What to use for angina in a patient with hypotension and a history of Coronary Artery Bypass Grafting (CABG)?

Management of Angina in Hypotensive Patients with History of CABG

For angina in hypotensive patients with a history of CABG, long-acting nitrates are the preferred first-line treatment as they can relieve angina without further compromising blood pressure. 1

Understanding the Clinical Challenge

Treating angina in hypotensive patients with previous CABG presents a unique challenge because:

• Many traditional anti-anginal medications (beta-blockers, non-dihydropyridine CCBs) can worsen hypotension
• Post-CABG patients often have complex coronary anatomy with both native vessel and graft disease
• Graft disease is more likely to involve thrombus formation (37% vs 12% in native vessels) 2

Treatment Algorithm

First-line therapy:

• Long-acting nitrates (oral or transdermal)
  • Provide effective angina relief through venodilation and coronary vasodilation
  • Cause less significant reduction in blood pressure than other anti-anginals
  • Can be used safely in patients with history of CABG 1
  • Should be administered with a nitrate-free interval to prevent tolerance

Important considerations for nitrate therapy:

• Start with low doses and titrate carefully in hypotensive patients
• Monitor for potential hypotension, especially with position changes
• Use caution with concomitant phosphodiesterase inhibitors (contraindicated) 3
• Consider intermittent dosing regimens to avoid tolerance development

If nitrates alone are insufficient:

1. Consider low-dose dihydropyridine CCBs (if systolic BP >90 mmHg)

   • Can be added to nitrates for additional angina control
   • Cause less negative inotropic effects than non-dihydropyridine CCBs
   • Use with caution and monitor BP closely

2. Consider morphine sulfate for breakthrough angina

   • Provides both analgesic and anxiolytic effects
   • May be administered during nitrate therapy with careful BP monitoring
   • Can be repeated every 5-30 minutes as needed for symptom control 1

3. Evaluate for urgent coronary angiography

   • Particularly important if angina persists despite medical therapy
   • Post-CABG patients with unstable angina often have graft disease (85% of cases with CABG >5 years ago) 2

Special Considerations

• Avoid beta-blockers in hypotensive patients as they may worsen hypotension and reduce cardiac output
• Avoid non-dihydropyridine CCBs (diltiazem, verapamil) as they can cause significant bradycardia and worsen hypotension
• Target BP management: In patients with CAD, BP should be lowered slowly with caution to avoid DBP <60 mmHg which may worsen myocardial ischemia 1

Pitfalls to Avoid

1. Do not use sublingual nitroglycerin repeatedly without addressing the underlying cause of persistent angina

   • Excessive use may lead to tolerance
   • Persistent angina requires further evaluation 3

2. Do not delay angiography if angina is refractory to medical therapy

   • Post-CABG patients with unstable angina have higher rates of graft thrombosis
   • Graft disease is more refractory to medical therapy than native vessel disease 2

3. Do not overlook volume status

   • Hypotension may be related to hypovolemia
   • Cautious volume optimization may help improve BP and coronary perfusion

By following this approach, you can effectively manage angina in hypotensive patients with prior CABG while minimizing the risk of worsening hypotension or other adverse outcomes.