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Biomedical subjects

Augusto D Pichard

Publications and source records attributed to Augusto D Pichard.

122 records · Page 7Linked to original sources

Late thrombosis in cypher stents after the discontinuation of antiplatelet therapy.

Drug-eluting stents, since their approval in the United States, have become the treatment of choice for de novo coronary artery narrowing due to their ability to reduce restenosis and the need for repeat revascularization. We present two patients who underwent percutaneous coronary intervention for the treatment of multivessel coronary artery disease; both patients were treated with sirolimus-eluting stents (SES) and bare metal stents (BMS).

Adult↗

Intracoronary radiation therapy using a novel beta emitter for in-stent restenosis Tungsten WRIST.

BACKGROUND: Intracoronary beta-radiation therapy reduces in-stent restenosis (ISR). We aimed to determine the safety and feasibility of intracoronary radiation therapy (IRT) utilizing tungsten (188W), a beta emitter. METHODS: A total of 30 patients with angiographic evidence of ISR in a previously treated native coronary artery underwent percutaneous coronary intervention (PCI; balloon angioplasty, ablation by atherectomy, or laser angioplasty). After the intervention, a noncentered delivery catheter with a side guide 0.014-in. wire carrying a tungsten (188W) coil, with an active length of 33 mm, was inserted. Patients were randomized to a radiation dose of 18, 22, or 25 Gy at 2 mm from the center of the source. Aspirin and Plavix, at 300 mg loading dose, were administered prior to intervention. Plavix 75 mg/day was prescribed for 6 months after the procedure. RESULTS: At 6 months follow-up, the overall binary angiographic restenosis rate was 18.8%. Target vessel revascularization (TVR) was 23% and target lesion revascularization related major adverse cardiac events (TLR-MACE) was 13.3%, without any intergroup differences. A comparison with the original Washington Radiation for In-stent restenosis Trial (WRIST) radiation cohort utilizing an 192Iridium source (prescription dose 15 Gy at 2 mm from the source) showed similar TVR and TLR-MACE rates of 30% and 18%, respectively. The TVR and TLR-MACE rates in the WRIST placebo cohort were 70% and 66%, respectively. CONCLUSIONS: Vascular brachytherapy with tungsten (188W) is feasible and safe. The 6-month clinical outcomes are similar to the original WRIST radiation group.

Anti-Inflammatory Agents, Non-Steroidal↗

Optimizing dosimetry with high-dose intracoronary gamma radiation (21 Gy) for patients with diffuse in-stent restenosis.

BACKGROUND: The efficacy of intracoronary gamma radiation (IRT-gamma) in reducing recurrent in-stent restenosis (ISR) is well established using doses of 14-18 Gy. We sought to examine whether an escalation in dose to 21 Gy is safe and confers additional benefit in reducing repeat revascularization and major adverse cardiac events (MACE) in patients with diffuse ISR. METHODS: Forty-seven patients with diffuse ISR (lesion length 20-80 mm) in native coronary arteries (n=25) and saphenous vein grafts (n=22) underwent percutaneous transluminal coronary angioplasty and/or additional stents followed by IRT-gamma using the Checkmate system (Cordis) with a dose of 21 Gy. All patients were discharged with clopidogrel for 12 months and aspirin indefinitely. Six-month angiographic and 12-month clinical outcomes of these patients were compared to 120 patients treated with 18 Gy using the same system. RESULTS: At baseline, patients in the 21-Gy group had more multivessel, vein graft disease and history of prior myocardial infarctions and coronary artery bypass grafts (P<.001). The use of debulking devices and stents was less in this group (P<.001). Procedural and in-hospital complications were similar. Follow-up at 6 months revealed nonsignificant but lower late loss (in-stent, 0.33+/-0.7 mm; in-lesion, 0.41+/-0.6 mm) in the 21-Gy group compared to the 18-Gy group; follow-up at 12 months revealed a trend toward less overall myocardial infarction, although repeat revascularization and MACE rates were similar. CONCLUSIONS: IRT-gamma therapy for diffuse ISR lesions with a 21-Gy dose is clinically safe and feasible with marked reduction in late loss but does not confer additional benefit with regard to repeat revascularization and MACE when compared to a dose of 18 Gy.

Adult↗

Bivalirudin compared with IIb/IIIa inhibitors in patients with in-stent restenosis undergoing intracoronary brachytherapy.

