What is the most appropriate next step for a 58-year-old male with recurrent chest tightness and significant stenosis of the right coronary artery, currently on aspirin (acetylsalicylic acid), metoprolol, atorvastatin, and isosorbide mononitrate?

Management of Recurrent Angina in a Patient with Known Coronary Artery Disease

Referral for percutaneous coronary intervention (PCI) is the most appropriate next step for this patient with recurrent angina and significant right coronary artery stenosis that has progressed despite optimal medical therapy.

Clinical Assessment

This 58-year-old male presents with:

• Worsening chest tightness with exertion over the past three weeks
• Radiation of pain to left arm
• Resolution with rest
• Known coronary artery disease diagnosed 6 months ago
• Previous stress test showing reversible defect in inferior wall of left ventricle
• Previous cardiac catheterization showing 80% stenosis of right coronary artery
• Initial decision for medical management with:
  • Aspirin 325 mg daily
  • Metoprolol 50 mg daily
  • Atorvastatin 80 mg daily
  • Isosorbide mononitrate 125 mg daily
  • PRN sublingual nitroglycerin (never used)
• Current vital signs: HR 52/min, RR 16/min, BP 100/62 mmHg
• EKG showing sinus bradycardia at 52/min
• Normal physical examination

Decision Analysis

Why PCI is indicated now:

1. Recurrence of symptoms despite optimal medical therapy: The patient's symptoms initially resolved with medical management but have now recurred, suggesting progression of disease or inadequate control 1.

2. Significant stenosis with documented ischemia: The patient has both anatomical (80% RCA stenosis) and functional (positive stress test) evidence of significant coronary artery disease 1.

3. Guideline recommendation: European Society of Cardiology guidelines recommend coronary angiography and revascularization for patients with recurrent ischemia despite medical therapy, particularly those with post-infarction unstable angina 1.

Why other options are less appropriate:

1. Increasing isosorbide mononitrate dose (to 240 mg):

   • Already on high dose (125 mg)
   • Current BP is 100/62 mmHg - increasing nitrates could worsen hypotension
   • Recurrent symptoms indicate failure of current medical therapy approach

2. Increasing metoprolol dose (to 100 mg):

   • Current HR is already 52/min - increasing beta-blocker could worsen bradycardia
   • Unlikely to address underlying stenosis that has progressed

3. Adding clopidogrel 75 mg daily:

   • While dual antiplatelet therapy is beneficial after PCI 1, adding clopidogrel alone without addressing the mechanical obstruction is insufficient
   • Would be appropriate after PCI, not as an alternative to it

4. Referral for electrophysiology:

   • No indication of arrhythmia requiring EP evaluation
   • The patient's symptoms are clearly anginal in nature

Management Algorithm

1. Refer for coronary angiography with intent to perform PCI

   • Immediate evaluation of current stenosis severity
   • Assessment of other potential lesions
   • PCI of the culprit lesion (RCA) 1

2. Post-PCI management:

   • Continue aspirin indefinitely
   • Add clopidogrel 75 mg daily for at least 12 months 1
   • Continue high-intensity statin (atorvastatin 80 mg)
   • Adjust beta-blocker dose to target heart rate 55-60 bpm
   • Consider reducing or discontinuing isosorbide mononitrate based on symptoms and blood pressure

Important Considerations

• Timing: Prompt referral is essential as the patient has clear evidence of unstable angina with known significant coronary stenosis 1

• Medical therapy optimization: After PCI, medical therapy should be optimized to prevent restenosis and progression of atherosclerosis 2

• Potential pitfalls:

  1. Delaying revascularization could lead to myocardial infarction
  2. Simply intensifying medical therapy when revascularization is indicated may place the patient at unnecessary risk
  3. The current bradycardia and relatively low blood pressure limit the ability to further uptitrate anti-anginal medications

• Follow-up: After PCI, the patient should be monitored for restenosis, which typically occurs within 1-8 months 2

The evidence clearly supports referral for PCI as the most appropriate next step for this patient with recurrent angina despite optimal medical therapy and documented significant coronary stenosis.