Zotarolimus-eluting stent utilization in small-vessel coronary artery disease (ZEUS)

Drug-coated balloon: an effective alternative to stent strategy in small-vessel coronary artery disease-a meta-analysis

Background

Small-vessel coronary artery disease (CAD) is frequently observed in coronary angiography and linked to a higher risk of lesion failure and restenosis. Currently, treatment of small vessels is not standardized while having drug-eluting stents (DES) or drug-coated balloons (DCBs) as possible strategies. We aimed to conduct a meta-analytic approach to assess the effectiveness of treatment strategies and outcomes for small-vessel CAD.

Methods

Comprehensive literature search was conducted using PubMed, Embase, MEDLINE, and Cochrane Library databases to identify studies reporting treatment strategies of small-vessel CAD with a reference diameter of ≤3.0 mm. Target lesion revascularization (TLR), target lesion thrombosis, all-cause death, myocardial infarction (MI), and major adverse cardiac events (MACE) were defined as clinical outcomes. Outcomes from single-arm and randomized studies based on measures by means of their corresponding 95% confidence intervals (CI) were compared using a meta-analytic approach. Statistical significance was assumed if CIs did not overlap.

Results

Thirty-seven eligible studies with a total of 31,835 patients with small-vessel CAD were included in the present analysis. Among those, 28,147 patients were treated with DES (24 studies) and 3,299 patients with DCB (18 studies). Common baseline characteristics were equally distributed in the different studies. TLR rate was 4% in both treatment strategies [0.04; 95% CI 0.03-0.05 (DES) vs. 0.03-0.07 (DCB)]. MI occurred in 3% of patients receiving DES and in 2% treated with DCB [0.03 (0.02-0.04) vs. 0.02 (0.01-0.03)]. All-cause mortality was 3% in the DES group [0.03 (0.02-0.05)] compared with 1% in the DCB group [0.01 (0.00-0.03)]. Approximately 9% of patients with DES developed MACE vs. 4% of patients with DCB [0.09 (0.07-0.10) vs. 0.04 (0.02-0.08)]. Meta-regression analysis did not show a significant impact of reference vessel diameter on outcomes.

Conclusion

This large meta-analytic approach demonstrates similar clinical and angiographic results between treatment strategies with DES and DCB in small-vessel CAD. Therefore, DES may be waived in small coronary arteries when PCI is performed with DCB.

Small Vessel Coronary Artery Disease: Rationale for Standardized Definition and Critical Appraisal of the Literature

Small vessel coronary artery disease (CAD) is present in 30% to 67% of patients undergoing percutaneous coronary intervention according to different series, representing an unmet clinical need in light of an increased risk of technical failure, restenosis, and need for repeated revascularization. The definition of small vessel is inconsistent across trials, and no definite cutoff value has yet been determined. The lack of consensus on the definition of small vessel CAD has contributed to the high degree of heterogeneity in the safety and efficacy of the various revascularization options. Therefore, the aim of this article is to provide a critical appraisal of existing reports and to propose a reference vessel diameter of <2.5 ​mm definition of small vessel CAD to guide future clinical trials and clinical decision-making.

Predictors of Favorable Angiographic Outcomes After Drug-Coated Balloon Use for de novo Small Vessel Coronary Disease (DCB-ONLY)

