Antithrombotic Therapy in Valvular Heart Disease—Native and Prosthetic

Effect of CYP2C9, VKORC1, CYP4F2 and GGCX genetic variants on warfarin maintenance dose and explicating a new pharmacogenetic algorithm in South Indian population

OBJECTIVE

To determine the influence of genetic polymorphisms on warfarin maintenance dose and to explicate an algorithm using the pharmacogenetic and clinical factors to determine the maintenance and/or starting dose of warfarin in South Indian patients receiving warfarin therapy.

METHODS

Patients receiving stabilized warfarin therapy (n=257) were included in the study. Single nucleotide polymorphisms (SNPs) of CYP2C9 (rs1799853 and rs1057910), VKORC1 (rs9923231, rs7196161, rs2884737, rs9934438, rs8050894, rs2359612 and rs7294), CYP4F2 (rs2108622) and GGCX (rs11676382) were genotyped by the quantitative real time-PCR method.

RESULTS

The mean daily maintenance dose of warfarin was found to be 4.7 ± 2.1 mg/day. Patients with the CYP2C9*1/*2, *1/*3 and *2/*3 variant genotypes required a 51.0 (2.8 mg), 60.9 (2.3 mg) and 62.2 % (2.2 mg) lower daily maintenance dose of warfarin, respectively, than those patients with the CYP2C9*1/*1 wild-type genotype (5.2 mg) (p<0.0001). The genetic variants of CYP2C9, VKORC1 and GGCX were associated with decreased warfarin dose, except for rs7196161, rs7294 and rs2108622 which were associated with an increased warfarin dose. Genetic variations of CYP2C9 (*2 and *3), VKORC1 (rs9923231, rs7294, rs9934438 and rs2359612), CYP4F2, GGCX and non-genetic factors such as age, body weight, clinical status (post mechanical valve replacement) could explain up to 62.1 % of the overall variation (adjusted r (2) 60.2 %, p<0.0001) in warfarin maintenance dose.

CONCLUSION

Genetic polymorphisms of CYP2C9, VKORC1, CYP4F2 and GGCX are important predictive factors of warfarin maintenance dose, and the developed algorithm will be useful to predict the required maintenance and/or starting warfarin dose in South Indian populations.

VKORC1 and CYP2C9 Genotype Variations in Relation to Warfarin Dosing in Korean Stroke Patients

Background and Purpose

Variant alleles of CYP2C9 and VKORC1 account for differences in anticoagulation response. We sought to establish a warfarin dosing formula for individualized target International Normalization Ratio of Prothrombin Times (INRs) using data from single nucleotide polymorphisms (SNPs) in VKORC1 and CYP2C9 in Korean patients.

Methods

Ischemic stroke patients displaying stable target INR for at least 3 months before enrollment were analyzed. Warfarin and vitamin K levels were measured to adjust for confounders. Phenotypes were defined using the 'warfarin response index' (WRI) defined as INR divided by the daily maintenance warfarin dose. We tested SNPs in CYP2C9 (3 sites: 430C>T (rs1799853), 1075A>C (rs1057910), 1076T>C) and VKORC1 (14 sites: 381C>T, 861C>A (rs17880887), 2653G>C, 3673A>G, 5496G>T, 5808T>G (r17882154), 6009C>T, 6484T>C (rs9934438), 6853C>T (rs17886369), 7566T>C, 8767G>C, 8814T>C, 9041G>A (rs17880624), and 9071G>T) using a standard sequencing method. Multivariate linear regression analysis was applied to establish the formula for warfarin dosage.

Results

All 204 patients had excellent drug compliance. The mean INR was 2.22 (+0.56) and mean daily maintenance dose of warfarin was 3.92 mg (+1.54). Patients with low WRI were younger (P<0.001) with high body mass index (P=0.003), high prevalence of wild-type CYP2C9 polymorphism (1075A>C, P<0.001), and six heterozygote SNPs in VRORC1 (P<0.001), which were tightly interlinked (381T>C, 3673G>A, 6484T>C, 6853C>G. 7566C>T, 9041G>A) (r²=1). Based on these data, a warfarin dosing formula was established.

Conclusions

WRI is influenced by age, body mass index and SNPs in VKORC1 and CYP2C9 in Korean stroke patients. The obtained warfarin dosing formula may be clinically applicable.

