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Roxana Mehran

Publications and source records attributed to Roxana Mehran.

At least 127 records · Page 7Linked to original sources
PubMed2003

Long-term follow-up of patients after gamma intracoronary brachytherapy failure (from GAMMA-I, GAMMA-II, and SCRIPPS-III).

We report the long-term outcome of 225 patients who failed gamma-brachytherapy for in-stent restenosis. Total adverse events, target vessel revascularization, and myocardial infarction were higher after repeat percutaneous coronary intervention versus coronary artery bypass grafting. Therefore, coronary artery bypass grafting may be the preferable first-line therapy in these patients until other therapies (i.e., drug-eluting stents) are available. Shorter time from brachytherapy to radiation failure and late thrombosis after brachytherapy were independent predictors of adverse events.

Brachytherapy↗
PubMed2003

Correlation of coronary arterial remodeling determined by intravascular ultrasound with angiographic diameter reduction of 20% to 60%.

Negative remodeling is commonly observed in stenotic coronary lesions. It is unknown whether negative remodeling is an early or late event. This study was designed to elucidate when negative remodeling occurs in the development of coronary stenosis. Remodeling was assessed by preintervention intravascular ultrasound in 104 native coronary lesions with intermediate stenosis (20% to 60% of diameter stenosis measured by quantitative coronary angiography). Positive remodeling was defined as lesion external elastic membrane (EEM) cross-sectional area (CSA) greater than the proximal reference, intermediate remodeling as lesion EEM CSA between those of the proximal and distal references, and negative remodeling as lesion EEM CSA less than the distal reference. Positive, intermediate, and negative remodeling were observed in 18%, 32%, and 50%, respectively, of lesions with intermediate stenosis. Lesions with negative and intermediate remodeling had more hard plaque compared with those with positive remodeling (79% vs 70% vs 42%, p = 0.02). Calcium was more frequent in lesions with negative and intermediate remodeling than in those with positive remodeling (52% vs 55% vs 16%, p = 0.01). Lesions with negative remodeling had smaller EEM CSA (11.5 +/- 5.2 vs. 13.7 +/- 3.4 vs 14.5 +/- 5.6 mm(2), p = 0.03) and less plaque (7.9 +/- 4.6 vs 10.8 +/- 3.4 vs 10.8 +/- 4.9 mm(2), p = 0.004) compared with positive and intermediate remodeling lesions, although lumen CSA (3.7 +/- 1.7 vs 2.8 +/- 0.8 vs 3.6 +/- 1.3 mm(2), p = 0.1) and area stenosis (57 +/- 15% vs 59 +/- 14% vs 56 +/- 10%, p = 0.7) were similar. Negative remodeling is frequently observed in lesions with intermediate stenosis. This suggests that negative remodeling occurs early in lesion formation.

Aged↗
PubMed2003

Intravascular brachytherapy for native coronary ostial in-stent restenotic lesions.

OBJECTIVES: We analyzed the effects of vascular brachytherapy (VBT) on ostial in-stent restenosis (ISR). BACKGROUND: In-stent restenosis has a high recurrence rate after percutaneous reintervention. The recurrence rate of ostial ISR lesions and the impact of VBT remain unknown. METHODS: We evaluated 133 patients with native coronary ostial ISR from a pooled database of 990 patients enrolled in randomized VBT trials. Independent quantitative angiography was performed at baseline and follow-up in 45 gamma, 27 beta, and 61 placebo patients. RESULTS: Binary restenosis was significantly higher in placebo than radiated patients (75.4% vs. 17.8% in gamma vs. 22.2% in beta, p < 0.0001). The treatment effect of both gamma (odds ratio [OR] 0.06; 95% confidence interval [CI] 0.02 to 0.17) and beta VBT (OR 0.10; 95% CI 0.03 to 0.31) was maintained after controlling for differences in baseline lesion length. Proximal and distal radiation edge restenosis rates were similar among the groups. Vascular brachytherapy of true aorto-ostial lesions (n = 34) was similarly beneficial: restenosis rates of placebo versus gamma or beta patients of 83.3% versus 6.7% versus 28.6%, p = 0.0002. CONCLUSIONS: Conventional treatment of ostial ISR is associated with a recurrence rate of over 75%. Vascular brachytherapy with either gamma or beta sources results in significant and similar reductions in restenosis compared with placebo. Similar benefits after VBT prevail in true aorto-ostial lesions.

Aorta↗
PubMed2003

Effect of percutaneous coronary interventions for in-stent restenosis in degenerated saphenous vein grafts without distal embolic protection.

