Antiplatelet and anticoagulant therapy in elective percutaneous coronary intervention

An architecturally rational hemostat for rapid stopping of massive bleeding on anticoagulation therapy

Hemostatic devices are critical for managing emergent severe bleeding. With the increased use of anticoagulant therapy, there is a need for next-generation hemostats. We rationalized that a hemostat with an architecture designed to increase contact with blood, and engineered from a material that activates a distinct and undrugged coagulation pathway can address the emerging need. Inspired by lung alveolar architecture, here, we describe the engineering of a next-generation single-phase chitosan hemostat with a tortuous spherical microporous design that enables rapid blood absorption and concentrated platelets and fibrin microthrombi in localized regions, a phenomenon less observed with other classical hemostats without structural optimization. The interaction between blood components and the porous hemostat was further amplified based on the charged surface of chitosan. Contrary to the dogma that chitosan does not directly affect physiological clotting mechanism, the hemostat induced coagulation via a direct activation of platelet Toll-like receptor 2. Our engineered porous hemostat effectively stopped the bleeding from murine liver wounds, swine liver and carotid artery injuries, and the human radial artery puncture site within a few minutes with significantly reduced blood loss, even under the anticoagulant treatment. The integration of engineering design principles with an understanding of the molecular mechanisms can lead to hemostats with improved functions to address emerging medical needs.

Guidance Molecules in Vascular Smooth Muscle

Several highly conserved families of guidance molecules, including ephrins, Semaphorins, Netrins, and Slits, play conserved and distinct roles in tissue remodeling during tissue patterning and disease pathogenesis. Primarily, these guidance molecules function as either secreted or surface-bound ligands that interact with their receptors to activate a variety of downstream effects, including cell contractility, migration, adhesion, proliferation, and inflammation. Vascular smooth muscle cells, contractile cells comprising the medial layer of the vessel wall and deriving from the mural population, regulate vascular tone and blood pressure. While capillaries lack a medial layer of vascular smooth muscle, mural-derived pericytes contribute similarly to capillary tone to regulate blood flow in various tissues. Furthermore, pericyte coverage is critical in vascular development, as perturbations disrupt vascular permeability and viability. During cardiovascular disease, smooth muscle cells play a more dynamic role in which suppression of contractile markers, enhanced proliferation, and migration lead to the progression of aberrant vascular remodeling. Since many types of guidance molecules are expressed in vascular smooth muscle and pericytes, these may contribute to blood vessel formation and aberrant remodeling during vascular disease. While vascular development is a large focus of the existing literature, studies emerged to address post-developmental roles for guidance molecules in pathology and are of interest as novel therapeutic targets. In this review, we will discuss the roles of guidance molecules in vascular smooth muscle and pericyte function in development and disease.

Antiplatelet and anticoagulation therapy during percutaneous coronary interventions: A review for the interventionalist

Pharmacotherapy for percutaneous coronary interventions is essential to optimize the balance between thrombosis and bleeding. Currently, choices abound for the selection of antiplatelet and anticoagulation therapies during percutaneous intervention (PCI). This review article discusses the mechanisms, pharmacokinetics/dynamics, and clinical data behind the various pharmacotherapies including; aspirin, thienopyridines, glycoprotein IIb/IIIa inhibitors, vorapaxar, heparin, direct thrombin inhibitors, and factor Xa inhibitors.

Targeted thrombolysis strategies for neuroprotective effect

Stroke is usually treated by systemic thrombolytic therapy if the patient presents within an appropriate time window. There is also widespread interest in the development of thrombolytic agents that can be used in cases of delayed presentation. Current agents that can be used in cases of delayed presentation of nerve damage by thrombus. Current systemic thrombolytic therapy is associated with adverse effects such as fibrinogenolysis and bleeding. In an attempt to increase the efficacy, safety, and specificity of thrombolytic therapy, a number of targeted thrombolytic agents have been studied in recent years. This review focuses on the concepts underlying targeted thrombolytic therapy and describes recent drug developments in this field.

