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Biomedical subjects

M Nobuyoshi

Publications and source records attributed to M Nobuyoshi.

At least 37 records · Page 2Linked to original sources
PubMed1999

Intravascular ultrasound assessment of the relation between early and late changes in arterial area and neointimal hyperplasia after percutaneous transluminal coronary angioplasty and directional coronary atherectomy.

Previous serial intravascular ultrasound (IVUS) analysis after percutaneous transluminal coronary angioplasty or directional coronary atherectomy showed (1) early (within 1 month) increase in arterial area, (2) late (1- to 6-month) decrease in arterial area, and (3) an increase in plaque area from immediately to 6 months after intervention. To further understand these findings, we used serial IVUS to study the relations between changes in arterial and plaque area during the follow-up period after coronary intervention. Serial IVUS was performed before intervention and immediately, 24 hours, 1 month, and 6 months after percutaneous transluminal coronary angioplasty (n = 35) or directional coronary atherectomy (n = 26) in 57 patients. Arterial, lumen, and plaque areas were measured at the lesion site with the smallest preintervention and follow-up lumen areas at all time points. The increase in plaque area in the first month after intervention was accompanied by an equal or greater increase in arterial area (r = 0.670, p <0.0001). There was a decrease in arterial area from 1 to 6 months after intervention, which correlated inversely with both the increase in plaque area (r = 0.434, p <0.0001) or arterial area (r = 0.515, p <0.0001) during the first month after intervention and directly with the 1- to 6-month increase in plaque area (r = 0.460, p <0.0001). Comparison of the late (1 to 6 months) and early (within 1 month) delta arterial versus delta plaque area regression lines suggested that the late decrease in arterial area was superimposed on the relation between delta arterial area and delta plaque area. These relations were especially strong in restenotic (vs nonrestenotic) lesions. The early increase and late decrease in stenosis arterial area and neointimal hyperplasia appear to be interrelated, especially in restenotic stenoses.

Angioplasty, Balloon, Coronary↗
PubMed1999

Serial volumetric intravascular ultrasound assessment of arterial remodeling in left main coronary artery disease.

Serial volumetric intravascular ultrasound (IVUS) was used to study de novo, nontreated left main coronary arteries (LMCAs) in 31 patients. Using an automated contour detection algorithm, analysis of 7.2 +/- 2.5 mm long segments included arterial, lumen, and plaque volumes and plaque burden (plaque/arterial volumes). During follow-up (7.7 +/- 2.4 months), the percent change in lumen volume correlated with the percent change in arterial volume (r = 0.897, p <0.0001), but not with the percent change in plaque volume (r = 0.066, p = 0.7263). Percent changes in arterial volume correlated with percent changes in plaque + media volume (r = 0.448, p = 0.0115), indicating arterial remodeling. However, there was a spectrum of responses ranging from inadequate remodeling (decrease in lumen volume despite no increase or a decrease in plaque volume: i.e., arterial shrinkage) to overcompensation (an increase in lumen volume despite an increase in plaque volume). Serial volumetric IVUS (1) confirms the existence of both positive and negative remodeling in LMCA, and (2) shows that in moderate LMCA disease, luminal changes resulted primarily from positive versus negative remodeling, not plaque progression and/or regression.

Aged↗
PubMed1999

Thrombectomy with AngioJet catheter in native coronary arteries for patients with acute or recent myocardial infarction.

