Yukio Nishida

No-reflow phenomenon and lesion morphology in patients with acute myocardial infarction.

Background—The no-reflow phenomenon is associated with poor functional and clinical outcomes for patients with acute myocardial infarction (AMI). In the era of primary intervention, accurately identifying lesions at high risk of no reflow is of crucial importance. At present, no study into the relationship between lesion morphology and no reflow has been performed. The aim of this study was to investigate the relationship between preintervention intravascular ultrasound (IVUS) lesion morphology and the no-reflow phenomenon. Methods and Results—This study comprised 100 consecutive patients with AMI who underwent preintervention IVUS and were successfully recanalized with primary balloon angioplasty or stenting. IVUS was again performed to identify and exclude any mechanical vessel obstruction in cases of thrombolysis in myocardial infarction flow grade 0, 1, or 2 after intervention in the absence of angiographic stenosis. Angiographic no reflow was seen in 13 patients (13%). Univariate analysis indicated that hypercholesterolemia, fissure and dissection, lipid pool–like image, lesion, and reference external elastic membrane cross-sectional area correlate with the no-reflow phenomenon. Multivariate logistic regression analysis showed that lipid pool–like image (P <0.05; odds ratio 118; 95% CI, 1.28 to 11 008) and lesion elastic membrane cross-sectional area (P <0.05; odds ratio 1.55; 95% CI 1.01 to 2.38) are independent predictive factors of no-reflow phenomenon after reperfusion for AMI. Conclusions—Large vessels with lipid pool–like image are at high risk for no reflow after primary intervention for AMI. Also, plaque content may play a role in damage to the microcirculation after primary intervention for AMI.

C-Reactive Protein and Lesion Morphology in Patients With Acute Myocardial Infarction

Background Elevated serum C‐reactive protein (CRP) is of clinical significance in the management of acute coronary syndromes, but there have been few in vivo studies detailing the relation between lesion morphology and elevated CRP in the setting of acute myocardial infarction (AMI). In this study, we investigated the relation between lesion morphology as seen under preintervention intravascular ultrasound (IVUS) and CRP in the acute phase of AMI. Methods and Results Our patient population comprised 90 consecutive patients with AMI who underwent preintervention IVUS within 6 hours of the onset of symptoms. Patients were divided into an elevated CRP group (≥3 mg/L) or a normal CRP group on the basis of serum CRP levels. There were no differences in patient characteristics or angiographic findings. We observed significantly more plaque rupture in the elevated CRP group than in the normal CRP group (70% versus 43%, P=0.01). A multivariate logistic regression model revealed that the presence of ruptured plaque alone correlated with elevation of serum CRP (P=0.02; odds ratio, 3.35; 95% CI, 1.22 to 9.18). Conclusions Elevated CRP may be related to the presence of ruptured plaque. Our results suggest that in the setting of AMI, elevated CRP levels may reflect the inflammatory activity of a ruptured plaque. (Circulation. 2003;108:282‐285.)

Predicting angiographic distal embolization following percutaneous coronary intervention in patients with acute myocardial infarction

The aim of this study was to investigate the relation between lesion morphology identified by intravascular ultrasound (IVUS) before intervention and angiographic distal embolization after percutaneous coronary intervention (PCI) in patients with acute myocardial infarction (AMI). PCI for AMI has already been established as beneficial therapy, although some complications remain unresolved. Distal embolization is 1 of the important complications of PCI. Recently, some new devices have been developed for the prevention of distal embolization. However, few studies exist that look into the relation between lesion morphology and distal embolization. IVUS was performed safely in 140 consecutive patients with AMI before coronary intervention. No patient received thrombolytic therapy. From the incidence of angiographic distal embolization, patients were divided into 2 groups--an embolization group and a nonembolization group--and clinical background, IVUS, and angiographic information were evaluated. Distal embolization was observed in 12 patients (9%). Peak creatine kinase levels (3,877 +/- 2,285 vs 2,293 +/- 1,792 IU/L, p <0.05) and the incidence of angiographic thrombus (25% vs 5%, p <0.05) and intracoronary mobile mass detected by IVUS (75% vs 16%, p <0.001) were higher for patients in the embolization group. From the multivariate logistic regression analysis, only an intracoronary mobile mass detected by IVUS emerged as a predictor of distal embolization (odds ratio 53, 95% confidence interval 2.7 to 1,040, p <0.01). Patients with an intracoronary mobile mass detected by IVUS are prone to distal embolization after PCI and larger infarction. IVUS imaging before PCI may be useful for determining which patients need a distal protection device.

