PACEmaker & Beta-Blocker Therapy Post-Myocardial Infarct

描述（由申请人提供）： PACEmaker和β受体阻滞剂治疗后心肌梗死（PACE-MI）试验将研究起搏器促进的β受体阻滞剂治疗是否能降低心肌梗死患者的总死亡率和非致命性再梗死的联合终点，这些患者有心动过缓的β受体阻滞剂禁忌症。目前，这些患者没有接受β受体阻滞剂治疗，因为治疗可能会发生潜在危险的缓慢性心律失常。由于β受体阻滞剂是降低心肌梗死后死亡率和再梗死的高效药物，特别是在高危亚组中，因此越来越重视其使用。理论上，如果首先植入起搏器以提供备用频率支持，则排除β受体阻滞剂治疗的心动过缓患者可以接受β受体阻滞剂治疗。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试验的具体目的是检验心肌梗死后起搏器易化β受体阻滞剂治疗是否在该患者亚组中具有临床优势。这一目标将在这项多中心临床试验中实现，在该试验中，心肌梗死1个月内患有心动过缓或心脏传导阻滞的β受体阻滞剂禁忌症的患者将随机接受标准治疗（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。这一特定目标具有重要意义，因为它将：1）提供数据支持（如果假设得到验证）医疗保险覆盖政策的变化; 2）为起搏器辅助β受体阻滞剂治疗的治疗模式提供支持; 3）强调β受体阻滞剂治疗的重要性，即使在现代心肌梗死管理中，特别是在目前治疗不足的老年人群中。试验的主要复合终点是总死亡率加上非致死性再梗死。参加试验的患者将接受两年的随访。样本量为1124例患者，将入组60家临床试验机构。

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.