服用高剂量的维生素、矿物质并不降低心脏病患者再发心脏事件的风险

服用高剂量的维生素、矿物质并不降低心脏病患者再发心脏事件的风险 首都医科大学附属北京安贞医院 胡宾 第62届ACC年会上公布的一项研究显示，心脏病患者服用高剂量的维生素和矿物质并不降低再发心脏事件发生的风险。 但美国国立卫生研究院的试验显示，结合螯合疗法，高剂量的维生素和矿物质可能为心脏病患者提供额外的益处。 TACT研究证实了EDTA螯合疗法结合高剂量维生素和矿物质治疗既往有心脏病患者是安全有效的。2012年研究显示，与安慰剂相比，螯合疗法降低心脏事件发生。心脏事件包括心脏病发作，卒中，冠脉血运重建，因心绞痛再次入院，和死亡。 这项研究的首席专家Gervasio 教授认为，服用维生素的心脏病患者并未获益，而联合治疗即螯合治疗加用高剂量的维生素明显获益，但需要进一步研究以明确。 1956年就有学者使用EDTA螯合剂治疗心血管疾病。螯合疗法包括静脉注射合成的氨基酸，后者可与一定矿物质和金属如钙、铬、铅结合。这项试验的学者分别评估螯合疗法、高剂量的维生素及其联合治疗，以明确两种治疗方法的单独及协同效应。 TACT试验纳入1,708名既往有心脏病的患者，其中82%为男性，94%为白种人，大约一半为肥胖患者，三分之二的患者患有糖尿病，68%患有高血压，83%既往做过CABG、支架置入或者球囊扩张术，随机分为四组（2 x 2析因便于明确每一种治疗方法的效果）。患者每天予静脉注射40螯合治疗或者安慰剂，至少持续约3小时。 并每天予以安慰剂或者高剂量的维生素两次。平均随访时间超过4年， 大于一半的患者在随访过程中停用维生素。 结果显示，与安慰剂相比，服用维生素和矿物质并不降低初级终点事件，服用维生素和安慰剂分别降低为27%和30% 。 而服用螯合剂和维生素治疗组的初级终点事件降低约26%，而对应的安慰机组为 32%，具有统计学差异。 在这些研究中，多数患者正在服用有循证医学证据的药物: 84%的患者服用阿司匹林，72%的服用 beta受体阻滞剂，而 73%服用他汀类药物。 High-Dose Oral Vitamins, Minerals do not Reduce Recurrent Cardiac Events in Heart Attack Patients · Heart attack patients given a combination of high-dose oral vitamins and minerals do not exhibit a significant reduction in recurrent cardiac events, according to research presented today at the American College of Cardiology's 62nd Annual Scientific Session. However, the results of one component of the NIH-funded Trial to Assess Chelation Therapy (TACT) study, shows that when combined with active chelation therapy, high-dose vitamins and minerals may provide some additional benefit. The TACT study tested the safety and effectiveness of both EDTA chelation therapy and high-dose vitamin/mineral supplements in individuals with prior heart attacks. Previous results presented in November 2012 suggested that chelation treatment, with or without supplements, provided a modest reduction in cardiac events compared to a placebo treatment. These cardiac events were combined and included recurrent heart attack, stroke, coronary revascularization, hospitalization for angina and death. The presentation today focused on the effects of the vitamin/mineral supplements, with or without chelation, compared to placebo caplets, as well as the comparative results of all four study groups (active chelation plus active oral vitamins, active chelation plus placebo oral vitamins, placebo chelation plus active oral vitamins, and placebo chelation plus placebo oral vitamins). "We did not see a significant benefit of vitamins alone for patients who had a heart attack," said Gervasio A. (Tony) Lamas, MD, lead author of the study and chief of the Columbia University Division of Cardiology at Mount Sinai Medical Center in Miami Beach, Fla. "Interestingly, patients who received both high dose vitamins and active chelation compared to placebo of both appeared to have additional benefit, but more research is needed to understand the results." Since 1956, alternative medicine practitioners have used EDTA chelation to treat cardiovascular disease. Chelation therapy involves multiple intravenous infusions of a synthetic amino acid called EDTA, which binds to certain minerals and metals, including calcium, lead and cadmium. The study investigators proposed studying chelation and high dose vitamins as separate and combined components to determine potential individual and synergistic effects of the two treatments. TACT enrolled 1,708 patients with prior heart attacks who were randomly assigned to an active or placebo chelation group and an active or placebo vitamin group. This 2 x 2 factorial design allowed the investigators to clarify the independent contributions of each treatment. Patients received 40 intravenous chelation treatments (or placebo), each lasting about three hours, over about a year and a half. They were also assigned to take three pills twice daily, which contained either high-dose vitamins and minerals or placebo. Average follow-up was over four years. About half of the patients enrolled in the trial stopped taking the vitamins during the study follow-up; researchers say patient preference was the leading reason, given the number of caplets taken daily. The primary comparison of the study, oral vitamins and minerals versus an oral placebo, did not show a significant reduction in the primary endpoint: 27 percent in the vitamin group and 30 percent of those receiving, placebo. The analysis of the four study groups showed that the active/active arm had 108 (26 percent) events and the placebo/placebo arm had 139 (32 percent) events — a statistically significant difference. The patients in the trial were 82 percent male, 94 percent Caucasian and about half were obese. All had experienced a previous heart attack. Thirty-two percent had diabetes, 68 percent had high blood pressure and 83 percent had previously undergone bypass surgery, stent implantation or balloon angioplasty. Patients were followed for an average of 55 months. The trial was conducted in 134 sites in the United States and Canada from 2002-2011. Upon entering the study, many patients were already taking evidence-based medications: 84 percent took daily aspirin to reduce risk of stroke and heart attack, 72 percent were on beta-blockers to treat high blood pressure and 73 percent took statins to treat high cholesterol.