Katsumi Ueno

Restenosis after successful percutaneous transluminal coronary angioplasty: serial angiographic follow-up of 229 patients.

To further understand the temporal mode and mechanisms of coronary restenosis, 229 patients were studied by prospective angiographic follow-up on day 1 and at 1, 3 and 6 months and 1 year after successful percutaneous transluminal coronary angioplasty. Quantitative measurement of coronary stenosis was achieved by cinevideodensitometric analysis. Actuarial restenosis rate was 12.7% at 1 month, 43.0% at 3 months, 49.4% at 6 months and 52.5% at 1 year. In 219 patients followed up for greater than or equal to 3 months, mean stenosis diameter was 1.91 +/- 0.53 mm immediately after coronary angioplasty, 1.72 +/- 0.52 mm on day 1, 1.86 +/- 0.58 mm at 1 month and 1.43 +/- 0.67 mm at 3 months. In 149 patients followed up for greater than or equal to 6 months, mean stenosis diameter was 1.66 +/- 0.58 mm at 3 months and 1.66 +/- 0.62 mm at 6 months. In 73 patients followed up for 1 year, mean stenosis diameter was 1.65 +/- 0.56 mm at 6 months and 1.66 +/- 0.57 mm at 1 year. Thus, stenosis diameter decreased markedly between 1 month and 3 months after coronary angioplasty and reached a plateau thereafter. In conclusion, restenosis is most prevalent between 1 and 3 months and rarely occurs beyond 3 months after coronary angioplasty.

Considerable Time From the Onset of Plaque Rupture and/or Thrombi Until the Onset of Acute Myocardial Infarction in Humans Coronary Angiographic Findings Within 1 Week Before the Onset of Infarction

BackgroundIt has been thought that the thrombi and bleeding in plaques that occur after plaque rupture or endothelial damage from vessels with mild stenosis suddenly occlude the lumen and cause acute myocardial infarction (AMI). However, our hypothesis is that thrombi and bleeding may not suddenly occlude the lumen. Methods and ResultsThe study group consisted of 20 patients who had coronary angiograms performed within 1 week (3±3 days) before AMI and 20 control patients who had coronary angiograms performed 6 to 18 months (282±49 days) before AMI. The features of infarct-related coronary segments (IRCS) at 3 days before AMI were the presence of a significant stenosis of >50% (95% in incidence and 71±12% diameter stenosis) and Ambrose’s type II eccentric lesions (plus multiple irregularities), an indicator of plaque rupture and/or thrombi (60% [70%]), and the features at 1 year before AMI were mild stenosis of <50% (95% incidence and 30±18% diameter stenosis) with rare Ambrose’s type II eccentric lesions (plus multiple irregularities) (10% [10%]). The same relation was observed in each of the 4 subgroups with Q-wave infarction, non–Q-wave infarction, preceding effort angina within 1 month before AMI, and no preceding effort angina. ConclusionsThe appearance of marked progression and Ambrose’s type II eccentric lesion on coronary angiograms 3 days before AMI suggests the presence of a considerable time from the onset of plaque rupture and/or thrombi until the onset of AMI. These features may be predictors of AMI. The concept provides new insight into the mechanism and prevention of human AMIs.

Difference of Tissue Characteristics Between Early and Very Late Restenosis Lesions After Bare-Metal Stent Implantation An Optical Coherence Tomography Study

Background— Although in-stent restenosis (ISR) after bare-metal stent (BMS) implantation peaks in the early phase, very late (VL) ISR occasionally is observed beyond a few years after BMS implantation. To date, this mechanism has not been fully clarified. Methods and Results— We compared the morphological characteristics of VL-ISR (>5 years, without restenosis within the first year) (n=43) to those of early (E) ISR (within the first year) (n=39) using optical coherence tomography (OCT). Qualitative restenotic tissue analysis included assessment of tissue structure (homogeneous or heterogeneous), presence of microvessels, disrupted intima with cavity, and intraluminal material and was performed at every 1-mm slice of the entire stent. The proportions of cross-sections with heterogeneous intima in the entire stent was significantly higher in the VL-ISR group compared to the E-ISR group (60.5±28.5% versus 5.8±11.5%, P<0.0001), with heterogeneous intima being more frequently observed at the minimum lumen area site in the VL-ISR group (90.7% versus 17.9%, P<0.0001). Disrupted intima with cavity and intraluminal material also were observed more frequently in the VL-ISR group for the entire stent (18.6% versus 0%, 20.9% versus 2.6%, P<0.03) as well as at the minimum lumen area site (13.9% versus 0%,16.2% versus 0%, P<0.03). Conclusions— The morphological characteristics of restenotic tissue in VL-ISR were different from those in E-ISR and similar to atherosclerotic plaque. In BMS, progression of the atherosclerotic process within neointima after stent implantation may be associated with VL-ISR.

