Development and validation of a mobile application based on a machine learning model to aid in predicting dosage of vitamin K antagonists among Indian patients post mechanical heart valve replacement

Patients who undergo heart valve replacements with mechanical valves need to take Vitamin K Antagonists (VKA) drugs (Warfarin, Nicoumalone) which has got a very narrow therapeutic range and needs very close monitoring using PT-INR. Accessibility to physicians to titrate drugs doses is a major problem in low-middle income countries (LMIC) like India. Our work was aimed at predicting the maintenance dosage of these drugs, using the de-identified medical data collected from patients attending an INR Clinic in South India. We used artificial intelligence (AI) - machine learning to develop the algorithm. A Support Vector Machine (SVM) regression model was built to predict the maintenance dosage of warfarin, who have stable INR values between 2.0 and 4.0. We developed a simple user friendly android mobile application for patients to use the algorithm to predict the doses. The algorithm generated drug doses in 1100 patients were compared to cardiologist prescribed doses and found to have an excellent correlation.

Análisis de la calidad de la anticoagulación con antagonistas de la vitamina K en tres escenarios clínicos en México / Analysis of the quality of anticoagulation with vitamin K antagonists in three clinical scenarios in Mexico

Resumen Introducción: Los antagonista de la vitamina K (AVK) son una alternativa terapéutica en los pacientes con enfermedad tromboembólica venosa; sin embargo, numerosos factores afectan su farmacología. Objetivo: Evaluar la calidad de la anticoagulación AVK durante tres diferentes periodos en México. Métodos: Estudio prospectivo, anidado en cohortes de pacientes en tres escenarios clínicos entre los años 2013-2019. Se incluyeron pacientes no hospitalizados con indicación para recibir AVK por al menos 12 meses, quienes fueron manejados de acuerdo con el criterio del médico tratante. Resultados: Las características generales de los pacientes fueron similares entre los grupos, excepto por la indicación para usar los AVK. Se analizaron los resultados de 4148 pacientes y 38 548 evaluaciones de INR. Los tiempos en rango terapéutico durante las tres fases del estudio y los datos acumulados fueron significativamente mayores en la clínica de anticoagulación. Solo el número de visitas de control de los pacientes se asoció significativamente con los resultados, a diferencia de la edad, el sexo y el tipo de AVK. Conclusiones: Los AVK se utilizan ampliamente, pero es difícil alcanzar la meta terapéutica, sobre todo en servicios clínicos no especializados. La creación de clínicas de anticoagulación es una necesidad urgente en el sistema mexicano de salud.

Abstract Introduction: Vitamin K antagonists (VKA) are a therapeutic alternative in patients with venous thromboembolic disease; however, numerous factors affect their pharmacology. Objective: To evaluate the quality of VKA anticoagulation at three different time periods in Mexico. Methods: Prospective study, nested in patient cohorts at three different clinical scenarios between 2013 and 2019. Outpatients with indication for treatment with VKAs for at least 12 months were included. Patients were managed according to the criteria of the treating physician. Results: Patient general characteristics were similar between groups, except for the VKA indication. The results of 4,148 patients and 38,548 INR assessments were analyzed. The times in therapeutic range during the three phases of the study and pooled data were significantly higher for the anticoagulation clinic. Only the number of patient visits was significantly associated with the results, unlike age, gender, and type of VKA. Conclusions: VKAs are widely used, but it is difficult for therapeutic goals to be achieved, especially in non-specialized clinical services. Creation of anticoagulation clinics is an urgent need for the Mexican health system.

