Use of Bivalirudin for Anticoagulation in Interventional Cardiovascular Procedures

Anticoagulation is imperative to reduce the incidence of thrombotic complications in patients undergoing percutaneous interventional cardiovascular procedures; however, this is at the expense of increased risk of bleeding. The optimal anticoagulation strategy for these procedures remains unclear. Unfractionated heparin is the most commonly used anticoagulant during interventional procedures, but has several limitations, such as relatively high incidence of bleeding events, occurrence of heparin-induced thrombocytopenia, and a paradoxical thrombotic effect. Contemporary studies have demonstrated that bivalirudin decreases the occurrence of bleeding complications, but potentially increases the risk of acute stent thrombosis. This review discusses the pharmacology of bivalirudin and its current clinical application in patients undergoing percutaneous coronary intervention and transcatheter aortic valve replacement procedures

Incidence, Patterns, and Associations Between Dual-Antiplatelet Therapy Cessation and Risk for Adverse Events Among Patients With and Without Diabetes Mellitus Receiving Drug-Eluting Stents: Results From the PARIS Registry.

OBJECTIVES: The aim of this study was to examine the frequency and clinical impact of different cessation patterns of dual-antiplatelet therapy (DAPT) after percutaneous coronary intervention with drug-eluting stents among patients with and those without diabetes mellitus (DM). BACKGROUND: Early DAPT suspension after percutaneous coronary intervention increases the risk for major adverse cardiac events. However, temporal variability in risk and relation to DAPT cessation patterns among patients with DM remain unclear. METHODS: Using data from the PARIS (Patterns of Non-Adherence to Anti-Platelet Regimens in Stented Patients) registry, 1,430 patients with DM (34%) and 2,777 without DM (66%) treated with drug-eluting stents were identified. DAPT cessation modes were classified as temporary interruption (<14 days), disruption because of bleeding or poor compliance, and physician-recommended discontinuation. RESULTS: During 2-year follow-up, DM was associated with an increased risk for thrombotic events but a similar risk for bleeding. The cumulative incidence of DAPT cessation was significantly lower in patients with versus those without DM (50.1% vs. 55.4%; p < 0.01), driven largely by less frequent physician-guided discontinuation beyond 1 year. In contrast, 2-year rates of interruption and disruption were similar between groups. When DAPT was interrupted or discontinued under physician guidance, the risk for major adverse cardiac events was unchanged compared with patients with DM on uninterrupted DAPT. Conversely, when DAPT was disrupted, the risk for major adverse cardiac events increased compared with uninterrupted DAPT, regardless of diabetic status, with no evidence of statistical interaction. CONCLUSIONS: DAPT cessation patterns vary according to diabetic status, with less frequent physician-guided discontinuation among patients with DM. The presence of DM does not emerge as a modifier of cardiovascular risk after DAPT cessation

Causes, Timing, and Impact of Dual Antiplatelet Therapy Interruption for Surgery (From the PARIS Registry)

Temporary interruption of dual antiplatelet therapy (DAPT) is not infrequently required in patients undergoing percutaneous coronary intervention (PCI). We sought to describe the procedures and outcomes associated with DAPT interruption in patients treated with DAPT following successful PCI from the Patterns of non-adherence to anti-platelet regimens in stented patients registry (n = 5018). DAPT interruption was prespecified as physician recommended cessation forcohort, 490 patients (9.8%) experienced 594 DAPT interruptions over 2 years following PCI. Only 1 antiplatelet agent was interrupted in 57.2% cases and interruption was frequently recommended by noncardiologists (51.3%). Where type of surgery was reported, majority of DAPT interruptions occurred for minor surgery (68.4% vs 31.6%) and a similar cessation pattern of single versus dual antiplatelet cessation was observed regardless of minor or major surgery. Subsequent to DAPT interruption, 12 patients (2.4%) experienced 1 thrombotic event each, of which 5 (1.0%) occurred during the interruption period. All events occurred in patients who either stopped both agents (8 of 12) or clopidogrel-only (4 of 12), with no events occurring due to aspirin cessation alone. In conclusion, in the Patterns of Non-adherence to Anti-platelet Regiments in Stented Patients registry, 1 in 10 patients were recommended DAPT interruption for surgery within 2 years of PCI. Interruption was more common for a single agent rather than both antiplatelet agents regardless of severity of surgery, and was frequently recommended by noncardiologists. Only 1% of patients with DAPT interruption experienced a subsequent thrombotic event during the interruption period, which mainly occurred in patients stopping both antiplatelet agents

Dual-Antiplatelet Therapy Cessation and Cardiovascular Risk in Relation to Age: Analysis From the PARIS Registry.

