Very late drug-eluting stent thrombosis

Intra-stent tissue evaluation within bare metal and drug-eluting stents > 3 years since implantation in patients with mild to moderate neointimal proliferation using optical coherence tomography and virtual histology intravascular ultrasound

OBJECTIVE

We aimed to compare neointimal tissue characteristics between bare-metal stents (BMS) and drug-eluting stents (DES) at long-term follow-up using optical coherence tomography (OCT) and virtual histology intravascular ultrasound (VH-IVUS).

BACKGROUND

Neoatherosclerosis in neointima has been reported in BMS and in DES.

METHODS

Thirty patients with 36 stented lesions [BMS (n=17) or DES (n=19)] >3years after implantation were prospectively enrolled. OCT and VH-IVUS were performed and analyzed independently. Stents with ≥70% diameter stenosis were excluded.

RESULTS

The median duration from implantation was 126.0months in the BMS group and 60.0months in the DES group (p <0.001). Lipid-laden intima (58.8% vs. 42.1%, p=0.317), thrombus (17.6% vs. 5.3%, p=0.326), and calcification (35.3% vs. 26.3%, p=0.559) did not show significant differences between BMS and DES. When divided into 3 time periods, the cumulative incidence of lipid-laden neointima from >3years to <9years was similar between BMS and DES (42.9% vs. 42.1%, p=1.000). Furthermore, it continued to gradually increase over time in both groups. OCT-derived thin-cap fibroatheroma (TCFA) was observed in 17.6% of BMS- and 5.3% of DES-treated lesions (p=0.326). No stents had evidence of intimal disruption. The percentage volume of necrotic core (16.1% [9.7, 20.3] vs. 9.7% [7.0, 16.5], p=0.062) and dense calcium (9.5% [3.8, 13.6] vs. 2.7% [0.4, 4.9], p=0.080) in neointima tended to be greater in BMS-treated lesions. Intra-stent VH-TCFA (BMS vs. DES 45.5% vs. 18.2%, p=0.361) did not differ significantly.

CONCLUSION

At long-term follow-up beyond 3 years after implantation, the intra-stent neointimal tissue characteristics appeared similar for both BMS and DES.

Safety and efficacy outcomes of overlapping second-generation everolimus-eluting stents versus first-generation drug-eluting stents

The safety and efficacy outcomes of stent overlap with second-generation drug-eluting stents (DES) have not been well established. This study aimed to compare the 1-year clinical outcomes of overlapping everolimus-eluting stents (EES) with those of overlapping first-generation DES. This retrospective analysis included 350 patients treated with overlapping EES (169 patients with 237 lesions), sirolimus-eluting stents (SES, 102 patients with 252 lesions), or paclitaxel-eluting stents (PES, 79 patients with 182 lesions). End points were major adverse cardiovascular events (MACE: defined as the composite of death, myocardial infarction, or target lesion revascularization), target vessel revascularization, and definite stent thrombosis at 1 year. During a follow-up of 1 year, overall MACE occurred in 6.5% of EES-, 16.8% of SES-, and 10.1% of PES-treated patients (p = 0.026). Myocardial infarction was lowest in the EES group versus SES and PES groups (0 vs 1.0% vs 2.5%, respectively; p = 0.080), and mortality was similar (3.6% vs 9.0% vs 5.1%, p = 0.162). The EES patients showed a trend toward lower rates of 1-year target lesion revascularization (3.1% vs 8.2% vs 6.5%, p = 0.181) and target vessel revascularization (3.7% vs 9.1% vs 11.7%, p = 0.051) compared with the SES- and PES-treated patients. The cumulative incidence of definite stent thrombosis was lowest in the EES group (0 for EES vs 3.9% for SES vs 2.5% for PES, p = 0.014). In conclusion, stent overlap with EES versus first-generation DES was associated with lower rates of MACE and stent thrombosis. Our results suggest that the use of EES when deploying overlapping stents is effective and safe.

Outcome of percutaneous coronary intervention utilizing drug-eluting stents in patients with reduced left ventricular ejection fraction

Ischemic cardiomyopathy with depressed left ventricular ejection fraction (LVEF) is predictive of death after percutaneous coronary intervention (PCI), but its association with stent thrombosis (ST) and the need for repeat revascularization is less clearly defined. In total 5,377 patients undergoing PCI were retrospectively evaluated. Multivariable Cox proportional hazards regression and competitive outcome analysis were employed. The primary end point was 1-year major adverse cardiac events (all-cause death, Q-wave myocardial infarction, ST, and target lesion revascularization [TLR]). Individual end points of ST and of TLR were also evaluated. Patients with normal LVEF (>50%) were compared to those with mild (41% to 50%), moderate (25% to 40%), and severe (<25%) decreases in LVEF. Patients with abnormal LVEF were older and more commonly diabetic and had renal insufficiency and heart failure syndrome (p <0.001 for all variables). These patients demonstrated more angiographically complex lesions and less frequently received a drug-eluting stent. The primary end point was significantly increased in patients with lower LVEF (9.7% for normal LVEF vs 20.6% for severely decreased LVEF, p <0.001). ST occurred more frequently in these patients (1.4% for normal LVEF vs 6% for severely decreased LVEF, p <0.001), but clinically driven TLR did not significantly change across LVEF categories. After adjustment, only moderate and severe LVEF decreases (i.e., LVEF ≤40%) demonstrated an association with major adverse cardiac events and with the individual outcome of ST. Subgroup analysis of patients receiving only a drug-eluting stent or a bare-metal stent demonstrated no statistically significant differences for the probability of ST. In conclusion, decreased LVEF is not associated with clinically driven TLR but does increase the risk of ST. Patients with LVEF ≤40% appear to be at significantly higher risk for ST and therefore might benefit from interventional and pharmacologic strategies aimed at minimizing this risk.

Simultaneous very late angiographic stent thrombosis of 2 drug-eluting stents: a case report

Very late angiographic stent thrombosis (VAST) is a known serious complication of drug-eluting stents (DESs). Most VAST events occur shortly after the discontinuation of aspirin and/or clopidogrel. This case is unique in that the patient had recently discontinued only aspirin and involves simultaneous VAST of 2 separate stents. Although the safety profile of DES does not seem to differ from those of bare metal stents in regard to thrombosis in the acute (within 24 hours) and subacute (24 hours-30 days) phases, data suggest an increase in thrombotic events in the late (after 30 days) and very late (after 12 months) phases after DES deployment. Results from a recent pooled analysis suggest that DES does not increase the risk of stent thrombosis under appropriate multidrug antiplatelet therapy. In this case, the patient self-discontinued daily aspirin 2 months before the simultaneous total occlusion of 2 DESs 37 months after placement. This was 34 months after an initial 3-month course of clopidogrel and 13 months after a 30-day course of clopidogrel. This case provides additional evidence to the importance of continued dual antiplatelet therapy and attention to compliance in patients with DESs.