Biomedical subjects

Martin B Leon

Publications and source records attributed to Martin B Leon.

At least 55 records · Page 3Linked to original sources

PubMed2005

Effectiveness of the concomitant use of bivalirudin and drug-eluting stents (from the prospective, multicenter BivAlirudin and Drug-Eluting STents [ADEST] study).

Sirolimus-eluting stents (SESs) reduce restenosis compared with bare metal stents. Safety issues with drug-eluting stents are particularly important given concerns of possible increased thrombogenicity. Compared with heparin plus glycoprotein IIb/IIIa inhibitors, the direct thrombin inhibitor bivalirudin has been shown to reduce the risk of hemorrhagic complications in patients receiving bare metal stents, with similar efficacy in preventing ischemic complications. The safety and efficacy of percutaneous coronary intervention (PCI) with SESs and bivalirudin anticoagulation have not been prospectively studied. This prospective study performed at 9 United States hospitals evaluated 1,182 patients referred for PCI with SESs in whom the procedural anticoagulant was bivalirudin. Clopidogrel was administered before PCI in 79% of patients, and only 5.3% received procedural glycoprotein IIb/IIIa inhibitors. At 30 days, major adverse cardiac events occurred in 7.1% of patients, including 0.3% mortality, 4.4% myocardial infarction (defined as creatine kinase-MB >3x normal), 1.7% target vessel revascularization, and 0.6% stent thrombosis. Major bleeding occurred in only 0.8% of patients. Thus, use of bivalirudin as the procedural anticoagulant to support SES implantation in a "real world" population of patients undergoing PCI results in low rates of major adverse cardiac events, stent thrombosis, and major bleeding.

Angioplasty, Balloon, Coronary↗

PubMed2005

Bifurcation coronary lesions treated with the "crush" technique: an intravascular ultrasound analysis.

OBJECTIVES: We report intravascular ultrasound (IVUS) findings after crush-stenting of bifurcation lesions. BACKGROUND: Preliminary results with the crush-stent technique are encouraging; however, isolated reports suggest that restenosis at the side branch (SB) ostium continues to be a problem. METHODS: Forty patients with bifurcation lesions underwent crush-stenting with the sirolimus-eluting stent. Postintervention IVUS was performed in both branches in 25 lesions and only the main vessel (MV) in 15 lesions; IVUS analysis included five distinct locations: MV proximal stent, crush area, distal stent, SB ostium, and SB distal stent. RESULTS: Overall, the MV minimum stent area was larger than the SB (6.7 +/- 1.7 mm2 vs. 4.4 +/- 1.4 mm2, p < 0.0001, respectively). When only the MV was considered, the minimum stent area was found in the crush area (rather than the proximal or MV distal stent) in 56%. When both the MV and the SB were considered, the minimum stent area was found at the SB ostium in 68%. The MV minimum stent area measured <4 mm2 in 8% of lesions and <5 mm2 in 20%. For the SB, a minimum stent area <4 mm2 was found in 44%, and a minimum stent area <5 mm2 in 76%, typically at the ostium. "Incomplete crushing"--incomplete apposition of SB or MV stent struts against the MV wall proximal to the carina--was seen in >60% of non-left main lesions. CONCLUSIONS: In the majority of bifurcation lesions treated with the crush technique, the smallest minimum stent area appeared at the SB ostium. This may contribute to a higher restenosis rate at this location.

Angioplasty, Balloon, Coronary↗

PubMed2005

Intravascular ultrasound study of patterns of calcium in ruptured coronary plaques.

