AHA2013年会公布的美国一项研究表明，在年龄大于50岁且伴有糖尿病的心肌梗死后患者中，EDTA螯合剂治疗可显著减少心血管事件。但该研究并未充分证明对所有的伴糖尿病心梗后患者常规用螯合疗法。论文11月19日在线发表于《循环》。

　　此项TACT研究以年龄≥50岁且既往伴有心肌梗死的患者为受试者，共633例糖尿病患者，被随机分为EDTA螯合剂组（322例）或安慰剂组（311例）。主要终点为死亡、心梗再发、卒中、冠脉血运重建或心绞痛住院；次要终点为心血管死亡、心梗再发或卒中。

　　结果显示，在633例（37%）糖尿病患者中，EDTA组的5年主要终点发生率显著降低（25%对38%；危险比[HR] 0.59）。对多亚组实施Bonferroni校正之后上述结果依然具有显著性（校正P=0.002）。EDTA组的全因死昂率和次要终点发生率均显著降低，但对多亚组进行校正之后显著性消失。减少1项主要终点的需治疗数为6.5。在1075例非糖尿病患者中相关事件则无减少。

　　原文阅读：

     The Effect of an EDTA-based Chelation Regimen on Patients With Diabetes Mellitus and Prior Myocardial Infarction in the Trial to Assess Chelation Therapy （TACT）

　　Abstract

　　Background—The Trial to Assess Chelation Therapy （TACT） showed clinical benefit of an EDTA-based infusion regimen in patients aged ≥50 years with prior myocardial infarction. Diabetes mellitus before enrollment was a prespecified subgroup.

　　Methods and Results—Patients received 40 infusions of EDTA chelation or placebo. A total of 633 （37%） patients had diabetes mellitus （322 EDTA and 311 placebo）。 EDTA reduced the primary end point （death, reinfarction, stroke, coronary revascularization, or hospitalization for angina; 25% versus 38%; hazard ratio, 0.59; 95% confidence interval [CI], 0.44–0.79; P<0.001） for over 5 years. The result remained significant after Bonferroni adjustment for multiple subgroups （99.4% CI, 0.39–0.88; adjusted P=0.002）。 All-cause mortality was reduced by EDTA chelation （10% versus 16%; hazard ratio, 0.57; 95% CI, 0.36–0.88; P=0.011）， as was the secondary end point （cardiovascular death, reinfarction, or stroke; 11% versus 17%; hazard ratio, 0.60; 95% CI, 0.39–0.91; P=0.017）。 However, after adjusting for multiple subgroups, those results were no longer significant. The number needed to treat to reduce 1 primary end point over 5 years was 6.5 （95% CI, 4.4–12.7）。There was no reduction in events in non–diabetes mellitus （n=1075; P=0.877）， resulting in a treatment by diabetes mellitus interaction （P=0.004）。

　　Conclusions—Post–myocardial infarction patients with diabetes mellitus aged ≥50 demonstrated a marked reduction in cardiovascular events with EDTA chelation. These findings support efforts to replicate these findings and define the mechanisms of benefit. However, they do not constitute sufficient evidence to indicate the routine use of chelation therapy for all post–myocardial infarction patients with diabetes mellitus.