Comparison of Atrial Fibrillation in the Young versus That in the Elderly: A Review

The incidence and prevalence of atrial fibrillation (AF) are projected to increase significantly worldwide, imposing a significant burden on healthcare resources. The disease itself is extremely heterogeneous in its epidemiology, pathophysiology, and treatment options based on individual patient characteristics. Whilst ageing is well recognised to be an independent risk factor for the development of AF, this condition also affects the young in whom the condition is frequently symptomatic and troublesome. Traditional thinking suggests that the causal factors and pathogenesis of the condition in the young with structurally normal atria but electrophysiological "triggers" in the form of pulmonary vein ectopics leading to lone AF are in stark contrast to that in the elderly who have AF primarily due to an abnormal substrate consisting of fibrosed and dilated atria acting in concert with the pulmonary vein triggers. However, there can be exceptions to this rule as there is increasing evidence of structural and electrophysiological abnormalities in the atrial substrate in young patients with "lone AF," as well as elderly patients who present with idiopathic AF. These reports seem to be blurring the distinction in the pathophysiology of so-called idiopathic lone AF in the young versus that in the elderly. Moreover with availability of improved and modern investigational and diagnostic techniques, novel causes of AF are being reported thereby seemingly consigning the diagnosis of "lone AF" to a rather mythical existence. We shall also elucidate in this paper the differences seen in the epidemiology, causes, pathogenesis, and clinical features of AF in the young versus that seen in the elderly, thereby requiring clearly defined management strategies to tackle this arrhythmia and its associated consequences.

Long-term safety and efficacy of a pasteurized nanofiltrated prothrombin complex concentrate (Beriplex P/N): a pharmacovigilance study

Background

The rapid reversal of the effects of vitamin K antagonists is often required in cases of emergency surgery and life-threatening bleeding, or during bleeding associated with high morbidity and mortality such as intracranial haemorrhage. Increasingly, four-factor prothrombin complex concentrates (PCCs) containing high and well-balanced concentrations of vitamin K-dependent coagulation factors are recommended for emergency oral anticoagulation reversal. Both the safety and efficacy of such products are currently in focus, and their administration is now expanding into the critical care setting for the treatment of life-threatening bleeding and coagulopathy resulting either perioperatively or in cases of acute trauma.

Methods

After 15 yr of clinical use, findings of a pharmacovigilance report (February 1996–March 2012) relating to the four-factor PCC Beriplex P/N (CSL Behring, Marburg, Germany) were analysed and are presented here. Furthermore, a review of the literature with regard to the efficacy and safety of four-factor PCCs was performed.

Results

Since receiving marketing authorization (February 21, 1996), ∼647 250 standard applications of Beriplex P/N have taken place. During this time, 21 thromboembolic events judged to be possibly related to Beriplex P/N administration have been reported, while no incidences of viral transmission or heparin-induced thrombocytopenia were documented. The low risk of thromboembolic events reported during the observation period (one in ∼31 000) is in line with the incidence observed with other four-factor PCCs.

Conclusions

In general, four-factor PCCs have proven to be well tolerated and highly effective in the rapid reversal of vitamin K antagonists.

Interactions between cardiovascular and cerebrovascular disease

OPININION STATEMENT: All patients with ischemic stroke should undergo a comprehensive assessment of cardiovascular risk. Patients with carotid artery disease, symptoms of cerebral ischemia and high cardiovascular risk profiles should be considered for noninvasive testing for coronary artery disease (CAD). Routine testing for CAD before carotid endarterctomy is not recommended. Patients with coexisting coronary and carotid artery disease should be more aggressively treated for reducing their "very high" risk of cardiovascular events. In patients candidates to carotid revascularization, a preoperative coronary angiography and coronary revascularization are not recommended. Warfarin is recommended in all patients with moderate to high risk of stroke. Novel oral anticoagulants represent an attractive alternative to warfarin. However, their place in therapy in clinical practice is not yet established. Percutaneous closure of the left atrial appendage for stroke prophylaxis may be considered in selected patients with atrial fibrillation and contraindications for oral anticoagulant therapy. Warfarin is not indicated in patients with heart failure who are in sinus rhythm. Percutaneous closure of patent foramen does not seem to be superior to medical therapy for the prevention of recurrences in patients with cryptogenic stroke.

The emerging role of cardiovascular MRI for suspected cardioembolic stroke

Stroke is a leading cause of morbidity and long-term disability worldwide and is often the result of embolic material from the heart or proximal aorta. These are referred to as cardioembolic sources of stroke. The investigation of patients with suspected cardioembolic stroke has traditionally been the mainstay of echocardiography. Cardiac magnetic resonance imaging (MRI) is a powerful imaging technique that has rapidly evolved over the last decade and is playing an ever increasing role in clinical cardiovascular imaging. This review of the literature aims to furnish the reader with an understanding of the role of cardiac MRI across the spectrum of causes of cardioembolic sources of stroke by providing the reader with an overview of the indications, technical considerations, a proposed imaging algorithm, and capabilities of this technology with selected illustrated examples of disease entities.

