PACEmaker & Beta-Blocker Therapy Post-Myocardial Infarct

描述(由申请人提供)： 起搏器和贝塔阻滞剂治疗心肌梗死后(PACE-MI)试验将调查起搏器促进的贝塔阻滞剂治疗是否降低了患有心肌梗死且对贝塔阻滞剂有心动过缓禁忌症的患者的总死亡率和非致命性再梗塞的综合终点。目前，这些患者没有接受β受体阻滞剂的治疗，因为治疗过程中可能会出现潜在的危险的缓慢性心律失常。由于β受体阻滞剂在减少心肌梗死后的死亡率和再梗塞方面是非常有效的药物，特别是在高危亚组中，它们的使用越来越受到重视。理论上，如果首先植入起搏器以提供后备频率支持，则无法接受β受体阻滞剂治疗的心动过缓患者可以使用β受体阻滞剂进行治疗。由于这些患者通常被排除在临床试验之外，因此没有直接数据支持这一建议。PACE-MI试验的具体目的是测试心肌梗死后起搏器促进的β受体阻滞剂治疗是否在这一亚组患者中具有临床优势。这一目标将在这项多中心临床试验中实现。在这项多中心临床试验中，心肌梗死一个月内对β受体阻滞剂有心动过缓或心脏阻断禁忌症的患者将被随机分为接受标准治疗(不包括β受体阻滞剂，因为这些患者有禁忌症)或标准治疗加起搏器和β受体阻滞剂。这一具体目标具有重要意义，因为它将：1)提供数据支持(如果假设得到证实)联邦医疗保险覆盖政策的改变；2)为起搏器促进的Beta受体阻滞剂疗法的治疗范式提供支持；3)强调即使在心肌梗死管理的现代时代，尤其是在目前治疗不足的老年人口中，β受体阻滞剂疗法的重要性。试验的主要指标是总死亡率加上非致命性再梗塞。参与试验的患者将被跟踪两年。样本规模为1124名患者，他们将在60个地点登记。

DESCRIPTION (provided by applicant): The PACEmaker & Beta-Blocker Therapy Post-Myocardial Infarction (PACE-MI) Trial will investigate whether pacemaker facilitated beta blocker therapy decreases the combined endpoint of total mortality plus nonfatal reinfarction in patients who have suffered a myocardial infarction and have bradycardia contraindications to beta blockers. Currently, these patients are not treated with beta blockers due to the likelihood of developing potentially dangerous bradyarrhythmias from treatment. Because beta blockers are highly effective agents in reducing mortality and reinfarction post-myocardial infarction, particularly in high risk subgroups, there has been increasing emphasis on their use. The patients with bradycardia precluding beta blocker therapy could, in theory, be treated with beta blockers if a pacemaker is implanted first to provide backup rate support. As these patients have been routinely excluded from clinical trials, there is no direct data to support such a recommendation. The specific aim of the PACE-MI Trial is to test whether pacemaker facilitated beta blocker therapy after myocardial infarction confers a clinical advantage in this subgroup of patients. This aim will be accomplished in this multicenter clinical trial in which patients within one month of a myocardial infarction who have either bradycardia or heart block contraindications to beta blockers will be randomized to receive either standard therapy (which would not include a beta-blocker as these patients have contraindications) or standard therapy plus a pacemaker and beta-blocker. This specific aim has important implications in that it will: 1) Provide data to support (if the hypothesis is verified) a change in Medicare coverage policy; 2) Provide support for the treatment paradigm of pacemaker facilitated betablocker therapy; 3) Highlight the importance of beta blocker therapy even in the modern era of management of myocardial infarction, particularly in the currently under treated elderly population. The trial primary composite is total mortality plus nonfatal reinfarction. Patients enrolled in the trial will be followed for two years. The sample size will be 1124 patients who will be enrolled in 60 sites.