Everolimus-Eluting Stents Found Equivalent to First-Generation Stents in Most Patients at 1 Year
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In a real-world comparison of drug-eluting stents (DES) in an unselected patient population, everolimus-eluting stents (EES) were both safe and effective. However, use of the second-generation device conferred no clinically relevant advantage at 1 year compared with first-generation stents, according to a study published online April 18, 2011, ahead of print in the American Journal of Cardiology.
The single-center, retrospective study by Ron Waksman, MD, of Washington Hospital Center (Washington, DC), and colleagues, included data from 6,615 consecutive CAD patients at Washington Hospital Center who had received EES (n = 519; Xience V, Abbott Vascular, Redwood City, CA; Promus, Boston Scientific, Natick, MA), paclitaxel-eluting stents (PES; n = 2,036), or sirolimus-eluting stents (SES; n = 4,060) between 2003 and 2009.
The patient population was unselected and included subjects with acute MI requiring PCI and cardiogenic shock as well as a substantial number of type C lesions. The 3 stent groups were well-matched for all conventional CAD risk factors except systemic hypertension, which was highest in patients who received EES.
At 30-day follow-up, no differences were found among the 3 groups for any clinical endpoints examined. By 6 months, disparities began to emerge in unadjusted outcomes. Mortality was highest in PES-treated patients (4.9%) compared with either EES- or SES-treated patients (P for trend = 0.05). The composites of death/Q-wave MI and MACE also were increased in PES patients at 5.1% and 7.7%, respectively (P = 0.04 and P = 0.02). TLR and TVR rates, meanwhile, were most elevated in SES patients at 3.5% (P = 0.04) and 5.1% (P = 0.002), as was Academic Research Consortium-defined definite stent thrombosis at 1.0% (P = 0.05).
The researchers then compared 12-month outcomes between EES and each of the 2 stents, showing improved performance with EES for different endpoints (tables 1 and 2).
Table 1. Outcomes at 12 Months: EES vs. PES
|
EES |
PES |
P Value |
Death |
4.5% |
7.1% |
0.03 |
TLR |
3.4% |
4.6% |
0.24 |
TVR |
5.6% |
7.1% |
0.46 |
Death or Q-Wave MI |
4.5% |
7.4% |
0.02 |
Definite Stent Thrombosisa |
0 |
0.7% |
0.09 |
a Defined according to Academic Research Consortium criteria.
Table 2. Outcomes at 12 Months: EES vs. SES
|
EES |
SES |
P Value |
Death |
4.5% |
5.2% |
0.45 |
TLR |
3.4% |
5.8% |
0.3 |
TVR |
5.6% |
8.6% |
0.05 |
Death or Q-Wave MI |
4.5% |
5.4% |
0.39 |
Definite Stent Thrombosisa |
0 |
1.08% |
0.003 |
a Defined according to Academic Research Consortium criteria.
However, after multivariate analysis that adjusted for differences in baseline characteristics, the advantage held by EES over PES for death/Q-wave MI was no longer significant (HR 1.14; 95% CI 0.59-2.20; P = 0.70).
The finding that EES patients had significantly lower rates of definite stent thrombosis than SES patients requires additional clarification, the researchers note.
Study Has Limitations
In the paper, Dr. Waksman and colleagues acknowledge the small number of patients included in the analysis and the fact that it is a single-center, observational study.
Ajay J. Kirtane, MD, SM, of Columbia University Medical Center (New York, NY), expressed similar thoughts during a telephone interview with TCTMD. “The sample size of this study is not necessarily great enough to detect any minor differences between these stents,” he said. In addition, “physicians were able to choose any 1 stent over another, and it is difficult to know why. There may have been minor differences here that were not adequately captured when the researchers did their analysis.”
Concerns raised about DES safety in 2006 may also have had an effect on physicians choosing DES vs. BMS during the study period of 2003 to 2009, Dr. Kirtane pointed out, noting, “That is why it becomes difficult in this ‘real-world’ setting to ascertain whether some of the differences we are seeing may be related to practice patterns as opposed to intrinsic differences between the stents themselves.”
The researchers also stressed that no real conclusion about the use of these stents in routine clinical practice can be made based on these data without additional studies. In an e-mail communication with TCTMD, Dr. Waksman added, “We do accept that our analysis was restricted to 1-year follow-up and it would be interesting to see whether the results hold up during longer-term follow-up.”
Choosing the Right Stent
Regardless of the outcomes seen in this study, Drs. Waksman and Kirtane both said that any of the 3 DES examined in this study are safe and effective.
“In general, physicians should be reassured that most DES will perform well,” Dr. Kirtane noted.
Dr. Waksman agreed. “This study shows that, outside the rigors of a randomized clinical trial, both the first-generation DES and everolimus-eluting stents do extremely well in an unselected patient population,” he said.
“Therefore, because the advances in stent technology and adjunctive pharmacotherapy used in the treatment of atherosclerotic coronary artery disease have become so safe and efficacious,” Dr. Waksman continued, “the physician’s decision [about which stent to use] will ultimately be based upon the coronary anatomy, ease of device deliverability, and patient choice, particularly in the context of the duration of [dual antiplatelet therapy] and cost.”
Study Details
All patients were given 325 mg aspirin prior to stent implantation and advised to continue this regimen indefinitely. Patients also received a loading dose of 300 or 600 mg clopidogrel then 75 mg/day for 12 months.
Source:
Mahmoudi M, Delhaye C, Wakabayashi K, et al. Outcomes after unrestricted use of everolimus-eluting stent compared to paclitaxel- and sirolimus-eluting stents. Am J Cardiol. 2011;Epub ahead of print.
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Disclosures
- Drs. Waksman and Kirtane report no relevant conflicts of interest.
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