Quadruple Valve Replacement with Mechanical Valves: An 11-Year Follow-up Study

<p><b>Background:</b> We performed the first quadruple valve replacement with mechanical valves, combined with the correction of complex congenital heart disease on November 17, 1999. We report here the 11-year follow-up study.</p><p><b>Methods:</b> A 47-year-old man with subacute rheumatic endocarditis, a ventricular septal defect, and an obstruction of the right ventricular outflow tract required replacement of the aortic, mitral, tricuspid, and pulmonary valves; repair of the ventricular septal defect; and relief of the obstruction of the right ventricular outflow tract. The surgery was done on November 17, 1999, after careful systemic preparation of the patient. Warfarin therapy with a target international normalized ratio (INR) range of 1.5 to 2.0 was used. Follow-up included monitoring the INR, recording the incidences of thromboembolic and bleeding events, electrocardiography, radiography, and echocardiography evaluations.</p><p><b>Results:</b> The patient's INR was maintained between 1.5 and 2.0. All 4 mechanical prosthetic heart valves worked well. He is in generally good health without any thromboembolic or bleeding complications.</p><p><b>Conclusions:</b> Long-term management is challenging for patients who have experienced quadruple valve replacement with mechanical valves; however, promising results could mean that replacement of all 4 heart valves in 1 operation is feasible in patients with quadruple valve disease, and an INR of 1.5 to 2.0 could be appropriate for Chinese patients with undergoing valve replacement with mechanical valves.</p>

Age- and weight-adjusted warfarin initiation nomogram for ischaemic stroke patients

OBJECTIVES

Specific guidelines for initial dosing of warfarin in ischaemic stroke patients have not been developed. Therefore, we have developed an age- and weight-adjusted warfarin initiation nomogram (AW-WIN) for ischaemic stroke patients and then evaluated the efficacy and safety of AW-WIN compared with physician-determined warfarin dosing (PDWD).

METHODS

The age- and weight-adjusted warfarin initiation nomogram was administered to 104 acute ischaemic stroke patients between January 2008 and February 2009. A historical control group (PDWD) of 96 patients was selected from comparable patients who were discharged with warfarin during the previous year. Time-to-therapeutic international normalized ratios (INRs) and the incidence of excessive anticoagulation were compared in the AW-WIN and PDWD groups.

RESULTS

The general characteristics, risk factors, and stroke mechanism of the AW-WIN and PDWD groups did not differ significantly. The mean time to INR ≥ 2.0 was significantly shorter in the AW-WIN than in the PDWD group (4.9 ± 0.7 vs. 6.2 ± 0.8 days, P = 0.0008). After adjustment for potential confounding variables, the AW-WIN group reached target INR faster than the PDWD group (hazard ratio, 1.76; 95% confidence interval, 1.26-2.45; P = 0.001). The time-to-therapeutic INR ≥1.7 was shorter (P = 0.0002), the proportion of patients with therapeutic INR (2-3) at 5 days was higher (P = 0.002), and the rate of excessive anticoagulation of ≥3.5 INR during hospitalization was lower (P = 0.024) in the AW-WIN than in the PDWD group.

CONCLUSIONS

AW-WIN reduces the time to target INR and the risk of excessive anticoagulation. AW-WIN may be an efficient and safe method of anticoagulation during the acute phase of ischaemic stroke.

A rare case of occipital stroke as a consequence of nonbacterial thrombotic endocarditis in ovarian clear cell carcinoma: a case report

Hypercoagulability occurs in 15% of patients with malignancy and represents a clinical spectrum ranging from abnormal coagulation tests but no clinically evident thromboembolic disease, to arterial and venous thrombosis, migratory thrombophlebitis, nonbacterial thrombotic endocarditis (NBTE) and disseminated intravascular coagulation. The combination of increased procoagulant activity and decreased fibrinolytic activity accelerates the prothrombotic potential of endothelial cells in malignancy. NBTE is a rare manifestation of cancer-induced hypercoagulability and is commonly seen with mucin-producing adenocarcinomas, but rarely seen with ovarian clear cell carcinoma (OCCC). Cerebrovascular embolization ranges from 14–91% in NBTE. We report a rare case of a 62-year-old female presenting with occipital stroke as a consequence of NBTE in OCCC. Association of NBTE in OCCC has only been reported in 2 cases so far, but presentation with stroke has never been reported in the literature.

Maintenance dose of warfarin in sheep and effect of diet: a preliminary report

Sheep models are widely used to evaluate the feasibility of various cardiac assist devices. Anticoagulation therapy postoperatively, however, is seldomly reported on. Continuous heparin infusion is often used, but is cumbersome due to long-term line management with the risk of infection and dislodgement. We contemplated using warfarin instead and started a pilot dose-finding study. Three sheep were given oral warfarin between 0.1 and 0.3 mg/kg/day. Prothrombin time was monitored and INR was calculated daily. If the INR did not reach a target of 2.5-3.5, warfarin dose was doubled. We found that sheep required a dose of warfarin between 1.6 and 2.4 mg/kg/day to raise the INR to the target zone. In a subsequent study to evaluate the effect of diet on INR in sheep, three sheep were fed alfalfa hay or alfalfa pellets in a crossover design. All the animals were given warfarin at the dose of 1.6 mg/kg. The diet was switched when the INR reached the target zone of 2.5-3.5. Hay-fed animals reached the target INR on days 6 and 7. On the other hand, pellet-fed animals did not reach the target value by day 7 with the initial dose and required 2.4 mg/kg of warfarin to achieve the goal. Hay raised the INR faster and higher than pellets with the same warfarin dose. Hay may be advantageous when using oral warfarin therapy in sheep.

