Very late stent thrombosis of a sirolimus-eluting stent

Very late drug-eluting stent thrombosis after nonsteroidal anti-inflammatory drug treatment despite dual antiplatelet therapy

BACKGROUND

Drug-eluting coronary stent implantation emerged as a safe and effective therapeutic approach by preventing coronary restenosis and reducing the need for further revascularization. However, in contrast to bare metal stents, recent data suggest a unique underlying pathology, namely late coronary stent thrombosis and delayed endothelial healing.

OBJECTIVE

To report a case of very late coronary stent thrombosis (834 days after implantation) requiring repeat urgent target-vessel revascularization. Importantly, six days before the acute coronary event, combined nonsteroidal anti-inflammatory drug therapy was initiated.

RESULTS

Although a dual antiplatelet regimen was continuously maintained, aggregation measurements indicated only partial antiplatelet effect, which returned to the expected range when nonsteroidal anti-inflammatory drugs were omitted.

CONCLUSIONS

The observation indicates that, even 834 days after drug-eluting stent implantation, effective combined antiplatelet therapy might be crucial in certain individuals and the possible impact of drug interactions should not be underestimated. Further efforts should focus on the challenging task of identifying patients or medical situations with prolonged, increased risk of stent thrombosis.

Safety and efficacy of the drug-eluting stent: a double-edged sword?

Like the introduction of bare metal stents (BMS), that of drug-eluting stents (DES) represented a quantum leap in the interventional cardiology community's ongoing efforts to conquer restenosis. However, recent concerns over late thrombosis (LT) have tempered the initial enthusiasm. Nonetheless, when compared with BMS, the slightly higher DES-LT is counterbalanced by the device's markedly lower incidence of restenosis, resulting in net equivalent rates of death, myocardial infarction, and overall major adverse cardiovascular events. This article summarizes for the noncardiology practitioner the benefits and risks of DES, as well as essentials of postprocedural care of the DES patient. We discuss the pathophysiology of stent thrombosis, pivotal DES trials, and adjunct antiplatelet pharmacology. In December 2006, the Food and Drug Administration convened an expert panel to review these devices. Their recommendations, as well as the joint statement from the American College of Cardiology/American Heart Association/Society of Cardiovascular Angiography and Interventions, are outlined.

Intravascular bioresorbable polymeric stents: a potential alternative to current drug eluting metal stents

Stent implantation following angioplasty is the standard treatment of coronary artery disease necessitating interventional procedures. The use of stents as a platform for local drug delivery is a popular strategy to achieve local pharmacological treatment to the diseased artery. Drug eluting stents (DES) are now largely preferred to bare metal stents when stent implantation is necessary. Lately, there have been several reports questioning the long-term safety of DES. An alternative to these drug eluting metal stents are bioresorbable polymeric stents (BPS) because of the many advantages of bioresorbable material. However, the fundamental differences in polymeric and metallic materials make the development of such an alternative a significant challenge. This review discusses the different advantages of BPS and the many constrains and requirements of such devices. An up to date commented review of published data concerning BPS is presented. Considerations are given on using BPS as local drug delivery systems as well as on evaluating BPS performances.

Comparison of intravascular ultrasonic imaging with versus without incomplete stent apposition at follow-up after drug-eluting stent implantation

BACKGROUND

Incomplete stent apposition (ISA) at follow-up has been reported to be more common after drug-eluting stent (DES) implantation than after bare-metal stent (BMS) implantation. The aim of this study was to use intravascular ultrasound (IVUS) to evaluate the coronary characteristics after drug-eluting stent implantation in patients with ISA at follow-up.

METHODS

From the IVUS database of our institute, a total of 89 patients with 125 native lesions who underwent DES implantation into de novo lesions with IVUS imaging at 6-month follow-up were identified, and 15 (16.9%) patients had documented ISA at follow-up by IVUS. The ISA group was compared with a matched control group of patients (n = 30) who had no evidence of ISA at follow-up.

RESULTS

Of the 15 documented ISA at follow-up after DES implantation, two located at the edge (within 5 mm from stent margin) while 13 in the body of the stent. The maximum area and arc of ISA measured 5.3 +/- 2.2 mm(2) and 163 +/- 67 degrees , respectively. In patients with ISA, the maximum EEM area of stent segment with ISA was significantly larger than the adjacent stent segment without ISA (24.1 +/- 3.3 vs. 20.1 +/- 3.1 mm(2), P = 0.002), while stent area, plaque plus media (P&M) area and intrastent lumen area were comparable (P > 0.05). Compared to the matched control cohort without ISA at follow-up, the maximum EEM area was also significantly larger (24.1 +/- 3.3 vs. 18.8 +/- 4.2 mm(2), P < 0.001), while the areas of reference EEM and lumen, stent, P&M behind the stent, intimal hyperplasia and intrastent lumen were all comparable between the two groups (P > 0.05).

CONCLUSION

ISA at follow-up after DES implantation for de novo coronary lesions was associated with a larger EEM area.

Overview of the 2006 Food and Drug Administration Circulatory System Devices Panel meeting on drug-eluting stent thrombosis

Drug-eluting stents (DES) seemed likely to mitigate the problem of restenosis and have become the predominant stent deployed during percutaneous coronary intervention (PCI). Sustained concerns about the rate of stent thrombosis (ST), particularly very late ST (>1 year following PCI) led to a meeting of the Circulatory System Devices Advisory Panel to address "on-label" and "off-label" use as well as appropriate duration of dual antiplatelet therapy following DES. Over 40 presentations by members of the FDA, industry personnel, and leaders in the field of interventional cardiology helped set forth the body of data available on DES. Standardized definitions of ST created by the Academic Research Consortium were applied to existing randomized trials and registries. At the end of the 2-day session, the consensus of the panel was that "on-label" DES use is not associated with increased incidence of death and myocardial infarction (MI), although it is associated with increased rates of very late ST. "Off-label" use is associated with increased risk of death or MI when compared with "on-label" use. Insufficient data exist to determine the duration of clopidogrel that would minimize ST and bleeding risk, but the panel agreed with the current ACC/AHA/SCAI guidelines regarding dual antiplatelet therapy for at least 12 months in patients at low risk for bleeding, especially with "off-label" use. More data from trials designed with better control arms and prespecified analyses of complex patients and lesions subsets over longer periods of follow-up are needed.