Kouki Matsuno

Publications (3)9.16 Total impact

• Article: Postrevascularization recovery of fatty acid utilization in ischemic myocardium: A randomized clinical trial of potassium channel opener

  Yoichi Kuwabara, Satoshi Watanabe, Jiro Nakaya, Rei Hasegawa, Kouki Matsuno, Toru Kuroda, Yuji Mikami, Kiyotaka Fujii, Akira Miyazaki, Toshihiro Saito, Yoshiaki Masuda
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  ABSTRACT: BackgroundAbnormal fatty acid metabolism persists in hibernating myocardium, even after reperfusion. This study was designed to determine whether the K+ channel opener, nicorandil, improves fatty acid utilization after percutaneous transluminal coronary angioplasty (PTCA) MethodsPatients undergoing elective PTCA were randomly assigned to treatment (group N, n=26) or control groups (group C, n=22). Group N received intracoronary and intravenous nicorandil during PTCA. Myocardial fatty acid use and perfusion were quantitatively evaluated by means of iodine-123-beta-methyl-p-iodophenyl-pentadecanoic acid single photon emission computed tomography (I-123 BMIPP SPECT) and thallium-201 (TI-201) imaging before PTCA, 72 hours after PTCA, and 3 months after PTCA. Left ventricular function was also evaluated by means of contrast ventriculography before and 3 to 6 months after PTCA. ResultsThe I-123 BMIPP defect score in group N significantly decreased, from 28%±13% to 20%±20% after PTCA and to 18%±17% 3 months later: In contrast, the I-123 BMIPP defect score in group C increased from 28%±20% to 36%±15% (P<.05 versus group N) after PTCA, then returned to 28%±17% (P<.05 versus group N) 3 months after PTCA. Recovery of left ventricular function paralleled the recovery of I-123 BMIPP uptake. ConclusionsNicorandil improves the recovery of myocardial fatty acid utilization and cardiac function after PTCA. KATP channel activation may have a protective effect during coronary artery occlusion and improve subsequent recovery.
  Journal of Nuclear Cardiology 04/2012; 7(4):320-327. · 2.67 Impact Factor
• Article: Effect of mental stress on left ventricular ejection fraction and its relationship to the severity of coronary artery disease

  Toru Kuroda, Yoichi Kuwabara, Satoshi Watanabe, Jiro Nakaya, Rei Hasegawa, Takeshi Shikama, Kouki Matsuno, Yuji Mikami, Kiyotaka Fujii, Toshihiro Saito, Yoshiaki Masuda
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  ABSTRACT: To evaluate the relationship between the mental stress-induced decrease in left ventricular ejection fraction (LVEF) and the severity of exercise-induced ischaemia, 20 patients with stable coronary artery disease (CAD) underwent radionuclide ventriculography during mental stress testing and stress myocardial perfusion single-photon emission tomography (SPET). We also examined whether changes in haemodynamic and neurohormonal parameters are related to changes in LVEF during mental stress. The LVEF decreased from 54.8%&#4517.7% to 49.8%&#4516.2% with mental stress (P<0.0005). Ten of the 20 patients (50.0%) had a &#835% decrease in LVEF. The remaining ten patients had no or a <5% decrease in LVEF. There was a significant correlation between the change in LVEF during mental stress and the size of the reversible defect on stress myocardial perfusion SPET (r=-0.80, P<0.0005), with close regional correspondence (75% identical). This correlation was less strong in the 12 patients with a total defect score at rest of <10 (r=-0.69, P=0.014) than in the eight patients with a total defect score at rest of ⁶ (r=-0.94, P=0.001). The changes in blood pressure and heart rate were not significantly correlated with the change in LVEF, but the percent change in adrenaline concentration correlated with the change in LVEF. It is suggested that mental stress impairs systolic function by inducing transient myocardial ischaemia. The effect of neurohormonal responses during mental stress on LV systolic function may also be important in patients with CAD.
  European journal of nuclear medicine and molecular imaging 11/2000; 27(12):1760-1767. · 4.99 Impact Factor
• Article: Functional evaluation of myocardial viability by99mTc tetrofosmin gated SPECT —A quantitative comparison with18F fluorodeoxyglucose positron emission CT (18F FDG PET)—

  Yoichi Kuwabara, Satoshi Watanabe, Jiro Nakaya, Masaki Fujiwara, Rei Hasegawa, Kouki Matsuno, Toru Kuroda, Yuji Mikami, Kiyotaka Fujii, Toshiharu Himi, Yoshiaki Masuda
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  ABSTRACT: To validate functional analysis of gated SPECT in detecting myocardial viability, seventeen patients (male 15, female 2, mean age 58) with angiographically proven chronic ischemic heart disease (RCA 6, LAD 10, LCX 1) and eight normal volunteers (all male) were studied. All patients underwent18F FDG PET and99mTc tetrofosmin (TF) gated SPECT within a week. After being displayed in a polar map, myocardial perfusion was regionally determined by the mean count in 9 segments at end diastole (ED) and end systole (ES) in gated SPECT. Systolic function was determined by the count increase ratio from ED to ES (WTI: ES — ED/ED). Glucose metabolism was assessed by18F FDG PET in the segments correspondent to those defined for SPECT. TF %uptake of < 60% was defined as hypoperfusion, and FDG %uptake of < 50% was defined as reduced glucose metabolism. Results: The myocardial segments were classified into 3 categories: “normal” perfusion (n = 85), “mismatch” (reduced perfusion with reserved FDG uptake, n = 25) and “matched” reduced perfusion and metabolic reduction (n = 26). Mean WTI in “mismatch” segment was 0.38 ± 0.21, and was significantly greater than that in “matched reduced” segments, 0.15 ± 0.20 (p < 0.001). It was also greater than that in “normal” segments, 0.27 ± 0.16. Regression analysis showed that association between WTI and FDG %uptake was significant (r = 0.57, p < 0.0005) for the ischemic segments (“mismatch” + “matched”, n = 51), but the association was weak for the entire segments although it was statistically significant (r = 0.26, p = 0.02, n = 136). Conclusion: For the segments determined as infarct by perfusion image, systolic functional analysis by gated SPECT is helpful in differentiation of a viable myocardial region or artifact from a scar. Nevertheless, further clinical and technical assessment is required for ECG gating to eliminate overestimation of viability and to warrant clinical use.
  Annals of Nuclear Medicine 04/1999; 13(3):135-140. · 1.50 Impact Factor