Takashi Muramatsu

The success of drug-coated balloon (DCB) therapy for de novo coronary lesions relies on optimal lesion preparation. However, evidence supporting the use of cutting balloons (CBs) for lesion preparation in DCB-only strategies remains limited. The NATURE trial assessed the effectiveness of CB compared with standard balloon (SB) predilatation in achieving optimal lesion preparation for a DCB-only strategy. The NATURE trial was a prospective, multicentre, randomised study conducted at 19 Japanese centres. Patients with de novo coronary lesions suitable for a DCB-only strategy were randomised (1:1) to lesion preparation with CB or SB. Post-predilatation assessment included coronary angiography, intravascular ultrasound (IVUS), and fractional flow reserve (FFR). The primary endpoint was optimal lesion preparation, defined as the simultaneous presence of: (1) no flow-limiting dissection, (2) residual diameter stenosis ≤ 30% by quantitative coronary angiography, and (3) FFR > 0.80. Among 201 patients included in the intention-to-treat population, optimal lesion preparation was achieved in 35.6% of the CB group and 30.0% of the SB group (adjusted risk ratio 1.19, 95% confidence interval 0.87-1.65; p = 0.28). Avoidance of flow-limiting dissection was high in both groups (98.0% vs 97.0%). CB predilatation resulted in lower residual diameter stenosis (30.8 ± 11.8% vs 34.5 ± 13.3%; p = 0.04) and less acute recoil (1.18 ± 0.36 vs 1.31 ± 0.50 mm; p = 0.03). Trends towards larger lumen dimensions on IVUS were also observed with CB. In patients undergoing DCB-only PCI for de novo coronary lesions, CB predilatation provided modest angiographic advantages compared with SB but did not significantly increase the rate of optimal lesion preparation. Optimal lesion preparation is essential for successful drug-coated balloon (DCB) therapy because DCBs do not provide mechanical scaffolding to maintain vessel patency. In this multicentre randomised trial, cutting balloon predilatation resulted in greater acute luminal expansion and less recoil than standard balloon predilatation, although it did not significantly increase the overall rate of optimal lesion preparation defined by angiographic and physiological criteria. These findings suggest that cutting balloons may offer modest mechanical advantages during lesion preparation in DCB-only PCI. However, the clinical significance of these acute angiographic advantages requires confirmation in larger trials and through longer-term follow-up.

AIMS: The global distribution of lipoprotein(a) [Lp(a)] levels varies due to racial and ethnic differences. However, the clinical relevance of Lp(a) levels in Japanese patients has not been fully explored. METHODS: We investigated the association of Lp(a) levels, the Suita score, and the presence of high-risk plaque (HRP) as well as that of ≥ 50% stenosis, quantitative plaque volume, and the value of coronary artery calcium score in coronary computed tomographic angiography (CCTA), among 272 Japanese patients (mean age: 65 years) in whom serum Lp(a) levels were measured due to suspected coronary artery disease. HRP was defined as positive remodeling and/or low attenuation. Plaque volume was quantified as the percent plaque volume. RESULTS: HRP was identified in 33 (12.1%) patients. The prevalence of HRP, ≥ 50% stenosis, and percent plaque volume progressively increased with higher Lp (a) levels and Suita scores. In multivariate analyses, Lp(a) and the Suita score independently predicted HRP when assessed as continuous (p = 0.02, p＜0.001, respectively) or categorical variables (p = 0.005, p = 0.007, respectively). Patients in the highest tertile of Lp(a) and classified as high- or intermediate-risk by the Suita score had the highest HRP risk, whereas those in the lower 2 tertiles and low-risk group had the lowest. Incorporating Lp(a) into the Suita score improved the prediction of HRP beyond the Suita score alone (p = 0.005). CONCLUSIONS: The combinatorial value of assessing Lp(a) levels and Suita score may provide useful insight regarding Japanese patients undergoing CCTA for the prediction of HRP.

AIMS: In percutaneous coronary intervention (PCI), a suboptimal choice of guiding catheter may compromise coaxial alignment and backup support, prolonging procedures and increasing radiation and contrast exposure. We assessed whether a computed tomography (CT)-driven, artificial intelligence (AI)-guided preprocedural simulation could improve procedural efficiency and safety. METHODS AND RESULTS: In a single-centre prospective registry with historical controls, 55 consecutive elective procedures performed with CT-based AI-assisted guiding-catheter selection were compared with 55 procedures performed without assistance. The primary endpoint was total procedure time from arterial access to completion. Secondary endpoints included time to coronary engagement, radiation dose, contrast volume, and guiding-catheter-related events. Computed tomography--based AI assistance was associated with shorter procedures (mean 68.5 vs. 91.8 min), shorter engagement time, lower radiation dose, and lower contrast use. Guiding-catheter exchanges were fewer, and catheter-related events were lower (3.6 vs. 16.4%; risk ratio 0.22; 95% confidence interval 0.05-0.98). Procedural success was 100% in both groups with no in-hospital major adverse cardiac or cerebrovascular events. CONCLUSION: A CT-driven, CT-based AI-guided simulation for guiding-catheter selection was associated with greater procedural efficiency and a favourable profile in elective PCI. This approach, which standardizes catheter choice and is associated with fewer empirical catheter exchanges, warrants confirmation in multicentre randomized studies and may help optimize resource utilization in routine PCI.

BACKGROUND: In the presence of a potent P2Y12inhibitor such as prasugrel, the additional clinical antithrombotic benefit of aspirin is unclear. The feasibility of prasugrel monotherapy without aspirin after percutaneous coronary intervention (PCI) has been demonstrated in chronic coronary syndrome, but is yet to be assessed in patients with non-ST elevation acute coronary syndrome (NSTE-ACS) and low anatomical complexity. METHODS AND RESULTS: ASET-Japan is a single-arm study investigating the safety of prasugrel 12-month monotherapy with a locally approved dose (loading 20 mg; maintenance 3.75 mg), started immediately after successful PCI using platinum-chromium everolimus-eluting SYNERGY stents. The primary ischemic endpoint is a composite of cardiac death, spontaneous target vessel myocardial infarction, or definite stent thrombosis; the primary bleeding endpoint is Bleeding Academic Research Consortium (BARC) Type 3 and 5 bleeding. ASET-Japan recruited 101 NSTE-ACS patients from 11 Japanese sites. The mean (±SD) age was 69.1±12.3 years and 36.6% had a PRECISE-DAPT score >25. The mean anatomical SYNTAX score was 7.9±4.7. At 1 year, the primary ischemic endpoint occurred in 1 patient (1.0%; cardiac death). Two BARC Type 3a bleeding events occurred (2.0%): 1 due to a gastric ulcer and 1 to a descending colon malignancy. CONCLUSIONS: Low-dose (3.75 mg/day) prasugrel monotherapy started immediately after SYNERGY stent deployment was feasible and safe in selected NSTE-ACS patients.