Percutaneous coronary intervention for small vessel coronary artery disease

Paclitaxel drug-coated balloons: a review of current status and emerging applications in native coronary artery de novo lesions

The paclitaxel drug-coated balloon (DCB) is an emerging device in percutaneous coronary intervention, which has shown promising results by means of a high-concentration, rapid local release of an antirestenotic drug without the use of a durable polymer or metal scaffold. DCB have already proven effective in clinical trials for the treatment of in-stent restenosis. Its coronary applications may potentially be widened to a host of complex coronary de novo lesion subsets, such as small-caliber vessels, diabetes, and diffuse lesions, where the use of stents may be hampered by suboptimal results. Recently, this technology has rapidly evolved with newer studies added to assess the value of DCB in coronary applications other than in-stent restenosis. We present a review of the role of DCB in de novo coronary lesions based on this latest clinical evidence.

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.

Anatomical predictors of major adverse limb events after infrapopliteal angioplasty for patients with critical limb ischaemia due to pure isolated infrapopliteal lesions

OBJECTIVE

To identify anatomical factors associated with major adverse limb events (MALE) after angioplasty as the basis for a novel morphology-driven classification of infrapopliteal lesions.

DESIGN

Retrospective-multicenter study.

MATERIALS AND METHODS

Between March 2004 and October 2010, 1057 limbs from 884 patients with CLI due to isolated infrapopliteal lesions were studied. Freedom-from MALE, defined as major amputation or any reintervention, was assessed out to 2 years by the Kaplan-Meier methods. Anatomical predictors and risk stratification for MALE were analyzed by multivariate analysis.

RESULTS

Freedom-from MALE was 47 ± 1% at 2 years. Lesion calcification, target vessel diameter<3.0 mm, lesion length>300 mm and no below-the-ankle (BA) run-off were positively associated with MALE by multivariate-analysis. The total number of risk factors was used to calculate the risk score for each limbs for subsequent categorization into 3 groups with 0 or 1 (low-risk), 2 (moderate-risk) and 3 or 4 (high-risk) factors. Freedom-from MALE at 2 year-rates was 59% in low-risk, 46% in moderate-risk, and 29% in high-risk, respectively.

CONCLUSION

Target vessel diameter <3.0 mm, lesion calcification, lesion length > 300 mm and no-BA run-off were associated with MALE after infrapopliteal angioplasty. Risk stratification based on these predictors allows estimation of future incidence of MALE in CLI with isolated infrapopliteal lesions.

New technologies aimed at percutaneous intervention in the small coronary artery

Percutaneous coronary intervention (PCI) of small vessels can be complicated by technically difficult access to the target lesion, an increased risk of major adverse cardiac events and in-stent restenosis requiring repeat revascularization. Conventional management of such lesions is with drug-eluting stent implantation; however, these have only partly attenuated the problem. In response, several medical device companies are competing to produce new technologies aimed at PCI in small coronary arteries. Such innovations include thin-strutted stents, stent-on-a-wire systems, drug-coated balloons, endothelial progenitor cell-catching stents and biodegradable stent systems. To date, none of these techniques have been sufficiently validated for use in small coronary arteries to justify a change in practice; however, small-vessel coronary artery disease is an increasingly common problem, and PCI of target lesions with reference vessel diameter <3.0 mm is likely to increase, especially in view of the increasing prevalence of diabetes, warranting further well-designed studies. The prospect of mounting a self-expandable biodegradable drug-eluting stent directly onto a guidewire could potentially be an exciting future development.

Proximal and distal maximal luminal diameters as a guide to appropriate deployment of the ABSORB everolimus-eluting bioresorbable vascular scaffold: a sub-study of the ABSORB Cohort B and the on-going ABSORB EXTEND Single Arm Study

OBJECTIVES

Due to the limited distensibility of the everolimus-eluting bioresorbable vascular scaffold (ABSORB) compared to metallic platform stents, quantitative coronary arteriography (QCA) is a mandatory requirement for ABSORB deployment in the on-going ABSORB EXTEND Single-Arm Study. Visual assessment of vessel size in the ABSORB Cohort B study often lead to under and over-sizing of the 3 mm ABSORB in coronary vessels (recommended range of the vessel diameter ≥ 2.5 mm and ≤ 3.3 mm), with an increased risk of spontaneous incomplete scaffold apposition post ABSORB deployment. We report whether mandatory QCA assessment of vessel size pre-implantation, utilizing the maximal luminal diameter (Dmax) and established interpolated reference vessel diameter (RVD) measurements, has improved device/vessel sizing.

METHODS

Pre-implantation post-hoc QCA analyses of all 101 patients from ABSORB Cohort B (102 lesions) and first consecutive 101 patients (108 lesions) from ABSORB EXTEND were undertaken by an independent core-laboratory; all patients had a 3 mm ABSORB implanted. Comparative analyses were performed.

RESULTS

Within ABSORB Cohort B, a greater number of over-sized vessels (> 3.3 mm) were identified utilizing the Dmax compared to the interpolated RVD (17 vessels, 16.7% vs. 3 vessels, 2.9%; P = 0.002). Comparative analyses demonstrated a greater number of appropriate vessel-size selection (75 vessels, 69.4% vs. 48 vessels, 47.1%; P = 0.001), a trend towards a reduction in implantation in small (< 2.5 mm) vessels (29 vessels, 26.9% vs. 40 vessels, 39.2%; P = 0.057) and a significant decrease in the implantation in large (> 3.3 mm) vessels (4 vessels, 3.7% vs. 17 vessels, 16.7%; P = 0.002) in ABSORB EXTEND. Bland-Altman plots suggested a good agreement between operator and core-laboratory calculated Dmax measurements.

CONCLUSIONS

The introduction of mandatory Dmax measurements of vessel size prior to ABSORB implantation significantly reduced the under-sizing of the 3.0 mm scaffold in large vessels validating the use of this technique in vessel sizing prior to ABSORB implantation.