Low-intensity international normalized ratio (INR) oral anticoagulant therapy in Chinese patients with mechanical heart valve prostheses

The purpose of this study was to define the optimal international normalized ratio (INR) intensity of oral anticoagulant therapy in Chinese patients with valve replacement surgery. We studied 1,658 patients who underwent mechanical valve replacement in Beijing Anzhen Hospital; the focus of the study was on correlation between intensity of anticoagulant therapy and thromboembolism/hemorrhage complications. We further followed up 1,508 patients for 46 ± 16 months (range 1-61 months). Average INR was 2.13 ± 0.56, and warfarin dose was 3.09 ± 0.85 mg/day. The incidence rate of anticoagulation-related thromboembolism was 1.17 per 100 patient-years (%/pt-y), and the incidence rate of anticoagulation-related hemorrhage was 2.02%/pt-y. The incidence rate of total complications (i.e., combined thromboembolism and hemorrhages) was 3.24%/pt-y. The rate of total complications in group on INR 1.3-2.3 (aortic valve replacement: 1.3-1.8; mitral valve replacement and double valve replacement: 1.8-2.3) was the lowest among all anticoagulant therapy regimens followed. In conclusion, the relatively low anticoagulant strategy presented above efficiently prevents thrombosis and hemorrhage complications.

Rationale and design of a Global Rheumatic Heart Disease Registry: the REMEDY study

BACKGROUND

Rheumatic heart disease (RHD) is the principal cause of valvular heart disease-related mortality and morbidity in low- and middle-income countries. The disease predominantly affects children and young adults. It is estimated that RHD may potentially be responsible for 1.4 million deaths annually worldwide and 7.5% of all strokes occurring in developing countries. Despite the staggering global burden, there are no contemporary data documenting the presentation, clinical course, complications, and treatment practices among patients with RHD.

METHODS

The REMEDY study is a prospective, international, multicenter, hospital-based registry planned in 2 phases: the vanguard phase involving centers in Africa and India will enroll 3,000 participants with RHD over a 1-year period. We will document clinical and echocardiographic characteristics of patients at presentation. Over a 2-year follow-up, we will document disease progression and treatment practices with particular reference to adherence to secondary prophylaxis and oral anticoagulation regimens. With 3,000 patients, we will be able to reliably determine the incidence of all-cause mortality, worsening heart failure requiring hospitalization, systemic embolism (including stroke), and major bleeding individually among all participants. We will identify barriers to care in a subgroup of 500 patients.

CONCLUSION

The REMEDY study will provide comprehensive, contemporary data on patients with RHD and will help in the development of strategies to prevent and manage RHD and its complications.

What do you do with the antiplatelet agents in patients with drug eluting stents who then receive a mechanical valve?

Dual antiplatelet therapy (DAT) with aspirin and clopidogrel is a cornerstone of treatment during and after percutaneous coronary interventions with drug-eluting stent (DES) implantation. Oral anticoagulation (OAC) is the recommended treatment for patients with mechanical heart valves. When patients with DES need a mechanical heart valve or vice versa, we face the difficult choice of their antithrombotic therapy. Different institutions empirically follow a combination of OAC and single or DAT, the so-called triple antithrombotic therapy (TT) aiming to find the best balance between the thrombotic and bleeding risk for this subset of patients. A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether there is an optimal antithrombotic management for patients with DES undergoing mechanical heart valve or vice versa. Altogether, more than 148 papers were found using the reported search, of which 16 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. We conclude that DES implantation in patients who could potentially need valve surgery in the future should be discouraged and bare-metal stent or an aortic bioprosthesis preferred. However, in high-risk patients with DES, the recommendation is to postpone elective surgery for 1 year and, if surgery cannot be deferred, continue aspirin during the perioperative period. Moreover, when OAC is given in combination with clopidogrel and/or low-dose aspirin, the target INR should be 2.0-2.5 (Class IIb, level of evidence C). As per the long-term management, antithrombotic management with DAT alone in mechanical aortic valve replacement might be possible, but there is not enough evidence to support it. The available evidence suggests that triple anticoagulation (OAC + DAT) is associated with the best clinical outcome compared with all the other possible strategies. The duration of TT should be 3 months after sirolimus DES implantation, and 6 months after paclitaxel DES implantation, followed by long-term therapy with OAC plus clopidogrel or aspirin with either PPIs, or H2-receptor antagonists (Class IIa Level of Evidence C).

