5/21: Is Nitroglycerin Dangerous in Right Ventricular Myocardial Infarction?
Bottom Line Up Top: Nitroglycerin can be safely administered to patients regardless of infarct territory. If hypotension does occur, is it usually transient and can be managed with intravenous fluids.
Clinical Scenario: A 63-year-old man with a history of hypertension, diabetes, and high cholesterol presents to the emergency department with crushing chest pain. You obtain an ECG which shows elevated ST segments in the inferior leads with elevation in lead III greater than lead II, ST elevation in V1, and depressions in V2. This is concerning for an inferior infarction with extension into the right ventricle. The patient appears visibly uncomfortable. Cardiology is emergently consulted, aspirin is given, but you wonder how to manage this patient’s pain until definitive treatment occurs.
What Your Gut Says: Nitroglycerin could help with his pain, but based on its pharmacology, it will cause vasodilation, reduce preload and thus cause significant and potentially dangerous hypotension. We would not want to cause an adverse outcome for this patient.
What The Evidence Says: Guidelines recommend against the use of nitroglycerin in right ventricular myocardial infarction (RVMI) due to the concern for vasodilation and reduced preload leading to hypotension. This is based on a study in 1989 that compared 20 patients with inferior wall acute myocardial infarction who became hypotensive after nitrates to 20 patients with inferior wall acute myocardial infarction who did not become hypotensive after nitrates. 15 of the 20 hypotensive patients had evidence of right ventricular involvement while only 2 of 20 in the non-hypotensive group did. The authors suggested that the hypotension after nitrate administration resulted from right ventricular involvement and thus, nitrates should be used carefully (Ferguson 1989). This was a retrospective observational study without known routes or dosages of nitroglycerin administration, small sample size, and there was simultaneous administration of calcium blocking agents in a number of the patients. Despite the low quality evidence, the American Heart Association (AHA) (O’Connor 2010) and European Society of Cardiology (ESC) (Bryne 2023) state that nitrates are contraindicated in RVMI.
Since then, several studies have challenged the prior findings culminating in a systematic review of 5 studies (n=1,113) (Wilkinson-Stokes 2022). The outcomes included hemodynamics, GCS, syncope, arrest and death and compared outcomes in patients who were administered nitroglycerin for acute right sided myocardial infarction to patients with acute myocardial infarction involving any other anatomic region. They found no statistical difference in adverse events after nitrates were administered between the two groups. Any adverse events that did occur were transient and not clinically significant. This held true even when 400 µg of sublingual nitroglycerin was administered (Wilkinson-Stokes 2022).
The authors conclude that based on this review the AHA and ESC recommendation against the use of nitrates in right ventricular myocardial infarction is not supported. Adverse events from nitrates are transient and easily managed making it reasonable to administer nitrates in right ventricular myocardial infarctions.
Although this review includes improved evidence for the use of nitrates, no high quality evidence suggests improved outcomes in STEMI despite its widespread use. Any potential benefit of pain relief and perfusion has to be balanced with the potential risk of hypotension. If the patient is normotensive with significant pain, it is very reasonable to give nitrates and closely monitor. For patients with a marginal or low blood pressure, consider starting low dose nitrates in intravenous form or avoiding nitroglycerin altogether
Read More:
1. Revisiting Nitroglycerin in MI with Right-Side Ventricular Involvement
2. Is there Evidence of Harm for Nitroglycerin in Right Ventricular MI?
Related Topics:
Does nitroglycerin offer any benefit other than analgesia?: GISSI-3, ISIS-4
References
Ferguson J, Diver D, Boldt M, Pasternak R. Significance of Nitroglycerin-Induced Hypotension with Inferior Wall Acute Myocardial Infarction. The American Journal of Cardiology 1989 Aug;64(5):311-314.
O’Connor E, Brady W, Brooks S, Diercks D, Egan J, Ghaemmaghami C, Menon V, O’Neil B, Travers A, Yannopoulos D. Part 10: Acute coronary syndromes: 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation 2010 Nov;2(122):S787-817.
Byrne R, Rossello X, Coughlan J, Barbato E, Berry C, Chieffo A, Claeys M, Dan G, Dweck M, 2023 ESC Guidelines for the Management of Acute Coronary Syndromes: Developed by the task force on the management of acute coronary syndromes of the European Society of Cardiology (ESC). European Heart Journal 2023 Oct;38 (44):3720–3826
Wilkinson-Stokes M, Betson J, Sawyer S. Adverse events from nitrate administration during right ventricular myocardial infarction: a systematic review and meta-analysis. Emerg Med J. 2023 Feb;40(2):108-113. doi: 10.1136/emermed-2021-212294. Epub 2022 Sep 30. PMID: 36180168.