We evaluated the angiographic parameter and clinical outcomes of drug-coated balloon (DCB) to assess the optimal angiographic criteria in de novo small vessel disease (SVD). Patients (n = 424, mean age: 64.4 ± 11.2 years, men: 69.8%) at 20 sites in Korea were prospectively enrolled. The primary end point was late luminal loss (LLL) at 9-month follow-up angiography. Secondary end points included restenosis rates, target lesion failure (TLF), and DCB-related thrombosis during the 12-month follow-up period. We included 403 patients for analysis excluding 21 patients who required bailout stenting. Baseline mean reference vessel .diameter was 2.52 ± 0.39 mm and mean minimal luminal diameter (MLD) was 0.71 ± 0.40 mm. The mean MLD was 1.54 ± 0.37 mm after DCB. Late luminal loss was -0.01 ± 0.43 mm and restenosis was noted in 26 patients (12.2%). Minimal luminal diameter >1.6 mm and %diameter stenosis (DS) <45% after DCB was associated maintenance of MLD without LLL at 9-months. Multivariate analysis demonstrated that %DS at baseline and post-MLD was associated with the restenosis. During 12-month follow-up, TLF was 2.6% including 1 cardiac death, 1 myocardial infarction, and 10 ischemia-driven target lesion revascularizations. Drug-coated balloon showed a low restenosis and lower LLL despite high in-segment DS. Post-MLD and % DS may be helpful to get optimal results in de novo SVD after DCB.

Impact of catheter size on reliability of quantitative coronary angiographic measurements (comparison of 4Fr and 6Fr catheters)

To evaluate the feasibility of catheter down sizing for QCA, the reliability of a 4Fr catheter as a calibration device was evaluated. Repeated coronary angiograms of 9 lesions were obtained using 4Fr and 6Fr catheters under otherwise identical conditions. The calibration factor was measured 10 times by 4Fr and 6Fr catheters. QCA measurements including minimal lumen diameter (MLD), interpolated normal reference (Int N), percent diameter stenosis (%DS), and lesion length (LL) were performed by two technicians twice with a 3-month interval. The intraobserver and interobserver variability of each parameter was evaluated using intraclass correlation coefficients (ICCs). Mean of mean SD of calibration factor was significantly larger in 4Fr than in 6Fr in 9 lesions. The mean of mean coefficient of variance was significantly larger in 4Fr catheters vs in 6Fr catheters. A 6Fr catheter showed excellent reliability for both intraobserver and interobserver variability in MLD, Int N, %DS, and LL. In contrast, 4Fr showed that reliability in intraobserver variability depended on the analyst. Although reliability of interobserver variability in Int N measured by the 4Fr catheter was >0.80, the value was less than that by the 6Fr catheter. Taking these results into consideration, 4Fr catheters are less reliable than 6Fr catheters when measuring QCA data especially for follow-up data that need most accurate measurements of MLD and %DS. It would be better to use a 6Fr catheter to evaluate QCA measurements such as acute gain, late loss, restenosis rate, and device size.

Comparison of Long-Term Outcomes in Real-World Patients Between Resolute Zotarilumus-Eluting and Paclitaxel-Eluting Stents in Small Vessel

OBJECTIVE

To compare the long-term clinical outcomes between Resolute zotarolimus-eluting stent (R-ZES) and paclitaxel-eluting stent (PES) in patients with small coronary artery disease.

BACKGROUND

Patients with a small vessel diameter are independently associated with increased risk of adverse cardiac events after drug-eluting stent implantation.

METHODS

A cohort of 265 patients treated with R-ZES (185 patients with 211 lesions) or PES (80 patients with 100 lesions) in small vessel (≤2.5 mm) lesions were retrospectively analyzed. The primary end point of the study was the composite of major adverse cardiac events. The secondary end points included target lesion revascularization (TLR), target vessel revascularization (TVR), and stent thrombosis at 3 years.

RESULTS

The baseline characteristics were similar between the 2 groups. In the R-ZES group, the mean stent diameter was smaller and the total stent length per lesion was longer. Major adverse cardiac events occurred in 8 (10%) patients who had received PES and in 7 (3.8%) patients who had received R-ZES (P = .07). The rates of 3-year TLR (2.2% vs 2.5%; P = 1.00) and TVR (5.4% vs 10.0%; P = .17) showed no statistically significant difference between the R-ZES and PES groups. The rate of stent thrombosis was 0.5% in the R-ZES group and 2.5% in the PES group (P = .21).

CONCLUSION

The rates of major adverse cardiac events and cardiac death were similar in the R-ZES-treated group compared with the PES-treated group.