Tetsuo Kamiishi's research while affiliated with Tokyo Medical and Dental University and other places

Background: Tissue prolapse (TP) is sometimes observed after percutaneous coronary intervention (PCI), but its clinical significance remains unclear. We investigated the relationship between TP volume on optical coherence tomography (OCT) after PCI and underlying plaque morphologies and the impact of TP on clinical outcomes. Methods: We investigated 178 native coronary lesions with normal pre-PCI creatine kinase-myocardial band (CK-MB) values (154 lesions with stable angina; 24 with unstable angina). TP was defined as tissue extrusion from stent struts throughout the stented segments. All lesions were divided into tertiles according to TP volume. The differences in plaque morphologies and 9-month clinical outcomes were evaluated. Results: TP volume was correlated with lipid arc (r=0.374, p<0.0001) and fibrous cap thickness (r=-0.254, p=0.001) at the culprit sites. The frequency of thin-cap fibroatheroma (TCFA) was higher in the largest TP tertile (≥ 1.38 mm(3)) (p=0.015). In multivariate analysis, right coronary artery lesion (odds ratio [OR]: 2.779; p=0.005), lesion length (OR: 1.047; p=0.003), and TCFA (OR: 2.430; p=0.022) were related to the largest TP tertile. Lesions with post-PCI CK-MB elevation (>upper reference limit) had larger TP volume than those without (1.28 [0.48 to 3.97] vs. 0.70 [0.16 to 1.64] mm(3), p=0.007). The prevalence of cardiac events during the 9-month follow-up was not significantly different according to TP volume. Conclusions: TP volume on OCT was related to plaque morphologies and instability, and post-PCI myocardial injury, but not to worse 9-month outcomes.

Background: Lipoprotein(a) [Lp(a)] can influence the development and disruption of atherosclerotic plaques through its effect on lipid accumulation. The purpose of this study was to evaluate the relationship between serum Lp(a) levels and plaque morphology of an infarct-related lesion and non-infarct-related lesion of the coronary artery in acute myocardial infarction (AMI). Methods and results: Coronary plaque morphology was evaluated in 68 patients (age 62.1±12.1 years, mean±SD; men n=58, women n=10) with AMI by intravascular ultrasound with radiofrequency data analysis before coronary intervention and by 64-slice computed tomography angiography within 2 weeks. Patients were divided into a group with an Lp(a) level of 25 mg/dl or more (n=20) and a group with an Lp(a) level of less than 25 mg/dl (n=48). Intravascular ultrasound with radiofrequency data analysis identified four types of plaque components at the infarct-related lesion: fibrous, fibrofatty, dense calcium, and necrotic core. The necrotic core component was significantly larger in the group with an Lp(a) level of 25 mg/dl or more than in the group with an Lp(a) level of less than 25 mg/dl (27.6±8.0 vs. 15.7±10.0%, P=0.0001). Coronary plaques were classified as calcified plaques, noncalcified plaques, mixed plaques, and low-attenuation plaques on 64-slice computed tomography angiography. Computed tomography indicated that the group with an Lp(a) level of 25 mg/dl or more had a greater number of total plaques, noncalcified plaques, and low-attenuation plaques in whole coronary arteries than did the group with an Lp(a) level of less than 25 mg/dl (5.3±1.8 vs. 3.7±2.2, P=0.0061; 4.0±2.0 vs. 1.2±1.3, P=0.0001; 2.2±2.1 vs. 0.5±0.7, P=0.0001, respectively). Conclusion: Elevated serum Lp(a) levels are associated with the number of plaques and plaque morphology. Patients with a high Lp(a) level during AMI require more intensive treatment for plaque stabilization.

