坂倉 建一

The KCB01 (KIZASHI™) is a novel cutting balloon catheter with blades integrally formed with the balloon. It is designed to overcome the drawbacks of conventional cutting balloons in terms of lesion delivery, crossability and procedural complications while maintaining the same dilation capacity. To evaluate the efficacy and safety of the KCB01, a prospective, open-label, single-arm study was conducted at nine sites in Japan on percutaneous coronary intervention-eligible patients with stenotic lesions that exhibited residual indentation even after conventional balloon dilation at nominal pressure. Seventy-six patients were enrolled between November 2022 and June 2023, and 73 eligible patients were included in the primary analysis. The mean age was 73.5 ± 7.4 years, and 79.5% of the patients were male. The target lesion characteristics included bifurcation lesions (42.5%), in-stent restenosis lesions (20.5%), and severely calcified lesions (54.8%). The primary endpoint was procedural success, defined as the KCB01 crossing the target lesion, no residual indentation, and < 50% residual stenosis rate after KCB01 dilation (assessed using quantitative coronary angiography). The angiographic images obtained during the procedure were evaluated in a core laboratory. The procedural success rate was 87.7% (95% confidence interval [CI]: 77.9-94.2), with the lower limit of the 95% CI (77.9%) exceeding the performance goal of 76.5%. Clinical success rate was achieved in 94.5% of cases (95% CI: 86.6-98.5%), with no major adverse cardiac events reported until discharge. Furthermore, no device deficiencies related to the KCB01 were observed. These results suggest the safety and efficacy of the KCB01.

In-stent protrusion is sometimes observed after the stent implantation to the culprit lesion of ST-segment elevation myocardial infarction (STEMI). However, it remains unclear whether additional interventions are necessary for non-obstructive in-stent protrusions. The purpose of this retrospective study was to compare clinical outcomes of patients with STEMI between with and without angiographically visible in-stent protrusions, and to evaluate the association between angiographically visible in-stent protrusions and long-term clinical outcomes in patients with STEMI. We included 639 patients with STEMI who underwent stent implantation and divided them into the protrusion group (n = 59) and the clear stent group (n = 580). In-stent protrusion was defined as an angiographically visible in-stent contrast filling defect at final angiography. The primary endpoint was major adverse cardiovascular events (MACE), which were defined as the composite of all cause death, non-fatal myocardial infarction, and ischemia-driven target vessel revascularization. During the median follow-up duration of 620 (213-1379) days, MACE were more frequently observed in the protrusion group than in the clear stent group (p = 0.002). The multivariate Cox hazard analysis revealed that in-stent protrusion was significantly associated with MACE after controlling for multiple confounding factors (HR 2.373, 95% CI 1.311-4.294, p = 0.004). In conclusion, angiographically visible in-stent contrast filling defect at final angiography is a marker for worse clinical outcomes in primary PCI. When interventional cardiologists recognize visible irregular protrusion after stent implantation for STEMI, additional intervention or careful clinical follow up may be needed.

Objective Angiotensin-converting enzyme inhibitors (ACEis), angiotensin receptor blockers (ARBs), and beta-blockers (BBs) are commonly prescribed for patients with non-ST-segment elevation myocardial infarction (NSTEMI). However, the target blood systolic pressure (SBP) or pulse rate (PR) in these patients has not been established. This study aimed to assess the association between SBP/PR control at discharge and the clinical outcomes in patients with NSTEMI. Methods We retrospectively analyzed 596 patients with NSTEMI who received both ACEis/ARBs and BBs at discharge. Patients were categorized into a good control group (SBP ≤130 mmHg and PR ≤80 bpm, n=379) and poor control group (SBP >130 mmHg or PR >80 bpm, n=217). The primary endpoint was major cardiovascular events (MACEs), defined as the composite of all-cause death, non-fatal myocardial infarction, and heart failure readmission. Results During a median follow-up of 1,267 days, 205 MACEs occurred. Kaplan-Meier curves showed higher MACE rates in the poor control group than in the good control group (p=0.003). A multivariate Cox hazard analysis revealed that the good control group was inversely associated with MACEs (hazard ratio 0.748, 95% confidence interval: 0.561-0.997, p=0.048) after controlling for confounding factors. Conclusion Good control of SBP and PR was inversely associated with long-term adverse events in patients with NSTEMI who received both ACEis/ARBs and BBs. This study highlights the significance of optimizing medication titrations at discharge.

Slow flow is the most common complication of rotational atherectomy (RA). Compared with long single sessions, short single sessions may reduce the incidence of slow flow just after RA. This study aimed to compare the incidence of slow flow just after RA between short single session and long single session strategies. This multicenter, 1:1 randomized clinical trial was conducted at 3 hospitals in Japan. The short single session strategy was defined as repeating short single sessions (up to 15 s) of RA, whereas the long single session strategy was defined as repeating long single sessions (20-30 s) until the burr crossed the target lesion. The primary outcome was slow flow just after RA, which was defined as [(initial TIMI-frame count before RA) × 1.1 minus (TIMI-frame count just after RA)] less than 0. During the study period, 266 patients were included in the final study population and were randomly assigned to the Short single session group (n = 132) or the long single session group (n = 134). The protocol adherence rate was equally high in both groups (Short single session: 98.5% versus long single session 94.8%, p = 0.172). The incidence of slow flow just after RA was similar between the 2 groups (short single session:14.4% versus long single session: 14.9%, p > 0.999). In conclusion, this randomized trial did not show a benefit of the short single session strategy compared with the long single session strategy in RA with respect to the prevention of slow flow (Unique identifier: UMIN000047231).