太田 秀彰

Slow-flow or no-reflow phenomenon is a common procedural complication during percutaneous coronary intervention (PCI). Given the presence of fragile plaque or thrombotic materials, we hypothesized that long-time predilatation using a perfusion balloon in conjunction with intracoronary nicorandil administration reduces the risk of slow-flow or no-reflow in patients presenting with acute coronary syndrome (ACS). Subjects were patients presenting with ACS who underwent PCI between April 2020 and April 2022. We retrospectively investigated the incidence of slow-flow or no-reflow during the procedure as well as in-hospital outcomes in comparison between the cases undergoing 3-min predilatation using a perfusion balloon in conjunction with intracoronary nicorandil administration followed by DES implantation (PB group) and those with direct stenting (DS group). Among 439 ACS patients, 36 patients in the PB group and 51 patients in the DS group were examined. Mean age was 70 years and 78.2% was male. Distal protection devices were more frequently used in the DS group than in the PB group (31.3% vs. 11.1%, p = 0.02). The incidence rate of slow-flow or no-reflow was significantly lower in the PB group than in the DS group (2.8% vs. 23.5%; p < 0.01). Six cases (11.7%) in the DS group required intra-aortic balloon pumping (IABP), while none in the PB group required (p < 0.01). In-hospital clinical outcomes did not differ between the two groups. Prolonged perfusion balloon predilatation in conjunction with intracoronary nicorandil administration was safe and feasible. This novel strategy could be an attractive alternative to conventional direct stenting for ACS patients.

OBJECTIVE: To examine the clinical outcomes of optical coherence tomography (OCT)-guided percutaneous coronary intervention (PCI) in patients presenting with ST-segment elevation myocardial infarction (STEMI). METHODS: We retrospectively investigated 533 consecutive patients who underwent primary PCI for STEMI between June 2016 and December 2020. The primary endpoint was a target lesion failure (TLF; defined as a composite of cardiac death, target vessel myocardial infarction, or target lesion revascularization). Propensity score (PS) matching was performed to allow direct comparison of OCT-guided and intravascular ultrasound (IVUS)-guided PCI. RESULTS: Patients in the OCT group (n=166) were younger than those in the IVUS group (n=367) and had a significantly higher left ventricular ejection fraction and estimated glomerular filtration rate. Killip class IV and left main stem disease were more common in the IVUS group. The median peak creatine kinase level was comparable between the two groups (1953 U/L vs 1603 U/L). A significantly larger amount of contrast was used in the OCT group (200 mL vs 165 mL; p<0.001). The cumulative incidence of TLF during a median follow-up of 2.2 years did not differ significantly between OCT and IVUS groups (9.6% vs 13.6%; p=0.221) but cardiac mortality was significantly higher in the IVUS group (8.7% vs 3.6%; p=0.047). After PS matching (n=161 in each group), there was no significant between-group difference in TLF or any other clinical outcome measures. CONCLUSIONS: OCT-guided PCI demonstrated clinical outcomes in patients with STEMI that were comparable to those of IVUS-guided PCI despite considerable differences in background characteristics.