Coronary calcium is intimately associated with coronary atherosclerotic plaque development, although it is controversial as to whether coronary calcium is associated with plaque instability. We analyzed 101 IVUS-detected ruptured plaques and compared them with 101 computer-matched control plaques without evidence of plaque rupture. The arc of calcium was measured every 0.5 mm within 10-mm-long segments that spanned the minimum lumen cross-sectional area, and the number and length of calcium deposits were assessed. Ruptured plaques had a significantly larger number of individual calcium deposits than control plaques (3.5 +/- 1.7 vs 1.8 +/- 1.1, p <0.001). However, the arc of the largest calcium deposit was smaller and the length of the largest calcium deposit in each plaque was shorter in ruptured plaques compared with control plaques (67.3 degrees +/- 41.4 degrees vs 114.9 degrees +/- 77.4 degrees , p <0.001, and 1.6 +/- 1.3 vs 4.0 +/- 2.7 mm, p <0.001, respectively). There was no difference in the number of superficial calcium deposits between the 2 groups, although ruptured plaques had significantly smaller arcs of superficial calcium compared with control plaques (56.2 degrees +/- 35.5 degrees vs 95.8 degrees +/- 65.2 degrees , p <0.001). Conversely, the number of deep calcium deposits was significantly larger in ruptured plaques than in control plaques (1.8 +/- 1.4 vs 0.3 +/- 0.6, p <0.001), although the arc of deep calcium was similar in the 2 groups. Ruptured plaques had quantitatively less calcium, especially superficial calcium, but a larger number of small calcium deposits, especially deep calcium deposits. In conclusion, ruptured plaques are associated with a larger number of calcium deposits within an arc of <90 degrees , a larger number of deep calcium deposits, and a remodeling index.

Aged↗

PubMed2005

Intravascular ultrasonic assessment of stent diameters derived from manufacturer's compliance charts.

We used intravascular ultrasound (IVUS) to assess the accuracy of manufacturers' stent balloon compliance charts. Many interventional cardiologists rely on manufacturers' compliance charts to select stent size and optimize stent diameters according to inflation pressures during percutaneous procedures. We randomly selected 212 patients who had de novo coronary lesions that had been treated with a single, bare metal, > or =3.0-mm stent (Bx velocity, NIR, TETRA/PENTA, S660/S670/S7) under IVUS guidance. Cases of stent overlap and postdilatation with another balloon were excluded. Predicted stent diameters were derived from each manufacturer's compliance charts, and stent size and final maximal deployment pressures were derived from each physician's report. IVUS-measured minimum stent diameters (range 1.4 to 4.0 mm, mean 2.79 +/- 0.48) were smaller than predicted diameters (range 3.1 to 4.57 mm, mean 3.79 +/- 0.44). The ratio of IVUS to predicted diameters ranged from 44% to 97% (mean 74 +/- 10%). This finding was common to all 3 stent sizes: 74 +/- 12% for 3.0 mm, 73 +/- 9% for 3.5 mm, and 74 +/- 9% for 4.0-mm stents (p = 0.9). This finding was also common to all 4 stent manufacturers, 72 +/- 8% for Boston Scientific, 76 +/- 11% for Guidant, 73 +/- 9% for Cordis, and 74 +/- 11% for Medtronic (p = 0.13), and to different stent lengths. Only 3.8% of the stents achieved 90% of the predicted minimum stent diameters, and only 24.6% achieved 80% of the predicted minimum stent diameters. In conclusion, in human coronary arteries, minimal stent diameter measured by IVUS is significantly smaller than that predicted by in vitro compliance charts. These differences are independent of stent manufacturer, length, diameter, and deployment pressure.

Aged↗

PubMed2005

Comparison of thrombosis and restenosis risk from stent length of sirolimus-eluting stents versus bare metal stents.

