What is the management of dyskinetic right coronary artery (RCA)?

Management of Dyskinetic Right Coronary Artery (RCA)

For patients with dyskinetic right coronary artery due to spontaneous coronary artery dissection (SCAD), conservative medical management is recommended as the first-line approach unless there is ongoing ischemia, hemodynamic instability, or high-risk anatomy.

Diagnosis and Assessment

• Dyskinetic RCA is most commonly caused by:

  • Spontaneous coronary artery dissection (SCAD)
  • RCA occlusion (thrombotic or embolic)
  • Vasospasm

• Key diagnostic findings:

  • Coronary angiography is the primary diagnostic tool 1
  • Consider intracoronary imaging (OCT/IVUS) only if revascularization is already decided 2
  • Assess for hemodynamic compromise, which may manifest as:
    • Right ventricular dysfunction
    • Hypotension
    • Bradyarrhythmias or tachyarrhythmias 3

Management Algorithm

1. Initial Assessment

• Determine hemodynamic stability
• Assess for ongoing ischemia (persistent pain, ECG changes)
• Evaluate coronary flow status

2. Management Based on Clinical Presentation

A. Hemodynamically Stable Patients with Preserved Coronary Flow

• Conservative medical therapy is recommended 1, 2:
  • Aspirin for at least 12 months
  • Beta-blockers (unless contraindicated)
  • P2Y12 inhibitor (typically clopidogrel) for 1-12 months
  • Consider statins for plaque stabilization

B. Hemodynamically Unstable Patients or Ongoing Ischemia

• Revascularization is indicated 1, 2:
  • PCI with stenting (with caution due to high failure rate in SCAD)
  • Consider CABG for left main involvement or failed PCI
  • After stenting, use dual antiplatelet therapy with aspirin and ticagrelor (or prasugrel) for one year 1

C. Right Ventricular Dysfunction Management

• Volume resuscitation to maintain adequate RV preload 4
• Avoid vasodilators and diuretics which can worsen RV function 4
• Consider inotropic support if needed 4
• Treat bradyarrhythmias which can limit cardiac output 4

Special Considerations

SCAD-Related Dyskinetic RCA

• PCI in SCAD carries significant risks 2:
  • High failure rate (approximately 50%)
  • Risk of extending dissection
  • Risk of iatrogenic dissection
• Intravascular imaging should be used to confirm true lumen when PCI is performed 1, 2
• Avoid thrombolytics as they can extend dissection 2

Post-Management Follow-up

• Cardiac rehabilitation
• Screening for fibromuscular dysplasia (FMD) in other vascular beds (present in up to 72% of SCAD cases) 1, 2
• Management of post-SCAD chest pain may include long-acting nitrates, calcium channel blockers, or ranolazine 2

Common Pitfalls to Avoid

1. Unnecessary PCI: Avoid routine PCI when the patient is stable with preserved coronary flow 1, 2
2. Thrombolytic therapy: Can extend dissection and worsen outcomes in SCAD 2
3. Vasodilators and diuretics: Can exacerbate RV dysfunction in RCA-related ischemia 4
4. Underestimating non-dominant RCA lesions: Even small non-dominant RCA occlusions can lead to fatal outcomes in some cases 3
5. Missing associated FMD: Screen for FMD in other vascular beds, as it is present in up to 72% of SCAD cases 1, 2

The right ventricle has a remarkable ability to recover even after prolonged occlusion, making appropriate management crucial for optimizing outcomes and reducing morbidity and mortality 4.