The AngioJet thrombectomy catheter removes thrombi by rheolytic fragmentation and suction. The purpose of this study was to identify the efficacy and safety of this new device. Myocardial infarction (MI) is associated with intracoronary thrombus. Intracoronary thrombus has been identified as a risk factor of unfavorable outcome after percutaneous transluminal coronary angioplasty. To what extent the AngioJet is applicable or effective for acute or recent MI in native coronary artery is not clear. Thrombectomy with the AngioJet was attempted in 31 patients with 31 native coronary arteries selected from 304 patients with acute or recent MI. Follow-up angiography was performed at 3 to 6 months. Procedure success was achieved in 29 patients (94%). Adjunctive balloon angioplasty was performed after AngioJet thrombectomy in 30 patients (97%), and in only 1 patient (3%) AngioJet thrombectomy was the sole procedure. Subsequent stenting after balloon angioplasty was attempted successfully in 12 patients (40%) without thrombotic complications. Thrombolysis In Myocardial Infarction trial flow grading increased from 0.70 +/- 0.97 before to 2.61 +/- 0.88 after AngioJet thrombectomy (p <0.0001), to 2.84 +/- 0.64 after adjunctive procedures (p = 0.070). At follow-up angiography restenosis rate was 21% but Thrombolysis In Myocardial Infarction flow 3 was present in all patients. The restenosis rate of stented patients was 8%. There were no major events during in-hospital and follow-up. The AngioJet can be used safely and successfully to remove thrombus from the native coronary artery of patients with MI. Thrombus removal makes subsequent stenting safe and uncomplicated. The restenosis rate was considered to be acceptable.

Angioplasty, Balloon, Coronary↗
PubMed1999

[Efficacy of hemostatic puncture closing device for hemostasis and early ambulation after coronary angiography and angioplasty: results of a multicenter trial].

To assess the efficacy and safety of a hemostatic puncture closing device for reducing patient immobilization after cardiac catheterization from a percutaneous femoral artery approach, we conducted a prospective, randomized trial at 4 participating centers. A total of 240 patients (183 men, 57 women, mean age 61 +/- 10 yr; 157 patients underwent diagnostic angiography, 83 patients underwent coronary angioplasty) were randomized to either the device group (n = 120) or the manual compression group (n = 120). There were no statistical differences in age, gender, weight or sheath size between the 2 groups. A 7, 8F sheath was used in 53 patients of the device group and in 43 patients of the manual compression group. One hundred and two patients (85%) in the device group and 96 patients (80%) in the manual compression group received heparin. Protamine was used in one patient of the device group and 23 patients of the manual compression group. Activated clotting time just prior to sheath removal was 206 +/- 64 sec in the device group and 170 +/- 47 sec in the manual compression group (p < 0.01). Successful placement of the device was achieved in 118 of 120 patients (98%). Time to hemostasis was significantly shorter in the device group (0.8 +/- 3.2 vs 12.2 +/- 5.3 min, p < 0.01). Time to ambulation could be reduced in the device group (5.3 +/- 3.7 vs 10.9 +/- 5.1 hr, p < 0.01). The following complication rates occurred in the device group as compared with the manual compression group: hematoma, 16% vs 10%; bleeding, 8% vs 3%; pseudoaneurysm, 0% vs 1%, respectively. None of these differences was statistically significant. These results indicate that early ambulation using a hemostatic puncture closing device is feasible without significantly increasing the risk of peripheral vascular complications.

Adult↗
PubMed1998

Stenting after thrombectomy with the AngioJet catheter for acute myocardial infarction.

The presence of massive intracoronary thrombi may contraindicate stenting. The AngioJet catheter rheolytic thrombectomy prepared the road for an easy and uneventful stenting in 2 patients with acute myocardial infarction (AMI) and thrombi. This combination provides a promising strategy for patients with AMI and angiographic evidence of massive thrombi.

Aged↗
PubMed1998

Initial and follow-up results of the ACS multi-link stent: a single center experience.

