Which of the following is NOT a contraindication to nitroglycerin in ACS?

• A. Hypotension (SBP < 90–100)
• B. Suspected right ventricular infarct with preload dependence
• C. Use of phosphodiesterase-5 inhibitors within 24–48 hours
• D. Hypertension

Answer: (D)

Nitroglycerin in ACS is used to relieve chest pain and decrease myocardial oxygen demand by dilating veins, which lowers preload and reduces wall stress. The dangerous situations to avoid are those that can drop blood pressure too far or reduce preload when the heart depends on it. A suspected right ventricular infarct is preload-dependent, so further decreasing preload with nitrates can cause drastic drops in cardiac output and blood pressure. Combining nitrates with PDE-5 inhibitors significantly lowers systemic vascular resistance, risking life-threatening hypotension. Hypotension itself is a direct contraindication because nitrates further lower blood pressure.

Hypertension is not a contraindication. In fact, nitrates can be helpful in hypertensive ACS by reducing afterload and preload, relieving ischemia, as long as blood pressure remains sufficient to maintain perfusion. So the option describing hypertension is the one that is not a contraindication.