Study looks at differences in drug-eluting vs. bare metal stents

　　奥兰多11月4日——根据AHA2007一项最新的临床结果显示，与裸金属支架相比，药物洗脱支架在开通闭塞的动脉时并不会增加死亡率和心脏病发作率。
 

　　MASS试验比较了应用药物洗脱支架（涂有药物以减少血栓和再狭窄）和裸金属支架的患者（没有药物涂层的支架）。他们审查了2003.4.1~2004.12.31期间马萨诸塞州私立医院急诊中心的所有PCI病例，按标准，筛选出20,654例强制执行PCI术后随访病例进行研究。

　　该研究的主要负责人，哈佛医学院副教授Laura Mauri说：“这是美国最大的比较药物洗脱支架和裸金属支架长期结果的研究。”

　　PCI，也叫血管成形术。应用于血管阻塞或血管狭窄的病人。在手术过程中，一个称为导管的细管插入腹股沟或大腿的血管中，穿过阻塞的冠状动脉，导线顶端有个小球囊，充起并推开阻塞物，使更多血液流向心脏。通常，将叫做支架的极细的金属丝网放到合适的位置支撑血管预防狭窄。但是有可能出现支架血栓（支架内血液凝集），给予病人抗血小板的药物以减少支架血栓形成几率。

　　Mauri说：“过去认为药物洗脱支架术后一年内重复手术几率很小，是因为之前我们缺乏对DES及BMS长期效果比较研究。”

　　Mauri补充说，这个试验有几个好处：它是一项长期大规模随访研究，它反映出目前美国临床实际状况，即大多数患者接受DES治疗；它包括了所有行PCI术的患者，不仅是那些可以随机入选的患者。

Study looks at differences in drug-eluting vs. bare metal stents

ORLANDO, Nov. 4 – Drug-eluting stents to open blocked coronary arteries caused no more risks for death or heart attack than bare metal stents, according to a late-breaking outcomes trial presented at the American Heart Association’s Scientific Sessions 2007.

The Massachusetts stent (MASS Stent) trial compared death rates between patients who received drug-eluting stents (stents coated with a drug to reduce restenosis or re-narrowing of the artery) and those who received bare metal stents (stents not coated with a drug).  They reviewed records of all adults undergoing percutaneous coronary intervention (PCI) with stenting between April 1, 2003 and December 31, 2004 at all acute care non-U.S. governmental hospitals in Massachusetts.  Using this criterion, they identified 20,654 patients from a state database with mandatory follow-up after PCI.

“This is the largest study of patients comparing drug-eluting stents and bare metal stents for long-term outcomes in the U.S.,” said Laura Mauri, M.D., principal investigator of the trial and assistant professor of medicine at Harvard Medical School and Brigham and Women’s Hospital in Boston, Mass.

PCI, also called angioplasty, is done in patients who have blocked or narrowed heart arteries.   During the procedure, a thin tube called a catheter is inserted into a blood vessel in the groin or leg, and then threaded through to the blocked coronary artery.  A small balloon at the tip of the wire is then inflated to push back the blockage and allow more blood flow to the heart.  Often, a tiny wire mesh tube called a stent is put in place to hold the vessel open and prevent restenosis (reclosing of the artery).  However, stent thrombosis (blood clots forming inside the stent) is possible.  Patients are prescribed anti-clotting drugs after the procedure to lessen the chance of stent thrombosis.

“It was previously established that drug-eluting stents make it less likely that patients will need repeat procedures within the first year after a stent procedure,” Mauri said. “What we were less certain about before this study was the long-term safety of drug-eluting stents compared to bare metal.”

Mauri adds that this trial has several benefits for addressing this issue.“It is a very large study with long-term follow up, it reflects contemporary U.S. practice- where most patients receive drug-eluting stents-and it includes all patients who were undergoing PCI-not just those who would have qualified for a randomized trial.”

Patients were followed up for at least two years after receiving a stent.Researchers compared the number of deaths, heart attacks, and revascularization procedures (either bypass surgery or another PCI) between the two groups.The adjusted incidence of mortality at two years was 9.4 percent for those with drug-eluting stents and 11.9 percent for those with bare metal stents.