Mamoo Nakamura

University of Pittsburgh, Pittsburgh, PA, USA

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Publications (18)72.31 Total impact

  • Article: Efficacy of reduced-dose sirolimus-eluting stents in the human coronary artery: serial IVUS analysis of neointimal hyperplasia and luminal dimension.
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    ABSTRACT: Using serial intravascular ultrasound (IVUS), the efficacy of reduced-dose sirolimus-eluting stents (SESs) in the prevention of neointimal hyperplasia (NH) and maintenance of luminal patency in human coronary arteries was evaluated. In the animal model, a broad therapeutic window regarding sirolimus doses in suppressing NH has been reported. Serial cross-sectional and volumetric IVUS analyses were performed in 44 patients treated with SES that contained lower sirolimus doses (either 45% or 70%) than standard SES. For cross-sectional analysis, minimum lumen area (MLA) was measured. Percent (%) NH volumetric obstruction was calculated as 100 x NH volume/stent volume. IVUS measurements were similar between the two drug-dose groups. At 12 months follow-up, only one case developed late incomplete stent apposition. Between 4 and 12 months, a slight increase of in-stent % area loss and % NH obstruction was noted (3.5% +/- 10.4% to 6.7% +/- 10.7% and 1.9% +/- 5.0% to 4.4% +/- 8.0%, respectively). The majority of studied cases, however, sustained less than a 10% volumetric (93% of studied cases) and area loss (75% of studied cases) in the stented segment up to 12 months. At 12 months, % area loss within the stented segments and 5-mm reference segments were comparable (7.0% +/- 19.6% versus 6.7% +/- 10.7%). Although slight increases of NH were noted, SESs, delivering two reduced drug doses, appeared to be effective for maintaining luminal patency during 12 months follow-up.
    Catheterization and Cardiovascular Interventions 01/2008; 70(7):946-51. · 2.29 Impact Factor
  • Article: Characterization of late incomplete stent apposition: a comparison among bare-metal stents, intracoronary radiation and sirolimus-eluting stents.
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    ABSTRACT: Late incomplete stent apposition (LISA) develops following implantation of conventional bare-metal stents (BMS) or drug-eluting stents, or after adjunctive intracoronary radiation (IR). However, no study has systematically compared the morphology of LISA seen with various treatment modalities. To compare the morphometric features of LISA accompanying BMS, IR or sirolimus-eluting stents (SES) using serial intravascular ultrasound (IVUS). A query of Stanford University's IVUS database of the Cardiovascular Core Analysis Laboratory was performed to identify LISA cases. Dedicated software programs were used for volumetric IVUS analyses. In 30 LISA cases (12 BMS, 6 IR and 12 SES), there was no intertreatment difference in the degree of LISA (lumen area minus stent area at follow up). Serial analyses of LISA segments showed that vessel area of SES and IR showed significant increase at follow up as compared with post procedure, while there was no significant change in plaque area. In contrast, the BMS group showed no increase in vessel area, whereas plaque area revealed significant reduction. Eight of 12 BMS cases were treated by directional atherectomy before stenting; however, there was no difference in the area change between patients with or without pre-stent atherectomy. Post-procedure plaque thickness beneath the stent struts of LISA was thinner for SES as compared with BMS. Plaque reduction primarily contributes to LISA after BMS, whereas vessel expansion is the predominant factor in LISA development for IR and SES. Thus, the mechanism of LISA may vary among different interventional treatments.
    The Journal of invasive cardiology 01/2008; 19(12):515-8. · 1.84 Impact Factor
  • Article: Determinants of lumen loss between years 1 and 2 after cardiac transplantation.
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    ABSTRACT: We previously reported that negative remodeling, not plaque progression, correlated with lumen loss during the first year after cardiac transplantation and that cytomegalovirus antibody seropositivity correlated with increased negative remodeling and greater lumen loss. Whether these findings persist between years 1 and 2 after transplantation is unknown. Serial 3-dimensional intravascular ultrasound analysis in the left anterior descending coronary artery was performed in 30 cardiac transplant recipients at year 1 and 2 after transplantation. Vessel, lumen, and plaque area were determined at 0.5-mm axial intervals in the first 50 mm of the left anterior descending coronary artery, and volumes were computed using Simpson's method. Univariate and multivariate regression analyses were performed to identify clinical predictors of change in coronary dimensions. Although mean vessel area did not change (13.6+/-3.4 to 13.4+/-3.3 mm/mm(3), P=0.45), mean plaque area increased (3.4+/-2.3 to 3.8+/-2.2 mm/mm(3), P=0.012), resulting in significant mean lumen area loss (10.3+/-2.5 to 9.6+/-2.3 mm/mm(3), P=0.016). However, the degree of luminal change strongly correlated with the degree of change in vessel size (R=0.81, P<0.0001), but not with change in plaque amount (R=-0.19, P=0.32). In fact, in 57% of the patients who demonstrated lumen loss, negative remodeling contributed more to lumen loss than did plaque progression. Diabetes at 2 years was the only significant independent clinical predictor of plaque progression and lumen loss. Despite significant plaque progression, negative remodeling correlated with coronary lumen loss between years 1 and 2 after cardiac transplantation.
