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Compared with bare metal stents (BMS), second-generation drug-eluting stents (DES) offer as good or better 1-year outcomes for patients with ST-segment elevation myocardial infarction (STEMI), according to a new network meta-analysis.

The findings were published online November 26, 2013,  ahead of print in Circulation: Cardiovascular Interventions.

To compare the long- and short-term safety and efficacy of second-generation DES with BMS for use in primary percutaneous coronary intervention (PCI) in STEMI, researchers led by Samir R. Kapadia, MD, of the Cleveland Clinic (Cleveland, OH), conducted a network meta-analysis of 21 trials that compared use of all stent types (first-generation DES, second-generation DES, and BMS) for this indication. Together, the studies included 12,866 randomized patients. The data consisted of:

Direct evidence (2 trials comparing second-generation DES with BMS)

Indirect evidence (15 trials comparing BMS with first-generation DES and 4 comparing first-generation and second-generation DES)

Both 30-day and 1-year rates of stent thrombosis (ST), myocardial infarction (MI), and target vessel revascularization (TVR) were significantly lower among patients who received second-generation DES, compared with BMS. There was no difference in mortality between BMS and second-generation DES (table 1).

Table 1. Safety and Efficacy Outcomes: DES vs. BMS

Abbreviations: ST, stent thrombosis; MI, myocardial infarction; TVR, target vessel revascularization.

Importantly, a significantly lower incidence of stent thrombosis was seen with second-generation DES as early as 30 days (OR 0.36; 95% CI 0.15-0.82) and between 31 days and 1 year (OR 0.49; 95% CI 0.30-0.79) compared with BMS. This finding was also true for definite stent thrombosis at 1 year (OR 0.3; 95% CI 0.11-0.83).

Second-Generation DES Safer for ST

“The main question on everybody’s mind is if BMS are better than DES for [stent thrombosis] risk,” Dr. Kapadia told TCTMD in a telephone interview. “This was a concern that was raised in several trials, which were all related to the first-generation DES. If this is true or not for the newer DES is the question.”

According to the findings, second-generation DES, “are not only safe but safer [than BMS]. We thought they would be as good, not even better. In acute MI, we should not be hesitant to use DES over BMS. … The only advantage [to using a BMS] currently is there remains some controversy as to how long to continue dual antiplatelet therapy when using second-generation DES.” These findings are reinforced by the fact that they reflect the clinical experience of most of the interventional community, Dr. Kapadia said.

He added that he was not surprised that overall mortality rates were not superior with DES, despite improvements in the other outcomes. “The other endpoints are clinically significant, and mortality is difficult to prove with these kinds of numbers,” Dr. Kapadia said.

Limitations of the Data

“This study suggests that newer DES are possibly safer than first-generation DES in STEMI and even safer than BMS, at least in terms of [stent thrombosis],” said Gregg W. Stone, MD, of Columbia University Medical Center (New York, NY), in an email correspondence with TCTMD. “However, this analysis is limited by very little direct data, relying heavily on indirect data. The definition of what comprises a first- vs. a second-generation DES is also arbitrary, and the rationale for pooling durable fluoropolymer-based everolimus-eluting cobalt-chromium stents with bioabsorbable polymer-based biolimus A9-eluting stainless steel stents is uncertain. These 2 devices may have very different safety and efficacy profiles.”

“There is a great need for a large, adequately powered randomized trial of different contemporary stent types vs. BMS in STEMI,” Dr. Stone stressed. “If such a trial were to show a reduction in stent thrombosis, the world’s perspective on the safety of DES would be forever changed. We anticipate starting the randomized HORIZONS-AMI II trial next year to directly answer this question.”

Study Details

First-generation DES included sirolimus-eluting and paclitaxel-eluting stents. Second-generation DES included cobalt-chromium everolimus eluting stents (EES), platinum-chromium EES, zotarolimus-eluting stents (ZES), permanent polymer ZES and biodegradable polymer biolimus-eluting stents. Duration of dual antiplatelet therapy ranged from 3 to 12 months. Most patients were middle-aged males with a high incidence of cardiovascular risk factors. The most common infarct-related vessel was the left anterior descending artery, followed by the right coronary and left circumflex arteries.

Source:

1. Philip F, Agarwal S, Bunte M et al. Stent thrombosis with second-generation drug-eluting stents compared with bare-metal stents: Network meta-analysis of primary percutaneous coronary intervention trials in ST-segment–elevation myocardial infarction. Circ Cardiovasc Interv. 2013;Epub ahead of print.

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