Prevalence and Clinical Course of the Juveniles with Brugada‐Type ECG in Japanese Population

Background: Although many studies on Brugada syndrome have been done, with many reports of genetic findings and clinical features, little evidence exists to support the role of this syndrome in sudden cardiac death in a juvenile population. We sought to determine the prevalence and clinical course in children exhibiting Brugada‐type ECG in a community‐based population.

Use of preintervention intravascular ultrasound in patients with acute myocardial infarction.

This study was designed to determine whether preintervention intravascular ultrasound (IVUS) imaging can assist in predicting the likelihood of acute coronary occlusion after primary angioplasty. Primary angioplasty is in widespread use for the treatment of acute myocardial infarction (AMI), although its usefulness is sometimes compromised by postprocedural acute coronary occlusion. If preintervention IVUS could be used to predict acute coronary occlusion, the task of determining treatment strategies for AMI would be significantly eased. Preintervention IVUS was performed without complications in 46 patients with AMI using manually prepared contrast medium. Coronary angiography was performed 1 hour after successful percutaneous transluminal coronary angioplasty. Acute coronary occlusion was seen in 13 of 46 patients (28%). There were no differences in the clinical characteristics and angiographic results between the patients with and without occlusion. In patients with acute occlusion, the incidence of eccentric plaque (85% vs 36%, p <0.01) and echolucent area (92% vs 15%, p <0.01) was significantly higher than in the occlusion-free patients. Most of the echolucent areas were associated with eccentric plaques (88%). Eccentric plaques characterized by echolucent areas are prone to acute occlusion after primary balloon angioplasty for AMI. Preintervention IVUS is both a safe and a useful adjunct to primary angioplasty.

Detection of restenosis after percutaneous coronary intervention in three major coronary arteries by transthoracic Doppler echocardiography.

BACKGROUND The aim of this study was to evaluate the diagnostic potential of coronary flow velocity reserve (CFR) measurement by transthoracic Doppler echocardiography (TTDE) to detect restenosis in the 3 major coronary arteries: the left anterior descending coronary artery, right coronary artery, and left circumflex coronary artery. METHODS The lesions of 175 patients who were scheduled for follow-up coronary angiography and TTDE 6 months after undergoing stents implantation were studied. CFR was assessed by TTDE in the targeted arteries into which stents had been implanted. RESULTS Coronary stents were implanted in a total of 238 angiographic lesions in 175 patients. Doppler recordings of coronary flow in the 3 major arterial lesions were obtained in 211 of the 238 angiographic lesions (89% feasibility). CFR was significantly lower in lesions with restenosis than those without restenosis (1.70 +/- 0.32 vs 2.65 +/- 0.66, P < .01). A CFR value < 2.0 was 89% sensitive and 91% specific for detecting restenosis in the 3 major coronary arteries. Sensitivity and specificity were 86% and 91%, respectively, in the left anterior descending coronary artery (95% feasibility); 92% and 92%, respectively, in the right coronary artery (85% feasibility); and 91% and 92%, respectively, in the left circumflex coronary artery (81% feasibility). CONCLUSION CFR assessment by TTDE is an accurate method for monitoring restenosis, not only in the left anterior descending but also in the right and left circumflex coronary arteries in patients previously subjected to percutaneous coronary intervention.

Intravascular ultrasound‐guided balloon angioplasty for treatment of in‐stent restenosis

We investigated the usefulness of intravascular ultrasound (IVUS)‐guided balloon angioplasty for in‐stent restenosis in 37 lesions of 34 consecutive patients. We divided these patients into two groups: a group in which the balloon size was determined by quantitative coronary angiography (QCA group; 17 patients, 19 lesions) and a group in which the balloon size was determined by IVUS (IVUS group; 17 patients, 18 lesions). We compared short‐term and 6‐month outcomes for these groups. In the IVUS group, we used a balloon of a size equal to 95% of the media‐to‐media diameter at the distal to the stent, as determined by IVUS. No significant differences were observed in patient or lesion characteristics between the two groups. The clinical success rate was 100% in both groups, and no clinical events were observed in either of the groups. The balloon/artery ratio was larger in the IVUS group than in the QCA group (1.33 ± 0.35 vs. 1.16 ± 0.13, P < 0.05), and the recurrent restenosis rate was lower (17% vs. 53%, P < 0.05). These results suggest that repeat balloon angioplasty using a balloon size determined by IVUS is useful for in‐stent restenosis. Cathet. Cardiovasc. Intervent. 47:298–303, 1999.