Selection of coronary stent length varies from covering only the zone of maximum obstruction to stenting from normal- to normal-appearing vessels. With bare metal stenting, for any given lesion there is a high restenotic risk associated with longer stent length. With drug-eluting stents, the relation between stent length and restenosis has not been evaluated. In the angiographic follow-up cohort of the SIRIUS trial that compared the sirolimus-eluting Bx Velocity stent with the standard Bx Velocity stent (n = 699), we constructed a multiple regression model to predict 8-month percent diameter stenosis using the main effects of lesion length and excess stent length beyond the lesion length and adjusting for known predictors of restenosis. Stent length exceeded lesion length in 94% of lesions overall. Mean difference in length was 8.3 +/- 8.3 mm (mean lesion length 14.6 +/- 5.9 mm, mean stent length 22.9 +/- 9.6 mm). Stented lesion length and excess stent length were associated with absolute increases in percent diameter stenosis per 10 mm of 9.1% (p <0.0001) and 3.6% (p = 0.053) in the bare metal arm and 3.5% (p = 0.047) and 2.1% (p = 0.040) in the sirolimus-eluting stent arm. Although the effects of lesion length and excess stent length on restenosis were markedly decreased with sirolimus-eluting stents (vs bare metal stents), a small restenotic penalty is still paid for excessive stent length. Longer stent-to-lesion length strategies should be used only when a shorter stent is likely to result in incomplete lesion coverage and edge dissection, a strong determinant of stent thrombosis.

Angioplasty, Balloon, Coronary↗

PubMed2005

Outcomes with the paclitaxel-eluting stent in patients with acute coronary syndromes: analysis from the TAXUS-IV trial.

OBJECTIVES: We sought to investigate the outcomes of paclitaxel-eluting stent implantation in patients with unstable angina or non-ST-segment elevation myocardial infarction undergoing percutaneous coronary intervention (PCI). BACKGROUND: Whether the paclitaxel-eluting stent is safe and effective in patients with acute coronary syndromes (ACS) is unknown. METHODS: In the TAXUS-IV trial, 1,314 patients with stable or unstable ischemic syndromes undergoing PCI were randomized to treatment with either the slow-release, polymer-based, paclitaxel-eluting TAXUS stent or a bare-metal EXPRESS stent (Boston Scientific Corp., Natick, Massachusetts). The results were stratified by the acuity of the presenting clinical syndrome. RESULTS: Acute coronary syndromes were present in 450 patients (34.2%), 237 of whom were assigned to paclitaxel-eluting stents and 213 to bare-metal stents. The baseline and procedural characteristics were well matched between the groups. Clinical outcomes at 30 days were similar with both stents. At one-year follow-up, patients with ACS assigned to the paclitaxel-eluting stent compared to the control stent had strikingly lower rates of target lesion revascularization (TLR) (3.9% vs. 16.0%, p < 0.0001) and major adverse cardiac events (11.1 vs. 21.7%, p = 0.002). By multivariate analysis, ACS was an independent predictor of in-stent restenosis in the cohort treated with bare-metal stents (hazard ratio [HR] = 2.03 [95% confidence interval (CI) 1.05 to 3.92], p = 0.035), while among patients randomized to the paclitaxel-eluting stents, ACS was an independent predictor of freedom from restenosis (HR = 0.27 [95% CI 0.08 to 0.97], p = 0.04). CONCLUSIONS: The use of the paclitaxel-eluting TAXUS stent was safe in patients with unstable ischemic syndromes, and was associated with marked reduction of ischemia-driven TLR and adverse cardiac events at one year.

Antineoplastic Agents↗

PubMed2005

Gender-based outcomes after paclitaxel-eluting stent implantation in patients with coronary artery disease.

