JACC: Higher cardiac death in DES vs. BMS puzzles researchers

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Patients implanted with drug-eluting stents (DES) saw a reduction in long-term rates of major adverse cardiac events, but had higher rates of cardiac death compared to those with bare-metal stents (BMS), according to the results of the DEDICATION trial published Aug. 17 in the Journal of the American College of Cardiology.

“DES stents have proven more effective than BMS to prevent coronary stent restenosis and the need for repeat revascularization in a variety of patients,” the authors wrote. “However, concerns have arisen about the long-term benefit of DES, because DES may predispose to stent thrombosis.”

To expand on existing data, Anne Kaltoft, MD, of the Aarhus University Hospital in Skejby, Denmark, and colleagues evaluated the long-term outcomes of DES and BMS implantation during primary PCI in 626 STEMI patients.

During the DEDICATION (Drug Eluting and Distal Protection in Acute Myocardial Infarcation) trial, the researchers enrolled patients who presented with STEMI and were referred within 12 hours to have either a DES or BMS placed in an infarct-related lesion.

Patients were randomly assigned to receive treatment, with or without distal protection, via DES (313 patients) or BMS (313 patients).

Of the 313 patients who received DES, 46 percent eluted sirolimus (Cypher, Cordis), 41 percent paclitaxel (Taxus, Boston Scientific) and 13 percent zotarolimus (Endeavor, Medtronic). Of the patients who received BMS, 38 percent of stents were made of cobalt alloy and 62 percent were stainless steel.

Patients were followed up for three years and the researchers used primary endpoints of major adverse cardiac events (MACE) including cardiac death, nonfatal recurrent MI and target lesion revascularization (TLR).

Trial results showed that that MACE rates were higher in the BMS arm compared to the DES arm, 18.2 percent versus 11.5 percent, respectively. In addition, rates of TLR were significantly higher in the BMS arm compared to patients implanted with DES, 16.3 percent versus 6.1 percent, respectively.

However, in both instances of all-cause mortality and cardiac death, rates were higher in the DES arm compared to the BMS arm. These rates were 10.5 percent versus 6.4 percent and 6.1 percent versus 1.9 percent, respectively.

According to the researchers, 12 patients in the DES stent group died before discharge: four from stent thrombosis and eight from progressive heart failure (HF). Additionally, seven deaths occurred after discharge in this group of patients: five from probable stent thrombosis and two from HF.

In comparison, four patients in the BMS arm died prior to discharge, while two deaths occurred after discharge.

“The rate of all-cause mortality was not significantly different, but the rate of cardiac mortality was significantly increased in the DES group, which is in contrast to most previous studies,” the authors wrote.

The researchers also reported similar rates of MI and stroke in the two study arms.

The authors wrote that “the very low cardiac mortality rate in our BMS group is hard to interpret, and the excess cardiac DES mortality should be interpreted accordingly and might have occurred by chance.

“The present randomized study with long-term follow-up shows that in patients with STEMI, implantation of a DES, compared with a BMS significantly reduces the rate of MACE and the need for revascularization. Despite this reduction, patients with STEMI who have a DES implanted seem to have a higher risk of cardiac death that cannot be attributed to reinfarction or stent thrombosis,” the authors concluded.

A slideshow of the available data that was previously presented at the 2010 American College of Cardiology scientific session in Atlanta is available here.