Takayasu arteritis presenting as severe ascending aortic arch dilation and aortic regurgitation in a 10-year-old female

Takayasu arteritis (TA) is a large-vessel arteritis affecting the aorta and its major branches. It is a rare disease in children less than 10 years old, and its diagnosis is frequently delayed, likely because of TA's rarity and nonspecific symptoms early in the disease. Females are affected disproportionately, with a female to male ratio of 8.5 to 1. Recently, the European League against Rheumatism published an international consensus statement for making the diagnosis of childhood TA. Criteria include angiographic abnormalities of the aorta and/or its branches, pulse deficit or claudication, blood pressure discrepancy, bruits, hypertension, and elevated acute phase reactants. We described a 10-year-old female with severe TA of the ascending aorta and who presented with classic signs and symptoms of this rare disease.

Cardiac workup of ischemic stroke

Stroke is the leading cause of disability in developed countries and the third cause of mortality. Up to 15-30% of ischemic strokes are caused by cardiac sources of emboli being associated with poor prognosis and high index of fatal recurrence. In order to establish an adequate preventive strategy it is crucial to identify the cause of the embolism. After a complete diagnostic workup up to 30% of strokes remain with an undetermined cause, and most of them are attributed to an embolic mechanism suggesting a cardiac origin.There is no consensus in the extent and optimal approach of cardiac workup of ischemic stroke. Clinical features along with brain imaging and the study of the cerebral vessels with ultrasonography or MRI/CT based angiography can identify other causes or lead to think about a possible cardioembolic origin.Atrial fibrillation is the most common cause of cardioembolic stroke. Identification of occult atrial fibrillation is essential. Baseline ECG, serial ECG('s), cardiac monitoring during the first 48 hours, and Holter monitoring have detection rates varying from 4 to 8% each separately. Extended cardiac monitoring with event loop recorders has shown higher rates of detection of paroxysmal atrial fibrillation.Cardiac imaging with echocardiography is necessary to identify structural sources of emboli. There is insufficient data to determine which is the optimal approach. Transthoracic echocardiography has an acceptable diagnostic yield in patients with heart disease but transesophageal echocardiography has a higher diagnostic yield and is necessary if no cardiac sources have been identified in patients with cryptogenic stroke with embolic mechanism.

Antithrombotic therapy in cardiac embolism

Anticoagulation is indicated in most cardioembolic ischemic strokes for secondary prevention. In many cardiac conditions, anticoagulation is also indication for primary stroke prevention, mainly when associated to vascular risk factors. Anticoagulation should be started as soon as possible, as it is safe even in moderate acute strokes. The efficacy of early anticoagulation after cardioembolic stroke in relation to outcome has not been assessed adequately, but there is evidence from animal models and clinical studies that anticoagulation with unfractionated heparin is associated with a better outcome mediated in part by its anti-inflammatory properties.

Bleeding and thromboembolic outcomes for patients on oral anticoagulation undergoing elective colon and rectal abdominal operations

PURPOSE

Patients on chronic oral anticoagulation can be challenging to manage in the perioperative period.

METHODS

Review of patients on warfarin undergoing elective abdominal colon and rectal operations at a single institution from 2000 to 2006.

RESULTS

One forty-six patients underwent 165 abdominal procedures. Mean (±SEM) age was 67 ± 1 years; 59% of patients were men. Median estimated blood loss was 200 ml, and 19% received intraoperative blood products while 19% of patients received a postoperative transfusion. Sixteen patients (10%) experienced bleeding complications (three requiring reoperation). No risk factors for bleeding were identified by multivariate analysis (MVA). Five patients (3%) suffered a postoperative thromboembolic event. Preoperative anticoagulation for cerebrovascular disease was a risk factor for thromboembolism (p = 0.03). Overall operative morbidity was 30% with no identifiable risk factor in MVA. Mortality was nil.

CONCLUSION

Postoperative bleeding and thromboembolism in patients on chronic anticoagulation are not insignificant (10% and 3%, respectively). Patients on warfarin for cerebrovascular disease are at increased risk for thromboembolic events postoperatively and should be placed on appropriate prophylaxis and monitored.

Ovarian Clear Cell Carcinoma Presenting as Non-bacterial Thrombotic Endocarditis and Systemic Embolization

Non-bacterial thrombotic endocarditis (NBTE) is a rare manifestation of cancer-induced hypercoaguability. It most commonly occurs in association with mucin-producing adenocarcinomas and has rarely been described with ovarian clear cell carcinoma (OCCC). We report a case of NBTE with multi-organ embolic infarcts occurring in a patient with early stage clear cell ovarian cancer. A 56 years old Caucasian female presented with leg pain, and left flank discomfort. Evaluation revealed multi-organ infarction, extensive deep vein thrombosis (DVT), and the incidental presence of an asymptomatic large ovarian mass with a laboratory picture consistent with disseminated intravascular coagulation (DIC). The diagnosis of NBTE was supported by echocardiogram and multiple negative bacteriological studies. She underwent surgical extirpation of an early stage OCCC and initiation of anticoagulation. Postoperatively, the patient’s hypercoaguability promptly resolved with gradual resolution of vegetations. Subsequent recurrence of the malignancy was heralded by a return of the prothrombotic state. This case shows a rarely reported association between NBTE and OCCC. It illustrates how the clinical picture of NBTE can dominate the initial presentation of an early stage and otherwise asymptomatic malignancy. Late recognition can lead to significant morbidity and a rapidly fatal course. Recurrent thromboembolism may be the first indication of disease recurrence.

