Small vessel coronary artery disease: How small can we go with myocardial revascularization?

Systematic Review on Role of Drug Eluting Stent (DES) Versus Drug-Coated Balloon (DCB) in Small Vessel Coronary Artery Disease

PURPOSE OF REVIEW: This review aims to explain the current advancements in the treatment modalities for small vessel coronary artery disease (SVCAD) and de novo lesions post-percutaneous coronary intervention (PCI), focusing on drug-coated stents (DES) and drug-coated balloons (DCB). Its goal is to address the lack of standards in the management of these lesions and to assess the potential of DCB as a preferential treatment strategy over DES in the long term. RECENT FINDINGS: Technological advancements have improved drug-eluting stents (DES) and drug-coated balloons (DCB) which offer a more promising avenue for managing SVCAD. According to new data, DCBs, initially recognized for their efficacy in preventing restenosis within three to five years of stent placement, may offer superior outcomes compared to DES in certain clinical scenarios. This review shows that DCBs have a favorable therapeutic profile in the treatment of SVCAD, and they could be considered as an alternative to DES. Although the initial data is compelling, definitive conclusions cannot be met without further large-scale, long-term clinical trials. The implication of these findings suggests a shift in the future of SVCAD management and requires additional research to substantiate the long-term benefits of DCB use in SVCAD. Should ongoing and future studies corroborate the current evidence, DCB could emerge as the standard of care for SVCAD, significantly influencing clinical practices and future research.

Comparison of Small Blood Vessel Diameter with Intravascular Ultrasound and Coronary Angiography for Guidance of Percutaneous Coronary Intervention

Major cardiovascular events (MACEs) are a cause of major mortality worldwide. The narrowing and blockage of coronary arteries with atherosclerotic plaques are diagnosed and treated with percutaneous coronary intervention (PCI). During this procedure, coronary angiography (CAG) remains the most widely used guidance modality for the evaluation of the affected blood vessel. The measurement of the blood vessel diameter is an important factor to consider in order to decide if stent colocation is suitable for the intervention. In this regard, a small blood vessel (<2.75 mm) is majorly left without stent colocation; however, small vessel coronary artery disease (SvCAD) is a significant risk factor for the recurrence of MACEs, maybe due to the lack of a standardized treatment related to the diameter of the affected blood vessel; therefore, a more precise measurement is needed. The use of CAG for the measurement of the blood vessel diameter has some important limitations that can be improved with the use of newer techniques such as intravascular ultrasound (IVUS), although at higher costs, which might explain its underuse. To address differences in blood vessel diameter measurements and identify specific cases where IVUS might be of additional benefit for the patient, we conducted a retrospective study in patients who underwent PCI for MACEs with affection for at least one small blood vessel. We compared the measurements of the affected small blood vessels' diameter obtained by CAG and IVUS to identify cases of reclassification of the affected blood vessel; additionally, we underwent a multivariate analysis to identify risk factors associated with blood vessel reclassification. We included information from 48 patients with a mean ± SD age of 69.1 ± 11.9 years; 70.8% were men and 29.2% were women. The mean diameter with CAG and IVUS was 2.1 mm (95% CI 1.9-2.2), and 2.8 (2.8-3.0), respectively. The estimated difference was of 0.8 mm (95% CI 0.7-0.9). We found a significant positive low correlation in diameter measurements of small blood vessels obtained with CAG and IVUS (r = 0.1242 p = 0.014). In total, 37 (77%) patients had a reclassification of the affected blood vessel with IVUS. In 21 cases, the affected blood vessel changed from a small to a medium size (2.75-3.00 mm), and in 15 cases, the affected vessel changed from a small to a large size (<3.00 mm). The Bland-Altman plot was used to evaluate agreement in measurements with CAG and IVUS. The change in blood vessel classification with IVUs was important for the decision of intervention and stent collocation. The only variable associated with reclassification of blood vessels after adjustment in a multivariate analysis was T2D (type 2 diabetes) (p = 0 0.035). Our findings corroborate that blood vessels might appear smaller with CAG, especially in patients with T2D; therefore, at least in these cases, the use of IVUS is recommended over CAG.

