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Biomedical subjects

Augusto D Pichard

Publications and source records attributed to Augusto D Pichard.

At least 73 records · Page 4Linked to original sources
PubMed2004

Effects of gamma radiation on the noninjured and unprotected left main.

The aim of this study was to evaluate the effect of gamma radiation on the noninjured, unprotected left main coronary artery. Noninjured vessel segments are often radiated during treatment of in-stent restenosis with PCI and gamma radiation. Angiographic analysis using QCA methods was performed on 55 left main arteries of patients (32 with radiation of the left main compared to 23 controls) who participated in the Washington Radiation for In-Stent Restenosis Trials (WRIST). Baseline demographics and follow-up were comparable between the two groups, concluding that gamma radiation with long radiation safety margins is feasible and safe. Gamma radiation of noninjured irradiated left main vessels when used to facilitate wide radiation margins for proximal irradiated injured LAD and LCx is safe and does not compromise the vessel integrity and its lumen.

Aged↗
PubMed2004

Gamma radiation for in-stent restenosis: effect of lesion length on angiographic and clinical outcomes.

The relation between lesion length and effectiveness of gamma radiation treatment (gamma-RT) has not been well described. We evaluated the acute and long-term outcome according to baseline lesion length in 130 patients treated with (192)Ir in the Washington Radiation for In-Stent Restenosis Trial; 44 (35.5%) had baseline short in-stent restenosis (ISR) lesions (length < 15 mm) and 80 (64.5%) long ISR lesions (length > or = 15 mm). At 6-month follow-up after gamma-RT, the short ISR group had larger lumen dimensions and lower late loss than the long ISR group. Restenosis rate was significantly higher in patients with long ISR for both the placebo (74% vs. 39%; P = 0.01) and the gamma-RT arm (31% vs. 5.3%; P = 0.04). gamma-RT significantly improved the angiographic outcome in the short-lesion groups but had the more pronounced effect on the reduction of clinical events after treatment of long ISR group. Lesion length remains a powerful predictor of recurrent ISR and clinical events after treatment of ISR even with gamma-RT.

Brachytherapy↗
PubMed2004

Use of IIb/IIIa inhibitors in patients with in-stent restenosis treated with intracoronary gamma-radiation. Integrilin WRIST.

The Integrilin Washington Radiation for In-Stent Restenosis Trial (WRIST) aimed to study the impact of IIb/IIIa inhibitors as adjunct therapy to intracoronary radiation therapy (IRT) for patients with in-stent restenosis (ISR). The impact of GP IIb/IIIa inhibitor (eptifibatide) as adjunct therapy to vascular brachytherapy using (192)Ir emitter was examined in patients with in-stent restenosis. In the study, 150 patients were assigned to eptifibatide (Integrilin) and 150 patients to heparin only. Clinical composite endpoints at 30 days were similar between the patients treated with and without eptifibatide (4.7% vs. 4.0%; P = 0.78). There was a similarity in the non-Q-wave myocardial infarction (MI) rates between the eptifibatide and the control group. Major bleeding was similar in patients treated with and without eptifibatide. Overall, the use of eptifibatide as adjunct therapy for patients with ISR that are treated with IRT did not impact the clinical outcome at 30 days.

Aged↗
PubMed2004

Vascular complications following coronary intervention correlate with long-term cardiac events.

We aimed to study the consequences and late outcomes of patients who experienced peripheral vascular complications (PVCs) following percutaneous coronary interventions (PCI). A retrospective analysis of the medical records of 10,669 patients who underwent PCI and experienced PVC between 1995 and 2002 was conducted. One thousand ninety-six patients (10.27% of the study cohort) had PVC post-PCI. After PCI, patients with PVC had higher rates of in-hospital complications (P < 0.001) when compared to patients without PVC, including Q-wave myocardial infarction (MI; 1.2% vs. 0.3%), coronary artery bypass grafting (CABG; 3.8% vs. 0.6%), and death (4.0% vs. 1.0%). At 1-year follow-up, late complications of MI (37.4% vs. 25.4%), non-Q-wave MI (34.9% vs. 22.7%), death (12.9% vs. 5.9%), and CABG (5.7% vs. 4.5%) were higher (< 0.001) in patients with PVC compared to those without. Multivariate analysis identified PVC as a significant predictor of 1-year mortality (P = 0.045). This study underscores the need to make diligent efforts to minimize PVC and follow up these patients for future coronary events.