Antithrombotic medication for cardioembolic stroke prevention

Embolism of cardiac origin accounts for about 20% of ischemic strokes. Nonvalvular atrial fibrillation is the most frequent cause of cardioembolic stroke. Approximately 1% of population is affected by atrial fibrillation, and its prevalence is growing with ageing in the modern world. Strokes due to cardioembolism are in general severe and prone to early recurrence and have a higher long-term risk of recurrence and mortality. Despite its enormous preventive potential, continuous oral anticoagulation is prescribed for less than half of patients with atrial fibrillation who have risk factors for cardioembolism and no contraindications for anticoagulation. Available evidence does not support routine immediate anticoagulation of acute cardioembolic stroke. Anticoagulation therapy's associated risk of hemorrhage and monitoring requirements have encouraged the investigation of alternative therapies for individuals with atrial fibrillation. New anticoagulants being tested for prevention of stroke are low-molecular-weight heparins (LMWH), unfractionated heparin, factor Xa inhibitors, or direct thrombin inhibitors like dabigatran etexilate and rivaroxaban. The later exhibit stable pharmacokinetics obviating the need for coagulation monitoring or dose titration, and they lack clinically significant food or drug interaction. Moreover, they offer another potential that includes fixed dosing, oral administration, and rapid onset of action. There are several concerns regarding potential harm, including an increased risk for hepatotoxicity, clinically significant bleeding, and acute coronary events. Therefore, additional trials and postmarketing surveillance will be needed.

Are bicuspid aortic valves a limitation for aortic valve repair?

OBJECTIVE

To compare the mid-term results after aortic valve (AV) repair in bicuspid AVs with those in tricuspid AVs.

METHODS

Between 2000 and 2010, 100 patients (mean age 47.2 years) underwent AV repair procedures for insufficient bicuspid AV (n=43) and tricuspid AV (n=57). Aortic regurgitation (AR) more than moderate was present in 31/43 and 21/57 patients in the bicuspid AV and the tricuspid AV group, respectively. Concomitant root replacement by either the reimplantation or the remodeling technique was performed in 42 patients (bicuspid AV 17/43, tricuspid AV 25/57). All patients were prospectively studied with postoperative and further annual clinical assessment and echocardiography. Follow-up was 99% complete with a mean follow-up time of 22 months.

RESULTS

Three patients died during the initial hospitalization, all due to postoperative cardiac failure. Overall actuarial 3 years' survival was 93±4.2% without significant differences between the two groups. Overall actuarial 3 years' freedom from AV-related reoperation was 86±5.1% without significant differences between the groups (85±9.7% for bicuspid AV, 86±6.0% for tricuspid AV; log-rank test: p=0.98). Overall actuarial 3 years' freedom from recurrent AR≥moderate was 100% and AR>trace was 71.3±8.2% without significant differences between the groups (76.5±11.7% for bicuspid AV, 71.4±9.4 for tricuspid AV; log-rank test: p=0.97).

CONCLUSIONS

The mid-term outcome in terms of survival, freedom from reoperation or recurrent AR is similar for both groups of patients after AV repair procedures. Therefore, we advocate valve repair also in patients presenting with an insufficient bicuspid AV.

[Infective endocarditis: the role of surgery]

Infective endocarditis (IE) is a serious disease which can carry a bad prognosis if it is not appropriately treated. Sometimes the clinical evolution is unfavourable despite an optimal medical therapy with antibiotics. Surgery in these cases has an important role to eliminate the source of infection or to perform a valve replacement. The surprising evolution of patients operated in critic circumstances take us to analyze the role of early surgery. As physicians, we need to know these patients' risks and to establish the adequate surgical indications.