OBJECTIVES: This study was designed to investigate the impact of percutaneous coronary interventions (PCIs) in degenerated saphenous vein grafts (SVGs) without distal embolic protection. BACKGROUND: Distal embolic protection devices have been shown to reduce the incidence of no reflow/slow flow during PCI of de novo lesions in degenerated SVGs. It is unclear whether PCI of in-stent restenosis (ISR) lesions in degenerated SVGs is associated with no reflow/slow flow and whether distal embolic protection is beneficial in these cases as well. METHODS: We studied 54 consecutive patients with treated ISR lesions in degenerated SVGs who underwent PCI without distal embolic protection in a single center. Procedural and in-hospital outcomes were examined. The average age was 71 +/- 8 years; 32% of the patients had diabetes. The mean lesion length was 13 +/- 6 mm and the procedural success rate was 98% (53/54). Cutting balloon angioplasty was used in 46% (25/54) of cases, and a new stent was inserted in 46% (25/54) of patients. Gamma brachytherapy was performed in 19% (10/54) of patients. During the procedure there were no episodes of no reflow/slow flow, and there were no patients with in-hospital Q-wave or non-Q-wave myocardial infarction. There was one in-hospital noncardiac death. CONCLUSIONS: In this consecutive series of patients with ISR of degenerated SVGs undergoing PCI without distal protection, there were no episodes of slow flow/no reflow and no procedure-related myocardial infarctions. It appears that distal embolic protection may not be necessary during PCI of ISR lesions in degenerated SVGs.

Aged↗
PubMed2003

Deferoxamine enhances neovascularization and recovery of ischemic skeletal muscle in an experimental sheep model.

BACKGROUND: Iron chelators have been reported to interfere with inflammatory cells and possibly enhance vascular growth factor expression. The objective of this study was to investigate the efficacy of the iron chelator deferoxamine mesylate in preventing skeletal muscle ischemia. METHODS: The latissimus dorsi muscle (LDM) was mobilized in 20 adult sheep. Two separate pockets were created in each sheep. Autologous fibrin sealant with or without 100 mg/mL of deferoxamine mesylate (10 pockets) was added to the pockets. Deferoxamine mesylate alone was also applied to another 10 pockets, whereas the 10 other pockets served as controls. RESULTS: Conventional, indirect immunofluorescent enface staining showed that in nonmobilized, nonischemic LDM the capillary density was 196 +/- 14 capillaries/mm2 in the distal and 207 +/- 19 capillaries/mm2 in the middle part. After severe ischemic shock (subtotal mobilization), the muscle did not recover completely even after 2 months (149 +/- 15 capillaries/mm2 in the distal part and 177 +/- 16 capillaries/mm2 in the middle part of the LDM). Fibrin application only increased muscle neovascularization. The number of capillaries per mm2 of muscle increased to 250 +/- 25 in the distal part and to 271 +/- 24 in the middle part of the LDM. However, when fibrin was applied with added deferoxamine mesylate, the capillary density increased to 361 +/- 25 capillaries/mm2 in the distal part (p < 0.05 vs fibrin only; controls) and to 401 +/- 20 capillaries/mm2 in the middle part of the LDM (p < 0.05 vs fibrin only and p < 0.001 vs controls). The data are concordant with the blood flow estimation before and after mobilization (severe ischemic shock) in the different parts of the LDM. CONCLUSIONS: Local application of deferoxamine mesylate enhances neovascularization and recovery of surgically induced skeletal muscle ischemia in a sheep model.

Animals↗
PubMed2003

Impact of gender on the incidence and outcome of contrast-induced nephropathy after percutaneous coronary intervention.

BACKGROUND: Contrast-induced nephropathy (CIN) is a recognized complication after percutaneous interventions (PCI). We sought to determine the impact of gender on incidence and clinical outcome of CIN. METHODS AND RESULTS: Of a total 8,628 patients who underwent PCI, there were 1,431 (16.5%) who developed CIN (defined as > 25% rise in creatinine after PCI). Patients were followed clinically for one year. CIN was present in 23.6% of female versus 17.4% of male patients (p < 0.0001). Multivariate analysis showed that female gender (OR = 1.4, 95% CI = 1.25 1.60; p < 0.0001), pre-PCI chronic renal failure (CRF) (OR= 1.8, 95% CI = 1.53 2.10, p < 0.0001), diabetes mellitus (OR = 1.5, 95% CI = 1.34 1.70; p < 0.0001), age (OR = 1.01, 95% CI = 1.01 1.02, p < 0.0001), and hypertension (OR = 1.2, 95% CI = 1.06 1.36, p = 0.0035) were independent predictors of CIN. Clinical outcomes after CIN were examined in patients with or without CRF. Among patients without CRF who developed CIN, females (n = 465) had higher rates of one-year mortality, and MACE comparing to males (n = 710) without CRF (14% vs. 10% mortality, 36% vs. 30% MACE; p = 0.05 and 0.06, respectively). In patients with CRF who developed CIN, we found no significant gender differences in one-year clinical events (37% vs. 36% mortality, 42% vs. 45% MACE; p = 0.8 and 0.6, respectively). By multivariate analysis only baseline CRF, diabetes, age, functional NYHA IV class were identified as independent predictors of one-year mortality in patients with CIN after PCI. CONCLUSIONS: Female gender is an independent predictor of CIN development after PCI and a marker of worse 1-year mortality after CIN in patients without baseline CRF. After CIN is developed, pre-PCI CRF, diabetes mellitus, age, severe heart failure (not gender) are independent predictors of one-year mortality.