OBJECTIVES: The aim of this study was to examine the association between dual-antiplatelet therapy (DAPT) cessation and cardiovascular risk after percutaneous coronary intervention in relation to age. BACKGROUND: Examination of outcomes by age after percutaneous coronary intervention is relevant given the aging population. METHODS: Two-year clinical outcomes, incidence, and effect of DAPT cessation on outcomes were compared by ages ≤55, 56 to 74, and ≥75 years from the PARIS (Patterns of Non-Adherence to Antiplatelet Regimens in Stented Patients) registry. DAPT cessation included physician-recommended discontinuation, interruption for surgery, and disruption (from noncompliance or bleeding). Clinical endpoints were major adverse cardiac events (MACE) (a composite of cardiac death, definite or probable stent thrombosis, spontaneous myocardial infarction, or clinically indicated target lesion revascularization), a secondary restrictive definition of MACE (MACE2) excluding target lesion revascularization, and bleeding. RESULTS: A total of 1,192 patients (24%) were ≤55 years, 2,869 (57%) were 56 to 74 years, and 957 (19%) were ≥75 years of age. Patients ≥75 years of age had higher DAPT cessation rates and increased risk for MACE2, death, cardiac death, and bleeding compared with younger patients. Discontinuation and interruption were not associated with increased cardiovascular risk across age groups, whereas disruption was associated with increased risk for MACE and MACE2 in younger patients but not in patients ≥75 years of age (p for trend <0.05). CONCLUSIONS: Nonadherence and outcomes vary by age, with patients ≥75 years having the highest DAPT cessation rates. We observed no association between outcomes and DAPT cessation in patients ≥75 years, whereas discontinuation was associated with lower MACE rates and disruption with increased MACE rates in patients <75 years

Prevalence, predictors, and outcomes of patient prosthesis mismatch in women undergoing TAVI for severe aortic stenosis: Insights from the WIN-TAVI registry

Objective: To evaluate the incidence, predictors and outcomes of female patients with patient-prosthesis mismatch (PPM) following transcatheter aortic valve intervention (TAVI) for severe aortic stenosis (AS). Background: Female AS TAVI recipients have a significantly lower mortality than surgical aortic valve replacement (SAVR) recipients, which could be attributed to the potentially lower PPM rates. TAVI has been associated with lower rates of PPM compared to SAVR. PPM in females post TAVI has not been investigated to date. Methods: The WIN-TAVI (Women's INternational Transcatheter Aortic Valve Implantation) registry i

Use of prasugrel vs clopidogrel and outcomes in patients with acute coronary syndrome undergoing percutaneous coronary intervention in contemporary clinical practice: Results from the PROMETHEUS study.

BACKGROUND AND OBJECTIVES: We sought to determine the frequency of use and association between prasugrel and outcomes in acute coronary syndrome patients undergoing percutaneous coronary intervention (PCI) in clinical practice. METHODS: PROMETHEUS was a multicenter observational registry of acute coronary syndrome patients undergoing PCI from 8 centers in the United States that maintained a prospective PCI registry for patient outcomes. The primary end points were major adverse cardiovascular events at 90days, a composite of all-cause death, nonfatal myocardial infarction, stroke, or unplanned revascularization. Major bleeding was defined as any bleeding requiring hospitalization or blood transfusion. Hazard ratios (HRs) were generated using multivariable Cox regression and stratified by the propensity to treat with prasugrel. RESULTS: Of 19,914 patients (mean age 64.4years, 32% female), 4,058 received prasugrel (20%) and 15,856 received clopidogrel (80%). Prasugrel-treated patients were younger with fewer comorbid risk factors compared with their counterparts receiving clopidogrel. At 90days, there was a significant association between prasugrel use and lower major adverse cardiovascular event (5.7% vs 9.6%, HR 0.58, 95% CI 0.50-0.67, P<.0001) and bleeding (1.9% vs 2.9%, HR 0.65, 95% CI 0.51-0.83, P<.001). After propensity stratification, associations were attenuated and no longer significant for either outcome. Results remained consistent using different approaches to adjusting for potential confounders. CONCLUSIONS: In contemporary clinical practice, patients receiving prasugrel tend to have a lower-risk profile compared with those receiving clopidogrel. The lower ischemic and bleeding events associated with prasugrel use were no longer evident after accounting for these baseline differences

Associations Between Complex PCI and Prasugrel or Clopidogrel Use in Patients With Acute Coronary Syndrome Who Undergo PCI: From the PROMETHEUS Study.

