Seiichi Hayakawa

Publications (5)13.07 Total impact

• Article: Morphologic characterization and quantification of superficial calcifications of the coronary artery--in vivo assessment using optical coherence tomography.

  Masaya Matsumoto, Daiji Yoshikawa, Hideki Ishii, Seiichi Hayakawa, Miho Tanaka, Soichiro Kumagai, Mutsuharu Hayashi, Toyoaki Murohara
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  ABSTRACT: Coronary calcification is proportional to the extent and severity of atherosclerotic disease, and is a predictor of cardiac events. Furthermore, coronary calcification protruding into the lumen is considered as one type of vulnerable plaque. Optical coherence tomography (OCT) can provide in vivo imaging of the detailed vessel wall structure of the coronary artery with high resolution, as in the histological approach. We analyzed coronary calcification in that fashion using OCT in vivo. This study consisted of 70 superficial coronary calcifications of 39 consecutive patients who underwent percutaneous coronary intervention. After revascularization, OCT was performed in the treated vessel. We analyzed morphologic characteristics and the quantification of OCT-determined coronary calcification. Superficial coronary calcifications were classified into two groups depending on whether they did not intrude the lumen (type I) or did (type II). The distance from the lumen and the volume of each calcification were then measured. Superficial coronary calcifications were classified into two groups; type I, n = 39 (56%) and type II, n = 31 (44%). Type II calcifications were located significantly closer to the lumen [80 microm (60-130) vs.130 microm (90-260), p = 0.015], and tended to be smaller, but did not show a significant difference [0.65 (0.2631.3) mm3 vs. 1.2 (0.47-1.9) mm3, p = 0.153] compared to those of type I. In conclusion, OCT could visualize superficial coronary calcifications in detail and enable us to evaluate in vivo morphologic characterizations and quantify them.
  Nagoya journal of medical science 08/2012; 74(3-4):253-9.
• Article: Impact of the first-generation drug-eluting stent implantation on periprocedural myocardial injury in patients with stable angina pectoris.

  Takuya Okada, Daiji Yoshikawa, Hideki Ishii, Masaya Matsumoto, Seiichi Hayakawa, Kyoko Matsudaira, Miho Tanaka, Soichiro Kumagai, Mutsuharu Hayashi, Hirohiko Ando, Tetsuya Amano, Toyoaki Murohara
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  ABSTRACT: Percutaneous coronary intervention (PCI) with a drug-eluting stent (DES) is one of the standard treatments for patients with stable angina pectoris (AP). In spite of a notable effect in preventing restenosis after PCI, DES cannot improve the mortality of patients compared to a bare-metal stent (BMS). On the other hand, periprocedural myocardial injury (PMI) is related to poor prognosis in patients undergoing PCI. We compared DES to BMS in the incidence of PMI in patients with stable AP. We enrolled 265 consecutive patients with AP undergoing successful stent implantation. A blood sample was obtained from all patients immediately before and 24h after PCI. PMI was defined as an increase in creatine kinase-myocardial band isozyme fraction (CK-MB) greater than the upper limit of reference range 24h after PCI. During the study period, sirolimus- and paclitaxel-eluting stents were used as DES. The strategy of PCI including the type of stent to implant was left to the discretion of the operator. Patients were divided into two groups (DES group, n=136 and BMS group, n=129). The incidence of PMI was significantly higher in the DES group than in the BMS group (24% vs. 12%, p=0.015). Use of DES remained an independent predictor of PMI on multivariate logistic regression analysis after adjustment for confounding factors (odds ratio 2.20, 95% CI, 1.07-4.51, p=0.032). Implantation of the first-generation DES including sirolimus- and paclitaxel-eluting stents was associated with a higher incidence of PMI in patients with AP compared to BMS.
  Journal of Cardiology 06/2012; 60(4):264-9. · 1.28 Impact Factor
• Article: Association of plasma omega-3 to omega-6 polyunsaturated fatty acid ratio with complexity of coronary artery lesion.

  Seiichi Hayakawa, Daiji Yoshikawa, Hideki Ishii, Miho Tanaka, Soichiro Kumagai, Masaya Matsumoto, Mutsuharu Hayashi, Tsuyoshi Sugiura, Kazunori Hayashi, Hirohiko Ando, Tetsuya Amano, Toyoaki Murohara
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  ABSTRACT: Eicosapentaenoic acid (EPA) of the omega-3 polyunsaturated fatty acids (ω-3 PUFA) family plays important roles in the prevention of cardiovascular disease (CVD), while, arachidonic acid (AA) of the ω-6 PUFA family promotes inflammatory and prothrombotic influences. The complexity of coronary lesions represents the vulnerability of patients. The aim of this study was to investigate the association between the plasma EPA/AA ratio and the prevalence of complex coronary lesion morphology. This study consisted of 206 consecutive patients with stable angina pectoris (sAP). Each coronary lesion was determined either as complex or simple based on angiographic findings. To examine the plasma fatty acid level, blood samples were obtained. Patients were divided into three groups according to the obtained plasma EPA/AA ratio: the highest tertile, n=67, the 2nd tertile, n=70, or the lowest tertile, n=69. A higher incidence of complex coronary lesion was obtained from patients with a lower plasma EPA/AA ratio [43 (62%) vs. 31 (44%) vs. 25 (37%), p=0.011]. High-sensitivity CRP levels and a low plasma EPA/AA ratio could independently predict the prevalence of complex coronary lesions on multivariate logistic regression analysis [odds ratio 1.83 (95%CI 1.03-3.25), p=0.038 and odds ratio 2.10 (95%CI 1.11-3.94), p=0.02)]. In patients with sAP, a low plasma EPA/AA ratio was significantly associated with a high prevalence of complex coronary lesions.
  Internal Medicine 01/2012; 51(9):1009-14. · 0.94 Impact Factor
• Article: Impact of the low- to high-density lipoprotein cholesterol ratio on composition of angiographically ambiguous left main coronary artery plaque.