BACKGROUND: Bivalirudin is replacing heparin in percutaneous coronary interventions (PCIs), including vascular brachytherapy (VBT). The aim of the study was to compare bivalirudin with eptifibatide in patients with in-stent restenosis (ISR) undergoing PCI and VBT. METHODS: One hundred forty-four patients treated with bivalirudin as a single antithrombotic agent were compared with 150 patients treated with eptifibatide. Bivalirudin as a bolus of 0.75 mg/kg followed by 1.75 mg/kg/h infusion until the end of the procedure, and eptifibatide as a double bolus of 180 microg/kg followed by 2 microg/kg/min infusion for 18 h after the procedure were used. The main outcome measures were in-hospital events and 30-day clinical outcomes. RESULTS: Baseline clinical characteristics were similar except that patients in the eptifibatide group were younger (P=.02) and had more saphenous vein graft lesions (P<.001). Patients in the bivalirudin group had a higher number of lesions in the right coronary artery (P<.001) and a higher number of vessels treated (P<.001). Postprocedure creatinine phosphokinase (CPK)-MB levels were significantly lower in the bivalirudin group (P<.03). In-hospital events showed significantly less minor bleeding (P=.01) and a trend toward lower major bleeding and major adverse cardiac events (MACE) in the bivalirudin group (P=.06). Thirty-day outcomes showed a significantly lower incidence of non-Q-wave myocardial infarction (MI) in the bivalirudin group (P=.004). CONCLUSION: Bivalirudin, as a single antithrombotic agent during PCI and VBT, is associated with significantly lower postprocedural CPK-MB elevation, minor bleeding complications, 30-day non-Q-wave MI rates, and a trend toward lower major bleeding and in-hospital MACE when compared with eptifibatide.

Anticoagulants↗

Impact of vessel calcification on outcomes after coronary stenting.

BACKGROUND: Calcified coronary arteries have few viable smooth muscle cells capable of proliferating, and, subsequently, might exhibit less in-stent restenosis. We therefore studied the outcome of stenting in patients with different amounts of coronary calcification. METHODS: Six hundred twenty-one patients who underwent bare metal stenting of calcific native coronary arteries were studied retrospectively. Pre- and postinterventional intravascular ultrasound (IVUS) and qualitative and quantitative coronary angiography (QCA) were performed in 662 lesions. The arc of calcium was measured, and arteries were grouped (A, B, C, and D) according to the calcium arc in IVUS (0-90 degrees , 91-180 degrees , 181-270 degrees , and 271-360 degrees , respectively). Arteries with a superficial calcium arc of < or =270 degrees (Group E) were compared to arteries with >270 degrees calcification (Group F). RESULTS: Clinical and lesion characteristics were similar, and the major complication rate was low (1.9%) in all groups. In Groups A, B, C, and D, patients with more calcific arteries had more non-Q-wave myocardial infarction (MI) (P=.04-.002). Patients in Group F (more extensive superficial calcification) had an increased frequency of non-Q-wave MI compared to Group E. Malapposition of stents to vessel wall and use of rotational atherectomy were more frequent in Group F (P=.001). Late events including death, MI, and revascularization with either coronary artery bypass grafting or percutaneous coronary intervention (PCI) were not different among the groups. Extensive calcification of coronary arteries is associated with more frequent peri-procedural non-Q-wave MI. CONCLUSION: Despite the scarcity of viable cells, the late event rate in severely calcified arteries is not different from mildly calcified arteries. This may be due to more frequent malapposition of stents to vessel wall and augmented trauma during PCI in severely calcified arteries.

Adult↗

Metabolic syndrome in patients with acute myocardial infarction is associated with increased infarct size and in-hospital complications.