Aged↗
PubMed2003

Radiocontrast nephropathy: identifying the high-risk patient and the implications of exacerbating renal function.

Radiographic procedures using contrast media are widely performed throughout the world. This necessitates physicians' awareness of radiocontrast nephropathy-the disorder that develops as a result of exposure to contrast agents. Although in the general population the risk of radiocontrast nephropathy is rather low, it may be very high in selected subsets of patients. This article focuses on the incidence, pathogenesis, risk factors, and prognosis of radiocontrast nephropathy and provides important insights on its prevention.

Contrast Media↗
PubMed2003

Understanding the consequences of contrast-induced nephropathy.

Several investigations have discovered important physiologic links in the development of contrast-induced nephropathy (CIN). Studies using a canine kidney model showed that contrast media produce a direct cytotoxic effect on the renal structures. Also, there is increasing evidence that apoptosis is involved in CIN as a result of cell injury. It has been suggested that hemodynamic changes resulting from administration of contrast media may contribute to the development of CIN, although the data are not conclusive. Several vasoactive substances, such as endothelin, prostaglandins, nitric oxide, and adenosine, have been implicated in the pathogenesis of CIN, as have immune mechanisms. Several factors contribute to the development of CIN, including preexisting renal insufficiency, older age, diabetes mellitus, reduced left ventricular systolic function, advanced heart failure, acute myocardial infarction, and shock. The authors also present the risk score they developed to help clinicians identify patients with different responses to contrast exposure.

Animals↗
PubMed2002

Comparison of clinical outcomes using stents versus no stents after percutaneous coronary intervention for proximal left anterior descending versus proximal right and left circumflex coronary arteries.

Previous studies have demonstrated that proximal left anterior descending (LAD) stenoses have higher rates of restenosis after angioplasty than stenoses in other coronary segments. Stenting strategies may reduce this high rate of LAD restenosis. The study population included 1,289 patients with proximal coronary artery stenoses treated with percutaneous coronary interventions (PCI) with or without stents for single-vessel coronary disease between 1994 and 1999. Patients were divided into 4 groups: non-stent PCI in the proximal LAD artery (n = 168), non-stent PCI in proximal right/circumflex artery (n = 217), stent in the proximal LAD artery (n = 364), and stent to proximal right/circumflex artery (n = 540). Procedural success was higher in the stenting groups, but there were no significant differences in the major in-hospital events between the different lesion locations among the groups. At 1-year follow-up, there was no difference in mortality or myocardial infarction between the groups. There was no significant difference in the rate of target lesion revascularization (TLR) in the patients with proximal LAD stents compared with the patients with proximal right/circumflex coronary artery stents (10.1% vs 13.8%, p = 0.11). In the patients who did not receive stents with proximal narrowings, there was a significant increase in TLR in the LAD group compared with the right/circumflex group (21.1% vs 12.5%, p = 0.04). Thus, patients with proximal stenoses treated with non-stenting strategies have lower procedural success than those treated with stenting strategies; the patients with proximal LAD non-stent PCI have significantly higher rates of clinical restenosis than patients with proximal right and circumflex stenoses. A stenting strategy for proximal LAD stenoses appears to attenuate the differences of clinical restenosis noted after non-stent PCI.

Aged↗
PubMed2002

Intramural coronary delivery of advanced antisense oligonucleotides reduces neointimal formation in the porcine stent restenosis model.

OBJECTIVES: We evaluated the long-term influence of intramural delivery of advanced c-myc neutrally charged antisense oligonucleotides (Resten-NG) on neointimal hyperplasia after stenting in a pig model. BACKGROUND: Neointimal hyperplasia after percutaneous coronary interventions is one of the key components of the restenotic process. The c-myc is a critical cell division cycle protein involved in the formation of neointima. METHODS: In short-term experiments, different doses (from 500 microg to 5 mg) of Resten-NG or saline were delivered to the stent implantation site with an infiltrator delivery system (Interventional Technologies, San Diego, California). Animals were euthanized at 2, 6 and 18 h after interventions, and excised vessels were analyzed for c-myc expression by Western blot. In long-term experiments, either saline or a dose of 1, 5 or 10 mg of Resten-NG was delivered in the same fashion, and animals were euthanized at 28 days after the intervention. RESULTS: Western blot analysis demonstrated inhibition of c-myc expression and was dose dependent. Morphometry showed that the intimal area was 3.88 +/- 1.04 mm(2) in the control. There was statistically significant reduction of intimal areas in the 5 and 10 mg groups (2.01 +/- 0.66 and 1.95 +/- 0.91, respectively, p < 0.001) but no significant reduction in the 1 mg group (2.81 +/- 0.56, p > 0.5) in comparison with control. CONCLUSIONS: This study demonstrated that intramural delivery of advanced c-myc neutrally charged antisense morpholino compound completely inhibits c-myc expression and dramatically reduces neointimal formation in a dose dependent fashion in a porcine coronary stent restenosis model, while allowing for complete vascular healing.

Angioplasty, Balloon, Coronary↗