  Nobutake Kurebayashi, Daiji Yoshikawa, Hideki Ishii, Bummei Sato, Hirohiko Ando, Takuya Okada, Seiichi Hayakawa, Naoki Okumura, Satoshi Isobe, Kyosuke Takeshita, Mutsuharu Hayashi, Tadayuki Uetani, Tetsuya Amano, Toyoaki Murohara
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  ABSTRACT: A high low-density lipoprotein cholesterol (LDL-C) to a high-density lipoprotein cholesterol (HDL-C) ratio is associated with cardiac events, while the left main coronary artery (LMCA) is considered to be an important target of atherosclerotic plaque accumulation. This aim of the present study was to investigate the relationship between a LDL-C/HDL-C ratio and the characteristics of tissue components of LMCA plaque. One-hundred-twenty consecutive patients with stable angina pectoris who received chronic statin treatment underwent percutaneous coronary intervention for the left coronary artery. We prospectively performed integrated backscatter (IB) intravascular ultrasound (IVUS) to their LMCAs and evaluated the tissue characteristics. According to the median value of their LDL-C/HDL-C ratios (2.4), they were divided into 2 groups [high LDL-C/HDL-C ratio (>2.4) (n=60) or low LDL-C/HDL-C ratio (≤ 2.4) (n=60)]. There was no significant difference in the data analyzed using conventional IVUS between the 2 groups. In the IB-IVUS analysis, patients with a high LDL-C/HDL-C ratio had a larger lipid volume and a smaller fibrous volume compared to patients with a low LDL-C/HDL-C ratio (52 ± 10% vs. 48 ± 10%, P=0.014 and 45 ± 9% vs. 50 ± 10%, P=0.010). A high LDL-C/HDL-C ratio was associated with a high percentage of lipid volume and a low percentage of fibrous volume in LMCA lesions. Our findings might well suggest the increased risk of cardiovascular events in patients with a high LDL-C/HDL-C ratio.
  Circulation Journal 06/2011; 75(8):1960-7. · 3.77 Impact Factor
• Article: Association of cardiorespiratory fitness with characteristics of coronary plaque: Assessment using integrated backscatter intravascular ultrasound and optical coherence tomography.

  Daiji Yoshikawa, Hideki Ishii, Nobutake Kurebayashi, Bummei Sato, Seiichi Hayakawa, Hirohiko Ando, Mutsuharu Hayashi, Satoshi Isobe, Takahiro Okumura, Akihiro Hirashiki, Kyosuke Takeshita, Tetsuya Amano, Tadayuki Uetani, Sumio Yamada, Toyoaki Murohara
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  ABSTRACT: BACKGROUND: Cardiorespiratory fitness (CRF) can predict future cardiovascular disease. Rupture of vulnerable plaque which often has a large lipid core with a thin fibrous cap causes acute coronary syndrome including sudden cardiac death. We tested our hypothesis that preserved CRF is associated with low lipid composition and thick fibrous cap thickness of coronary lesions. METHODS: We prospectively performed both integrated backscatter intravascular ultrasound (IB-IVUS) and optical coherence tomography (OCT) for 77 non-culprit coronary lesions in 77 consecutive angina pectoris patients who underwent percutaneous coronary intervention (PCI). Percentage of achieved of predicted peak oxygen consumption (%PPeak Vo(2)) calculated based on measured peak Vo(2) using a cardiopulmonary exercise test performed post PCI was adapted as an indicator of patient CRF. RESULTS: Patients were divided into two groups [those with preserved CRF (%PPeak Vo(2) >82%) (Group I) or others (Group II)]. Coronary plaques of Group I patients had significantly smaller lipid volume, greater fibrous volume, and thicker fibrous cap thickness than those of Group II (32±14% vs. 45±13%, p<0.001; 57±11% vs. 49±11%, p<0.001; and 177.7±20.9μm vs. 143.7±36.9μm, p<0.001). In multivariate linear regression analysis, %PPeak Vo(2) showed a significantly negative correlation with lipid volume and a positive correlation with fibrous volume and fibrous cap thickness (β=-0.418, p=0.001; β=0.361, p=0.006; and β=0.339, p=0.008). CONCLUSIONS: High %PPeak Vo(2) was associated with low lipid volume, high fibrous volume and thick fibrous cap thickness in coronary lesions. These results may well suggest an attenuated risk of cardiovascular events in patients with preserved CRF.
  International journal of cardiology 05/2011; · 7.08 Impact Factor