Mechanical heart valve thrombosis during pregnancy under non / 中南大学学报(医学版)

Anticoagulation drugs should be used for patients with mechanical heart valve (MHV) in case of potential risk of thrombosis. Pregnant women with MHV have to change therapies due to teratogenic effect of some anti-coagulation drugs. European Society of Cardiology clinical guidelines for the management of cardiovascular diseases during pregnancy gives specific suggestions for anticoagulation therapy.We have treated 2 patients with mechanical heart valve thrombosis (MVT) during pregnancy: One received low molecular weight heparin (LMWH) throughout the pregnancy and developed MVT at the third trimester of pregnancy; one developed MVT at the first trimester when replacing vitamin K antagonists (VKA) with LMWH. These patients raised secondary reflection on the balance between clinical guideline and personalized medicine. During LMWH therapy, we should dynamically monitor patients' anti-activated factor X (anti-Xa) level to evaluate coagulation function during pregnancy. When a pregnant woman with MHV develops symptoms of acute heart failure, stuck mechanical valve should be paid attention to and surgery should be promptly performed if necessary.

Consenso argentino en gestión efectiva de clínicas de anticoagulación para uso de antagonistas de la vitamina K / Argentine consensus in effective management of anticoagulation clinics for the use of vitamin K antagonists

Resumen El tratamiento de un paciente anticoagulado con antagonistas de la vitamina K (AVK) sigue siendo un desafío, especialmente en regiones donde, por el costo, los dicumarínicos son todavía la alternativa más buscada a la hora de elegir un anticoagulante oral. Las clínicas de anticoagulación han demostrado ser la forma más eficiente y segura de evitar complicaciones trombóticas y hemorrágicas y de mantener al paciente en rango óptimo de tratamiento. Sin embargo, requieren de una adecuada infraestructura y personal capacitado para que funcionen eficientemente. En este consenso argentino se propone una serie de parámetros para la gestión efectiva de una clínica de anticoagulación. El objetivo es lograr una elevada calidad desde el punto de vista clínico-asistencial a través de un laboratorio de hemostasia de excelencia. Los criterios desarrollados en el documento fueron consensuados por un amplio grupo de expertos especialistas en hematología y en bioquímica de todo el país. Estos criterios deben adaptarse a la irregular disponibilidad de recursos de cada centro, pero siempre se los debe tener en cuenta a la hora de indicar el tratamiento anticoagulante con estas drogas. Tener en consideración estas premisas nos permitirá optimizar la atención del enfermo anticoagulado con AVK y de esta forma minimizar las intercurrencias trombóticas y hemorrágicas a las que está expuesto, para así honrar nuestra promesa de no dañar al paciente.

Abstract Treating an anticoagulated patient with vitamin K antagonists (VKA) remains a challenge, especially in areas where dicoumarins are still the first drug of choice due to the cost of other oral anticoagulants. Anticoagulation clinics have proven to be the most efficient and safe way to avoid thrombotic and hemorrhagic complications and to keep patients in optimal treatment range. However, they require adequate infrastructure and trained personnel to work properly. In this Argentine consensus we propose a series of guidelines for the effective management of the anticoagulation clinics. The goal is to achieve the excellence in both the clinical healthcare and the hemostasis laboratory for the anticoagulated patient. The criteria developed in the document were agreed upon by a large group of expert specialists in hematology and biochemistry from all over the country. The criteria presented here must always be considered when indicating VKA although they had to be adapted to the unequal reality of each center. Taking these premises into consideration will allow us to optimize the management of the anticoagulated patient with VKA and thus minimize thrombotic and hemorrhagic intercurrences, in order to honor our promise not to harm the patient.

Trends and Predictors of Oral Anticoagulation in Patients with Atrial Fibrillation: A Serial Cross-Sectional Study from 2011 to 2016

