Antman E M, Dupont W D, Bonalsky J, Califf R M, Corwin S, Fink L, Hansen D E, Kawanishi D T, Kronenberg M W, McKay C R
Int J Cardiol. 1989 May;23(2):185-97. doi: 10.1016/0167-5273(89)90247-7.
Recent randomized clinical trials have shown that total mortality and cardiovascular mortality are reduced by the early intravenous administration of beta-blockers to patients suspected of suffering from acute myocardial infarction. These trials were conducted on patients meeting strict entry criteria. In order to assess this therapy when applied to a broader range of myocardial infarction patients, we performed a Phase IV study of metoprolol in acute myocardial infarction. The study was designed to test whether early (less than 8 hours from onset of chest pain) intervention by practicing physicians with open label intravenous metoprolol for cases of suspected acute myocardial infarction achieved mortality results similar to those obtained in large randomized clinical trials. We studied 3824 patients treated by 741 physicians representing a broad spectrum of clinical practice in the United States. Seventy-two percent of the patients entered into the study had confirmed myocardial infarction (39% anterior, 39% inferior, 22% other locations) and 85% of all individuals treated tolerated the full intravenous dose of 15 mg of metoprolol. The 15 day total mortality and cardiovascular mortality rates were 4.9% and 4.5%; 90 day mortality rates were 6.9 and 5.9%. Patients with anterior infarctions had a significantly greater cumulative mortality rate than patients with other types of infarctions. Marked bradycardia (heart rate less than 45 beats per minute) in the first 8 hours post treatment occurred in 4.7% cases and hypotension (systolic blood pressure less than 90 mm Hg) occurred in 9.8% of cases. When compared with the results of the Göteborg and MIAMI trials of metoprolol, it appears that there is no appreciable increase in mortality or morbidity when metoprolol is used in the community practice of acute coronary care.
近期的随机临床试验表明，对于疑似急性心肌梗死的患者，早期静脉注射β受体阻滞剂可降低总死亡率和心血管死亡率。这些试验是在符合严格入选标准的患者中进行的。为了评估这种疗法应用于更广泛的心肌梗死患者时的效果，我们开展了一项美托洛尔治疗急性心肌梗死的IV期研究。该研究旨在测试执业医师对疑似急性心肌梗死病例采用开放标签静脉注射美托洛尔进行早期（胸痛发作后少于8小时）干预，是否能取得与大型随机临床试验相似的死亡率结果。我们研究了由741名代表美国广泛临床实践的医师治疗的3824例患者。纳入研究的患者中有72%确诊为心肌梗死（39%为前壁梗死，39%为下壁梗死，22%为其他部位梗死），所有接受治疗的患者中有85%耐受了15mg美托洛尔的全静脉剂量。15天的总死亡率和心血管死亡率分别为4.9%和4.5%；90天死亡率分别为6.9%和5.9%。前壁梗死患者的累积死亡率显著高于其他类型梗死的患者。治疗后最初8小时内，4.7%的病例出现明显心动过缓（心率低于每分钟45次），9.8%的病例出现低血压（收缩压低于90mmHg）。与美托洛尔的哥德堡试验和迈阿密试验结果相比，在急性冠状动脉护理的社区实践中使用美托洛尔时，死亡率或发病率似乎没有明显增加。