Effects of adjunctive balloon angioplasty after intravascular ultrasound-guided optimal directional coronary atherectomy: The result of adjunctive balloon angioplasty after coronary atherectomy study (ABACAS)☆

OBJECTIVES This study was conducted to evaluate: 1) the effect of adjunctive percutaneous transluminal coronary angioplasty (PTCA) after directional coronary atherectomy (DCA) compared with stand-alone DCA, and 2) the outcome of intravascular ultrasound (IVUS)-guided aggressive DCA. BACKGROUND It has been shown that optimal angiographic results after coronary interventions are associated with a lower incidence ofrestenosis. Adjunctive PTCA after DCA improves the acute angiographic outcome; however, long-term benefits of adjunctive PTCA have not been established. METHODS Out of 225 patients who underwent IVUS-guided DCA, angiographically optimal debulking was achieved in 214 patients, then theywere randomized to either no further treatment or to added PTCA. RESULTS Postprocedural quantitative angiographic analysis demonstrated an improved minimum luminal diameter (2.88 +/- 0.48 vs. 2.6 +/- 0.51 mm; p = 0.006) and a less residual stenosis (10.8% vs.15%; p = 0.009) in the adjunctive PTCA group. Quantitative ultrasound analysis showed a larger minimum luminal diameter (3.26 +/- 0.48 vs. 3.04 +/- 0.5 mm; p < 0.001) and lower residual plaque mass in the adjunctive PTCA group (42.6% vs. 45.6%; p < 0.001). Despite the improved acute findings in the adjunctive PTCA group, six-month angiographic and clinical results were not different. The restenosis rate (adjunctive PTCA 23.6%, DCA alone 19.6%; p = ns) and target lesion revascularization rate (20.6% vs. 15.2%; p = ns) did not differ between the groups. CONCLUSIONS With IVUS guidance, aggressive DCA can safely achieve optimal angiographic results with low residual plaque mass, and this was associated with a low restenosis rate. Although adjunctive PTCA after optimal DCA improved the acute quantitative coronary angiography and quantitative coronary ultrasonography outcomes, its benefit was not maintained at six months.

Difference of Tissue Characteristics Between Early and Very Late Restenosis Lesions After Bare-Metal Stent ImplantationClinical Perspective

Background— Although in-stent restenosis (ISR) after bare-metal stent (BMS) implantation peaks in the early phase, very late (VL) ISR occasionally is observed beyond a few years after BMS implantation. To date, this mechanism has not been fully clarified. Methods and Results— We compared the morphological characteristics of VL-ISR (>5 years, without restenosis within the first year) (n=43) to those of early (E) ISR (within the first year) (n=39) using optical coherence tomography (OCT). Qualitative restenotic tissue analysis included assessment of tissue structure (homogeneous or heterogeneous), presence of microvessels, disrupted intima with cavity, and intraluminal material and was performed at every 1-mm slice of the entire stent. The proportions of cross-sections with heterogeneous intima in the entire stent was significantly higher in the VL-ISR group compared to the E-ISR group (60.5±28.5% versus 5.8±11.5%, P<0.0001), with heterogeneous intima being more frequently observed at the minimum lumen area site in the VL-ISR group (90.7% versus 17.9%, P<0.0001). Disrupted intima with cavity and intraluminal material also were observed more frequently in the VL-ISR group for the entire stent (18.6% versus 0%, 20.9% versus 2.6%, P<0.03) as well as at the minimum lumen area site (13.9% versus 0%,16.2% versus 0%, P<0.03). Conclusions— The morphological characteristics of restenotic tissue in VL-ISR were different from those in E-ISR and similar to atherosclerotic plaque. In BMS, progression of the atherosclerotic process within neointima after stent implantation may be associated with VL-ISR.