Aged↗
PubMed2004

Favorable effect of gamma-radiation for in-stent restenosis: effect of diabetes on angiographic and clinical outcomes.

The purpose of this study was to examine the effect of vascular brachytherapy with gamma-radiation (gamma-RT) in patients with diabetes mellitus (DM) with coronary in-stent restenosis (ISR). In the Washington Radiation for In-Stent Restenosis (WRIST) trial, 130 patients with ISR were treated with (192)Ir or placebo. Of the patients enrolled, 44 (34%) had DM (18 of them treated with gamma-RT and 26 with placebo). Gamma-radiation therapy of ISR in diabetics resulted in similar procedural success and in-hospital outcome compared to nondiabetics. At 6-month follow-up, both DM and non-DM patients treated with gamma-RT had significantly lower target lesion revascularization (TLR), target vessel revascularization, and major adverse cardiac event rates compared to placebo. DM remains a powerful predictor of TLR and major adverse cardiac events even after treatment of ISR with gamma-RT.

Adult↗
PubMed2004

Impact of radiation dose on late clinical outcome after intracoronary radiation therapy: three-year follow-up of Long WRIST.

To determine the safety and efficacy, including the impact, on the late recurrence rate of an incremental gamma-radiation dose from 15 to 18 Gy, we report the 3-year clinical outcome of Washington Radiation for In-Stent Restenosis Trial for Long Lesions (Long WRIST). One hundred eighty patients with recurrent in-stent restenosis (ISR) were enrolled in the Long WRIST series and treated with (192)Ir with 1 month of antiplatelet therapy. Between 6 months and 3 years, the need for repeat revascularization was low and similar among the three groups. At 3 years, target lesion revascularization (TLR) and major adverse cardiac events (MACE) were less frequent in the 18 Gy group than in the 15 Gy group (P = 0.12 for TLR, P < 0.05 for MACE) and less frequent in the 15 Gy group as compared to the placebo group (P < 0.05 for TLR and MACE). At 3 years, a higher dose of 18 Gy with (192)Ir continues to improve the outcome of patients treated for ISR when compared to patients treated with 15 Gy or placebo.

Analysis of Variance↗
PubMed2004

Intravascular ultrasound predictors of subacute vessel closure after balloon angioplasty or atherectomy.

BACKGROUND: Factors leading to subacute vessel closure after percutaneous coronary intervention (PCI) have not been well established in lesions treated with balloon angioplasty or atherectomy. METHODS AND RESULTS: We used intravascular ultrasound (IVUS) to determine the pre- and post-PCI characteristics involved in subacute vessel closure after PCI. Of 3,403 patients undergoing IVUS imaging during coronary balloon angioplasty or atherectomy, 8 patients (0.2%) developed angiographically documented subacute vessel closure within 1 week post-PCI and were compared to a group matched by procedure date (within 6 months), age, gender, stable or unstable angina, lesion location and treatment (balloon angioplasty or atherectomy). IVUS identified at least one cause for subacute vessel closure in 87% of patients (vs 25% in matched lesions, p < 0.01). Causes were all procedure-related and included inadequate final lumen (60%), dissection (50%) and thrombus (25%). Pre-procedure lesion characteristics were not different from matched lesions. CONCLUSIONS: Subacute vessel closure after balloon angioplasty or atherectomy is mostly related to insufficient post-procedure lumen dimension or dissection.