BACKGROUND: Potent P2Y12 inhibitors might offer enhanced benefit against thrombotic events in complex percutaneous coronary intervention (PCI). We examined prasugrel use and outcomes according to PCI complexity, as well as analyzing treatment effects according to thienopyridine type. METHODS: PROMETHEUS was a multicentre observational study that compared clopidogrel vs prasugrel in acute coronary syndrome patients who underwent PCI (n = 19,914). Complex PCI was defined as PCI of the left main, bifurcation lesion, moderate-severely calcified lesion, or total stent length ≥ 30 mm. Major adverse cardiac events (MACE) were a composite of death, myocardial infarction, stroke, or unplanned revascularization. Outcomes were adjusted using multivariable Cox regression for effect of PCI complexity and propensity-stratified analysis for effect of thienopyridine type. RESULTS: The study cohort included 48.9% (n = 9735) complex and 51.1% (n = 10,179) noncomplex patients. Second generation drug-eluting stents were used in 70.1% complex and 66.2% noncomplex PCI patients (P < 0.0001). Complex PCI was associated with greater adjusted risk of 1-year MACE (hazard ratio [HR], 1.29; 95% confidence interval [CI], 1.20-1.39; P < 0.001). Prasugrel was prescribed in 20.7% of complex and 20.1% of noncomplex PCI patients (P = 0.30). Compared with clopidogrel, prasugrel significantly decreased adjusted risk for 1-year MACE in complex PCI (HR, 0.79; 95% CI, 0.68-0.92) but not noncomplex PCI (HR, 0.91; 95% CI, 0.77-1.08), albeit there was no evidence of interaction (P interaction = 0.281). CONCLUSIONS: Despite the use of contemporary techniques, acute coronary syndrome patients who undergo complex PCI had significantly higher rates of 1-year MACE. Adjusted magnitude of treatment effects with prasugrel vs clopidogrel were consistent in complex and noncomplex PCI without evidence of interaction

INVESTIGATION ON THE MECHANICAL PROPERTIES OF PLA & ITS COMPOSITE FABRICATED THROUGH ADVANCED FUSION PLASTIC MODELLING

Advanced Fusion plastic modelling (AFPM) based rapid prototyping (RP) technique was emerged as one of the potential Technologies for serving numerous three-dimensional product for tool design purposes. Primarily, Poly Lactic Acid (PLA) and Acrylonitrile Butadiene Styrene (ABS) are the key materials used for RP purposes. However, a PLA based composite was developed for RP applications. In this paper, an effort was made to prepare a PLA composite using bronze and cellulose as an additive. The objective of the proposed PLA composites is to performe the mechanical properties such as tensile and flexural strength at varied AFPM parameters like nozzle diameter, layer thicknesses and printing speeds. Three PLA composites including natural PLA and PLA with cellulose and bronze additives was prepared. Here, efforts were made on optimised the mechanical properties with the different composites and printing. The tensile and flexural strength of the PLA and its composites samples have been examined and with the nozzle diameter of 0.4 mm, layer thickness of 0.2 mm and the printing speed of 30 mm/s exhibited natural PLA has better tensile and flexural strength properties. The results also confirmed that the addition of bronze and Cellulose as additive exhibits moderate strength mechanical than the natural PLA but it has a pourous nature because of the gas prodused in the printing process

Total synthesis of the alkaloid (−)-codonopsinine from L-xylose

The enantiopure total synthesis of (−)-codonopsinine is described from commercially available L-xylose in 20% overall yield. The key steps included Julia trans olefination and cascade epoxidation-cyclisation strategies

TaCl<SUB>5</SUB>-catalyzed cleavage of epoxides with aromatic amines

Tantalum(V) chloride has been demonstrated as an efficient catalyst in ring opening of epoxides with aromatic amines for the synthesis of β-amino alcohols for the first time