OBJECTIVES: We sought to determine whether gender influences the results of paclitaxel-eluting stent implantation. BACKGROUND: The TAXUS-IV trial demonstrated the safety and effectiveness of the slow-release, polymer-based, paclitaxel-eluting TAXUS stent compared to bare-metal stents in patients undergoing elective coronary intervention. Whether these results are generalizable to women is not known. METHODS: A total of 1,314 patients with coronary lesions 10- to 28-mm long in 2.5- to 3.75-mm vessels were randomized to TAXUS stent versus bare-metal EXPRESS stents (Boston Scientific Corp., Natick, Massachusetts). Outcomes examined were stratified by gender. RESULTS: A total of 662 patients (including 187 women) were assigned to the TAXUS stent, and 652 (180 women) received the control stent. Women were older than men, and had more hypertension, diabetes, renal insufficiency, unstable angina, and heart failure, but less smoking. Among patients receiving the TAXUS stent, women compared with men had higher unadjusted one-year rates of target lesion revascularization (TLR) (7.6% vs. 3.2%, p = 0.03), though female gender was not an independent predictor of TLR (odds ratio [OR] = 1.72 [95% confidence interval (CI) 0.68 to 4.37], p = 0.25). Moreover, restenosis rates were similar in men and women treated with the TAXUS stent (8.6% vs. 7.6%, respectively, p = 0.80), as was late loss (0.22 vs. 0.23 mm, p = 0.90). Compared to control stents, treatment with the TAXUS stent in women resulted in a significant reduction in nine-month restenosis (8.6% vs. 29.2%, p = 0.0001) and one-year TLR (7.6% vs. 14.9%, p = 0.02). The only independent predictor of freedom from restenosis in women was randomization to the TAXUS stent (OR = 0.28 [95% CI 0.11 to 0.74], p = 0.01). CONCLUSIONS: The benefits of the paclitaxel-eluting stent in reducing clinical and angiographic restenosis are generalizable to women.

Age Factors↗

PubMed2005

Stent underexpansion and residual reference segment stenosis are related to stent thrombosis after sirolimus-eluting stent implantation: an intravascular ultrasound study.

OBJECTIVES: We sought to determine the predictors of stent thrombosis after sirolimus-eluting stent (SES) implantation. BACKGROUND: A number of cases of stent thrombosis have been reported after commercial release of the SES in the "real world," such that the U.S. Food and Drug Administration issued a warning. METHODS: Fifteen patients who developed stent thrombosis after successful SES implantation were analyzed and compared with 45 matched control patients who had no evidence of stent thrombosis. RESULTS: Minimum stent cross-sectional area (MSA) (4.3 +/- 1.6 mm(2) vs. 6.2 +/- 1.9 mm(2), p < 0.001) and stent expansion (0.65 +/- 0.18 vs. 0.85 +/- 0.14, p < 0.001) were significantly smaller in the stent thrombosis group than in the matched control patients. There was no significant difference in the rate of SES malapposition between the groups. However, the presence of a significant residual reference segment stenosis was more common in the stent thrombosis group compared with the matched control group (67% vs. 9%, p < 0.001). Independent predictors of stent thrombosis were stent underexpansion (p = 0.03) and a significant residual reference segment stenosis (p = 0.02). CONCLUSIONS: Stent underexpansion and residual reference segment stenosis are associated with stent thrombosis after successful SES implantation.

Aged↗

PubMed2005

Gender differences in outcomes after primary angioplasty versus primary stenting with and without abciximab for acute myocardial infarction: results of the Controlled Abciximab and Device Investigation to Lower Late Angioplasty Complications (CADILLAC) trial.

BACKGROUND: Women with acute myocardial infarction (AMI) undergoing primary angioplasty have higher rates of morbidity and mortality than do men. Whether contemporary interventional treatment strategies have improved outcomes for women compared with men is unknown. METHODS AND RESULTS: In the CADILLAC trial, 2082 patients (27% women) with AMI within 12 hours of symptom onset were randomized to balloon angioplasty (PTCA; n=518), PTCA+abciximab (n=528), stenting (n=512), and stenting+abciximab (n=524). As compared with men, women had a lower body surface area; had a greater prevalence of diabetes, hypertension, and hyperlipidemia; experienced significant delays to treatment; and had better baseline and final TIMI grade 3 flows. Unadjusted 1-year event rates were higher for women, including death (7.6% versus 3.0%, P<0.001), ischemic target-vessel revascularization (TVR; 16.7% versus 12.1%, P=0.006), and major adverse cardiac events (MACE; 23.9% versus 15.3%, P<0.001). Female gender was an independent predictor of MACE and bleeding complications, although comorbid risk factors and body surface area but not gender predicted 1-year death. For women, primary stenting resulted in a reduction in 1-year MACE from 28.1% to 19.1% (P=0.01) and in ischemic TVR from 20.4% to 10.8% (P=0.002) compared with PTCA. The addition of abciximab to primary stenting significantly reduced the 30-day ischemic TVR without increasing bleeding or stroke rates. CONCLUSIONS: The higher mortality rate in women compared with men after interventional treatment for AMI may be explained by differences in body size and clinical risk factors, although female gender remains an important independent determinant of overall adverse outcomes. For women in the CADILLAC trial, the addition of abciximab reduced 30-day TVR without increasing bleeding risk, and primary stenting reduced 1-year TVR and MACE rates compared with PTCA.