The Palmaz-Schatz (PS) stent has effectively reduced restenosis; however its rigidity makes it sometimes difficult or impossible to deliver. The initial and follow-up outcomes with the ACS Multi-Link stent (deployed from April to November 1995) were evaluated in 70 patients (79 lesions): unplanned in 34% (abrupt closure 1%; threatened closure 5%; suboptimal results 28%) and planned in 66%. Three to six month follow-up angiograms were analyzable in 67 lesions; 96% procedural (in nine lesions PS stenting had failed) and 95% clinical success were achieved. In-hospital mortality was 1.4%. Myocardial infarction occurred in 2.9%, and subacute stent thrombosis in 1.4%. Stenting improved immediately the minimal luminal diameter (from 0.97+/-0.41 mm to 2.72+/-0.31 mm), but at 6 months it had decreased to 1.89+/-0.44 mm. Angiographic restenosis (<50% diameter stenosis) occurred in 11, a rate of 16.4%; target lesion revascularization (TLR) was required in six (re-PTCA in five or bypass surgery in one; 6/67=8.7%). Actuarial 1-2 year survival rate was 91%, 80% surviving free from major complications or need for TLR. We conclude that the ACS Multi-Link stent can be implanted in lesions unsuited for the PS stent with a high success rate, and an anticipated restenosis rate perhaps comparable to with the PS stent.

Aged↗
PubMed1998

Efficacy of coronary stenting versus balloon angioplasty in small coronary arteries. Stent Restenosis Study (STRESS) Investigators.

OBJECTIVES: The goal of this study was to compare the efficacy of elective stent implantation and balloon angioplasty for new lesions in small coronary arteries. BACKGROUND: Palmaz-Schatz stents have been designed and approved by the Food and Drug Administration for use in coronary arteries with diameters > or = 3.0 mm. The efficacy of elective stent placement in smaller vessels has not been determined. METHODS: By quantitative coronary angiography, 331 patients in the Stent Restenosis Study (STRESS) I-II were determined to have a reference vessel < 3.0 mm in diameter. Of these, 163 patients were randomly assigned to stenting (mean diameter 2.69 +/- 0.21 mm), and 168 patients were assigned to angioplasty (mean diameter 2.64 +/- 0.24 mm). The primary end point was restenosis, defined as > or = 50% diameter stenosis at 6-month follow-up angiography. Clinical event rates at 1 year were assessed. RESULTS: Baseline clinical and angiographic characteristics were similar in the two groups. Procedural success was achieved in 100% of patients assigned to stenting and in 92% of patients assigned to angioplasty (p < 0.001). Abrupt closure within 30 days occurred in 3.6% of patients in both groups. Compared with angioplasty, stenting conferred a significantly larger postprocedural lumen diameter (2.26 vs. 1.80 mm, p < 0.001) and a larger lumen at 6 months (1.54 vs. 1.27 mm, p < 0.001). Restenosis (> or = 50% diameter stenosis at follow-up) occurred in 34% of patients assigned to stenting and in 55% of patients assigned to angioplasty (p < 0.001). At 1 year, event-free survival was achieved in 78% of the stent group and in 67% of the angioplasty group (p = 0.019). CONCLUSIONS: These findings suggest that elective stent placement provides superior angiographic and clinical outcomes than balloon angioplasty in vessels slightly smaller than 3 mm.

Angioplasty, Balloon, Coronary↗
PubMed1998

Safety and cost-effectiveness of early discharge after primary angioplasty in low risk patients with acute myocardial infarction. PAMI-II Investigators. Primary Angioplasty in Myocardial Infarction.

