SciCombinator

Discover the most talked about and latest scientific content & concepts.

Concept: Coronary stent

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All other things being equal, most of us would agree that a coronary-artery stent that disappears after its useful function has been served would be preferable to a permanently indwelling device. Late stent failure occurs at a low but steady rate with the passage of time,(1) and an increasing body of evidence implicates an accelerated form of atherosclerosis inside the stent as a common underlying cause.(2) Moreover, the presence of a rigid metal scaffold in the vessel wall permanently abolishes physiologic vasomotion in the stented area. With this in mind, researchers have sought to develop self-degrading coronary stents with enough . . .

Concepts: Cardiology, Aneurysm, Coronary stent

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Drug-eluting stents (DES) have been in clinical use for nearly a decade; however, the relative short- and long-term efficacy and safety of DES compared with bare-metal stents (BMS) and among the DES types are less well defined.

Concepts: Randomized controlled trial, Drug-eluting stent, Coronary stent, Bare-metal stent, Hedge fund

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Abstract Background: For the narrow ureter that will not accommodate a ureteroscope, it is common practice to place a ureteral stent, to allow subsequent ureteroscopy in the passively dilated ureter. Surprisingly, there are limited data on the effectiveness or safety of these maneuvers. Methods: We retrospectively analyzed patients managed with ureteral stent placement followed by another attempt at ureteroscopy after an initial attempt of flexible ureteroscopy failed because the ureteroscope would not pass up an otherwise normal ureter. Results: Of 41 patients with follow-up who underwent ureteral stenting for this reason, the ureteroscope passed with ease poststenting in 29 (71%) and there was continued resistance in 12. Of these 12 patients, the ureteroscopy was continued despite resistance in 9, while another stent was placed in the remaining 3. Of these three patients, the third attempt at ureteroscopy was successful in two, and further attempts at ureteroscopy were not made after the third attempt failed in one. With a mean overall follow-up of 32 months, two patients (5%) developed ureteral strictures. Both were among nine patients in whom repeat ureteroscopy was performed despite resistance, with a rate of obstruction of 22% in this subgroup. Overall, ureteral stenting allowed successful ureteroscopy in 98% of patients. Conclusions: Ureteral stenting with subsequent ureteroscopy is a successful and safe method of addressing a narrow ureter that initially does not allow passage of a flexible ureteroscope, as long as persistent subsequent attempts to insert the ureteroscope are made only if it passes easily.

Concepts: Stent, Restenosis, Renal pelvis, Coronary stent, Ureteric stent, PASS

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OBJECTIVE: To investigate the accuracy of 128-slice dual-source CT using high-pitch spiral mode (HPS) for the assessment of coronary stents. METHODS: We conducted a prospective study on patients with previous stent implantation due to recurred suspicious symptoms of angina with positive findings at stress testing scheduled for coronary angiography (CA), while dual source computed tomography (DSCT) examinations were randomly done by one of the three different scan modes [HPS, sequential mode (SEQ), low-pitch spiral mode (LPS)] one week before CA examinations. The image quality, radiation dose and stent patency of DSCT were evaluated blinded to the results of CA. RESULTS: 180 patients with total 256 stents were enrolled in this study. There was no significant difference on the image quality of DSCT by HPS (1.4±0.5), SEQ (1.5±0.5) and LPS (1.3±0.6) (P>0.05). The noise of images reconstructed with B26f kernel in HPS is significantly increased than in SEQ/LPS (P<0.05), while no significant difference with images reconstructed with B46f kernel (P>0.05). Heart rate (HR) variability had a slight impact on the image quality for HPS (P<0.05), not for LPS/SEQ (P>0.05). In the assessment of stent restenosis compared with CA on per-stent basis, there was no significant difference on sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of DSCT using HPS (100%, 97.1%, 83.3%, 100%), LPS (92.3%, 95.9%, 80%, 98.6%) and SEQ (93.3%, 97.3%, 87.5%, 98.6%) (P>0.05). The effective dose of DSCT by HPS (1.0±0.5mSv) is significant less than that by SEQ (3.0±1.4mSv) or LPS (13.0±5.4mSv) (P<0.01). CONCLUSIONS: DSCT using HPS provides good diagnostic accuracy on coronary stent patency compared with CA, similar to that by SEQ/LPS, whereas with lower effective dose in patients with HR lower than 65bpm.

Concepts: Angina pectoris, Positive predictive value, Negative predictive value, Cardiology, Sensitivity and specificity, Stent, Drug-eluting stent, Coronary stent

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Current guidelines recommend combining clopidogrel with aspirin for up to 1 year after coronary stenting, but the value of clopidogrel beyond this time is uncertain.

Concepts: Cardiology, Percutaneous coronary intervention, Stent, Restenosis, Coronary stent, Bare-metal stent

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The EucaTax stent (EUPES) is a coronary stent with biodegradable polymer and camouflage coating that has been developed to promote the complete elution of drugs and decrease the risk of late complications. The aim of this study was to evaluate the efficacy and safety of the double-coated EUPES in patients with stable angina versus sirolimus-eluting stent CYPHER (SES) with permanent polymer coating.