Abciximab↗

PubMed2005

Impact of obesity on revascularization and restenosis rates after bare-metal and drug-eluting stent implantation (from the TAXUS-IV trial).

The effect of obesity on repeat coronary revascularization and restenosis in patients who undergo stent implantation has not been reported. We therefore examined the database from the multicenter randomized TAXUS-IV trial to determine the effect of body mass index (BMI) on outcomes after bare-metal and drug-eluting stent implantation. In TAXUS-IV, patients were randomized to receive a slow-release, polymer-based, paclitaxel-eluting stent or a bare-metal stent. Outcomes were stratified by baseline BMI. Of the 1,307 randomized patients who had documented BMI, 233 (17.8%) had normal weight (BMI <25 kg/m2), 531 (40.6%) were overweight (BMI < or =25 to 30 kg/m2), and 543 (41.5%) were obese (BMI > or =30 kg/m2). Patients who had been assigned to receive bare-metal stents and were overweight and obese compared with those who had normal weight had higher rates of 9-month binary restenosis (29.2% and 30.5% vs 9.3%, respectively; p = 0.01) and 1-year major adverse cardiac events (20.8% and 23.2% vs 11.1%, respectively; p = 0.02), whereas rates of these events did not differ significantly among those who received a paclitaxel-eluting stent (7.6% and 9.3% vs 4.9%, respectively for binary restenosis; p = 0.65; 11.3% and 10.4% vs 10.1%, respectively; p = 0.82 for major adverse cardiac events). By multivariate analysis, BMI > or =30.0 kg/m2 independently predicted binary restenosis (hazard ratio 4.26, p = 0.005), 1-year target vessel revascularization (hazard ratio 1.95, p = 0.04), and major adverse cardiac events (hazard ratio 1.95, p = 0.004) in patients who received bare-metal stents but not paclitaxel-eluting stents. In conclusion, obesity is an important risk factor for clinical and angiographic restenosis and for composite major adverse cardiac events in patients who receive bare-metal stents. Paclitaxel-eluting stents attenuate the increased risk associated with obesity, such that the intermediate-term prognosis after percutaneous coronary intervention is independent of weight.

Aged↗

PubMed2005

Intravascular ultrasound assessment of lesions with target vessel failure after sirolimus-eluting stent implantation.

Intravascular ultrasound (IVUS) evaluation was performed in 33 lesions with sirolimus-eluting stent (SES) failure: 4 thromboses, 26 in-stent restenoses (including 6 edge stenoses), 4 new stenoses >5 mm proximal to the stent, and 1 patient with no evidence of the implanted SES (presumably because of embolization). A minimum stent area <5.0 mm(2) (stent underexpansion) was observed in 67% of all SES failures (in particular, 67% of intrastent restenosis); negative remodeling was observed in 4 of 6 stent edge restenoses, and new lesions were secondary to an increase in plaque area.

Coronary Restenosis↗

PubMed2005

Creatine kinase-MB enzyme elevation and long-term clinical events after successful coronary stenting in lesions with ruptured plaque.

