YUKIO OZAKI

OBJECTIVES: We sought to examine associations between plaque characteristics by intravascular ultrasound (IVUS) and detectability of external elastic lamina (EEL) by optical frequency domain imaging (OFDI) in human coronary arteries. BACKGROUND: It is often challenging to detect EEL which represents vessel size by light-based imaging modalities due to light intensity attenuation through atherosclerotic plaque. METHODS: IVUS and OFDI prior to stent implantation were sequentially investigated per protocol. We identified corresponding cross-sections by minimum lumen area (MLA) or just distally to side branches as anatomical landmarks. Plaque characterization was determined by integrated backscatter IVUS analysis. We categorized detectable EEL arc by OFDI into four groups: 0≤ and <1 quadrant (group 1), 1≤ and <2 quadrants (group 2), 2≤ and <3 quadrants (group 3), or 3≤ and <4 quadrants (group 4). RESULTS: We prospectively studied 103 vessels in 93 patients with stable coronary artery disease. Corresponding 711 cross-sections were analyzed. Cross-sections with detectable EEL arc <2 quadrants (group 1 or 2) were observed in 86.1% of MLA sites but only in 29.3% of non-MLA sites (p < .05). Percentage plaque area (%PA) appeared to be the strongest predictor to detect EEL arc <2 quadrants with the cut-off of 60.3% (AUC 0.90; sensitivity 79.8%, specificity 85.5%). Lipid pool and calcification remained statistically significant in predicting detectable EEL arc <2 quadrants after adjustment with %PA. CONCLUSIONS: Presence of large plaque burden, lipid pool, and calcification significantly predicts the detectability of EEL by OFDI assessment. Locations with detectable EEL arc <2 quadrants should thus be avoided for optimal stent landing zone.

BACKGROUND: Beta-blockers are standard therapy for acute myocardial infarction (AMI). However, despite current advances in the management of AMI, it remains unclear whether all AMI patients benefit from β-blockers. We investigated whether admission heart rate (HR) is a determinant of the effectiveness of β-blockers for AMI patients. Methods and Results: We enrolled 3,283 consecutive AMI patients who were admitted to 28 participating institutions in the Japanese Registry of Acute Myocardial Infarction Diagnosed by Universal Definition (J-MINUET) study. According to admission HR, we divided patients into 3 groups: bradycardia (HR <60 beats/min, n=444), normocardia (HR 60 to ≤100 beats/min, n=2,013), and tachycardia (HR >100 beats/min, n=342). The primary endpoint was major adverse cardiac events (MACE), including all-cause death, non-fatal MI, non-fatal stroke, heart failure (HF), and urgent revascularization for unstable angina, at 3-year follow-up. Beta-blocker at discharge was significantly associated with a lower risk of MACE in the tachycardia group (23.6% vs. 33.0%; P=0.033), but it did not affect rates of MACE in the normocardia group (17.8% vs. 18.4%; P=0.681). In the bradycardia group, β-blocker use at discharge was significantly associated with a higher risk of MACE (21.6% vs. 12.7%; P=0.026). Results were consistent for multivariable regression and stepwise multivariable regression. CONCLUSIONS: Admission HR might determine the efficacy of β-blockers for current AMI patients.

Previous studies have demonstrated that use of intravascular ultrasound (IVUS) during percutaneous coronary intervention (PCI) was associated with lower incidence of death, myocardial infarction, and target vessel revascularization. Recently, optical coherence tomography (OCT) has emerged as an alternative intravascular imaging device with better resolution. The aim of this study was to investigate frequency and prognostic impact of IVUS or OCT-guided PCI during urgent revascularization for acute myocardial infarction diagnosed by the universal definition. A total of 2788 patients who underwent urgent PCI were selected from a multicenter, Japanese registry of acute myocardial infarction diagnosed by universal definition (J-MINUET). Frequency, clinical characteristics and prognostic impact of the IVUS-, or OCT- guided PCI were investigated. Clinical endpoint was in-hospital death. Angiography-, IVUS-, and OCT-guided urgent PCI were performed in 689 (24.7%), 1947 (69.8%), and 152 (5.5%) patients. In-hospital death in each group was 10.4%, 5.1%, and 3.3%, respectively (P < 0.01). By univariate and multivariate logistic regression analysis, IVUS-guided PCI (vs. angiography-guided PCI, OR 0.49, 95% CI 0.30-0.81, P = 0.006) was a significant independent predictor of in-hospital death. Intravascular imaging guided-PCI was frequently adopted during urgent PCI for acute myocardial infarction diagnosed by universal definition and was associated with better in-hospital survival.

