In patients with heart transplants who develop an aggressive form of coronary artery disease, drug-eluting stents (DES) lower the rate of restenosis compared with bare-metal stents (BMS) by more than half, in addition to improving other angiographic measures, according to a study in the December 2008 issue of JACC: Cardiovascular Interventions.
Cardiac allograft vasculopathy (CAV) is a rapid, progressive form of diffuse arterial narrowing that affects 50% of all orthotopic heart transplant patients by 5 years after transplantation. The best treatment for CAV is unknown, with bypass surgery and repeat transplantation each having significant drawbacks. Percutaneous coronary intervention (PCI) with BMS has been used as a palliative therapy, but restenosis rates remain high.
Researchers led by Michael S. Lee, MD, of the University of California, Los Angeles Medical Center (Los Angeles, CA), retrospectively looked at 82 consecutive heart transplant patients with CAV who underwent PCI with either BMS (n = 82 lesions) or DES (n = 76 lesions) between 1995 and 2007 at their institution. Follow-up angiography was performed at a mean of 9.5 ± 5.5 months in 57 (70%) of the BMS-treated lesions and 12.6 ± 8.2 months in 58 (76%) of the DES-treated lesions.
The results showed significantly lower rates of binary restenosis (the primary endpoint), among other angiographic parameters, in DES-treated vs. BMS-treated lesions (table 1).
Table 1. Follow-up Angiography, BMS vs. DES
Endpoint
|
BMS
n = 58 lesions
|
DES
n = 55 lesions
|
P Value
|
MLD, mm
|
1.94 ± 0.78
|
2.31 ± 0.78
|
0.045
|
Percent Diameter Stenosis
|
34 ± 36
|
24 ± 20
|
0.06
|
Late Lumen Loss, mm
|
0.82 ± 1.03
|
0.24 ± 0.75
|
0.01
|
Binary Restenosis
|
30.0%
|
12.0%
|
0.02
|
Abbreviation: MLD, minimum lumen diameter.
In the DES group, there were no cases of stent thrombosis, defined as angiographic evidence of intrastent filling defect or stent occlusion associated with a clinical event. In the BMS arm, there were 2 total occlusions in stented lesions that were treated at angiographic follow-up, but it is unclear if these were, in fact, stent thromboses.
In terms of secondary clinical outcomes, 57 (70%) of the 82 patients in the analysis underwent repeat coronary angiography, 17 (21%) underwent target vessel revascularization, 11 (13%) underwent repeat heart transplantation, and 18 (22%) died. The paper did not break down these endpoints by stent type.
The authors note that the restenosis rate observed with DES is greater than that observed with PCI in native coronary arteries. The increased restenosis with PCI in CAV is most likely due to the underlying inflammation that characterizes the disease, they explain, which is marked by intense proliferation of the intima, media, and adventitia.
Dr. Lee and colleagues stressed that a randomized, controlled trial with extended follow-up is necessary to identify the best long-term revascularization strategy for this unique patient subgroup marked by high mortality.
“Until that time,” they write, “PCI with DES seems to be a reasonable option for patients with CAV.”
Source:
Lee MS, Kobashigawa J, Tobis J. Comparison of percutaneous coronary intervention with bare-metal and drug-eluting stents for cardiac allograft vasculopathy.
J Am Coll Cardiol Intv 2008;1:710-715.
Disclosure:
- The paper contained no statement regarding conflicts of interest.