Aged↗
PubMed2004

Safety of percutaneous coronary intervention alone in symptomatic patients with moderate and severe valvular aortic stenosis and coexisting coronary artery disease: analysis of results in 56 patients.

Whether percutaneous coronary intervention (PCI) alone is safe in patients with moderate or severe aortic stenosis (AS) and coexisting coronary artery disease (CAD), and whether aortic valve replacement (AVR) can be deferred in patients with moderate AS by undergoing PCI alone is not known. We conducted a retrospective study of surgically inoperable patients with AS who underwent PCI (moderate AS, n = 28; and severe AS, n = 28) and compared to those with AVR (n = 55). The clinical characteristics, procedural complications, in-hospital and long-term clinical outcomes of PCI were compared. Baseline and procedural characteristics were similar except that lower age, hypertension, and renal impairment were seen in the AVR group. In-hospital complications were comparable among the 3 groups. Six-month and 1-year rates of myocardial infarction (MI), non-Q-wave MI, death and out-of-hospital death were similar between AVR and moderate AS patients (p = NS) and significantly high (p < 0.04) in patients with severe AS. On multivariate analysis, severe AS was the only significant predictor of 6-month and 1-year mortality. Our study suggests that PCI is safe in patients with moderate AS and coexisting CAD but is associated with poor outcomes in patients with severe AS.

Aged↗
PubMed2003

Comparison of effectiveness and safety of three different antithrombotic regimens (bivalirudin, eptifibatide, and heparin) in preventing myocardial ischemia during percutaneous coronary intervention.

The aim of this retrospective, observational analysis was to compare the efficacy and safety of 3 antithrombotic regimens: bivalirudin, eptifibatide plus heparin, and heparin alone, with emphasis on preventing interventional procedural creatinine kinase-MB fraction (CK-MB) release, and consequently, myocardial necrosis.

Aged↗
PubMed2003

Incidence, predictors, and prognostic implications of bleeding and blood transfusion following percutaneous coronary interventions.

Bleeding related to percutaneous coronary intervention (PCI) occurs relatively frequently. We retrospectively investigated the incidence, predictors, and prognostic impact of periprocedural bleeding and transfusion in 10,974 patients who underwent PCI. Bleeding definitions were based on Thrombolysis In Myocardial Infarction (TIMI) criteria: (1) major bleeding (n = 588; 5.4%): if patients had a hemorrhagic stroke or if hematocrit decreased >15 points or by 10 to 15 points with clinical bleeding; (2) minor bleeding (n = 1,394; 12.7%): if hematocrit decreased <10 points with clinical bleeding or by 10 to 15 points without clinical bleeding; and (3) no bleeding (n = 8,992; 81.9%): if hematocrit decreased <10 points without clinical bleeding. Patients with major bleeding were older than patients with minor or no bleeding (67.8 +/- 11 vs 65.9 +/- 11 vs 63.6 +/- 11 years, respectively; p <0.001) and more often experienced intraprocedural complications, such as emergency use of an intra-aortic balloon pump (13.6% vs 6.5% vs 2.3%, respectively; p <0.001). Multivariate logistic regression analysis identified the use of an intra-aortic balloon pump (odds ratio [OR] 3.0, p <0.0001), procedural hypotension (OR 2.9, p <0.001), and age >80 years (OR 1.9 compared with age <50 years, p = 0.001) as the strongest predictors for major bleeding. Patients who had major bleeding had higher in-hospital and 1-year mortality compared with patients with minor or no bleeding. Bleeding was an independent predictor of in-hospital death. Thus, periprocedural major bleeding occurs relatively frequently and is associated with adverse outcomes. Patients >80 years of age who experience intraprocedural complications are at particularly high risk.

Age Factors↗
PubMed2003

Volumetric intravascular ultrasound evidence that distal embolization during acute infarct intervention contributes to inadequate myocardial perfusion grade.

