Yoshitake Nakamura

Efficacy of thrombectomy for acute myocardial infarction-Special focus on its efficacy according to different infarct-related arteries.

BACKGROUND The efficacy of thrombectomy during percutaneous coronary intervention (PCI) for ST-segment elevation acute myocardial infarction (STEMI) has not yet been fully evaluated. The aim of this retrospective study was to evaluate the usefulness of manual thrombectomy for STEMI and to clarify whether different infarct-related arteries (IRAs) influence the efficacy of thrombectomy. METHODS AND RESULTS We enrolled 183 patients with STEMI who underwent PCI within 24h after onset between October 2001 and January 2004. We divided these patients into 2 groups, namely 88 patients who had undergone PCI after manual thrombectomy (Th+ group) and 95 patients who were treated with PCI alone (Th- group). The Th+ group had lower incidences of distal embolization and no-reflow phenomenon than the Th- group (6.8% vs. 27.4%, p=0.0003; and 5.7% vs. 23.2%, p=0.0009, respectively). The percentage of complete ST-segment resolution (STR) after PCI and left ventricular ejection fraction 6 months after the procedure were significantly higher in the Th+ group (43.2% vs. 20%, p=0.002; and 60.1% vs. 54.8%, p=0.004, respectively). Regarding different IRAs, the percentage of complete STR was significantly higher in patients with proximal left anterior descending coronary artery (LAD) and right coronary artery (RCA) lesions in the Th+ group (37.5% vs. 9.7%, p<0.05; and 59.5% vs. 30.3%, p<0.05, respectively). Incidences of adverse events were similar in both groups. CONCLUSIONS Manual thrombectomy for STEMI can improve myocardial reperfusion after PCI and left ventricular function late after the procedure. With respect to different IRAs, manual thrombectomy for STEMI is more effective in proximal LAD and RCA lesions.

Increased Serum Levels of Circulating Intercellular Adhesion Molecule-1 in Patients with Myocarditis

Levels of circulating intercellular adhesion molecule-1 (cICAM-1) were measured by ELISA in the sera of 21 patients with unexplained cardiac dysfunction. By evaluating the biopsy or autopsy specimens, they were classified into two groups: a myocarditis group (n = 8) and a nonmyocarditis group (n = 13). Levels of cICAM-1 were significantly higher in the myocarditis group (p < 0.01). Increased levels of cICAM-1 (> 2 SD above the control mean) were detected in 6 of 8 patients in the myocarditis group. Therefore, the detection of increased levels of cICAM-1 could be a useful marker for myocarditis.

Restenosis after implantation of sirolimus-eluting stent begins suddenly, shows short term progression, and stops suddenly.

BACKGROUND AND PURPOSE The peak of restenosis in patients implanted with bare metal stents (BMS) is thought to be 6 months after BMS implantation, but the development of restenosis with respect to time and the peak of restenosis in patients implanted with drug-eluting stents (DES) is not known. This study aims to reveal the rate of development of restenosis with respect to time in patients implanted with DES. METHODS A total of 282 patients who underwent sirolimus-eluting stent (SES) implantation in native coronary arteries at our hospital were evaluated by serial quantitative angiography at 3 and 6 months, and based on the latter results, at 1 and 2 years after SES implantation. Clinical data were collected for up to 3 years. RESULTS Three-year follow-up data were obtained for 261 patients. The 3-year incidence of clinically driven target-lesion revascularization (TLR) was 6.1% (16/261); of the 16 cases, 5 occurred at 3-month follow-up, 7 at 6-month angiographic follow-up, and 1 at 1-year follow up, respectively. While minimum lumen diameter (MLD) of these vessels that underwent TLR at 6 months decreased rapidly after the 3-month angiographic follow-up, MLD of the vessels with 50-70% stenosis at 6-month angiographic follow-up was almost unchanged at 1-year angiographic follow-up; however, 3 lesions required late (i.e. beyond 1 year) revascularization. CONCLUSIONS It is difficult to predict SES restenosis by angiography. SES restenosis begins suddenly, shows short-term progression, and stops suddenly. However, treatment of de novo coronary stenosis with SES is associated with a sustained clinical benefit and a very low incidence of TLR.

Differences in the Development of Restenosis Over Time for Various Drug-Eluting Stents

Differences in the Development of Restenosis Over Time for Various Drug-Eluting Stents Introduction: Restenosis after stent implantation is one of the major limitations of percutaneous coronary intervention (PCI). Compared to bare metal stents (BMS), drug-eluting stents (DES) have a reduced incidence of restenosis. However, the temporal pattern of restenosis development in patients implanted with DES has not been clearly defined. Aim: This study aims to compare the efficacy of sirolimus-eluting stents (SES), paclitaxel-eluting stents (PES), zotarolimus-eluting stents (ZES), and everolimus eluting stents (EES) via sequential angiographic follow-up and to reveal the development of restenosis over time. Material and methods: Patients were randomized to receive SES, PES, ZES, or EES, and follow-up angiography was performed at 6, 12 and 24months after percutaneous coronary intervention. We analyzed late loss (LL) at each time point and defined 2 time periods: “early” (within first year of follow-up) and “late” (after the first year). Results: In all groups, mean minimal lumen diameter decreased slightly during the 2-year period after the procedure. Compared with the SES group, the PES and the ZES groups showed significantly greater late loss (LL) within 1 year. However, the SES group showed significantly greater LL compared with the other drug-eluting stents (DES) between 1 and 2 years. Conclusions: Serial angiographic analysis revealed differences in the rate of restenosis development over time for various DES. Of the studied DES, EES showed the best results in both early and late LL.