Outcomes after drug-coated balloon treatment for patients with calcified coronary lesions

OBJECTIVES To investigate the efficacy of drug-coated balloon (DCB) for calcified coronary lesions. BACKGROUND Calcified coronary lesions is associated with poor clinical outcomes after revascularization. Recently, DCB is emerging as an alternative strategy for de novo coronary lesions. However, reports describing the efficacy of DCB for calcified coronary lesions are limited. METHODS A total of 81 patients (96 lesions) who electively underwent DCB treatment for de novo coronary lesions were enrolled: 46 patients (55 lesions) in the calcified group and 35 patients (41 lesions) in the non-calcified group. Angiographic follow-up data and clinical outcomes after the procedure were evaluated. RESULTS The diameter of the DCB used was 2.5 ± 0.5 mm. No bail-out stenting was observed after DCB treatment. Rotational atherectomy was used in 82% of lesions in the calcified group. Follow-up angiography (median, 6.5 months after intervention) was performed for 59 patients (30 in the calcified group and 29 in the non-calcified group). Late lumen loss and rates of restenosis were comparable between the groups (0.03 mm in the calcified group vs -0.18 mm in the non-calcified group, P = 0.093 and 13.9% vs 3.03%, P = 0.095, respectively). The survival rates for target lesion revascularization free survival and major adverse cardiac events at 2 years were comparable between the groups (85.3% vs 93.4%, P = 0.64 and 81.4% vs 88.5%, P = 0.57, respectively). CONCLUSION Calcified coronary lesions might dilute the effect of DCB. However, clinical outcomes in the calcified group were similar to those in the non-calcified group.

Difference of Tissue Characteristics Between Early and Very Late Restenosis Lesions After Bare-Metal Stent ImplantationClinical Perspective: An Optical Coherence Tomography Study

Background— Although in-stent restenosis (ISR) after bare-metal stent (BMS) implantation peaks in the early phase, very late (VL) ISR occasionally is observed beyond a few years after BMS implantation. To date, this mechanism has not been fully clarified. Methods and Results— We compared the morphological characteristics of VL-ISR (>5 years, without restenosis within the first year) (n=43) to those of early (E) ISR (within the first year) (n=39) using optical coherence tomography (OCT). Qualitative restenotic tissue analysis included assessment of tissue structure (homogeneous or heterogeneous), presence of microvessels, disrupted intima with cavity, and intraluminal material and was performed at every 1-mm slice of the entire stent. The proportions of cross-sections with heterogeneous intima in the entire stent was significantly higher in the VL-ISR group compared to the E-ISR group (60.5±28.5% versus 5.8±11.5%, P<0.0001), with heterogeneous intima being more frequently observed at the minimum lumen area site in the VL-ISR group (90.7% versus 17.9%, P<0.0001). Disrupted intima with cavity and intraluminal material also were observed more frequently in the VL-ISR group for the entire stent (18.6% versus 0%, 20.9% versus 2.6%, P<0.03) as well as at the minimum lumen area site (13.9% versus 0%,16.2% versus 0%, P<0.03). Conclusions— The morphological characteristics of restenotic tissue in VL-ISR were different from those in E-ISR and similar to atherosclerotic plaque. In BMS, progression of the atherosclerotic process within neointima after stent implantation may be associated with VL-ISR.

Study of MRSA infection in hemodialysis unit. according to draw up the manual for MRSA infection control.

Compromised hostとして, 人工透析患者におけるMRSAは重要な感染症であり, その対策に苦慮しているのが現状である.岐阜市民病院人工透析室では平成2年11月から透析患者にMRSAが検出され, 平成4年12月までに19例のMRSA陽性者をみた.平成3年1月に病院全体のMRSA感染対策マニュアルが作成され, さらに透析室に合わせたMRSA感染対策マニュアルを平成4年1月に作成し, これに基づき対処したところ, 以後透析室では維持透析患者1名を除き, MRSA定期検査にて医療従事者を含め新たなる検出は認められなかった. しかし, 他病院, 他病棟からの透析依頼患者にMRSAが検出されるケースがみられ, それらの予後は著しく悪かった.透析室における全国レベルでのMRSA対策のマニュアル化が必要と思われる.