Xiongshao for restenosis after percutaneous coronary intervention in patients with coronary heart disease

BACKGROUND

Percutaneous coronary intervention (PCI) with stent placement is a standard treatment for coronary heart disease (CHD). In-stent restenosis after PCI remains an important clinical problem. Xiongshao capsule has been reported to be beneficial in preventing restenosis after PCI in CHD patients. However, the strength of evidence to support its use is unclear.

OBJECTIVES

To systematically assess the efficacy and safety of Chinese herbal medicine Xiongshao capsule in preventing restenosis after PCI in patients with CHD.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library (Issue 3 of 2012), MEDLINE (OVID) (1948 to week 1 March 2012), EMBASE (OVID) (1980 to week 10 2012), ISI Web of Science with Conference Proceedings (1970 to 14 March 2012), LILACS (1982 to 15 March 2012), Chinese biomedical literature database (1980 to May 2012), China National Knowledge Infrastructure (1994 to May 2012), Chinese Medical Current Contents (1994 to May 2012), VIP Database for Chinese Technical Periodicals (1989 to May 2012), Chinese Master's Theses Full-Text Database (1994 to May 2012), China Doctor Dissertation Full-Text Database (1994 to May 2012), and China Proceedings of Conference Full-Text Database (1994 to May 2012). We also searched ongoing trials and research registries.

SELECTION CRITERIA

All randomised controlled trials comparing Xiongshao capsule alone/plus conventional western medicine with the same conventional western medicine alone/plus placebo in participants with CHD who met the recognised diagnostic criteria and had successfully undergone a PCI procedure were included.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials and extracted data. Two review authors independently assessed the risk of bias of included trials using The Cochrane Collaboration tool, and any disagreements were resolved by discussion with a third review author. Data were pooled for meta-analysis using the fixed-effect model, and the results were expressed as risk ratios (RRs) with 95% confidence intervals (CIs).

MAIN RESULTS

Four trials involving 649 participants were included in this review. Two of these trials (459 participants) were designed as randomised, double-blind, placebo-controlled trials with an adequate methodological description; the other two trials (190 participants) described an inadequate methodological design. All four trials with 649 participants were included in the meta-analysis. Significant differences were noted in rates of restenosis, recurrence angina pectoris, and serious cardiovascular adverse events between Xiongshao capsule plus conventional western medicine and the same conventional western medicine alone; RR values (95% CIs) were 0.41 (0.22 to 0.75), 0.47 (0.31 to 0.72), and 0.47 (0.25 to 0.90), respectively. Xiongshao capsule plus conventional western medicine showed more significant reductions in restenosis (RR 0.52, 95% CI 0.33 to 0.80), recurrence angina pectoris (RR 0.26, 95% CI 0.18 to 0.38), and serious cardiovascular adverse events (RR 0.45, 95% CI 0.28 to 0.70) than the same conventional western medicine plus placebo. Safety outcomes and adverse events of the Xiongshao capsule were reported in two trials, which reported no adverse events.

AUTHORS' CONCLUSIONS

The summary estimates indicate a protective effect of Xiongshao on restenosis and suggest that Xiongshao capsule may be used to prevent restenosis after a PCI procedure in CHD patients. However, this evidence is derived from small randomised trials, all conducted in China, and two of the included trials showed important methodological limitations that undermine the validity of the findings. Additional high-quality research trials with sufficient sample size are required.