Comparison of thrombolysis versus surgery as a first line therapy for prosthetic heart valve thrombosis

Prosthetic valve thrombosis (PVT) is one of the most serious long-term complications after heart valve replacement, and optimal treatment remains unclear. The investigators report clinical characteristics and outcome of all consecutive patients with PVT treated with urgent surgery or thrombolysis with recombinant tissue plasminogen activator at a single center from January 1988 to December 2008. Thirty-one patients (mean age 59 years, range 20 to 75, 19% men) were diagnosed with PVT a median of 11 years after valve replacement (range 4 months to 32 years). Affected valve positions were mitral in 17 (55%), aortic in 8 (26%), and tricuspid in 6 (19%), and all but 1 were mechanical valves. Eighteen patients underwent urgent surgery, with 2 deaths in the immediate perioperative phase and 2 recurrences (11%) of PVT over a median follow-up period of 76 months. Of 13 patients treated with thrombolysis, there was immediate clinical improvement after a single administration of recombinant tissue plasminogen activator in 12 (92%), of whom 8 (61%) showed complete response with normalization of echocardiographic findings. The only nonresponder was subsequently referred for urgent surgery. Over a median follow-up period of 18 months, recurrence of PVT was seen in 4 patients (31%), with 1 fatal event in a patient refusing further anticoagulation treatment 1 week after successful thrombolysis. Other complications in the recombinant tissue plasminogen activator group included 1 stroke, 1 transient ischemic attack, 1 hemorrhagic complication requiring surgery, and 2 peripheral embolic events with spontaneous resolution. In conclusion, thrombolysis is an attractive first-line therapy for patients with PVT, with clinical outcomes comparing favorably with the standard surgical approach.

Global research priorities in rheumatic fever and rheumatic heart disease

We now stand at a critical juncture for rheumatic fever (RF) and rheumatic heart disease (RHD) control. In recent years, we have seen a surge of interest in these diseases in regions of the world where RF/RHD mostly occur. This brings real opportunities to make dramatic progress in the next few years, but also real risks if we miss these opportunities. Most public health and clinical approaches in RF/RHD arose directly from programmes of research. Many unanswered questions remain, including those around how to implement what we know will work, so research will continue to be essential in our efforts to bring a global solution to this disease. Here we outline our proposed research priorities in RF/RHD for the coming decade, grouped under the following four challenges: Translating what we know already into practical RHD control; How to identify people with RHD earlier, so that preventive measures have a higher chance of success; Better understanding of disease pathogenesis, with a view to improved diagnosis and treatment of ARF and RHD; and Finding an effective approach to primary prevention. We propose a mixture of basic, applied, and implementation science. With concerted efforts, strong links to clinical and public health infrastructure, and advocacy and funding support from the international community, there are good prospects for controlling these RF and RHD over the next decade.

Peripheral arterial ischemic events in cancer patients

Thromboembolic complications are the second leading cause of death in cancer patients. In contrast to the large body of literature on venous thromboembolism (VTE), relatively few reports have focused on the pathogenesis, incidence, management and outcomes of arterial thromboembolic events in patients with malignancy. The purpose of this article is to review the current literature on the etiology, mechanisms, and prognosis of arterial thromboembolic events in cancer patients and outline appropriate screening and management guidelines that may help lower the rates of morbidity and mortality related to these events.

The dental patient on oral anticoagulant medication: a literature review

Specific diseases and medications may considerably influence the delivery of oral care and the course of dental therapy. The purpose of this literature review is to examine the relationship between oral anticoagulant medication and dental treatment. Electronic and manual searches were conducted for clinical studies in the English literature for the years 1988-2010. The review process provided a total of 110 pertinent literature references, out of which 38 studies dealt with oral anticoagulants and dental treatment. Different treatment strategies relative to dental periprocedural anticoagulation regimens have been identified, and their accompanying thromboembolic and bleeding risks are being presented and discussed. Regarding to what extent a safe and successful dental treatment in patients on anticoagulant medication is feasible, the level of evidence is lacking. Until high-level data are provided, an individualised treatment approach after consultation with the physician of the patient is highly recommended.

Advances in aortic valve repair: focus on functional approach, clinical outcomes, and central role of echocardiography

The surgical classification of aortic regurgitation (AR) is based on cusp mobility. Based on this classification, there are 3 classes of AR: type I is defined as normal cusp mobility, type II is defined as excessive cusp mobility, and type III is defined as restricted cusp mobility. Patients often have multiple coexisting mechanisms. Because aortic valve (AV) repair is safe, effective, and durable, it likely will become a mainstream surgical option for the management of significant AR, even in the setting of a bicuspid valve. Intraoperative transesophageal echocardiography has a central role at all stages in AV repair. Before cardiopulmonary bypass, it can accurately diagnose the mechanism of AR to guide operative strategy for successful repair. After separation from cardiopulmonary bypass, it can comprehensively evaluate the AV repair, including the likelihood that the repair will be durable in the long-term. Important echocardiographic predictors of a durable AV repair include the absence of AR, cusp coaptation above the annular plane, a coaptation length >4 mm, and an effective cusp height >8 mm. The clinical applicability of AV repair continues to expand and likely will evolve into a mainstream surgical therapy for AR, including minimally invasive techniques.