    Transplantation 11/2007; 84(9):1097-102. · 4.00 Impact Factor
  • Article: Unrestricted use of drug-eluting stents compared with bare-metal stents in routine clinical practice: findings from the National Heart, Lung, and Blood Institute Dynamic Registry.
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    ABSTRACT: We investigated the effectiveness and safety of drug-eluting stents (DES) as used in routine clinical practice. Randomized trials have shown that DES prevent target vessel revascularization in selected patients, but whether this translates into superior outcomes, compared with bare-metal stents (BMS), for the full spectrum of patients treated with DES in North America is unknown. Patients in the National Heart, Lung, and Blood Institute Dynamic Registry enrolled in 2004 who received at least 1 DES (n = 1,460) were compared with 1,763 patients enrolled in the recruitment period immediately preceding the approval of DES (2001 to 2002) who received at least 1 BMS. Patients receiving DES more often had diabetes mellitus and less often presented with an acute myocardial infarction (MI). At 1 year, cumulative death and MI was 7.6% in DES- and 8.7% in BMS-treated patients (adjusted hazard ratio [HR] 0.88, 95% confidence interval [CI] 0.68 to 1.15; p = 0.34). The 1-year rate of target vessel revascularization was 5.0% in DES and 9.2% in BMS patients (p < 0.001), and the risk of any repeat revascularization by percutaneous coronary intervention or coronary bypass was lower in DES patients (adjusted HR 0.38, 95% CI 0.25 to 0.60; p < 0.001). Patients with both simple and complex lesion characteristics benefited from DES with lower risk of repeat target vessel revascularization by percutaneous coronary intervention compared with BMS (any complex lesion: adjusted HR 0.57, 95% CI 0.39 to 0.83; absence of any complex lesion: adjusted HR 0.44, 95% CI 0.28 to 0.71). The 1-year incidence of stent thrombosis was 1.0% in DES patients. The generalized use of DES resulted in better outcomes than BMS, with fewer clinically driven revascularization procedures and similar rates of death and MI at 1 year.
    Journal of the American College of Cardiology 11/2007; 50(21):2029-36. · 14.16 Impact Factor
  • Article: Changes in coronary anatomy and physiology after heart transplantation.
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    ABSTRACT: Cardiac allograft vasculopathy (CAV) is a progressive process involving the epicardial and microvascular coronary systems. The timing of the development of abnormalities in these 2 compartments and the correlation between changes in physiology and anatomy are undefined. The invasive evaluation of coronary artery anatomy and physiology with intravascular ultrasound, fractional flow reserve, coronary flow reserve, and the index of microcirculatory resistance (IMR) was performed in the left anterior descending coronary artery during 151 angiographic evaluations of asymptomatic heart transplant recipients from 0 to >5 years after heart transplantation (HT). There was no angiographic evidence of significant CAV, but during the first year after HT, fractional flow reserve decreased significantly (0.89 +/- 0.06 vs 0.85 +/- 0.07, p = 0.001), and percentage plaque volume derived by intravascular ultrasound increased significantly (15.6 +/- 7.7% to 22.5 +/- 12.3%, p = 0.0002), resulting in a significant inverse correlation between epicardial physiology and anatomy (r = -0.58, p <0.0001). The IMR was lower in these patients compared with those > or =2 years after HT (24.1 +/- 14.3 vs 29.4 +/- 18.8 units, p = 0.05), suggesting later spread of CAV to the microvasculature. As the IMR increased, fractional flow reserve increased (0.86 +/- 0.06 to 0.90 +/- 0.06, p = 0.0035 comparing recipients with IMRs < or =20 to those with IMRs > or =40), despite no difference in percentage plaque volume (21.0 +/- 11.2% vs 20.5 +/- 10.5%, p = NS). In conclusion, early after HT, anatomic and physiologic evidence of epicardial CAV was found. Later after HT, the physiologic effect of epicardial CAV may be less, because of increased microvascular dysfunction.
