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George Dangas

Publications and source records attributed to George Dangas.

87 records · Page 5Linked to original sources
PubMed2002

Meta-analysis of randomized and registry comparisons of ticlopidine with clopidogrel after stenting.

OBJECTIVES: We sought to determine whether clopidogrel is at least as efficacious as ticlopidine. BACKGROUND: Several trials have supported the enhanced safety and tolerability of clopidogrel compared with ticlopidine after coronary stent deployment. However, none of these individual trials were powered to detect possible differences in the efficacy for reducing ischemic end points. METHODS: Published data from trials and registries that compared clopidogrel with ticlopidine in patients receiving coronary stents were pooled, and a formal meta-analysis was performed. The rate of 30-day major adverse cardiac events (MACE), as defined in each trial, was used as the primary end point. RESULTS: There were a total of 13,955 patients. The pooled rate of major adverse cardiac events was 2.10% in the clopidogrel group and 4.04% in the ticlopidine group. After adjustment for heterogeneity in the trials, the odds ratio (OR) of having an ischemic event with clopidogrel, as compared with ticlopidine, was 0.72 (95% confidence interval [CI] 0.59 to 0.89, p = 0.002). Mortality was also lower in the clopidogrel group compared with the ticlopidine group-0.48% versus 1.09% (OR 0.55, 95% CI 0.37 to 0.82; p = 0.003). CONCLUSIONS: Based on all available evidence from randomized clinical trials or registries, clopidogrel, in addition to better tolerability and fewer side effects, is at least as efficacious as ticlopidine in reducing MACE. This finding may be due to the more rapid onset of an antiplatelet effect seen with the loading dose of clopidogrel, which was used in most of these studies, or to better patient compliance with clopidogrel therapy. Therefore, clopidogrel plus aspirin should replace ticlopidine plus aspirin as the standard antiplatelet regimen after stent deployment.

Aspirin↗
PubMed2002

Clinical outcome following percutaneous coronary interventions in patients with chronic renal failure.

The clinical outcome of patients with chronic renal failure (CRF) who undergo percutaneous coronary intervention (PCI) has not been systematically evaluated in a large cohort of patients. We retrospectively analyzed the in-hospital and 1-year clinical outcomes of 10,076 consecutive patients who underwent PCI between January 1994 and December 1997. A total of 95 patients (0.9%) had end-stage renal disease (ESRD) on dialysis, 786 patients (7.8%) had CRF, and 9,125 patients (90.6%) had normal renal function. Despite an angiographic success rate of 97% in all three groups, in-hospital mortality was significantly higher among patients with renal disease, whether they were on dialysis or not, when compared to patients without renal dysfunction (6.8% vs. 4.2% vs. 0.9%; P < 0.0001). At 1-year follow-up, mortality rate was 48.8% for ESRD, 25.7% for patients with CRF, and 5.5%, for patients without renal dysfunction (P < 0.0001). By multivariate analysis, high left ventricular ejection fraction and creatinine clearance were associated with decreased late mortality (OR = 0.84 and 0.95; P < 0.0001), whereas ESRD (OR = 3.65; P = 0.0002), non-Q-wave myocardial infarction (OR = 2.21; P < 0.0001), diabetes mellitus (OR = 1.99; P < 0.0001), and CRF (OR = 1.74; P = 0.003) were independent correlates of increased late mortality. Therefore, PCI in patients with impaired renal function, whether on dialysis or not, is associated with poor in-hospital and 1-year survival.

Aged↗
PubMed2002

New-device angioplasty in women: clinical outcome and predictors in a 7,372-patient registry.

BACKGROUND: Female gender has been identified as an independent predictor of early complications and mortality after conventional balloon angioplasty. To gain insight into the outcome of women after new-device angioplasty, we reviewed the early and late clinical outcome of 7,372 patients undergoing new-device angioplasty between 1991 and 1996 at the Washington Hospital Center. METHODS: Patients (2,077 women and 5,295 men) with native coronary artery (82.5%) or saphenous vein graft lesions undergoing new-device angioplasty were included in the study. In-hospital and 1-year major adverse cardiac events (MACE), including death, myocardial infarction, and target lesion revascularization (TLR), were recorded and compared on the basis of gender. Multivariable logistic regression analysis was performed to identify predictors of in-hospital and late mortality, follow-up MACE, and TLR. RESULTS: Women had more baseline comorbid risk factors and smaller reference vessel size compared with men. Women had a higher in-hospital cardiac mortality (1.39% vs 0.66%, P = 0.002), TLR (2.78% vs 1.81%, P = 0.008), and congestive heart failure (4.18% vs 2.29%, P < 0.001) compared with men. Overall in-hospital MACE tended to be higher among women (4.2% vs 3.3%, P = 0.074). Women had a higher 1-year mortality rate (4.39% vs 3.26%, P = 0.018), but a lower follow-up TLR (15.0% vs 18.1%, P = 0.001) and a lower overall MACE rate (29.2% vs 32.7%, P = 0.007) compared with men. Female gender was an independent predictor of in-hospital mortality (odds ratio 2.28, P = 0.02), but not late mortality. CONCLUSIONS: Although female gender appears to carry an inherent risk of in-hospital mortality after new-device angioplasty, the procedural success and mortality rates are favorable compared with those associated with balloon angioplasty series. The long-term clinical outcome of women after new-device angioplasty is excellent. The use of new devices is a safe and effective alternative strategy for the treatment of women with ischemic coronary artery disease. Device-specific outcomes, including stents, will require further evaluation.