BACKGROUND: Metabolic syndrome (MS), the combination of hypertension, obesity, dyslipidemia, and insulin resistance, is a precursor of diabetes mellitus (DM) and highly prevalent among patients with acute myocardial infarction (AMI). Diabetes mellitus is associated with larger infarct size and worse outcomes after AMI. This study examined infarct size and short-term outcomes among nondiabetic patients with MS following contemporary treatment of AMI. METHODS: Four hundred five consecutive patients with AMI treated with primary percutaneous coronary intervention were evaluated. Patients with diabetes (n=105) were excluded. Those with MS (n=167) included patients with three or more of the following criteria: hypertension, elevated fasting blood glucose, hypertriglyceridemia, low high-density lipoprotein, and obesity [body mass index (BMI)> or =30]. The control group (n=133) included patients without MS or DM. RESULTS: Baseline characteristics were similar except for hypertension, BMI, and dyslipidemia, which by study design were higher in the MS group. The MS group had larger infarct size as determined by peak creatine kinase-MB (79.8+/-133.8 vs. 30.84+/-51.5, P<.001). Overall in-hospital complications were higher in patients with MS (21.1% vs. 9.2%, P=.003). Metabolic syndrome is associated with a 10-fold increased risk of acute renal failure after myocardial infarction (7.9% vs. 0.8%, P=.007). CONCLUSION: Metabolic syndrome in nondiabetic patients with AMI is associated with larger infarct size, more in-hospital complications, and a marked increase of acute renal failure. Awareness of MS and preventative measures is crucial in this population to minimize infarct size and decrease morbidity after AMI.

Acute Kidney Injury↗

Bivalirudin versus unfractionated heparin in patients undergoing percutaneous coronary intervention after acute myocardial infarction.

BACKGROUND: Bivalirudin is replacing heparin as the anticoagulant agent of choice for elective percutaneous coronary intervention (PCI). This study aimed to assess the safety and clinical outcomes of bivalirudin versus unfractionated heparin (UFH) in patients undergoing PCI for acute myocardial infarction (AMI). METHODS: A cohort of 672 consecutive patients presenting with AMI without prior thrombolytic therapy were treated with either bivalirudin (216 patients) or UFH (456 patients). Platelet glycoprotein IIb/IIIa inhibitors were administered at the operator's discretion. The in-hospital, 30-day, and 6-month outcomes of the two groups were compared. RESULTS: Baseline clinical and angiographic characteristics were similar between the groups. In-hospital complications were similar, although there was a trend of a less major hematocrit drop in the bivalirudin group (0.9% vs. 3.1%, P=.09). All clinical outcomes were similar between the groups at 30-day and 6-month follow-ups. There was no statistical significance for acute thrombosis and subacute thrombosis between the groups, and there was no late thrombosis from either group. The event-free survival rate was similar between the groups (P=.41). CONCLUSION: The use of bivalirudin in patients undergoing PCI after AMI is safe and feasible. Bivalirudin should be considered as an alternative anticoagulant agent during PCI to treat patients presenting with AMI.

Aged↗

Comparison of paclitaxel-eluting stent and sirolimus-eluting stent expansion at incremental delivery pressures.

OBJECTIVES: We sought to compare the adequacy of paclitaxel-eluting stent (PES) and sirolimus-eluting stent (SES) expansion based on intravascular ultrasound (IVUS) imaging criteria at conventional delivery pressures. METHODS: Forty-six patients underwent SES implantation and 42 patients underwent PES implantation for de novo native coronary lesions<33 mm in length with reference lumen diameters of 2.5-3.5 mm. Stents were serially expanded with gradual balloon inflations at 14 and 20 atm. IVUS imaging was performed prior to intervention and after each balloon inflation. Stent expansion (minimal stent cross-sectional area/reference lumen cross-sectional area) was measured. Inadequate stent expansion was defined using the MUSIC criteria (all struts apposed, no tissue protrusion, and final lumen cross-sectional area>80% of the reference or >90% if minimal lumen cross-sectional area was <9 mm2). RESULTS: The baseline characteristics of the two groups were similar except for shorter lesion length, larger mean lumen cross-sectional area, larger lumen diameter, and lower plaque burden in the PES group. Stent expansion was inadequate in 80% of patients with SES versus 63% of patients with PES at 14 atm, although this was not statistically significant. After 20 atm, 48% of patients with SES remained underexpanded as compared with 35% of patients with PES. CONCLUSION: Drug-eluting stents showed significant underexpansion by MUSIC criteria at conventionally used inflation pressures. Higher balloon inflations are required especially during deployment of a SES. IVUS guidance is recommended to ensure optimal results and outcomes with both stents.

Aged↗

Safety and efficacy of manual stepping and overlapping of beta-emitter for diffuse in-stent restenosis lesions.

