasm 1, 2.
Lisinopril (ACE Inhibitor)
ACE inhibitors have no role in preventing coronary artery spasm and are not mentioned in any guideline recommendations for vasospastic angina management 1, 2.
ACE inhibitors are indicated for heart failure, hypertension, or post-MI with reduced ejection fraction—none of which apply to this patient with normal cardiac catheterization 1.
Aspirin
Aspirin does not prevent coronary vasospasm and has no established benefit in pure vasospastic angina without fixed atherosclerotic disease 1.
This patient has normal coronary arteries on catheterization, making antiplatelet therapy for atherosclerotic disease unnecessary 3.
Clinical Pearls and Caveats
Long-acting formulations are essential: Use sustained-release nifedipine preparations; immediate-release nifedipine is contraindicated in acute coronary syndromes without beta-blocker coverage (Class III: Harm) 1, 4.
Smoking cessation is mandatory as it is a major precipitant of coronary vasospasm 2.
Nocturnal symptoms are classic for vasospastic angina and support this diagnosis, as spasm typically occurs in early morning hours 1.
If monotherapy fails: The patient may eventually require combination therapy with long-acting nitrates plus calcium channel blockers, but nifedipine alone should be tried first at maximum tolerated doses (up to 120 mg/day) 1, 2.
Alternative calcium channel blockers: Diltiazem (180-360 mg/day) or verapamil (240-480 mg/day) are equally effective alternatives if nifedipine is not tolerated 1, 5, 6.
Answer: C. Nifedipine