Concepts: Angina pectoris, Cardiology, Percutaneous coronary intervention, Stent, Drug-eluting stent, Coronary stent

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Objective: We compare clinical outcomes among unselected patients undergoing PCI with drug-eluting stents (DES) stratified in categories of treating hospital PCI volume. Background: Previous observational evidence suggests an inverse relation between hospital percutaneous coronary intervention (PCI) volume and patients' outcomes. However, there are no mid-term outcomes data with the use of drug-eluting stents (DES). Methods: We used data from DES.DE (German Drug-Eluting Stent) registry to compare in-hospital and 1-year outcomes among unselected patients. Primary endpoints at one year follow-up were the rate of major adverse cardiac and cerebrovascular events (MACCE) and target vessel revascularization (TVR). Results: Between 2005 and 2006, 2,075 patients were treated in group I hospitals (<1,000 PCIs/year), 1,624 in group II hospitals (1,000-1,500 PCIs/year) and 1,790 in group III hospitals (>1,500 PCIs/year). Compared with group II and group III, group I allocation was associated with higher rates of overall hospital mortality (1.1% versus 0.2% versus 0.2%; p<0.0001) and severe bleeding (1.0% versus 0.4% versus 0.5%; p<0.05); similarly, poorer outcomes with respect to MACCE (7.2% versus 6.5% versus 4.7%; p<0.01), stent thrombosis (5.2% versus 5.0% versus 3.0%; p<0.01) and non-fatal stroke (1.5% versus 0.9% versus 0.7%; p<0.05) were documented in group I. Conversely, TVR rates were highest in group II (10.2% versus 14.2% versus 11.7%; p<0.01); these differences persisted after risk adjustment for heterogeneous baseline characteristics. Conclusions: In the era of modern coronary intervention technological advances such as DES have not offset the inverse relation between procedural volume and both in-hospital and 1-year outcomes after PCI. © 2013 Wiley Periodicals, Inc.

Concepts: Hospital, Cardiology, Percutaneous coronary intervention, Stent, Restenosis, Drug-eluting stent, Coronary stent, Inverse relation

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Background Patients at high risk for bleeding who undergo percutaneous coronary intervention (PCI) often receive bare-metal stents followed by 1 month of dual antiplatelet therapy. We studied a polymer-free and carrier-free drug-coated stent that transfers umirolimus (also known as biolimus A9), a highly lipophilic sirolimus analogue, into the vessel wall over a period of 1 month. Methods In a randomized, double-blind trial, we compared the drug-coated stent with a very similar bare-metal stent in patients with a high risk of bleeding who underwent PCI. All patients received 1 month of dual antiplatelet therapy. The primary safety end point, tested for both noninferiority and superiority, was a composite of cardiac death, myocardial infarction, or stent thrombosis. The primary efficacy end point was clinically driven target-lesion revascularization. Results We enrolled 2466 patients. At 390 days, the primary safety end point had occurred in 112 patients (9.4%) in the drug-coated-stent group and in 154 patients (12.9%) in the bare-metal-stent group (risk difference, -3.6 percentage points; 95% confidence interval [CI], -6.1 to -1.0; hazard ratio, 0.71; 95% CI, 0.56 to 0.91; P<0.001 for noninferiority and P=0.005 for superiority). During the same time period, clinically driven target-lesion revascularization was needed in 59 patients (5.1%) in the drug-coated-stent group and in 113 patients (9.8%) in the bare-metal-stent group (risk difference, -4.8 percentage points; 95% CI, -6.9 to -2.6; hazard ratio, 0.50; 95% CI, 0.37 to 0.69; P<0.001). Conclusions Among patients at high risk for bleeding who underwent PCI, a polymer-free umirolimus-coated stent was superior to a bare-metal stent with respect to the primary safety and efficacy end points when used with a 1-month course of dual antiplatelet therapy. (Funded by Biosensors Europe; LEADERS FREE ClinicalTrials.gov number, NCT01623180 .).

Concepts: Myocardial infarction, Cardiology, Percutaneous coronary intervention, Randomized controlled trial, Stent, Drug-eluting stent, Coronary stent, Bare-metal stent

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First-generation drug-eluting stents (DES) have been associated with impaired localized coronary vasomotion and delayed endothelialization. We aimed to compare coronary vasomotion after implantation of a newer-generation everolimus-eluting stent (EES), with a first-generation paclitaxel-eluting stent (PES). Coronary vasomotion was studied in 19 patients with EES and 13 with PES. Vasomotor response was measured proximally and distally to the stent and in a remote vessel (reference segment). Quantitative coronary angiography was performed offline. Endothelium independent vasomotion did not differ significantly between the two groups. EES showed significant vasodilatation while PES showed vasoconstriction at both proximal (+4.5 ± 3.6 vs -4.2 ± 6.9, p < 0.001) and distal (+4.6 ± 7.9 vs -4.8 ± 9.3, p = 0.003) segments. The reference segment did not show any significant difference in vasodilatation between the two groups (+9.8 ± 6.4 vs +7.2 ± 5.2, p = 0.17). Endothelium-dependent vasomotion at adjacent stent segments is relatively preserved after EES implantation while vasoconstriction was observed after PES implantation.

Concepts: Atherosclerosis, Cardiology, Atheroma, Stent, Radiology, Restenosis, Drug-eluting stent, Coronary stent

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This study sought to determine whether there is an ideal level of platelet reactivity (PR) to optimize safety and efficacy within the large multicenter ADAPT-DES (Assessment of Dual AntiPlatelet Therapy With Drug-Eluting Stents) study of 8,582 patients receiving successful drug-eluting stent implantation.

Concepts: Cardiology, Percutaneous coronary intervention, Antiplatelet drug, Stent, Restenosis, Drug-eluting stent, Coronary stent, Bare-metal stent