[Ischemic strokes as a presenting feature of marantic endocarditis despite heparin treatment]

We report on two patients hospitalized in intensive care unit for ischemic strokes presenting the feature of marantic endocarditis complicating lung's adenocarcinoma. These two cases turned out to be very interesting because of the occurrence of ischemic strokes even though the patients were receiving the recommended treatment, namely anticoagulation with heparin, in well-adjusted doses. The management of nonbacterial thrombotic endocarditis remains a challenge and its mortality is still high.

Acute ischemic stroke and infections

We present an overview of multiple infections in relation to acute ischemic stroke and the therapeutic options available. Conditions that are a direct cause of stroke (infectious endocarditis, meningoencephalitides, and human immunodeficiency virus infection), the pathophysiologic mechanism responsible for stroke, and treatment dilemmas are presented. Independently or in conjunction with conventional risk factors, chronic and acute infections can trigger an acute ischemic stroke through an accelerated process of atherosclerosis and immunohematologic alterations. Acute ischemic stroke has a negative impact on the antibacterial immune response, leading to stroke-induced immunodepression and infections, the most common poststroke medical complications. Poststroke infections are independent predictors of poor outcome. Antibiotic trials for poststroke infection prevention are reviewed. Although antibiotic prophylaxis is not the standard of care in acute stroke, current guidelines support prompt treatment of stroke-related infections.

Successful fibrinolytic treatment in a pregnant woman with acute mitral prosthetic valve thrombosis

Pregnant patients with mechanical prosthetic heart valves pose a great problem for medical management. The problem is even greater in a pregnant woman with mechanical valve thrombosis. This article describes a pregnant woman with prosthetic mitral valve thrombosis who had a successful fibrinolytic treatment.

Role of orally available antagonists of factor Xa in the treatment and prevention of thromboembolic disease: focus on rivaroxaban

Interpatient variability in the safety and efficacy of oral anticoagulation with warfarin presents several challenges to clinicians, thus underscoring the emergent need for new orally available anticoagulants with predictable pharmacokinetic and pharmacodynamic profiles and ability to target circulating clotting factors. Seven compounds including rivaroxaban, apixaban, betrixaban, and eribaxaban are orally available direct inhibitors of activated factor X currently in development for the prevention and treatment of venous thromboembolism and for thromboprophylaxis in patients with atrial fibrillation or following an acute coronary syndrome. At doses used in phase 2 and 3 clinical trials, rivaroxaban and apixaban demonstrated a predictable onset of effect, maximal plasma concentration, and half-life that was unaffected by age, renal, or hepatic disease. In clinical trials for the treatment and prevention of venous thromboembolism, rivaroxaban and apixaban produced equivalent or superior reductions in the development or progression of venous thromboembolism compared with either low molecular weight heparin or warfarin. Trials comparing the efficacy of rivaroxaban or apixaban to standard therapy for stroke prophylaxis in patients with atrial fibrillation are in process. Rivaroxaban, the sentinel compound in this class, is already approved in the European Union and Canada. It is likely to be approved for use in the United States in 2010.

Comparison of safety of subcutaneous enoxaparin as outpatient anticoagulation bridging therapy in patients with a mechanical heart valve versus patients with nonvalvular atrial fibrillation

Patients with mechanical heart valves (MHVs) are at a higher risk for thromboembolic events than patients with atrial fibrillation (AF). This difference is observed in the higher maintenance international normalized ratio (INR) range for patients with MHV and in the selection for anticoagulation bridge therapy when warfarin is interrupted perioperatively. However, once the decision is made to "bridge," the same therapeutic options, unfractionated heparin and subcutaneous low-molecular-weight heparin (LMWH), are applicable to the 2 patient populations. Unfractionated heparin requires extended hospitalization and is often not selected. A paucity of published data exist establishing the efficacy and safety of LMWH as a bridging agent. The aim of this study was to describe a single-center experience and to provide data supporting the use of enoxaparin as a bridging agent. The study assessed whether patients with MHV undergoing bridging for a variety of procedures had higher thromboembolic and hemorrhagic risk compared to patients with nonvalvular AF. We performed a retrospective cohort study of 173 patients (with MHV and AF) who underwent 230 bridging episodes with an LMWH, enoxaparin, from February 2002 through September 2007. Main outcome measurements were the incidence of thromboembolic and hemorrhagic events within 2 months after the procedure. Of total bridging episodes, 130 episodes met the inclusion criteria; 62 episodes occurred in the MHV population and 68 episodes occurred in the AF population. The procedures varied from minor invasive procedures to major surgeries. There were no deaths or thromboembolic events. Major and minor bleeding rates were similar between the MHV and AF groups (3.2% and 2.9%, 14.5% and 13.2% respectively, p = NS). The major bleeding rate was similar to published data on bridging therapy. Most bleeding episodes (73%) occurred within 7 days after the procedure. In conclusion, our study provided actual outpatient anticoagulation clinical data on using LMWH as an option for periprocedural bridging anticoagulation in patients with MHV.