OBJECTIVES: The second Primary Angioplasty in Myocardial Infarction (PAMI-II) study evaluated the hypothesis that primary percutaneous transluminal coronary angioplasty (PTCA), with subsequent discharge from the hospital 3 days later, is safe and cost-effective in low risk patients. BACKGROUND: In low risk patients with myocardial infarction (MI), few data exist regarding the need for intensive care and noninvasive testing or the appropriate length of hospital stay. METHODS: Patients with acute MI underwent emergency catheterization with primary PTCA when appropriate. Low risk patients (age <70 years, left ventricular ejection fraction >45%, one- or two-vessel disease, successful PTCA, no persistent arrhythmias) were randomized to receive accelerated care (admission to a nonintensive care unit and day 3 hospital discharge without noninvasive testing [n = 237] or traditional care [n = 234]). RESULTS: Patients who received accelerated care had similar in-hospital outcomes but were discharged 3 days earlier (4.2+/-2.3 vs. 7.1+/-4.7 days, p = 0.0001) and had lower hospital costs ($9,658+/-5,287 vs. $11,604+/-6,125 p = 0.002) than the patients who received traditional care. At 6 months, accelerated and traditional care groups had a similar rate of mortality (0.8% vs. 0.4%, p = 1.00), unstable ischemia (10.1% vs. 12.0%, p = 0.52), reinfarction (0.8% vs. 0.4%, p = 1.00), stroke (0.4% vs. 2.6%, p = 0.07), congestive heart failure (4.6% vs. 4.3%, p = 0.85) or their combined occurrence (15.2% vs. 17.5%, p = 0.49). The study was designed to detect a 10% difference in event rates; at 6 months, only a 2.3% difference was measured between groups, indicating an actual power of 0.19. CONCLUSIONS: Early identification of low risk patients with MI allowed safe omission of the intensive care phase and noninvasive testing, and a day 3 hospital discharge strategy, resulting in substantial cost savings.

Aged↗
PubMed1998

Intravascular ultrasound-guided optimized stent deployment. Immediate and 6 months clinical and angiographic results from the Multicenter Ultrasound Stenting in Coronaries Study (MUSIC Study)

OBJECTIVES: A study was set up to validate the safety and feasibility of intravascular ultrasound-guided stenting without subsequent anticoagulation, and its impact on the 6 months restenosis rate. METHODS: The study was designed to be multicentred, prospective, and observational. RESULTS: One hundred and sixty-one patients with stable angina and a de novo coronary artery lesion were enrolled. In four patients, the implantation of a Palmaz-Schatz (with spiral bridge) stent had failed. One of these four patients died 3 days following bypass surgery. In two other patients, intravascular ultrasound assessment was not performed. One hundred and twenty-five of the remaining 155 patients (81%) were treated with aspirin (100 mg x day(-1)), because all three criteria for optimized stent expansion were met. Twenty-two of the remaining 38 patients (25%), in whom at least one criterion was not met were treated with aspirin and acenocoumarol (3 months, INR 2.5-3.5), while 16 patients only received aspirin. Stent thrombosis was documented in two patients (1.3%) for which repeat angioplasty was performed. During the hospital stay, there were no deaths or Q-wave myocardial infarctions. Five patients (3.2%) sustained a non-Q-wave myocardial infarction. During the follow-up period (198+/-38 days, complete for all patients, except one), one patient (0.6%) sustained a Q-wave myocardial infarction, one (0.6%) underwent bypass surgery, and repeat angioplasty was performed in nine patients (5.7%). In two of the nine patients, repeat angioplasty involved another lesion. Therefore, the target lesion revascularization rate during follow-up was 4.5% (seven patients). At quantitative coronary angiography, the minimal lumen diameter (mean+/-SD) increased from 1.12+/-0.34 mm before to 2.89+/-0.35 mm after stenting. Repeat angiography at 6 months was performed in 144 patients (92%). The minimal lumen diameter at follow-up was 2.12+/-0.67 mm. Restenosis (diameter stenosis of 50% or more) was documented in 12 patients or 8.3%. When the two patients with documented stent thrombosis are included, the restenosis rate amounts to 97%. CONCLUSIONS: These data confirm that, in selected patients, stents can safely be implanted without the use of systemic anticoagulation, provided optimal stent expansion is achieved. The exact role of intravascular ultrasound in the achievement of these results needs to be established by appropriately designed studies. In the meantime, intravascular ultrasound coupled with the Palmaz-Schatz stent incorporating a spiral bridge, may have contributed considerably to the immediate angiographic outcome, which in turn may explain the favourable clinical and angiographic outcome at 6 months.