We studied 35 consecutive patients with myocardial infarction (MI) who were treated with direct infarct percutaneous coronary intervention (PCI) using standard angiographic (complete assessment of flow grade and blush grade) and pre- and post-PCI volumetric intravascular ultrasound analysis. Plaque reduction, which is evidence of distal embolization, contributes to inadequate tissue reperfusion in this lesion setting and supports the use of distal protection in the setting of an acute MI.

Aged↗
PubMed2003

Repeat intracoronary radiation for recurrent in-stent restenosis in patients who failed intracoronary radiation.

BACKGROUND: Intracoronary radiation therapy (IRT) is the only proven treatment for in-stent restenosis (ISR). It is, however, associated with a significant failure rate. The present study evaluated the outcomes of patients who underwent repeat intracoronary radiation for recurrent ISR. METHODS AND RESULTS: Fifty-one consecutive patients who failed a previous radiation treatment, presented with angina and angiographic evidence of ISR, and were treated with percutaneous coronary intervention (PCI) and repeat radiation to the same segment were studied. Twenty-five patients were treated with gamma radiation in a dose of 15 Gy, and 26 were treated with beta radiation doses of 18.3 to 23 Gy. The mean cumulative dose for this cohort was 39.5+/-11.9 Gy (range, 29 to 75.6 Gy). The outcomes of those patients were compared with outcomes of 299 patients who also failed initial radiation but were treated with repeat conventional PCI to a previously irradiated segment without repeat radiation. At 9 months after treatment, the repeat-IRT group had lower rates of target lesion revascularization (23.5% versus 54.6%; P<0.001) and major adverse cardiac events, including target vessel revascularization (29.4% versus 61.3%; P<0.001). At 9 months, patients with repeat IRT were free of angiographic and clinical events related to the radiation therapy. CONCLUSIONS: Repeat gamma or beta radiation to treat failed IRT for ISR after conventional PCI is safe and effective at 9 months and should be considered as a therapeutic option for this difficult patient subset.

Angina Pectoris↗
PubMed2003

Predictors of subacute stent thrombosis: results of a systematic intravascular ultrasound study.

BACKGROUND: Factors leading to subacute stent thrombosis after percutaneous coronary intervention (PCI) have not been well established. We assessed the pre- and post-PCI intravascular ultrasound (IVUS) characteristics of subacute stent thrombosis. METHODS AND RESULTS: We analyzed 7484 consecutive patients without acute myocardial infarction who were treated with PCI and stenting and underwent IVUS imaging during the intervention. Twenty-seven (0.4%) had angiographically documented subacute closure <1 week after PCI (median time to subacute closure, 24 hours). Subacute closure lesions were compared with a control group (selected to be 3 times the abrupt closer group) matched by procedure date (within 6 months), age, gender, stable or unstable angina, lesion location, and additional treatment (balloon angioplasty or atherectomy). Postintervention IVUS did not identify a cause in 22% and did identify at least 1 cause for abrupt closure in 78% of patients (versus 33% in matched lesions, P=0.0002). In 48% of the patients, there were multiple causes in 48% (versus 3% in matched lesions, P<0.0001). Causes included dissection (17%), thrombus (4%), and tissue protrusion within the stent struts leading to lumen compromise lumen (4%). A total of 83% of patients with >1 of these abnormal morphologies also had reduced lumen dimensions post-PCI (final lumen <80% reference lumen). Preprocedural lesion characteristics were not different from matched lesions. CONCLUSIONS: Subacute stent thrombosis is infrequently related to the preintervention lesion characteristics. Inadequate postprocedure lumen dimensions, alone or in combination with other procedurally related abnormal lesion morphologies (dissection, thrombus, or tissue prolapse), contribute to this phenomenon.

Angioplasty, Balloon, Coronary↗
PubMed2003

Intravascular ultrasound analysis of infarct-related and non-infarct-related arteries in patients who presented with an acute myocardial infarction.