Patients with acute coronary syndrome are at increased risk of acute and long-term events after stent implantation. We compared the impact of intravascular ultrasound detected plaque rupture on creatine kinase-MB (CK-MB) isoenzyme release and clinical outcomes by comparing 62 patients with ruptured plaques with 62 matched control patients who underwent stent implantation. Two thirds of the patients in each group presented with an acute coronary syndrome. There were no differences in procedural complications between groups, although patients with ruptured plaque had higher CK-MB elevation rates than those without ruptured plaque (1 to 3 times the upper limit of normal CK-MB, 35% vs 10%, p <0.001; >3 times the upper limit, 15% vs 2%, p = 0.02). Independent predictors of CK-MB elevation were presence of ruptured plaque (p = 0.03) and unstable angina (p = 0.04). Patients with ruptured plaque had higher composite rates of late events (target lesion revascularizations/myocardial infarctions/cardiac deaths) than controls (25% vs 9%, p = 0.03). These results were similar when only patients with acute coronary syndrome were studied. Plaque rupture morphology is associated with higher periprocedural CK-MB release and worse 1-year clinical outcome in patients treated with coronary stenting.

Analysis of Variance↗

PubMed2005

Percutaneous coronary intervention and adjunctive pharmacotherapy in women: a statement for healthcare professionals from the American Heart Association.

More than 1.2 million percutaneous coronary interventions are performed annually in the United States, with only an estimated 33% performed in women, despite the established benefits of percutaneous coronary intervention and adjunctive pharmacotherapy in reducing fatal and nonfatal ischemic complications in acute myocardial infarction and high-risk acute coronary syndromes. This statement reviews sex-specific data on the safety and efficacy of contemporary interventional therapies in women.

Angioplasty, Balloon, Coronary↗

PubMed2005

Relationship of late loss in lumen diameter to coronary restenosis in sirolimus-eluting stents.

BACKGROUND: Observed rates of restenosis after drug-eluting stenting are low (<10%). Identification of a reliable and powerful angiographic end point will be useful in future trials. METHODS AND RESULTS: Late loss (postprocedural minimum lumen diameter minus 8-month minimum lumen diameter) was measured in the angiographic cohorts of the SIRIUS (n=703) and E-SIRIUS (n=308) trials. Two techniques, the standard normal approximation and an optimized power transformation, were used to predict binary angiographic restenosis rates and compare them with observed restenosis rates. The mean in-stent late loss observed in the SIRIUS trial was 0.17+/-0.45 mm (sirolimus) versus 1.00+/-0.70 mm (control). If a normal distribution was assumed, late loss accurately estimated in-stent binary angiographic restenosis for the control arm (predicted 35.4% versus observed 35.4%) but underestimated it in the sirolimus arm (predicted 0.6% versus observed 3.2%). Power transformation improved the reliability of the estimate in the sirolimus arm (predicted 3.2% [CI 1.0% to 6.7%]) with similar improvements in the E-SIRIUS trial (predicted 4.0% [CI 1.2% to 7.0%] versus observed 3.9%). In the sirolimus-eluting stent arm, in-stent late loss correlated better with target-lesion revascularization than in-segment late loss (c-statistic=0.915 versus 0.665). CONCLUSIONS: Because distributions of late loss with a low mean are right-skewed, the use of a transformation improves the accuracy of predicting low binary restenosis rates. Late loss is monotonically correlated with the probability of restenosis and yields a more efficient estimate of the restenosis process in the era of lower binary restenosis rates.

Coronary Restenosis↗

PubMed2005

Contrast-induced nephropathy after percutaneous coronary interventions in relation to chronic kidney disease and hemodynamic variables.