Statin favorably stabilizes coronary plaque. We evaluated the impact of statin use before the onset of acute ST-elevation myocardial infarction (AMI) on culprit lesion plaque morphology. Methods: Patients (n=127, age 63.3 ± 13.1 year old, mean ± SD) with first AMI (within 12 hours after the onset) were divided into either a statin group (n=31) or a nonstatin group (n=96) based on statin use before the onset of AMI. Coronary plaque morphology of the culprit lesion was evaluated using intravascular ultrasound virtual histology (IVUS-VH) with radiofrequency data analysis before coronary intervention. The IVUS-VH identified 4 types of plaque components: fibrous, fibrofatty, dense calcium, and necrotic core. Values of high-sensitivity CRP (hs-CRP) at admission were measured. Dual SPECT using BMIPP and ²⁰¹ Tl was performed within 2 weeks after the AMI to measure perfusion-metabolism mismatch score, an indicator of viable myocardium, from each total defect score of Tl/BMIPP using 17-segment model and a semiquantitative visual score (0: normal, to 4: no uptake). Results: The IVUS-VH showed less percentage of necrotic core area (7.6 ± 6.8% vs 25.5 ± 6.8%, statin vs nonstatin, p<0.001), greater percentage of fibrous area (70.0 ± 14.2% vs 59.0 ± 8.2 %, p<0.001), and greater percentage of fibrofatty area (19.3 ± 12.7 % vs 11.6 ± 9.9 %, p<0.001) of the culprit lesion in the statin group than in the nonstatin group. The values of hs-CRP were lower in the statin group than in the nonstatin group (1.2 ± 0.8 mg/L vs 2.1 ± 2.4 mg/L, p<0.05) The values of mismatch score was higher in the statin group than in the nonstatin group (8.0 ± 2.5 vs 5.3 ± 2.7, p<0.001) Conclusions: Statin use before the onset of AMI may have effects on coronary plaque morphology of the AMI culprit lesion with less necrotic core and greater fibrous and fibrofatty component. Reducing necrotic core component of the culprit lesion with statin use before the onset of AMI may be related with lower inflammatory response and greater viable myocardium after AMI.

Background: Patients with Takayasu arteritis (TA) often show recurrence under steroid treatment without an elevation of C-reactive protein (CRP). There is a report that matrix metalloproteinase (MMP)-2, MMP-3, MMP-9 and pentraxin3 (PTX3) could be sensitive biomarkers, but the characteristics of these biomarkers have not been established. Methods and results: We enrolled 45 consecutive patients; 28 were grouped in an active phase as evidenced by clinical recurrence within 2 years of blood sampling. Circulating levels of high-sensitivity (hs)CRP, MMPs, and PTX3 were determined. Patients in an active phase showed higher levels of hsCRP, MMP-9, and PTX3. Area under the receiving operating characteristics curves of hsCRP and PTX3 were significantly higher than that of MMP-9. Among the 28 patients with active TA, 71% was positive for hsCRP and 82% for PTX3. Patients without recurrence showed significantly higher plasma levels of MMP-9. There was a positive correlation between the plasma MMP-3 level and the prednisolone dose. However, PTX3 and MMP-9 levels did not have such a correlation. Conclusions: PTX3 and MMP-9, which are not affected by prednisolone, could be sensitive biomarkers for assessing TA activity. Evaluation of MMP-9 may suggest prior existence of TA.

Statins favorably stabilize coronary plaque. We evaluated the impact of statin use before the onset of acute myocardial infarction (AMI) on culprit lesion plaque morphology. Patients (n = 127) with AMI were divided into either a statin group (n = 31) or a nonstatin group (n = 96) based on statin use before the onset of AMI. Coronary plaque morphology of the culprit lesion was evaluated using intravascular ultrasound virtual histology (IVUS-VH) with radiofrequency data analysis before coronary intervention. The IVUS-VH identified 4 types of plaque components: fibrous, fibrofatty, dense calcium, and necrotic core. The IVUS-VH showed less percentage of necrotic area, greater percentage fibrous area, and greater percentage of fibrofatty area of the culprit lesion in the statin group. In conclusion, statin use before the onset of AMI might have effects on coronary plaque morphology of the AMI culprit lesion with less necrotic core and greater fibrous and fibrofatty component.