    The American Journal of Cardiology 06/2007; 99(11):1603-7. · 3.37 Impact Factor
  • Article: Serial intravascular ultrasonic study of outcomes of coronary culprit lesions with plaque rupture following bare metal stent implantation in patients with angina pectoris.
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    ABSTRACT: Coronary culprit lesions with plaque rupture (PR) have been treated with different coronary interventions. However, it is unknown whether the presence of PR affects the restenotic process after coronary intervention. One hundred forty-two patients undergoing coronary bare metal stent implantation were enrolled in the present retrospective analysis. Case selection was based on availability of intravascular ultrasound (IVUS) and quantitative coronary angiographic examinations at baseline (before and after intervention) and at follow-up. Serial comparative analyses included qualitative and quantitative features of the culprit lesion and reference segments. PR was defined as an intraplaque cavity in communication with the lumen in the presence of a residual, disrupted cap. Patients were categorized according to the presence/absence of PR. Pre-interventional IVUS detected PR in 54 patients (38%). Baseline patient demographics were similar between the +PR and -PR groups. Quantitative IVUS analysis showed higher rates of positive remodeling and larger vessel and plaque areas in the +PR compared with -PR lesions (p <0.001 for all). At follow-up (7.2 +/- 2.6 months), no statistically significant difference was observed between the 2 groups in quantitative coronary angiographic or IVUS measurements. In conclusion, culprit lesions with PR exhibited larger plaque mass and higher rates of positive remodeling at preintervention IVUS examination. However, when treated with bare metal stents, the absence/presence of preintervention PR was not found to affect the rate or severity of in-stent restenosis in these culprit lesions.
    The American Journal of Cardiology 05/2007; 99(10):1394-8. · 3.37 Impact Factor
  • Article: Discordant changes in epicardial and microvascular coronary physiology after cardiac transplantation: Physiologic Investigation for Transplant Arteriopathy II (PITA II) study.
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    ABSTRACT: Investigating changes in coronary physiology that occur after cardiac transplantation has been challenging. Simultaneous and independent assessment of the epicardial artery by measuring fractional flow reserve (FFR) and of the microvasculature by calculating the index of microvascular resistance (IMR) with a single coronary pressure wire may be useful. Twenty-five asymptomatic patients with normal coronary angiograms underwent FFR, thermodilution-derived IMR and coronary flow reserve (CFR) and intravascular ultrasound (IVUS) evaluation soon after cardiac transplantation and 1 year later. FFR significantly worsened (0.90 +/- 0.05 at baseline to 0.85 +/- 0.06 at 1 year, p = 0.004). FFR correlated strongly with percent plaque volume as measured by IVUS (r = -0.58, p < 0.0001). IMR improved significantly (29.2 +/- 15.9 at baseline to 19.3 +/- 7.6 units at 1 year, p = 0.007). CFR increased, but not significantly (2.6 +/- 1.4 at baseline to 3.2 +/- 1.2 at 1 year, p = not significant). Diabetes and donor heart ischemic time independently predicted baseline IMR. Treatment with rapamycin independently predicted FFR at 1 year. New coronary physiologic measures, FFR and IMR, show that epicardial artery physiology worsens and correlates with anatomic changes, whereas microvascular physiology improves during the first year after cardiac transplantation. CFR, the traditional method for evaluating coronary circulatory physiology, did not identify these changes.
    The Journal of heart and lung transplantation: the official publication of the International Society for Heart Transplantation 08/2006; 25(7):765-71. · 3.54 Impact Factor
  • Article: Intravascular ultrasonic analysis of atherosclerotic vessel remodeling and plaque distribution of stenotic left anterior descending coronary arterial bifurcation lesions upstream and downstream of the side branch.
