Sirolimus-eluting stent implantation in small coronary arteries: A three dimensional intravascular ultrasound study from the SIRIUS trial

Intravascular ultrasound analysis of small vessel lesions treated with the Sparrow coronary stent system: results of the CARE II trial

OBJECTIVES

The aim of this study was to evaluate the Sparrow sirolimus-eluting stent (Sparrow-SES) against the Sparrow bare-metal stent (Sparrow-BMS) and conventional balloon-expandable bare-metal stent (BMS: Driver/Micro-Driver stent, Medtronic Vascular, Santa Rosa, CA).

BACKGROUND

The Sparrow stent (Biosensors International, Singapore) consists of a guide wire-based, self-expandable, ultra-thin nitinol stent. The performance of this device with sirolimus in a fully biodegradable polymer has not been determined.

METHODS

A total of 74 patients were included in this intravascular ultrasound (IVUS) sub-study of the CARE II trial, which was a prospective, randomized, multicenter trial in the treatment of single de novo native coronary artery lesions in vessels ranging from 2.0 mm to 2.75 mm in diameter (Sparrow-SES: n = 31, Sparrow-BMS: n = 22, BMS: n = 21).

RESULTS

Stent volume index (VI) was significantly increased 8-month later in Sparrow-SES and Sparrow-BMS, but not in BMS (4.0 ± 1.0 to 4.6 ± 1.0 mm(3) /mm, p<0.0001, 4.0 ± 0.6 to 4.4 ± 0.8 mm(3) /mm, p<0.05, and 5.2 ± 1.0 to 5.1 ± 0.9 mm(3) /mm, p=0.421, respectively). % neointimal obstruction in Sparrow-SES was significantly smaller than those in Sparrow-BMS and BMS at follow-up (17.6 ± 9.4 vs. 36.2 ± 13.8 and 39.9 ± 11.1%, p<0.001). Sparrow-SES showed a mean 15% stent expansion and good suppression of neointimal proliferation, resulting in a significantly lower percentage of change in lumen VI during follow-up period (Sparrow-SES: -6.2 ± 16.2%, Sparrow-BMS: -30.4 ± 11.6%, BMS: -40.4 ± 10.0%, p<0.001).

CONCLUSIONS

The self-expanding Sparrow-SES demonstrated chronic stent expansion, good suppression of neointimal proliferation and resulted in a more preserved lumen in stented small vessels compared with the Sparrow-BMS and conventional balloon expandable BMS.

Stent outcomes for infrapopliteal arterial occlusive disease

This study aimed to determine if the different stent types used in the treatment of infrapopliteal arterial occlusive disease provide any significant advantage over one another at 6 and 12-month follow-up. Consecutive patients undergoing stenting of infrapopliteal lesions were enrolled into a non-randomised prospective registry and followed-up for 1 year. Outcome measures included binary restenosis, target lesion revascularisation, major amputation, and change in Rutherford-Becker score and ankle-brachial index (ABI).Thirty-three patients were enrolled including four patients with bilateral disease. There were 20 target vessels in the drug-eluting stent (DES) group, 13 target vessels in the balloon-expandable bare metal stent (BE-BMS) group and 14 target vessels in the self expandableb are metal stent (SE-BMS) group. Most of the patients in the study were octogenarians except in the SE-BMS group where the mean age was 73 ± 9 years. At 12 months, seven patients had died (DES = 6, BE-BMS = 1) from cardiac and cancer-related diseases. In-stent and peri-stent binary restenosis were non-statistically different between all three groups. There was a nonstatistically significant trend towards higher target vessel revascularisation in the BE-BMS group. Survival curves in all stent types demonstrated restenosis to occur within the first 6 months post-procedure. There was no significant difference in the change in Rutherford-Becker score or ABI between the groups. No major limb amputations occurred during the 12-month period. In conclusion,we did not detect a significant difference in stent performance between the different stent types used to treat infrapopliteal arterial occlusive disease. The choice of stent did not seem to affect patient survival or major amputation-free survival at 1-year follow-up.

One-year outcome of small-vessel disease treated with sirolimus-eluting stents: a subgroup analysis of the e-SELECT registry

OBJECTIVES

To investigate the characteristics and one-year outcomes following sirolimus-eluting CYPHER Select Plus stent (SES) implantation in small (SmVD) and non-small vessel disease (NSmVD) in the international e-SELECT registry.

BACKGROUND

Large-scale registry data are lacking on DES outcomes in SmVD treatment.

METHODS

There were 4,700 SmVD (at least one vessel with estimated reference vessel diameter [RVD] < 2.5 mm, excluding 283 patients with unknown RVD vessels) and 10,139 NSmVD only patients.

RESULTS

The SmVD population was older, with more women, diabetics, and vessels treated, higher mean Charlson Comorbidity Index score (CCI), shorter lesions, and less STEMI presentation. The 1-year stent thrombosis (ST) rate (primary end-point), was significantly higher (1.3% vs. 0.7%) in SmVD versus NSmVD, mainly driven by early events. One-year major adverse cardiac event (MACE), myocardial infarction (MI), and clinically indicated target-lesion revascularization (TLR) rates were significantly higher in SmVD although death and major bleeding rates were similar in both groups. Complication rates were similar between pure (3,188 patients; only RVD < 2.5 mm) and mixed (1,795 patients; some RVD < 2.5 mm or unknown RVD) SmVD. Multivariate predictors for 1-year MACE in SmVD included saphenous vein graft or bifurcation lesions, major bleeding, any antiplatelet therapy discontinuation within 1 month, age, number of stents implanted, CCI, acute coronary syndrome, and insulin-dependent diabetes mellitus.

CONCLUSION

SES implantation for SmVD occurs more frequently in women, diabetics, and those with multivessel disease and comorbidities. One-year ST, MACE, MI, and clinically indicated TLR rates are higher, although low overall, in SmVD or mixed SmVD patients while death rates are similar to NSmVD.