We previously found that contrast-induced nephropathy (CIN) complicating percutaneous coronary intervention adversely affects patients with chronic kidney disease (CKD). Therefore, we further investigated whether the predictors and outcome of CIN after percutaneous coronary intervention differ among patients with versus without CKD. Among 7,230 consecutive patients, CIN (>or=25% or >or=0.5 mg/dl increase in preprocedure serum creatinine 48 hours after the procedure) developed in 381 of 1,980 patients (19.2%) with baseline CKD (estimated glomerular filtration rate [eGFR] <60 ml/min/1.73 m(2)) and in 688 of 5,250 patients (13.1%) without CKD. Decreased eGFRs, periprocedural hypotension, higher contrast media volumes, lower baseline hematocrit, diabetes, pulmonary edema at presentation, intra-aortic balloon pump use, and ejection fraction <40% were the most significant predictors of CIN in patients with CKD. Apart from intra-aortic balloon pump use, predictors of CIN in patients without CKD were the same as mentioned, plus older age and type of contrast media. Regardless of baseline renal function, CIN correlated with longer in-hospital stay and higher rates of in-hospital complications and 1-year mortality compared with patients without CIN. By multivariate analysis, CIN was 1 of the most powerful predictors of 1-year mortality in patients with preexisting CKD (odds ratio 2.37, 95% confidence interval 1.63 to 3.44) or preserved eGFR (odds ratio 1.78; 95% confidence interval 1.22 to 2.60). Thus, regardless of the presence of CKD, baseline characteristics and periprocedural hemodynamic parameters predict CIN, and this complication is associated with worse in-hospital and 1-year outcomes.

Aged↗

PubMed2005

Angiographic results of the first human experience with everolimus-eluting stents for the treatment of coronary lesions (the FUTURE I trial).

The purpose of this study was to report the angiographic findings of the first human evaluation of the everolimus-eluting stent (EES) for the treatment of noncomplex coronary lesions. Forty-two patients with de novo coronary lesions (2.75 to 4.00 mm vessels; lesion length, <18 mm) were prospectively randomized in a 2:1 ratio to receive either the EES (n = 27) or a metallic stent (n = 15). Baseline clinical and angiographic characteristics were similar among both groups. At 6-month follow-up, EES had a lower in-stent late lumen loss (0.10 +/- 0.22 vs 0.85 +/- 0.32 mm, p <0.0001) and in-segment diameter stenoses (20.7 +/- 12.3% vs 37.0 +/- 15.8%, p = 0.002). There was no in-stent restenosis with EES; however, 1 focal distal edge restenosis was present. There was 1 in-stent and 1 in-segment (proximal edge) restenosis in the metallic stent group. There was no stent thrombosis or aneurysm formation at follow-up in either group.

Aged↗

PubMed2005

Novel site-specific systemic delivery of Rapamycin with perfluorobutane gas microbubble carrier reduced neointimal formation in a porcine coronary restenosis model.

Earlier studies demonstrated that perfluorobutane gas microbubble carrier (PGMC) adheres to injured arteries and enhances the drug uptake specifically into the cells of the denuded vessel segment. The purpose of this study was to investigate the effect of PGMC-based systemic delivery of Rapamycin on expression of p27 in vascular tissue and restenosis in porcine coronary arteries after stent implantation. Eight pigs underwent coronary stent implantation (three stents per animal). Five pigs were treated with i.v. injection of PGMC with 2 mg of Rapamycin and three animals served as control. Four hours postprocedure, three pigs were sacrificed and stented segments were analyzed by high-performance liquid chromatography (HPLC) and Western blot. In chronic experiments, five pigs (15 stent sites) were sacrificed at 28 days following intervention and vessels were perfusion-fixed. HPLC of the treated arteries demonstrated high drug concentration in the vessel tissue, and Western blot analysis showed elevated expression of p27 at 4 hr postprocedure. Histomorphometry revealed significantly reduced (by 40%) neointimal formation in the PGMC/Rapamycin group compared with controls (1.84 +/- 0.84 vs. 4.77 +/- 1.71 mm2, respectively; P < 0.001). In the porcine coronary model, site-specific systemic delivery of Rapamycin utilizing PGMC resulted in overexpression of p27 and a significant reduction of neointimal formation within the stented segments.

Animals↗

PubMed2005

Novel method for extraction of a massive refractory coronary thrombus after stent implantation.

Percutaneous treatment of thrombotic coronary lesions is associated with an increased incidence of complications. In particular, management of massive coronary thrombus refractory to traditional methods of removal may be especially problematic. We report a novel application of the FilterWire distal protection device to retrieve a massive refractory native coronary thrombus present after drug-eluting stent implantation.

Adult↗