Angioplasty↗
PubMed2002

Acute angiographic and clinical results of the NIR w/SOX stent.

Acute angiographic and clinical results of the NIR w/SOX stent (Boston Scientific/Scimed, Inc., Maple Grove, Minnesota) were evaluated. Between March 2000 and May 2000, a total of 102 lesions in 88 patients underwent stenting with the NIR w/SOX stent. The reference vessel diameter and lesion length were 2.97 +/- 0.50 mm and 16.2 +/- 6.5 mm, respectively. The minimal lumen diameter increased from 0.68 +/- 0.45 to 3.07 +/- 0.50 mm. Stent delivery failure was observed in 4 lesions (3.9%). On the other hand, the NIR w/SOX stent was successfully delivered in 7 of 9 lesions that had unsuccessful delivery of other kinds of stents. Angiographic success was observed in all except 1 lesion where the NIR w/SOX stents could not be delivered. There were no procedural myocardial infarctions or deaths. In one case, procedural coronary bypass surgery was performed. There was no acute closure or subacute stent thrombosis. Despite unfavorable lesion characteristics, the NIR w/SOX stent achieves high procedural success and acceptable stent delivery. Furthermore, it may have a high probability to be delivered in lesions where other kinds of stent result in unsuccessful delivery.

Aged↗
PubMed2002

Coronary artery spasm associated with a moderately severe atherosclerotic stenosis in the proximal LAD.

Treatment of coronary artery spasm can be difficult; up to 25% of patients continue to have episodes of chest pain despite maximal therapy with calcium antagonists and nitrates. We describe the case of a 42-year-old female with severe coronary artery spasm associated with a moderately severe atherosclerotic stenosis of the proximal left anterior descending coronary artery. We discuss the diagnostic value of intravascular ultrasound and treatment options for spasm associated with atherosclerotic plaques.

Adult↗
PubMed2001

Update on In-stent Restenosis.

Although stents mitigate the risk of restenosis, in-stent restenosis (ISR) is still an important clinical problem. ISR usually occurs within the first 3 to 6 months after stenting, with little progression thereafter. ISR progresses through four distinct phases: thrombosis, inflammation, proliferation, and vessel remodeling. Platelets and macrophages play a crucial role in the formation of neointimal tissue via stimulation of vascular smooth muscle migration and proliferation at the injury site. The angiographic pattern of ISR conveys prognostic information on subsequent target vessel revascularization with diffuse proliferative ISR, with total occlusion having the worst prognosis. Stent length and final minimal lumen diameter are additional predictors of ISR. Certain gene polymorphisms may increase the risk of developing ISR. No curative therapeutic modality for ISR has been found; efforts have been focusing on prevention. In this regard, intracoronary radiation therapy has shown the best results, although the promise of several technologies, particularly the drug-eluting stents, will likely result in further reductions (or perhaps irradiation) in the incidence of ISR.

Journal Article↗
PubMed2001

A Comparison of Tirofiban and Abciximab in Patients Undergoing Coronary Stent Implantation: Rationale, Design, and Results of the TARGET Trial.

Three intravenous glycoprotein IIb/IIIa inhibitors, abciximab, tirofiban, and eptifibatide, when administered intravenously just before percutaneous intervention, have been shown to reduce the composite 30-day occurrence of death, myocardial infarction, or urgent target vessel revascularization. These agents differ from each other notably in chemical structure, pharmacokinetics, and pharmacodynamic activity. Whether they are clinically equivalent can be answered only by a well-designed, large scale, head-to-head randomized trial. The TARGET trial prospectively compared the efficacy of abciximab with that of tirofiban as an adjunct to coronary stent implantation in 4809 randomized patients with diverse characteristics. The 30-day results demonstrated that abciximab offered greater protection than tirofiban from major ischemic events, principally due to a significant reduction in peri-procedural myocardial infarction, with the greatest effect seen in patients with acute coronary syndromes. However, by 6 months the differences between the two agents had largely disappeared such that the composite rates of death, myocardial infarction, and target vessel revascularization were similar. The implications of this study on the cost-effective utilization of glycoprotein IIb/IIIa inhibitors are profound.