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    ABSTRACT: Bifurcation lesions remain a challenging lesion subset, even in the era of drug-eluting stents. The aim of this study was to investigate the longitudinal remodeling pattern and cross-sectional plaque location of bifurcation lesions. Seventy-four preintervention intravascular ultrasound studies of left anterior descending bifurcation lesions were analyzed, in which the lesion was located proximal (type A, n=32) or distal (type B, n=42) to the side branch. Vessel area and plaque area at the lesion (VAlesion and PAlesion) and at the reference site (VAreference and PAreference) were measured. The remodeling ratio was defined as VAlesion/VAreference, and the vessel compensation ratio was defined as (VAlesion-VAreference)/(PAlesion-PAreference). The geometric center of the lumen at the lesion site was identified, and the lesion site was divided into circumferential equal arcs to compare the cross-sectional distribution of percentage plaque area (100x[PAlesion/VAlesion]) between the 2 groups. The remodeling ratio (1.03+/-0.15 vs 0.94+/-0.14, p=0.01) and the vessel compensation ratio (0.0+/-0.36 vs -0.37+/-0.61, p<0.01) were significantly greater in type A than in type B lesions. The circumferential distribution pattern of percentage plaque area was significantly different between the groups (analysis of variance p<0.005), with greater percentage plaque area for the vessel wall opposite from the side branch in type B lesions (46.3+/-18.0% vs 54.6+/-15.4%, type A vs type B lesions, p<0.05). In conclusion, these results suggest that a major side branch may affect longitudinal lesion remodeling as well as the circumferential location of atherosclerotic plaque.
    The American Journal of Cardiology 08/2006; 98(2):193-6. · 3.37 Impact Factor
  • Article: Validation of a thermographic guidewire for endoluminal mapping of atherosclerotic disease: an in vitro study.
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    ABSTRACT: Temperature heterogeneity along the inner surface of an artery may be a surrogate marker of impending plaque rupture and has been associated with an increased likelihood of future coronary events. Initial studies using catheter-based thermographic devices have demonstrated that the changes in temperature are subtle, while the effects of coronary flow on measured temperature have not yet been examined. A novel guidewire-based system (ThermoCoil, Imetrx) designed to measure surface temperature in coronary arteries was used to study the effects of heat source intensity and flow on measured temperature. An in vitro model of a focal, eccentric, heat-generating lesion demonstrated that a guidewire-based system can detect changes in surface temperature with a precision of less than 0.08 degrees C. In this model, temperature measurements increased linearly with source temperature and decreased with increases in flow by an exponent of -0.33 (P < 0.001 for both). Flow rates and heat source properties can significantly influence the measurement and interpretation of thermographic data. The incorporation of 2D thermographic images may contribute further to the characterization of metabolically active plaques likely to cause acute coronary syndromes.
    Catheterization and Cardiovascular Interventions 06/2004; 62(2):221-9. · 2.29 Impact Factor
  • Article: Validation of a thermographic guidewire for endoluminal mapping of atherosclerotic disease: An in vitro study
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    ABSTRACT: Temperature heterogeneity along the inner surface of an artery may be a surrogate marker of impending plaque rupture and has been associated with an increased likelihood of future coronary events. Initial studies using catheter-based thermographic devices have demonstrated that the changes in temperature are subtle, while the effects of coronary flow on measured temperature have not yet been examined. A novel guidewire-based system (ThermoCoil, Imetrx) designed to measure surface temperature in coronary arteries was used to study the effects of heat source intensity and flow on measured temperature. An in vitro model of a focal, eccentric, heat-generating lesion demonstrated that a guidewire-based system can detect changes in surface temperature with a precision of less than 0.08°C. In this model, temperature measurements increased linearly with source temperature and decreased with increases in flow by an exponent of −0.33 (P < 0.001 for both). Flow rates and heat source properties can significantly influence the measurement and interpretation of thermographic data. The incorporation of 2D thermographic images may contribute further to the characterization of metabolically active plaques likely to cause acute coronary syndromes. Catheter Cardiovasc Interv 2004;62:221–229. © 2004 Wiley-Liss, Inc.
    Catheterization and Cardiovascular Interventions 05/2004; 62(2):221 - 229. · 2.29 Impact Factor
  • Article: Pseudo-candy wrapper: bifocal radial artery graft spasm following stent implantation.
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    ABSTRACT: We encountered a case of intractable radial artery graft spasm after stent implantation which was partially responsive to nominal nitroglycerin therapy. We report this case with intravascular ultrasound imaging at the radial artery spasm site.
    The Journal of invasive cardiology 05/2004; 16(4):201-3. · 1.84 Impact Factor
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    Article: Stent implantation for coronary aneurysm with edge stenosis: angiographic and intravascular analysis.
    Benjamin M Wu, Mamoo Nakamura, Mehrdad Rezaee
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    ABSTRACT: The incidence of coronary artery aneurysms is about 1 to 2%, with clinical course dependent on the size of the aneurysm. A case of moderate-size aneurysm in the proximal left anterior descending coronary artery with stenosis at both edges is presented. This was interrogated with intravascular ultrasound (IVUS), and based on the patient's presentation, a single stent, size-matched 1:1 to the proximal reference, was placed across the aneurysm and both lesions. Post-implantation IVUS demonstrated residual stenosis and minimal change in the neck size of the aneurysm. At 4 months, there was no thrombosis or in-stent restenosis, and the aneurysm was almost completely resolved.