BACKGROUND: Previous studies have reported diffuse destabilization of atherosclerotic plaques in acute myocardial infarction (AMI). METHODS AND RESULTS: We used intravascular ultrasound (IVUS) to assess 78 coronary arteries (38 infarct-related arteries [IRAs] with culprit and nonculprit lesions and 40 non-IRAs) from 38 consecutive AMI patients. IVUS analysis included qualitative and quantitative measurements of reference and lesion external elastic membrane (EEM), lumen, and plaque plus media (P&M) area. Positive remodeling was defined as lesion/mean reference EEM >1.0. Culprit lesions were identified by a combination of ECG, wall motion abnormalities (ventriculogram or echocardiogram), scintigraphic perfusion defects, and coronary angiogram. Culprit lesions contained more thrombus (23.7% versus 3.4% in nonculprit IRA plaques and 3.1% in non-IRA plaques; P=0.0011). Culprit lesions were predominantly hypoechoic (63.2% versus 37.9% of nonculprit IRA plaques and 28.1% of non-IRA plaques; P=0.0022). Culprit lesions were longer (17.5+/-10.1, 9.8+/-4.0, and 10.3+/-5.7 mm, respectively; P<0.0001), had larger EEM area (15.0+/-6.0, 11.5+/-5.7, and 12.6+/-5.6 mm2, respectively; P=0.0353) and P&M area (13.0+/-6.0, 7.5+/-3.7, 9.3+/-4.3 mm2, respectively; P<0.0001), smaller lumens (2.0+/-0.9, 4.1+/-3.1, and 3.4+/-2.5 mm2, respectively; P=0.0009), and more positive remodeling (79.4%, 59.0%, and 50.8%, respectively; P=0.0155). The frequency of plaque rupture/dissection was greater in culprit, nonculprit IRA, and non-IRA plaques in AMI patients than in a control group of chronic stable angina patients with multivessel IVUS imaging. CONCLUSIONS: Culprit plaques have more markers of instability (thrombus, positive remodeling, and large plaque mass); however, these markers of instability are not typically found elsewhere. This suggests that the vascular event in AMI patients is determined by local pre-event lesion morphologies.

Angina Pectoris↗
PubMed2003

Intracoronary radiation therapy improves the clinical and angiographic outcomes of diffuse in-stent restenotic lesions: results of the Washington Radiation for In-Stent Restenosis Trial for Long Lesions (Long WRIST) Studies.

BACKGROUND: The Washington Radiation for In-Stent Restenosis Trial for long lesions (Long WRIST) was designed to determine the safety and efficacy of vascular brachytherapy for the treatment of diffuse in-stent restenosis. METHODS AND RESULTS: A total of 120 patients with diffuse in-stent restenosis in native coronary arteries (lesion length, 36 to 80 mm) were randomized for either radiation with 192Ir with 15 Gy at 2 mm from the source axis or placebo. After enrollment, 120 additional patients with the same inclusion criteria were treated with 192Ir with 18 Gy and included in the Long WRIST High Dose registry. Antiplatelet therapy was initially prescribed for 1 month and was extended to 6 months in the last 60 patients of the Long WRIST High Dose registry. At 6 months, the binary angiographic restenosis rate was 73%, 45%, and 38% in the placebo, 15 Gy, and 18 Gy radiated groups, respectively (P<0.05). At 1 year, the primary clinical end point of major cardiac events was 63% in the placebo group and 42% in the radiated group with 15 Gy (P<0.05). The major cardiac event rate was further reduced with 18 Gy (22%; P<0.05 versus 15 Gy). Late thrombosis was 12%, 15%, and 9% in the placebo group, 15 Gy group with 1 month of antiplatelet therapy, and 18 Gy group with 6 months of antiplatelet therapy, respectively. CONCLUSIONS: Vascular brachytherapy with 192Ir is safe and reduces the rate of recurrent restenosis in diffuse in-stent restenosis. The efficacy of vascular brachytherapy on angiographic and clinical outcomes is enhanced with a radiation dose of 18 Gy and prolonged antiplatelet therapy.

Brachytherapy↗