Comparison of Clinical Outcomes Among Various Percutaneous Coronary Intervention Strategies for Small Coronary Artery Disease

It remains unclear which percutaneous coronary intervention (PCI) strategy is the most preferable in patients with small-vessel coronary artery disease (CAD). We sought to evaluate the clinical efficacy of various PCI strategies for patients with small-vessel CAD through a network meta-analysis of randomized controlled trials (RCTs). We searched multiple databases for RCTs investigating the efficacy of the following PCI strategies for small-vessel CAD (<3 mm in diameter): drug-coated balloons (DCB), early-generation paclitaxel-eluting stents and sirolimus-eluting stents (SES), newer-generation drug-eluting stents (DES), bare-metal stents (BMS), cutting balloon angioplasty, and balloon angioplasty (BA). The primary outcome was the trial-defined major adverse cardiovascular events (MACE), mostly defined as a composite of death, myocardial infarction, and revascularization. The secondary outcomes included each component of MACE and angiographic binary restenosis. We performed a sensitivity analysis for RCTs without BMS or first-generation DES. Our search identified 29 eligible RCTs, including 8,074 patients among the 8 PCI strategies. SES significantly reduced MACE compared with BA (hazard ratio 0.23, 95% confidence interval 0.10 to 0.54) with significant heterogeneity (I2 = 55.9%), and the rankogram analysis showed that SES was the best. There were no significant differences between DCB and newer-generation DES in any clinical outcomes, which was consistent in the sensitivity analysis. BMS and BA were ranked as the worst 2 for most clinical outcomes. In conclusion, SES was ranked as the best for reducing MACE. There were no significant differences in clinical outcomes between DCB and newer-generation DES. BMS and BA were regarded as the worst strategies for small-vessel CAD.

The clinical utility of circulating cell division control 42 in small-vessel coronary artery disease patients undergoing drug-coated balloon treatment

BACKGROUND

Cell division control 42 (CDC42) regulates atherosclerosis, blood lipids, and inflammation and thus affects coronary artery disease (CAD), but its utility in drug-coated balloon (DCB)-treated small-vessel CAD (SV-CAD) patients is unclear. This study intended to evaluate the change and prognostic role of CDC42 in SV-CAD patients underwent DCB.

METHODS

Serum CDC42 was measured by enzyme-linked immunosorbent assay in 211 SV-CAD patients underwent DCB at baseline, day (D) 1, D3, and D7, as well as in 50 healthy controls (HCs).

RESULTS

CDC42 was decreased in SV-CAD patients compared to HCs (P < 0.001), and it was negatively associated with total cholesterol (P = 0.015), low-density lipoprotein cholesterol (P = 0.003), C-reactive protein (P = 0.001), multivessel disease (P = 0.020), and American college of cardiology/American heart association type B2/C lesions (P = 0.039) in SV-CAD patients. Longitudinally, CDC42 decreased from baseline to D1 and then gradually increased to D7 (P < 0.001) in SV-CAD patients after DCB. Interestingly, high CDC42 (cut-off value = 500 pg/mL) at baseline (P = 0.047), D3 (P = 0.046), and D7 (P = 0.008) was associated with a lower accumulating target lesion failure (TLF) rate; high CDC42 at D3 (P = 0.037) and D7 (P = 0.041) was related to a lower accumulating major adverse cardiovascular event (MACE) rate in SV-CAD patients underwent DCB. Importantly, CDC42 at D7 (high vs. low) independently predicted lower accumulating TLF (hazard ratio (HR) = 0.145, P = 0.021) and MACE (HR = 0.295, P = 0.023) risks in SV-CAD patients underwent DCB.

CONCLUSIONS

Circulating CDC42 level relates to milder disease conditions and independently estimates lower risks of TLF and MACE in SV-CAD patients underwent DCB, but further validation is still needed.

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.

Long-term outcomes after stent implantation in very small vessel coronary artery disease

BACKGROUND

Percutaneous coronary interventions (PCI) in very small vessel lesions represent an intriguing aspect of coronary artery disease (CAD). Uncertainty still exists in stent implantation in very small caliber vessels. This study aimed to evaluate the long-term outcomes of patients treated with 2.0-mm drug-eluting stent (DES).

METHOD

This retrospective observational study included 134 patients undergoing PCI with 2.0-mm zotarolimus DES from December 2016 to May 2020. The primary endpoint was major adverse cardiovascular events (MACE) at 2-year follow-up, which was composed of all-cause mortality, target vessel myocardial infarction, and ischemia-driven target lesion revascularization. Multiple logistic regression analysis was used to identify the independent predictors of MACE, and odds ratios (OR) and 95% confidence intervals (CI) were calculated.

