Akihiko Takahashi

BACKGROUND: A combined strategy of atherectomy followed by intravascular lithotripsy (dual-prep strategy) for severely calcified lesions may optimize stent deployment, but mechanistic evidence from prospective optical coherence tomography (OCT) imaging is limited. This study was designed to comprehensively characterize patterns of calcium modification during a dual-preparation strategy and to explore imaging determinants of calcium fracture and stent expansion using serial and 3-dimensional OCT assessment. METHODS: This was a prespecified, multicenter, single-arm OCT substudy of the DUAL-PREP (atherectomy Devices and intravascUlAr Lithotripsy for the PREParation of heavy calcified coronary lesions) registry, enrolling patients with severely calcified lesions for whom combined treatment with atherectomy and intravascular lithotripsy was deemed preferable based on imaging findings. OCT was analyzed by an independent core laboratory. Multivariable models examined predictors of fracture and stenting performance, including calcium thickness, length, angle, calcified nodules, and morphology (circumferential, eccentric spiral, and eccentric straight types). RESULTS: OCT images were available for 114 of 118 patients (116 lesions; age, 75.9±9.1 years; 69.3% male). All lesions had an OCT calcium score of 4. Calcium fractures were uncommon after atherectomy (2/106 lesions [1.9%]) but markedly increased following intravascular lithotripsy (89/106 lesions [84.0%]; 2.05±1.59 fractures per lesion), with a further increase after stent implantation (101/109 lesions [92.7%]; 2.89±1.67 fractures per lesion). Final stent expansion index was 0.81±0.15 (eccentricity, 0.72±0.09; asymmetry, 0.39±0.15). Eccentric straight-type calcification was associated with a lower likelihood of fracture at final OCT (odds ratio, 0.07 [95% CI, 0.00–0.77]; P =0.029), whereas eccentric spiral and circumferential types showed higher fracture occurrence. CONCLUSIONS: This OCT analysis demonstrated a stepwise increase in calcium fracture during a dual-preparation strategy, with minimal fracture after atherectomy, a marked increase following intravascular lithotripsy, and a further increase after stent implantation. Calcium morphology may provide additional insight into fracture occurrence, supporting the potential value of 3-dimensional assessment in severely calcified lesions. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifier: jRCT1032230384.

Background: Distal transradial access (dTRA) has gained attention for its lower risk of vascular complications compared to conventional transradial access (TRA). However, its feasibility and safety in patients with out‐of‐hospital cardiac arrest (OHCA) undergoing emergency percutaneous coronary intervention (PCI) remain uncertain. Aim: To evaluate the procedural success, safety, and clinical outcomes of dTRA in OHCA patients undergoing emergency PCI. Methods: This retrospective single‐center study included 48 OHCA patients who underwent emergency PCI for presumed coronary etiology between January 2022 and December 2025. dTRA was the default access strategy unless contraindicated. Among them, dTRA was attempted in 44 patients. Patients in whom dTRA was successfully achieved were included in the main analysis. Clinical, procedural, and outcome data were comprehensively reviewed, including access‐site complications and neurological status. Results: dTRA was successfully achieved in 43 of 44 attempted cases (97.7%). The median door‐to‐balloon time was 67 min. Mechanical circulatory support was used in 38 patients (extracorporeal membrane oxygenation: 17; intra‐aortic balloon pumping: 29). Access‐site complications included one case of limb ischemia requiring amputation and three minor hematomas (EASY classification grade 3−5) with no major bleeding (BARC 3−5). The 30‐day mortality was 51.2% (22/43), and among the 21 survivors, 14 (66.7%) achieved a favorable neurological outcome (CPC 1−2). Conclusions: In this OHCA cohort requiring emergency PCI, dTRA was feasible and safe in the majority of patients, including those receiving mechanical support. However, critical ischemic complications may still occur under unstable systemic conditions, warranting careful patient selection and vigilant post‐procedural monitoring.

The distal radial approach (dTRA) is increasingly recognized as a viable alternative to the conventional radial approach in coronary interventions. However, its utility in ST-elevation myocardial infarction (STEMI)—where rapid revascularization is critical—remains underexplored. To evaluate the feasibility and procedural characteristics of dTRA in STEMI patients undergoing primary percutaneous coronary intervention (PCI), using a prespecified subanalysis of the SPEEDY PCI study. Among 370 STEMI patients enrolled, 63 underwent PCI via dTRA and 307 via the conventional radial approach. A propensity score–matched analysis was performed using Killip class, GRACE score, and door-to-sheath time as covariates. After matching, the dTRA group had significantly shorter sheath-to-balloon (12.5 ± 11.5 vs. 19.7 ± 11.7 min, p = 0.002) and door-to-balloon times (50.2 ± 25.9 vs. 62.3 ± 19.9 min, p = 0.007). Procedural success and 30-day mortality rates were comparable between groups. dTRA appears feasible and safe for STEMI patients in high-volume centers. While shorter time metrics were observed, these may reflect institutional practices and operator experience rather than the access site alone.

A 50‐year‐old man with a medical history of diabetes mellitus and hypertension was admitted to a university hospital for severe respiratory insufficiency caused by SARS‐CoV‐2 infection. His arterial blood pressure and blood oxygen levels were monitored through a plastic cannula inserted in the radial artery in the intensive care unit. After recovery from respiratory insufficiency, the patient was moved to a local hospital where hematoma formation and skin necrosis at the puncture site were noted. On the 25th day from the initial admission, the patient developed massive bleeding from the wound on the hematoma and was transferred to our hospital on emergency. A 6‐Fr sheath introducer was inserted through the right distal radial artery in the anatomical snuff box, and instant hemostasis was accomplished without external compression. Thereafter, percutaneous thrombin injection for the pseudoaneurysm was conducted under ultrasound guidance. However, bleeding from the pseudoaneurysm was still observed after radial sheath withdrawal. We then performed coil embolization of the radial artery, which involved a coil proximal to the aneurysm, four coils in the neck of the aneurysm, and two coils distal to the aneurysm. Permanent hemostasis was achieved with no further vascular complications.

This study investigated the incidence of vascular complications with PCI from DRA access among patients with and without ST-segment elevation.