    The Journal of invasive cardiology 04/2004; 16(3):149-51. · 1.84 Impact Factor
  • Article: Identification and treatment of vulnerable plaque.
    Mamoo Nakamura, David P Lee, Alan C Yeung
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    ABSTRACT: It is now well recognized that the rupture of vulnerable plaque, which consists of an atheromatous plaque core covered by a thin fibrous cap with ongoing inflammation, is a major cause of thrombus formation leading to the development of acute coronary syndrome. Several diagnostic techniques, including vascular imaging and serologic markers, are clinically available or currently under investigation for the detection of vulnerable plaque. A combination of several diagnostic modalities might allow effective screening of individuals at high risk for future cardiovascular events. Plaque stabilization with pharmacologic interventions--statins, beta-blockers, and angiotensin-converting enzyme inhibitors--might effectively prevent the development of acute coronary syndromes caused by plaque disruption.
    Reviews in cardiovascular medicine 02/2004; 5 Suppl 2:S22-33. · 0.58 Impact Factor
  • Article: Late incomplete stent apposition and focal vessel expansion after bare metal stenting.
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    ABSTRACT: Late incomplete stent apposition was observed in 2.4% of the 412 stented segments studied by serial intravascular ultrasound analyses. Most of these phenomena and all late vessel expansions with incomplete stent apposition developed in vessels in which lesions were treated by atherectomy before stenting, suggesting a potential association between mechanical injury from debulking and these phenomena.
    The American Journal of Cardiology 12/2003; 92(10):1217-9. · 3.37 Impact Factor
  • Article: Simultaneous assessment of fractional and coronary flow reserves in cardiac transplant recipients: Physiologic Investigation for Transplant Arteriopathy (PITA Study).
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    ABSTRACT: The utility of measuring fractional flow reserve (FFR) to assess cardiac transplant arteriopathy has not been evaluated. Measuring coronary flow reserve (CFR) as well as FFR could add information about the microcirculation, but until recently, this has required two coronary wires. We evaluated a new method for simultaneously measuring FFR and CFR with a single wire to investigate transplant arteriopathy. In 53 cases of asymptomatic cardiac transplant recipients without angiographically significant coronary disease, FFR and thermodilution-derived CFR (CFRthermo) were measured simultaneously with the same coronary pressure wire in the left anterior descending artery and compared with volumetric intravascular ultrasound (IVUS) imaging. The average FFR was 0.88+/-0.07; in 75% of cases, the FFR was less than the normal threshold of 0.94; and in 15% of cases, the FFR was < or =0.80, the upper boundary of the gray zone of the ischemic threshold. There was a significant inverse correlation between FFR and IVUS-derived measures of plaque burden, including percent plaque volume (r=0.55, P<0.0001). The average CFRthermo was 2.5+/-1.2; in 47% of cases, CFRthermo was < or =2.0. In 14%, the FFR was normal (> or =0.94) and the CFR was abnormal (<2.0), suggesting predominant microcirculatory dysfunction. FFR correlates with IVUS findings and is abnormal in a significant proportion of asymptomatic cardiac transplant patients with normal angiograms. Simultaneous measurement of CFR with the same pressure wire, with the use of a novel coronary thermodilution technique, is feasible and adds information to the physiological evaluation of these patients.
    Circulation 10/2003; 108(13):1605-10. · 14.74 Impact Factor
  • Article: Impact of diabetes mellitus on angiographically silent coronary atherosclerosis.
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    ABSTRACT: Constrictive remodeling occurs in significant atherosclerotic lesions of the diabetic patient, but the impact of diabetes mellitus (DM) on the angiographically normal coronary artery is still unclear. Morphometric analysis using intravascular ultrasound (IVUS) prior to intervention evaluated 54 sites in 33 DM patients and 106 in 62 non-diabetic patients. Vessel area (VA) and lumen area (LA) were measured at angiographically normal sites in the vessel. Plaque area (PA) was calculated as VA - LA. Percentage plaque area (%PA) was calculated as PA VA. Even in the angiographically normal site, mild coronary atherosclerosis was detected by IVUS in both groups. In the patients with DM, VA and LA were significantly smaller than in the non-diabetic patient (15.5 vs 17.8 mm(2), p<0.01; and 10.1 vs 12.2 mm(2), p<0.01 respectively), whereas % PA was similar (34.5 vs 31.6%). At angiographically normal sites where mild coronary atherosclerosis is detected by IVUS, the coronary artery of diabetic patients is smaller than that of the non-diabetic. These results suggest impaired compensatory enlargement or some other constrictive mechanism has already occurred in the early stages of coronary atherosclerosis in patients with DM.