Background: We aimed to describe the recent clinical characteristics of Takayasu arteritis (TA). Methods and Results: We enrolled 106 consecutive TA patients and compared the clinical characteristics of patients with TA onset before 1999 and after 2000, patients with onset at age less than 39 years and more than 40 years, patients with monophasic and relapsing-remitting clinical course, and patients with and without human lymphocyte antigen (HLA)-B52 allele. Among the patients with TA onset after 2000, the time from onset to diagnosis had decreased; the frequency of occlusion in aortic arch branches and the complication of moderate or severe aortic regurgitation (AR) had decreased, and the maximum dose of prednisolone and the use of immunosuppressive agents had increased. In patients with onset at age more than 40 years, the complications of coronary artery lesions and hypertension had increased, and the incidence of moderate or severe AR had decreased. In the relapsing-remitting group, the maximum dose of prednisolone and the use of immunosuppressive agents had increased, and the mean dose reduction rate of prednisolone was significantly high. There was no significant difference between patients with and without HLA-B52 allele. Conclusions: The prognosis of TA patients has improved over the past decade, which may be related to early diagnosis because of the development of noninvasive diagnostic imaging tools and improved medical treatments. (Circ J 2012; 76: 1004-1011)

We aimed to describe the recent clinical characteristics of Takayasu arteritis (TA). We enrolled 106 consecutive TA patients and compared the clinical characteristics of patients with TA onset before 1999 and after 2000, patients with onset at age less than 39 years and more than 40 years, patients with monophasic and relapsing-remitting clinical course, and patients with and without human lymphocyte antigen (HLA)-B52 allele. Among the patients with TA onset after 2000, the time from onset to diagnosis had decreased; the frequency of occlusion in aortic arch branches and the complication of moderate or severe aortic regurgitation (AR) had decreased, and the maximum dose of prednisolone and the use of immunosuppressive agents had increased. In patients with onset at age more than 40 years, the complications of coronary artery lesions and hypertension had increased, and the incidence of moderate or severe AR had decreased. In the relapsing-remitting group, the maximum dose of prednisolone and the use of immunosuppressive agents had increased, and the mean dose reduction rate of prednisolone was significantly high. There was no significant difference between patients with and without HLA-B52 allele. The prognosis of TA patients has improved over the past decade, which may be related to early diagnosis because of the development of noninvasive diagnostic imaging tools and improved medical treatments.

Kidney function is a known predictor of cardiovascular morbidity and mortality. Although patients with atrial fibrillation (AF) often have kidney dysfunction, less is known about the association between AF and kidney function. We sought to assess changes in kidney function after catheter ablation of AF. Patients who underwent catheter ablation of AF were recruited for the present prospective study. Estimated glomerular filtration rate (eGFR) was evaluated before and 1 year after the ablation. Three hundred eighty-six patients (paroxysmal AF, 135; persistent AF, 106; longstanding persistent AF, 145) were studied. Their baseline eGFR was 68 ± 14 mL · min(-1) · 1.73 m(-2). Sixty-six percent and 26% of patients had eGFR of 60 to 89 and 30 to 59 mL · min(-1) · 1.73 m(-2), respectively. Overall, 278 patients (72%) were arrhythmia free over a 1-year follow-up. In patients free from arrhythmia, eGFR increased 3 months later and was maintained until 1 year, whereas in patients with recurrences, eGFR had decreased over 1 year. Changes in eGFR over 1 year in patients free from arrhythmia differed significantly compared with those with recurrences (3 ± 8 versus -2 ± 8 mL · min(-1) · 1.73 m(-2); P<0.0001). In all quartiles of baseline eGFR, changes in eGFR over 1 year after the ablation were greater in patients free from arrhythmia compared with those with recurrences. Elimination of AF by catheter ablation was associated with improvement of kidney function over a 1-year follow-up in patients with mild to moderate kidney dysfunction.