RESULT

The lesions were diffuse (mean length 20.9 ± 5.51 mm) and belong to type B2/C lesions (90.3%). On follow-up, the MACE rate was 20.1% and mostly driven by late lumen loss demanding revascularization (11.9%). In multivariable analysis, chronic kidney disease (CKD) (OR: 4.291, 95% CI: 1.574-11.704, p = 0.004) and calcified lesions (OR: 3.688, 95% CI: 1.311-10.371, p = 0.013) were the independent predictors of subsequent cardiovascular events, whereas statin was associated with better outcomes (OR: 0.335, 95% CI: 0.119-0.949, p = 0.040).

CONCLUSION

2.0-mm DES is a feasible option for treating very small vessel CAD in complex lesions. Patients with CKD and calcified lesions carry the hazard of worse outcomes, and careful consideration should be taken before stenting in this high-risk population.

Five-year clinical outcomes of a 2.25 mm sirolimus-eluting stent in Japanese patients with very small coronary artery disease: final results of the CENTURY JSV study

The aim of this study is to evaluate the long-term safety and efficacy of the 2.25 mm bioresorbable-polymer sirolimus-eluting Ultimaster stent in a Japanese patient population. Treatment of coronary artery disease in very small vessels is associated with an increased risk for cardiac events. The CENTURY JSV study is a prospective, multicenter, single-arm study. Seventy patients with stable and unstable coronary artery disease with a coronary lesion eligible for implantation with a 2.25 mm stent were enrolled in this study. Patients underwent clinical follow-up through 5-year after the PCI procedure. The mean age was 70.4 ± 9.2 years. The prevalence of diabetes mellitus was 37.1%, all not insulin dependent. The incidence of major adverse cardiac events, defined as cardiac death, target vessel myocardial infarction (MI), and clinically driven target lesion revascularization (CD-TLR) at 5 years was 5.7%. A non-Q wave MI was noted in 1.4% and 4.3% underwent a CD-TLR. There was no stent thrombosis during the entire follow-up period. No cardiac events were reported between 2 and 5 years. This is the first study to demonstrate safety and effectiveness for 5 years after treatment of very small coronary disease with 2.25 mm-diameter DES.Clinical trial registration: UMIN000012928.

Drug-Coated Balloon for the Treatment of Small Vessel Coronary Artery Disease - A Randomized Non-Inferiority Trial

BACKGROUND

Drug-coated balloons (DCB) have shown promising results for the treatment of in-stent restenosis (ISR) and small vessel disease (SVD). However, data comparing the treatment efficacy of different DCBs are limited.

METHODS AND RESULTS

AGENT Japan is a prospective randomized controlled trial that compares the Agent balloon coated with a low-dose formulation of paclitaxel (2 μg/mm2) to the SeQuent Please paclitaxel-coated balloon (3 μg/mm2) for the treatment of SVD. Patients with target lesion length ≤28 mm and reference diameter between ≥2.00 and <3.00 mm were randomized 2 : 1 for treatment with Agent (n=101) or SeQuent Please (n=49). This trial also includes a separate single-arm substudy evaluating the clinical safety and effectiveness of Agent in patients with ISR. The primary endpoint of 6-month target lesion failure (TLF) was observed in 3.0% of Agent and 0.0% of SeQuent Please patients (difference=3.0%; 97.5% upper confidence bound [UCB]=9.57%, which is less than the prespecified margin of 13.2%; Pnon-inferiority=0.0012). There were no deaths or thrombosis, and angiographic and quality-of-life outcomes were comparable between groups. The AGENT Japan ISR substudy (n=30) primary endpoint was met because the one-sided 97.5% UCB for 6-month TLF (3.3%) was significantly less than the study success criterion of 15.1% (97.5% UCB=9.8%; P<0.0001).

CONCLUSIONS

Data from this study demonstrate good clinical outcomes with the Agent DCB when used to treat patients with SVD or ISR.

Novel application of drug-coated balloons in coronary heart disease: A narrative review

The incidence of coronary heart disease (CAD) has soared over the years, and coronary intervention has become an increasingly important therapeutic approach. The past decade has witnessed unprecedented developments in therapeutic medical instruments. Given that drug-coated balloons bring many benefits, they are indicated for an increasing number of conditions. In this article, we review the results of current clinical trials about drug-coated balloons and summarize their safety and clinical progression in different coronary artery diseases, laying the groundwork for basic research, and clinical therapeutics of this patient population.