Aged↗
PubMed1998

Atherosclerotic coronary lesions with inadequate compensatory enlargement have smaller plaque and vessel volumes: observations with three dimensional intravascular ultrasound in vivo.

OBJECTIVE: To compare vessel, lumen, and plaque volumes in atherosclerotic coronary lesions with inadequate compensatory enlargement versus lesions with adequate compensatory enlargement. DESIGN: 35 angiographically significant coronary lesions were examined by intravascular ultrasound (IVUS) during motorised transducer pullback. Segments 20 mm in length were analysed using a validated automated three dimensional analysis system. IVUS was used to classify lesions as having inadequate (group I) or adequate (group II) compensatory enlargement. RESULTS: There was no significant difference in quantitative angiographic measurements and the IVUS minimum lumen cross sectional area between groups I (n = 15) and II (n = 20). In group I, the vessel cross sectional area was 13.3 (3.0) mm2 at the lesion site and 14.4 (3.6) mm2 at the distal reference (p < 0.01), whereas in group II it was 17.5 (5.6) mm2 at the lesion site and 14.0 (6.0) mm2 at the distal reference (p < 0.001). Vessel and plaque cross sectional areas were significantly smaller in group I than in group II (13.3 (3.0) v 17.5 (5.6) mm2, p < 0.01; and 10.9 (2.8) v 15.2 (4.9) mm2; p < 0.005). Similarly, vessel and plaque volume were smaller in group I (291.0 (61.0) v 353.7 (110.0) mm3, and 177.5 (48.4) v 228.0 (92.8) mm3, p < 0.05 for both). Lumen areas and volumes were similar. CONCLUSIONS: In lesions with inadequate compensatory enlargement, both vessel and plaque volume appear to be smaller than in lesions with adequate compensatory enlargement.

Coronary Angiography↗
PubMed1998

Initial Experience with the ACS Multi-Link Stent: Serial Angiographic Follow-Up and Comparison with the Palmaz-Schatz Stent in Matched Lesions.

To evaluate the efficacy of the more flexible ACS Multi-Link stent, a prospective angiographic follow-up study was performed. Implantation of the ACS Multi-Link stent was attempted in 70 consecutive patients with 79 coronary lesions from April to November 1995. Clinical success defined as final % diameter stenosis of < 50% without death, bypass surgery or Q-wave myocardial infarction was achieved in 95% of the patients. There was 1 in-hospital death due to acute pulmonary embolism. In-hospital subacute stent occlusion occurred in 2 cases. Follow-up angiograms were obtained in 62 (83%) eligible lesions. The minimal luminal diameter improved from 0.97 +/- 0.41 to 2.72 +/- 0.30 mm, but started to decrease at 1 month (2.38 +/- 0.42 mm), and continued to decrease throughout the 6 months (1.96 +/- 0.41 mm). Angiographic restenosis (stenosis ³ 50%) occurred in 16% of the lesions, a rate smaller though not significantly different from the 25% with the Palmaz-Schatz stent. A revascularization procedure of the target lesion was required in 6% of the patients. Multivariate analysis identified lack of post-dilatation, type of lesion, lesion length and pre-procedural reference diameter to be predictors of angiographic restenosis. In conclusion, the ACS Multi-Link stent can be implanted successfully with a low complication rate and a clinical outcome at least comparable to the Palmaz-Schatz stent.

Journal Article↗
PubMed1998

Initial Experience with the ACS MultiLink Stent: Serial Angiographic Follow-up and Comparison with the Palmaz-Schatz Stent in Matched Lesions.