The effects of xuefu zhuyu and shengmai on the evolution of syndromes and inflammatory markers in patients with unstable angina pectoris after percutaneous coronary intervention: a randomised controlled clinical trial

We evaluated the effects of the Xuefu Zhuyu capsule (XFZY) and the Shengmai capsule (SM) on the evolution of syndromes and inflammatory markers in patients with unstable angina pectoris (UAP) after percutaneous coronary intervention (PCI). Ninety patients with UAP after PCI were randomly and equally assigned to three groups: the XFZY group, the SM group, and the placebo group, with 30 patients in each group. Six syndrome factors (including Qi deficiency, yin deficiency, yang deficiency, blood stasis, phlegm, and Qi stagnation) and 4 inflammatory markers (high-sensitivity C-reactive protein (Hs-CRP), endothelins-1 (ET-1), matrix metalloproteinases-9 (MMP-9), and homocysteine (Hcy)) were observed at week 0 and at the 1st, 4th and 12th weeks. In conclusion, the evolution of syndromes present in patients with UAP after PCI followed these trends (1) The deficiency syndromes gradually increased during a 12-week period, but the excess syndromes first gradually decreased and then mildly increased after PCI. (2) XFZY and SM can prevent excess syndromes from increasing in the later stages and prevent deficiency syndromes from increasing in all stages. (3) XFZY and SMcan reduce the levels of the inflammatory markers, especially in the later stages after PCI.

Systematic Review of Chinese Herbal Medicines for Preventing in-Stent Coronary Restenosis after Percutaneous Coronary Intervention

Percutaneous coronary intervention (PCI) with stent placement is a standard treatment for coronary artery disease (CAD). In-stent restenosis after PCI remains a challenging clinical problem. In China, Chinese herbal medicines (CHMs) are widely used for preventing restenosis. This paper systematically reviewed the literature on the effectiveness and safety of CHMs in preventing restenosis after PCI in patients with CAD. Electronic databases were searched for randomized controlled trials that compared CHMs plus RWM with the same RWM plus placebo in preventing restenosis after PCI. A total of 52 trials (4905 patients) on 34 CHMs met the inclusion criteria and were analyzed. Ten trials had low risk of bias. Methodological quality of included trials was generally poor. Meta-analysis showed that at the end of at least 3 months' followup, CHMs plus RWM could significantly reduce restenosis rate, cardiac mortality, recurrence rate of angina, acute myocardial infarction, numbers of repeat PCI, and numbers of coronary artery bypass graft. Reported adverse events included gastrointestinal upset, granulocytopenia, and increased alanine transaminase (ALT). CHMs may help prevent restenosis, thus reducing cardiac mortality after PCI. Caution should be exercised in drawing a definitive conclusion due to the poor methodological quality of the trials reviewed.

Overview of advances in cardiovascular disease treatment and prevention: the evolving role of antiplatelet therapy

PURPOSE

The role of antiplatelet therapy in preventing and treating cardiovascular disease is reviewed.

SUMMARY

Cardiovascular disease, especially coronary heart disease, contributes to substantial morbidity and mortality in the United States and raises healthcare costs. Current guidelines from the American College of Cardiology and the American Heart Association, in conjunction with the Society for Cardiovascular Angiography and Interventions, recommend percutaneous coronary intervention (PCI) and stent placement to improve cardiovascular outcomes in patients with acute coronary syndrome, which encompasses unstable angina and myocardial infarction. Following stent placement, dual antiplatelet therapy with aspirin and a thienopyridine (clopidogrel or ticlopidine) significantly reduces the incidence of early major adverse cardiac events and mortality compared with aspirin alone or in combination with warfarin, and is the current standard of care for patients undergoing PCI. Maintenance therapy should be continued for at least one month after placement of a bare-metal stent, and at least three months or six months after placement of a sirolimus- or paclitaxel-eluting stent; ideally, therapy should be continued for one year following PCI. Even utilizing this standard, however, adverse clinical events do occur. In addition, treatment is often discontinued within the first year after stent placement by either the healthcare provider or the patient.

CONCLUSION

Premature discontinuation of antiplatelet therapy is associated with an increased risk of adverse outcomes and can be avoided through better understanding of these risks by healthcare professionals and improved patient education.

