Is there a mortality benefit to nitroglycerin (nitro) in Non-ST-Elevation Myocardial Infarction (NSTEMI)?

No Proven Mortality Benefit of Nitroglycerin in NSTEMI

There is insufficient evidence to support that nitroglycerin provides a mortality benefit in patients with Non-ST-Elevation Myocardial Infarction (NSTEMI). 1 While nitroglycerin is commonly used for symptom relief in acute coronary syndromes, the evidence does not demonstrate improved survival outcomes specifically for NSTEMI patients.

Evidence Assessment

Guideline Recommendations

The American Heart Association/American College of Cardiology guidelines state that nitroglycerin should be considered primarily for symptom relief rather than mortality benefit:

• Nitroglycerin is recommended for patients with ischemic discomfort, with up to 3 doses of sublingual or aerosol nitroglycerin at 3-5 minute intervals until pain is relieved or blood pressure limits its use (Class I, LOE B) 1
• The 2010 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science explicitly states: "There is insufficient evidence to determine the benefit or harm of initiating nitroglycerin treatment in the prehospital setting or ED" 1

Mechanism of Action vs. Outcomes

Nitroglycerin provides several hemodynamic benefits:

• Dilates coronary arteries (particularly in regions of plaque disruption)
• Dilates peripheral arterial bed
• Dilates venous capacitance vessels 1

However, these physiological effects have not translated to mortality reduction in clinical trials:

• The GISSI-3 and ISIS-4 trials included almost 80,000 patients and found no difference in mortality with nitrate use compared to placebo 1
• One study specifically in NSTEMI patients showed that diltiazem was superior to intravenous glyceryl trinitrate (nitroglycerin) in reducing myocardial infarction size 1

Clinical Application

Appropriate Use of Nitroglycerin in NSTEMI

Nitroglycerin should be used for:

• Relief of ischemic chest pain
• Management of hypertension in the setting of ACS
• Management of pulmonary congestion 1

Important Contraindications

Nitroglycerin is contraindicated in patients with:

• Hypotension (SBP < 90 mm Hg or 30 mm Hg below baseline)
• Extreme bradycardia (< 50 bpm)
• Tachycardia in the absence of heart failure (> 100 bpm)
• Right ventricular infarction 1

Safety Considerations

• Careful monitoring is required when administering nitroglycerin to patients with acute MI
• Risk of severe hypotension and bradycardia has been reported, particularly within the first 24 hours of symptom onset 2
• Studies suggest that field administration of nitroglycerin is generally safe when appropriate precautions are taken 3, 4

Alternative Therapies with Mortality Benefit

Instead of focusing on nitroglycerin for mortality benefit, clinicians should prioritize therapies with proven survival advantages:

• Early aspirin administration (160-325 mg) 1
• Beta-blockers within the first 24 hours 1
• ACE inhibitors or ARBs, especially with anterior MI, LV dysfunction, heart failure, or diabetes 1
• Appropriate antiplatelet and anticoagulant therapy based on risk stratification 1

Conclusion

While nitroglycerin remains valuable for symptom management in NSTEMI, clinicians should not expect it to provide a mortality benefit. Treatment decisions should prioritize evidence-based therapies that have demonstrated improvements in survival outcomes.