From the Guidelines
Nitroglycerin is contraindicated in severe aortic stenosis due to the risk of precipitating dangerous hypotension and reducing cardiac output. According to the 2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR guideline for the evaluation and diagnosis of chest pain 1, severe symptomatic aortic stenosis is listed as a contraindication for exercise ECG and stress echocardiography, and contraindication to nitroglycerin is also mentioned as a limitation for stress echocardiography. The physiological rationale behind this contraindication is that nitroglycerin causes vasodilation, which reduces preload and afterload, potentially leading to decreased cardiac output and coronary perfusion in patients with severe aortic stenosis.
Key points to consider when evaluating the use of nitroglycerin in patients with aortic stenosis include:
- The severity of aortic stenosis, as absolute contraindication exists for severe stenosis, while relative contraindication applies to moderate cases
- The importance of close hemodynamic monitoring when using nitroglycerin in patients with moderate aortic stenosis
- The potential for other vasodilators, such as ACE inhibitors and nitroprusside, to share similar contraindications in severe aortic stenosis due to their effects on preload and afterload.
In clinical practice, it is essential to exercise caution when considering the use of nitroglycerin in patients with aortic stenosis, particularly those with severe disease, and to carefully weigh the potential benefits against the risks of precipitating hypotension and reducing cardiac output 1.
From the Research
Nitroglycerin Use in Aortic Stenosis
- Nitroglycerin is often considered contraindicated in patients with severe aortic stenosis due to the risk of precipitating profound hypotension 2, 3.
- However, studies have shown that cautious use of nitroglycerin in patients with moderate or severe aortic stenosis and presenting with acute pulmonary edema may be a safer strategy than traditionally thought 2.
- A retrospective study found that neither moderate nor severe aortic stenosis was associated with a greater risk of clinically relevant hypotension requiring intervention when nitroglycerin was used for acute pulmonary edema 2.
- Another study demonstrated that nitroprusside, a vasodilator, can improve myocardial performance in patients with severe aortic stenosis and left ventricular systolic dysfunction, and can be used as a bridge to aortic-valve replacement or oral vasodilator therapy 3.
- The effects of chronic nitrate administration on left ventricular hemodynamics during exercise in severe aortic stenosis do not correspond to the beneficial acute effects of nitroglycerin 4.
- Nitroglycerin is commonly used in the emergency department for various conditions, including angina, acute coronary syndromes, and acute heart failure, but its use in patients with aortic stenosis requires careful consideration 5, 6.