Clopidogrel and coronary stents: risks and benefits

Clopidogrel has become increasingly important in the management of patients with coronary stents. Clopidogrel is an oral agent that acts on the adeno-sine diphosphate receptor to irreversibly inhibit platelet aggregation. Along with aspirin, clopidogrel has a significant role in the treatment of atherothrombotic diseases. Recent concerns about late stent thrombosis highlight the need for long-term therapy with clopidogrel in addition to aspirin in these populations. This article reviews the role of clopidogrel in the treatment of atherothrombotic diseases and after coronary intervention, as well as the current approach in the prevention of stent thrombosis. It also discusses experimental and upcoming drugs that may be superior to clopidogrel.

Prevention of premature discontinuation of dual antiplatelet therapy in patients with coronary artery stents

BACKGROUND

and Overview. Dual antiplatelet therapy with aspirin and a thienopyridine has been shown to reduce cardiac events after coronary stenting. However, many patients and health care providers prematurely discontinue dual antiplatelet therapy, which greatly increases the risk of stent thrombosis, myocardial infarction and death.

CONCLUSIONS AND CLINICAL IMPLICATIONS

This advisory stresses the importance of 12 months of dual antiplatelet therapy after placement of a drug-eluting stent and educating patients and health care providers about hazards of premature discontinuation. It also recommends postponing elective surgery for one year, and if surgery cannot be deferred, considering the continuation of aspirin during the perioperative period in high-risk patients with drug-eluting stents.

Prevention of premature discontinuation of dual antiplatelet therapy in patients with coronary artery stents: a science advisory from the American Heart Association, American College of Cardiology, Society for Cardiovascular Angiography and Interventions, American College of Surgeons, and American Dental Association, with representation from the American College of Physicians

Dual antiplatelet therapy with aspirin and a thienopyridine has been shown to reduce cardiac events after coronary stenting. However, many patients and healthcare providers prematurely discontinue dual antiplatelet therapy, which greatly increases the risk of stent thrombosis, myocardial infarction, and death. This advisory stresses the importance of 12 months of dual antiplatelet therapy after placement of a drug-eluting stent and educating the patient and healthcare providers about hazards of premature discontinuation. It also recommends postponing elective surgery for 1 year, and if surgery cannot be deferred, considering the continuation of aspirin during the perioperative period in high-risk patients with drug-eluting stents.

Prevention of premature discontinuation of dual antiplatelet therapy in patients with coronary artery stents: a science advisory from the American Heart Association, American College of Cardiology, Society for Cardiovascular Angiography and Interventions, American College of Surgeons, and American Dental Association, with representation from the American College of Physicians

Dual antiplatelet therapy with aspirin and a thienopyridine has been shown to reduce cardiac events after coronary stenting. However, many patients and healthcare providers prematurely discontinue dual antiplatelet therapy, which greatly increases the risk of stent thrombosis, myocardial infarction, and death. This advisory stresses the importance of 12 months of dual antiplatelet therapy after placement of a drug-eluting stent and educating the patient and healthcare providers about hazards of premature discontinuation. It also recommends postponing elective surgery for 1 year, and if surgery cannot be deferred, considering the continuation of aspirin during the perioperative period in high-risk patients with drug-eluting stents.

Prevention of premature discontinuation of dual antiplatelet therapy in patients with coronary artery stents: A science advisory from the American Heart Association, American College of Cardiology, Society for Cardiovascular Angiography and Interventions, American College of Surgeons, and American Dental Association, with representation from the American College of Physicians

Dual antiplatelet therapy with aspirin and a thienopyridine has been shown to reduce cardiac events after coronary stenting. However, many patients and healthcare providers prematurely discontinue dual antiplatelet therapy, which greatly increases the risk of stent thrombosis, myocardial infarction, and death. This advisory stresses the importance of 12 months of dual antiplatelet therapy after placement of a drug-eluting stent and educating the patient and healthcare providers about hazards of premature discontinuation. It also recommends postponing elective surgery for 1 year, and if surgery cannot be deferred, considering the continuation of aspirin during the perioperative period in high-risk patients with drug-eluting stents.