Lack of evidence for intravenous vasodilators in ED patients with acute heart failure: a systematic review

There are nearly 700,000 annual US emergency department (ED) visits for acute heart failure (AHF). Although blood pressure is elevated on most of these visits, acute therapy remains focused on preload and not afterload reduction. Data from recent prospective studies suggest that patients with AHF with concomitant acute hypertension benefit from intravenous (IV) vasodilators. To better understand the use of vasodilators for such patients, we conducted a systematic review of (1) currently available intravenous vasodilators for ED patients with AHF, or (2) intravenous vasodilators that are not yet available, but have completed phase III clinical trials in AHF, and may be available for ED use in the future. We used multiterm search queries to retrieve research involving nitroglycerin, nitroprusside, enalaprilat, hydralazine, relaxin, and nesiritide. A total of 2001 unique citations were identified from 3 databases: PubMed, EMBASE, and CINAHL. Of these, 1966 were excluded on the basis of established review criteria, leaving 35 published articles for inclusion. Our primary finding was that intravenous nitrovasodilators, when used in the treatment of AHF in ED and ED-like settings, do improve short-term symptoms and appear safe to administer. There are no data suggesting that they impact mortality. Other commonly used vasodilators such as hydralazine and enalaprilat have very little published data about their safety and efficacy. Of note, few studies enrolled patients early in their course of treatment. Thus, to assess the specific impact of vasodilator therapy on both short- and long-term outcomes, future research efforts should focus on patient recruitment in the ED setting.