Is albumin (human albumin) helpful in patients with Hypertrophic Obstructive Cardiomyopathy (HOCM)?

Albumin is Not Recommended for Patients with Hypertrophic Obstructive Cardiomyopathy (HOCM)

Albumin administration is not recommended for patients with HOCM as it can potentially worsen outflow tract obstruction by increasing intravascular volume and preload.

Pathophysiological Considerations

Hypertrophic obstructive cardiomyopathy (HOCM) is characterized by dynamic left ventricular outflow tract obstruction (LVOTO), which can be worsened by:

1. Increased preload (volume)
2. Decreased afterload (vasodilation)
3. Increased contractility

Albumin administration increases intravascular volume, which can exacerbate LVOTO in HOCM patients through increased preload.

Evidence-Based Management of HOCM

First-Line Pharmacologic Therapy

• Beta blockers are the mainstay of treatment and first-line therapy for symptomatic HOCM 1

  • Mechanism: Negative inotropic effects and attenuation of adrenergic-induced tachycardia
  • Should be titrated to effectiveness or maximally tolerated doses

• Non-dihydropyridine calcium channel blockers (verapamil, diltiazem) are recommended when beta blockers are ineffective or not tolerated 1

  • Caution: Verapamil is potentially harmful in patients with severe dyspnea at rest, hypotension, very high resting gradients (>100 mm Hg), and in children <6 weeks of age

Advanced Pharmacologic Options

• Disopyramide in combination with beta blockers or calcium channel blockers for persistent symptoms 1
• Mavacamten (cardiac myosin inhibitor) for patients who don't respond to first-line therapy 1
  • Reduces LVOT gradients, improves symptoms and functional capacity
  • Requires risk evaluation and mitigation strategy due to potential for decreased LVEF

Volume Management in HOCM

The guidelines specifically address volume management in HOCM:

1. Avoid volume depletion - Hydration is important in patients with resting or provocable LVOTO 1

2. Cautious use of diuretics - Only for patients with persistent dyspnea with clinical evidence of volume overload and high left-sided filling pressures despite other HOCM guideline-directed management 1

   • Low-dose oral diuretics may be considered (Class 2b recommendation)
   • High-dose diuretics should be avoided as they can worsen obstruction

3. Avoid vasodilators - Discontinuation of vasodilators (ACE inhibitors, ARBs, dihydropyridine calcium channel blockers) may be reasonable as they can worsen symptoms caused by dynamic outflow tract obstruction 1

Why Albumin Should Be Avoided

Albumin administration would be counterproductive in HOCM patients because:

1. It increases intravascular volume, which can worsen LVOTO by increasing preload
2. The guidelines emphasize avoiding agents that could exacerbate outflow obstruction
3. No mention of albumin as a therapeutic option appears in any of the current guidelines for HOCM management

Management Algorithm for HOCM

1. First-line therapy: Beta blockers (titrated to effectiveness)
2. If ineffective or not tolerated: Non-dihydropyridine calcium channel blockers
3. For persistent symptoms: Add disopyramide or consider mavacamten
4. For refractory symptoms: Consider septal reduction therapy (surgical myectomy or alcohol septal ablation) at experienced centers

Common Pitfalls in HOCM Management

1. Inappropriate volume expansion (like albumin administration) - Can worsen LVOTO
2. Use of vasodilators - Can exacerbate outflow obstruction
3. High-dose diuretics - Can worsen obstruction through excessive volume depletion
4. Failure to titrate beta blockers adequately before declaring treatment failure
5. Use of positive inotropic agents - Can increase contractility and worsen obstruction

In conclusion, albumin administration should be avoided in HOCM patients as it can potentially worsen outflow tract obstruction by increasing preload, contrary to the principles of HOCM management outlined in current guidelines.