BACKGROUND: The effects of overlapping beta-emitter sources on the treatment of in-stent restenosis (ISR) lesions as a result of manual stepping are unknown. METHODS AND RESULTS: In the BETA WRIST (Beta Washington Radiation for In-stent Restenosis Trial), 17 out of the 50 patients who received radiation treatment had diffuse ISR in native coronaries that required manual stepping of the beta-emitter (90Y) source in order to cover the lesion and the edges. Fourteen of those patients received radiation with an overlap of up to 3 mm in the middle of the stented segment. The prescribed dose was 20.6 Gy to a distance of 1.0 mm from the surface of the inflated balloon, and the calculated dose to the vessel wall at the overlapped area did not exceed 75 Gy. There was no difference in late total occlusion (7.1% vs. 9.0%, P=NS) and target lesion revascularization (28.5% vs. 27.2%, P=NS) between patients with stepping and those without stepping. At 6 months, there was no evidence of perforation or aneurysm at the overlapped segments. Quantitative coronary angiographic (QCA) analysis revealed significantly reduced late loss in the overlapped segment compared to the adjacent segment (P=.04). Serial (postradiation vs. follow-up) IVUS measurement showed larger mean lumen cross-sectional area (CSA) (P=.0035) and smaller mean intimal hyperplasia (IH) CSA (P=.0010) in the overlapped segment compared to the adjacent segment. CONCLUSION: Manual stepping of beta-emitter source with a short overlapped segment is safe for diffuse ISR. Further increase in lumen dimension and reduction in IH formation are observed at the overlapped segment.

Adult↗

The initial course of in-stent restenosis influences the response to vascular brachytherapy.

BACKGROUND: Vascular brachytherapy (VBT) reduces the rate of recurrence of in-stent restenosis (ISR) by inhibiting intimal proliferation. However, the rate of cell proliferation, reflected by the speed of ISR development, is variable in ISR lesions and might influence the responsiveness of ISR to radiation. The aim of this study was to determine the influence of the initial ISR course on the clinical outcome of patients undergoing VBT. METHODS: In 1165 patients treated for ISR with VBT in the WRIST studies, we determined the time for ISR (time between initial stent implantation and restenosis), the time for VBT treatment (time between stent implantation and VBT), and previous ISR treatment with conventional strategies. Target lesion revascularization (TLR) at 6 months was available in all patients. RESULTS: Previous ISR treatment did not influence the result of VBT (TLR was 17% vs. 16% without previous angioplasty). Time to ISR influences the outcome of patients undergoing VBT; TLR decreased when ISR occurred later. TLR was 18.2%, 16.7%, and 11.1% when time to ISR was <90, 90-2700, and >270 days, respectively, P=.03. Early ISR (time for ISR <90 days) is a factor for radiation failure (OR=2.1, P<.05). In patients with early ISR, TLR is lower when VBT is delayed; TLR was 11% if performed 90 days after stent implantation as compared to 22% if VBT is performed early (<90 days), P<.05. CONCLUSION: The course of ISR development affects the long-term efficacy of VBT. Early restenosis remains a factor of treatment failure in the VBT era. Delaying VBT beyond 90 days after stent implantation reduces the rate of subsequent revascularization in these patients.

Aged↗

The proximal location of stenosis in the left anterior descending coronary artery is not a predictive factor of worse outcome in the era of the stent.

BACKGROUND: Patients treated for lesions in the proximal left anterior descending coronary artery (P-LAD) have worse outcome after balloon angioplasty as compared to patients treated for lesions in the distal left anterior descending coronary artery (D-LAD). We sought to examine if this discrepancy was still observed after stenting. METHODS: A total of 676 consecutive patients with a symptomatic monovessel disease in the LAD artery who underwent angioplasty with stenting were prospectively entered into a dedicated database. Among this cohort, 322 lesions were located in P-LAD and 354 in D-LAD. Patients with total occlusion, acute myocardial infarction (MI) or restenosis were excluded. RESULTS: Procedural characteristics were similar in the two groups. Procedural success was high with the same rates of in-hospital death and Q-wave MI for patients treated in P-LAD and D-LAD. At 1 year, the rate of target lesion revascularization (TLR) was 13.9% in the P-LAD group and 16.3% in the D-LAD group (P = .79), and the rate of event-free survival was 81.9% and 81% (P = .67), respectively. The treatment of ostial lesions (n = 23) was not related to worse outcome. In multivariate analysis, lesion location was not a predictor of major adverse cardiac events (MACE). CONCLUSION: This study shows that stenting of lesions in the P-LAD is as effective and safe as treatment of lesions located in D-LAD. Therefore, when stenting is feasible, the location of the lesion in the LAD is not predictive of worse outcome and, consequently, should not be taken into account in the choice of the revascularization strategy.

Aged↗