    Circulation Journal 05/2003; 67(5):423-6. · 3.77 Impact Factor
  • Article: Efficacy and feasibility of helixcision for debulking neointimal hyperplasia for in-stent restenosis.
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    ABSTRACT: The Helixcision system is a novel 6 Fr-compatible catheter designed to debulk tissue for in-stent restenosis lesions. The purpose of this study was to determine the efficacy and feasibility of this new system for removing neointimal hyperplasia. A total of 32 in-stent restenosis lesions in 32 patients were treated with helixcision followed by balloon angioplasty. Debulking efficacy was assessed with serial baseline intravascular ultrasound (IVUS) in a subset of 18 lesions. To investigate longitudinal efficacy, 3D analysis was also performed in 12 lesions with automated pullback to calculate average cross-sectional areas across the stent. Prior to procedure, the angiographic reference diameter was 2.60 +/- 0.46 mm. Immediately after procedure, minimum lumen diameter improved from 0.84 +/- 0.33 to 2.19 +/- 0.41 mm (P < 0.0001). IVUS showed a significant reduction of intimal area (IA) after helixcision (from 4.95 +/- 2.04 to 2.88 +/- 1.48 mm(2); P < 0.001). Adjunctive balloon angioplasty further improved lumen area (LA) mainly by stent expansion rather than IA reduction at the site of minimum lumen area. The degrees of IA reduction and LA improvement were closely similar in volumetric analysis. Thirty-day and 6-month clinical follow-up were available in 97% (n = 31) and 72% (n = 23) of the enrolled patients, respectively. At 30-day follow-up, no major adverse cardiac event was reported except for periprocedural CK elevation in two patients (6%). Target legion revascularization within 6 months was performed in six patients (26%). Preliminary results of helixcision indicate that this system is safe and feasible for the treatment of in-stent restenosis. The concordant results between 2D and 3D IVUS analyses suggest that this unique technology can achieve uniform longitudinal debulking throughout the stent. The long-term outcomes appeared to be favorable, considering the relatively diffuse lesion morphology.
    Catheterization and Cardiovascular Interventions 01/2003; 57(4):460-6. · 2.29 Impact Factor
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    Article: Impact of deep vessel wall injury on acute response and remodeling of coronary artery segments after cutting balloon angioplasty.
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    ABSTRACT: Deep vessel wall injury is believed to affect vessel dimension following coronary intervention. The cutting balloon is designed to treat coronary artery stenoses with dilatation and surgical incisions, thereby reducing excess vessel injury. This study examines the effect of deep vessel wall injury on acute and late coronary arterial response after cutting balloon angioplasty. Serial volumetric intravascular ultrasound (IVUS) analyses were performed in 63 lesions treated with cutting balloon angioplasty alone. Before intervention, the longitudinal range of the lesion segment that included the smallest lumen area (LA) was determined as LA <4 mm(2) and/or LA stenosis >60%. The exact corresponding site at postintervention and follow-up was aligned using peri- and intravascular landmarks. Average vessel area (VA), plaque area (PA), and LA were measured. Lesion segments were categorized as with or without deep vessel wall injury, which was defined as the presence of plaque/vessel wall fracture extending to the sonolucent (medial) layer. Before intervention, the lesion vessel size of deep injury group was smaller than that of the nondeep injury group (p <0.05 for average VA and PA), whereas average lesion LA, lesion length, and reference vessel size did not differ. Immediately after cutting balloon angioplasty, the deep injury group showed a significant increase in VA (p <0.0001) and a lesser decrease in PA (p <0.01) compared with the nondeep injury group. During follow-up, the increase of VA tended to be greater in the deep injury group than in the nondeep injury group (p = 0.06), whereas the change of PA did not differ. Consequently, LA decrease was less in the deep injury group than in the nondeep injury group (p <0.05). From these results, it is suggested that deep vessel wall injury tends to occur in lesions with relatively small size and such lesions show favorable vessel response after cutting balloon angioplasty.
    The American Journal of Cardiology 01/2003; 91(1):6-11. · 3.37 Impact Factor