To evaluate the efficacy of the more flexible ACS Multi-Link stent, a prospective angiographic follow-up study was performed. Implantation of the ACS Multi-Link stent was attempted in 70 consecutive patients with 79 coronary lesions from April to November 1995. Clinical success defined as final % diameter stenosis of < 50% without death, bypass surgery nor Q wave myocardial infarction was achieved in 95% of the patients. There was 1 in-hospital death due to acute pulmonary embolism. In-hospital subacute stent occlusion occurred in 2 cases. Follow-up angiograms were obtained in 62 (83%) eligible lesions. The minimal luminal diameter improved from 0.97 +/- 0.41 to 2.72 +/- 0.30 mm, but started to decrease at 1 month (2.38 +/- 0.42 mm), and continued to decrease throughout the 6 months (1.96 +/- 0.41 mm). Angiographic restenosis (stenosis ³ 50%) occurred in 16% of the lesions, a rate smaller though not significantly different from the 25% with the Palmaz-Schatz stent. A revascularization procedure of the target lesion was required in 6% of the patients. Multivariate analysis identified lack of post-dilatation, type of lesion, lesion length and pre-procedural reference diameter to be predictors of angiographic restenosis. In conclusion, the ACS Multi-Link stent can be implanted successfully with a low complication rate and a clinical outcome at least comparable to the Palmaz-Schatz stent.

Journal Article↗
PubMed1998

[Long-term clinical angiographic follow-up undergoing PTCA more than 10 years].

UNLABELLED: To evaluate longer-term outcome of the balloon angioplasty, a serial follow-up angiographic study at Early (< or = 1 year) and 10 year (yr)s was designed. Between April 1982 to December 1984, balloon angioplasty for native coronary arteries was successful in 320 patients (pts) (age: 60 +/- 9, male 81%, multi vessel disease 45%) or 436 de novo lesions (les) (LAD: 56%, RCA 20%, LCX 24%). At 10 yrs, 78% of pts were free from death, 66% free from death/MI/CABG, 48% free from death/MI/CABG/target lesion revascularization. 41% free from death/MI/CABG/target lesion revascularization/PTCA for new les (NL). Early follow-up angiography (FUA) was performed and cine films were available in 176 pts (55%). Seventy-three pts (23%) underwent target lesion revascularization and 11 pts died (cardiac: 3, non-cardiac: 8) within 1 yr. Excluding these 84 pts, 236 pts were eligible for longer term FU. FUA at 10 yrs was performed and cine films were available in 95 pts (40%). CAAS II was used for quantitative analysis. [table: see text] MLD did not change between Early and 10 yrs. Angiographic restenosis (defined as > 50% DS at FU) was occurred in 75/176 pts (43%) within 1 year and 15/95 pts (16 %) between 1 and 10 yrs (P < 0.0001). In contrast, NL was occurred in 26/176 pts (15%) within 1 year and 45/95 pts (47%) between 1 and 10 yrs (P < 0.0001). CONCLUSION: 1) Restenosis rarely occurred beyond 1 yr after balloon angioplasty. 2) Ischemic events beyond 1 yr were often related to development of NL rather than restenosis. 3) Safety and efficacy of balloon angioplasty appeared to be sustained at 10 yrs.

Angioplasty, Balloon, Coronary↗
PubMed1998

[PTCA for acute coronary syndrome].

The use of intravenous thrombolytic therapy have revolutionized the medical management of acute MI, prolonging survival and preserving LV function. Yet, despite these important beneficial effects, many deficiencies exist, such as the fewer lytic eligible patients, the low rate of complete reperfusion and high incidence of recurrent Ischemia and intracranial hemorrhage. To improve on these deficiencies, several PTCA strategies for acute MI have emerged, including primary PTCA, rescue PTCA, immediate PTCA, and delayed PTCA. If skilled intervention-list and cath lab team are available, the optimal reperfusion strategy is primary PTCA. If a cath lab is not available and the patient is eligible for thrombolysis, intravenous thrombolytic therapy should be administered. Nevertheless, PTCA still has significant limitations, including complex lesion morphology and restenosis. Preliminary experience support the feasibility and safety of coronary stenting in the setting of acute MI. A randomized trial using the heparin-coated Palmaz-Schatz stent for primary stenting in MI is ongoing. Until a randomized trial data are available, we recommend stenting for provisional stenting.

Acute Disease↗