Journal Article↗
PubMedDate not supplied

Complete vascular healing and sustained suppression of neointimal thickening after local delivery of advanced c-myc antisense at six months follow-up in a rabbit balloon injury model.

BACKGROUND: Neointimal hyperplasia following percutaneous transluminal coronary angioplasty (PTCA) is one of the major components of the process of restenosis. We evaluated the long-term impact of local delivery of c-myc neutrally charged antisense oligonucleotides (Resten-NG) upon neointimal formation following PTCA in a rabbit model. METHODS: PTCA was performed in the iliac arteries of 10 New Zealand white rabbits at 8 atm for 30 s, three times. An infusion of 500 micro g Resten-NG (n=6) or saline (n=4) was delivered to the site at 2 atm via the outer balloon pores of the transport catheter over 2 min. The diet was supplemented with 0.25% cholesterol for 10 days before and 6 months following PTCA. RESULTS: After 6 months, animals were sacrificed and vessels were fixed in formalin, processed and stained with hematoxylin, eosin, and movat. Histological analysis revealed complete vascular healing in both groups of animals. Planimetry showed that intimal areas were 1.71+/-0.25 and 0.65+/-0.36 mm2 in the control and antisense delivery groups, respectively (P<.05). CONCLUSION: We conclude that local delivery of Resten-NG significantly inhibited neointimal thickening following PTCA in a rabbit for up to 6 months.

Angioplasty, Balloon, Coronary↗
PubMedDate not supplied

Systemic targeted delivery of antisense with perflourobutane gas microbubble carrier reduced neointimal formation in the porcine coronary restenosis model.

HYPOTHESIS: The antisense phosphorodiamidate morpholino oligomer (PMO), AVI-4126, has been effective in reducing neointimal formation in animal models following delivery by pluronic gels, local delivery catheters and coated stents. Greater flexibility of repeated-dosage regimens and reduced procedure complexity may be provided by systemic injection of AVI-4126 bound to perfluorobutane gas microbubble carriers. The purpose of this study was to investigate the effects of perfluorocarbon gas microbubble carrier (PGMC)-based systemic delivery of AVI-4126 on expression of the c-myc in vascular tissue and restenosis after stent implantation. METHODS: Seven pigs underwent stent implantation (3 stents/animal). Five pigs received IV injection of PGMC and 2 mg of AVI-4126 (AVI BioPharma). Two served as control. Four hours postprocedure, 3 pigs were sacrificed and stented segments analyzed by high-performance liquid chromatography (HPLC) and Western blot. In chronic experiments, 4 pigs (12 stent sites) were sacrificed at 28 days. RESULTS: HPLC analysis of plasma samples of treated animals showed minimal presence of AVI-4126. HPLC of the treated arteries demonstrated easily detected concentrations of AVI-4126. Western blot analysis of the stented vessels demonstrated modest inhibition of c-myc. Morphometry showed that the neointimal area was significantly reduced in the AVI-4126/PGMC group compared with control (2.63+/-1.99 vs. 4.77+/-.1.71 mm2, respectively, P<.05). CONCLUSION: In the porcine coronary stent model, systemic targeted delivery of AVI-4126 using PGMC carrier significantly inhibited neointimal formation.

Animals↗
PubMedDate not supplied

How to diagnose, how to treat: renal artery stenosis-diagnosis and management.

Renal artery stenosis is considered to be one of the more frequent causes of secondary arterial hypertension. Through its progression renal artery stenosis can cause renal insufficiency, uncontrolled hypertension, and increased cardiovascular morbidity. A thorough clinical examination and the presence of a typical abdominal bruit may provide helpful hints to identify hypertensive patients with possible renal artery stenosis. Testing for renovascular hypertension includes renal artery imaging, assessment of its functional significance, and evaluation for possible revascularization. Renal artery stenosis secondary to fibromuscular dysplasia should be mechanically corrected. For atherosclerotic renal artery stenosis, medical management can be attempted so long as it does not cause a decline of kidney function. In patients who are candidates for renovascular revascularization, surgical intervention can be helpful in improving blood pressure control and possibly halting the progression of renal failure. Randomized controlled trials comparing direct stenting with other surgical methods are necessary to define the best revascularization strategy in patients with renovascular hypertension. A careful follow-up study after renal artery revascularization should evaluate possible benefits in halting the deterioration of chronic renal insufficiency.

Adult↗