Implantable cardioverter-defibrillators (ICDs) improve survival in patients who are at risk of sudden death. However, inappropriate therapy is commonly given to ICD recipients, and this situation may be associated with an increased risk of death. This study aimed to construct a risk stratification scheme by using decision tree analysis in patients who received inappropriate ICD therapy.Mortality was calculated from a retrospective data analysis of a multicenter cohort involving 417 ICD recipients. Inappropriate therapy was defined as therapy for nonventricular arrhythmias, including sinus tachycardia, supraventricular tachycardia, atrial fibrillation/flutter, oversensing, and lead failure. Inappropriate therapy included antitachycardia pacing, cardioversion, and defibrillation. The prognostic factors were identified by a Cox proportional hazards regression analysis, and we constructed a decision tree.During an average follow-up of 5.2 years, 48 patients (12%) had all-cause death. A multivariate Cox hazard model revealed that the age (hazard ratio [HR] 1.06, P < 0.001), ln B-type natriuretic peptide (BNP) (HR 1.47, P = 0.02), nonsinus rhythm at implantation (HR 2.70, P < 0.05), and inappropriate therapy occurring during sedentary/awake conditions (HR 3.51, P = 0.001) correlated with an increased risk of mortality. An inappropriate therapy due to abnormal sensing (HR 0.16, P = 0.04) decreased the risk of mortality. Furthermore, a decision tree analysis stratified the patients well by using 4 covariates: BNP, activity at the time of inappropriate therapy, mechanism of inappropriate therapy, and baseline rhythm at ICD implantation (log-rank test, P < 0.0001).We identified the predictors of mortality in inappropriate ICD therapy recipients and constructed a risk stratification scheme by using decision tree analysis.

Background Scarce data exist about the outcomes after percutaneous coronary intervention ( PCI ) in old patients. This study sought to provide an overview of PCI in elderly patients, especially nonagenarians, in a Japanese large prospective nationwide registry. Methods and Results We analyzed 562 640 patients undergoing PCI (≥60 years of age) from 1018 Japanese hospitals between 2014 and 2016 in the J-PCI (Japanese percutaneous coronary intervention) registry. Among them, 10 628 patients (1.9%), including 6780 (1.2%) with acute coronary syndrome ( ACS ) and 3848 (0.7%) with stable coronary artery disease, were ≥90 years of age. We investigated differences in characteristics and in-hospital outcomes among sexagenarians, septuagenarians, octogenarians, and nonagenarians. Older patients were more frequently women and had a greater frequency of heart failure and chronic kidney disease than younger patients. In addition, older patients had a higher rate of in-hospital mortality, cardiac tamponade, cardiogenic shock after PCI , and bleeding complications requiring blood transfusion. Nonagenarians had the highest risk of in-hospital mortality (odds ratio, 3.60; 95% CI , 3.10-4.18 in ACS ; odds ratio , 6.24; 95% CI, 3.82-10.20 in non- ACS ) and bleeding complications ( odds ratio, 1.79; 95% CI, 1.35-2.36 in ACS ; odds ratio , 2.70; 95% CI, 1.68-4.35 in non- ACS ) when referenced to sexagenarians. More important, transradial intervention was an inverse independent predictor of both in-hospital mortality and bleeding complications. Conclusions Older patients, especially nonagenarians, carried a greater risk of in-hospital death and bleeding compared with younger patients after PCI . Transradial intervention might contribute to risk reduction for periprocedural complications in elderly patients undergoing PCI .