Role of Hydralazine in Myocardial Infarction (MI)

Introduction to Hydralazine Use

The American Heart Association recommends that hydralazine is not used as monotherapy in myocardial infarction due to potential risks of provoking myocardial ischemia, but may be used in combination with isosorbide dinitrate in specific patient populations with heart failure following MI, particularly in African American patients or those intolerant to ACE inhibitors 1, 2, 3

Hydralazine is an arterial vasodilator with relatively little effect on venous tone and cardiac filling pressures 2, 3

Hydralazine is primarily used in combination with isosorbide dinitrate rather than as monotherapy in heart failure following MI 1, 3
The combination of hydralazine and isosorbide dinitrate provides complementary effects, with hydralazine causing arterial vasodilation and isosorbide dinitrate causing venous vasodilation 2, 3
This combination has shown mortality benefit in specific populations, including African American patients with NYHA class III-IV heart failure (Class I recommendation) and patients who cannot tolerate ACE inhibitors (Class IIa recommendation) 4, 5

Large-scale trials showed the hydralazine-isosorbide dinitrate combination reduced mortality (but not hospitalizations) in heart failure patients treated with digoxin and diuretics 3, 6
However, ACE inhibitors produced more favorable effects on survival compared to the hydralazine-isosorbide dinitrate combination 3, 6
A confirmatory trial specifically in African American patients showed significant benefit when adding hydralazine-isosorbide dinitrate to standard therapy with ACE inhibitors and/or beta blockers 3, 6

Hydralazine should not be used as first-line therapy for heart failure post-MI when patients can tolerate ACE inhibitors 3, 6
Common side effects of hydralazine include headache and gastrointestinal complaints 3
Compliance challenges exist due to high incidence of adverse reactions 3, 6

Use of hydralazine should be with caution in patients with cerebrovascular disease 4