BACKGROUND: This study compares the efficacy of coronary computed tomography angiography (CCTA) and near-infrared spectroscopy intravascular ultrasound (NIRS-IVUS) in patients with significant coronary stenosis for predicting periprocedural myocardial injury during percutaneous coronary intervention (PCI). METHODS: We prospectively enrolled 107 patients who underwent CCTA before PCI and performed NIRS-IVUS during PCI. Based on the maximal lipid core burden index for any 4-mm longitudinal segments (maxLCBI4mm) in the culprit lesion, we divided the patients into two groups: lipid-rich plaque (LRP) group (maxLCBI4mm ≥ 400; n = 48) and no-LRP group (maxLCBI4mm < 400; n = 59). Periprocedural myocardial injury was a postprocedural cardiac troponin T (cTnT) elevation of ≥5 times the upper limit of normal. RESULTS: The LRP group had a significantly higher cTnT (p = 0.026), lower CT density (p < 0.001), larger percentage atheroma volume (PAV) by NIRS-IVUS (p = 0.036), and larger remodeling index measured by both CCTA (p = 0.020) and NIRS-IVUS (p < 0.001). A significant negative linear correlation was found between maxLCBI4mm and CT density (rho = -0.552, p < 0.001). Multivariable logistic regression analysis identified maxLCBI4mm [odds ratio (OR): 1.006, p = 0.003] and PAV (OR: 1.125, p = 0.014) as independent predictors of periprocedural myocardial injury, while CT density was not an independent predictor (OR: 0.991, p = 0.22). CONCLUSION: CCTA and NIRS-IVUS correlated well to identify LRP in culprit lesions. However, NIRS-IVUS was more competent in predicting the risk of periprocedural myocardial injury.

AIMS: This study aimed to determine the effects of a proprotein convertase subtilisin-kexin type 9 inhibitor (PCSK9i) on coronary plaque volume and lipid components in patients with a history of coronary artery disease (CAD). METHODS AND RESULTS: This prospective, open-label, single-centre study analysed non-culprit coronary segments using near-infrared spectroscopy-intravascular ultrasound (NIRS-IVUS) at baseline and follow-up angiography. Following changes in the lipid-lowering treatment based on the most recent guideline, the enrolled subjects were divided into two groups: treatment with PCSK9i and statins (PCSK9i: 21 patients and 40 segments) and statins only (control: 32 patients and 50 segments). The absolute and percent LDL-C reductions were significantly greater in the PCSK9i group than in the control group (between group difference: 59.3 mg/dL and 46.4%; P < 0.001 for both). The percent reduction in normalized atheroma volume and absolute reduction in percent atheroma volume (PAV) were also significantly greater in the PCSK9i group (P < 0.001 for both). Furthermore, the PCSK9i group showed greater regression of maximal lipid core burden index for each of the 4-mm segments (maxLCBI4mm) than the control group (57.0 vs. 25.5; P = 0.010). A significant linear correlation was found between the percent changes in LDL-C and maxLCBI4mm (r = 0.318; P = 0.002), alongside the reduction in PAV (r = 0.386; P < 0.001). CONCLUSION: The lipid component of non-culprit coronary plaques was significantly decreased by PCSK9i. The effects of statin combined with PCSK9i might be attributed to the stabilization and regression of residual vulnerable coronary plaques in patients with CAD.

BACKGROUND: Myocardial perfusion imaging (MPI) and fractional flow reserve (FFR) are established approaches to the assessment of myocardial ischemia. Recently, various FFR cutoff values were proposed, but the diagnostic accuracy of MPI in identifying positive FFR using various cutoff values is not well established.Methods and Results:We retrospectively studied 273 patients who underwent stress MPI and FFR within a 3-month period. Results for FFR were obtained from 218 left anterior descending artery (LAD) lesions and 207 non-LAD lesions. Stress MPI and FFR demonstrated a good correlation in the detection of myocardial ischemia. However, the positive predictive value (PPV) of FFR for detecting MPI-positive lesions at the optimal FFR thresholds was insufficient (44% for LAD and 65% for non-LAD lesions). This was caused by a sharp drop in PPV at an FFR threshold of 0.7 or more. Notably, 41% of the lesions with normal MPI demonstrated FFRs <0.80. However, MPI-negative lesions had an extremely low lesion rate with FFR <0.65 (6%). Conversely, 78% and 41% of MPI-positive lesions had FFR <0.80 and <0.65, respectively. CONCLUSIONS: The data confirmed that decisions based on MPI are reasonable because MPI-negative patients have an extremely low rate of lesions with a FFR below the cutoff point for a hard event, and MPI-positive lesions include many lesions with FFR <0.65.