Abstract Background: Despite the efficacy of vitamin K antagonists against stroke in patients with atrial fibrillation (AF), the underuse of this therapy is well documented. Objectives: To evaluate trends and predictors of oral anticoagulants utilization in patients with AF. Methods: Observational, retrospective, serial cross-sectional study between 2011-2016. Comparisons between groups were performed using the Student t, Mann-Whitney and Chi-square tests. Logistic regression was used to identify independent predictors of anticoagulation. A p value < 0.05 was considered significant. Results: A total of 377 patients were analyzed. The mean age was 70 ± 15 years; 52% were male and 75% were anticoagulated (20% with VKA and 55% with DOAC). Over 5 years, the overall frequency of anticoagulation increased by 22.4%. The use of DOACs increased from 29% to 70%, whereas the use of VKA decreased from 36% to 17%. The use of antiplatelet agents alone also fell from 21% to 6%. The predictors of anticoagulation were previous episodes of AF (OR 3.1, p < 0.001), hypertension (OR 3.0, p < 0.001) and HASBLED score (OR 0.5, p < 0.001). The predictors of DOAC use were serum creatinine (OR 0.2, p = 0.002), left atrial size (OR 0.9, p = 0.003) and biological valve prosthesis (OR 0.1, p = 0.007). Of the 208 patients using DOACs, 63 (30%) received inadequate prescriptions: 5 with severe drug interactions and 58 with incorrect dosing. Conclusions: Between 2011 and 2016, DOACs were rapidly incorporated into clinical practice, replacing AVKs and antiplatelets, and contributing to greater use of anticoagulation in patients with AF.

Research progress of antithrombotic therapy after transcatheter aortic valve implantation / 中国胸心血管外科临床杂志

@#Traditional surgical aortic valve replacement is associated with a high risk of serious complications, especially in elderly patients with other preoperative diseases and unable to undergo thoracotomy. Therefore, transcatheter aortic valve implantation (TAVI) is now the accepted standard treatment for patients with symptomatic severe aortic stenosis at elevated risk for conventional surgical valve replacement. Currently, guidelines propose the use of dual antiplatelet therapy for the prevention of thromboembolic events after TAVI in the patients without an indication for oral anticoagulation. While, this strategy is empiric and largely based on expert consensus extrapolated from the arena of percutaneous coronary intervention. Antithrombotic therapy is associated with a significant occurrence of both thrombotic and bleeding complications, thus, the balance between thrombotic and bleeding risk is critical. This review summarizes current guidelines and the evidence underpinning them and explores the rational for using antiplatelet and/or anticoagulant strategies after TAVI.

Pacientes con fibrilación auricular no valvular tratados con antivitamina K o anticoagulantes directos: perfil de paciente y efectos a largo plazo / Patients with non-valvular atrial fibrillation on vitamin k antagonists or direct-acting oral anticoagulants: patients profile and long-term follow up outcomes

Resumen Introducción: La llegada de los anticoagulantes directos (ACD) ha supuesto un cambio en el tratamiento de la fibrilación auricular no valvular (FANV) en los últimos años. Los objetivos de este estudio son determinar el grado de control de la anticoagulación con antivitamina K (AVK) y su posible implicación en efectos cardiovasculares adversos mayores (ECAM) y evaluar las diferencias entre el grupo en tratamiento con AVK respecto del grupo con ACD. Pacientes y métodos: Estudio de cohorte prospectivo que incluyó a pacientes consecutivos diagnosticados con FANV valorados en el Servicio de Cardiología con un seguimiento de 18 meses. Se analizaron diferencias demográficas, clínicas y analíticas entre grupos, incluido el grado de control de la anticoagulación del grupo AVK y su posible relación con ECAM. Resultados: Se incluyó a 273 pacientes: 46.5% tratados con AVK, 42.5% con ACD y 11% sin tratamiento anticoagulante. El control de la anticoagulación con AVK fue del 62.1%, sin diferencias en ECAM en función de control. El grupo ACD presentó menos ECAM que el grupo de AVK (13.4 vs. 4.3%; HR, 0.90; 0.83-0.98; p = 0.01), con una menor mortalidad cardiovascular (0.0 vs. 5.5%; HR, 0.94; 0.90-0.98; p = 0.01) y total (0.9 vs. 12.6%; HR, 0.88; 0.82-0.94; p menor que 0,01), aunque sin diferencias significativas en eventos hemorrágicos (0.9 vs. 4.7%; p = 0.07) ni isquémicos (2.6 vs. 0.8%; p = 0.27). Discusión: Los pacientes con AVK poseen un perfil clínico diferente en comparación con los que reciben ACD. El control de anticoagulación del grupo de AVK fue inadecuado en casi la mitad de los casos. El grupo de AVK presentó más ECAM que el grupo de ACD.

Abstract Introduction: The arrival of direct-acting oral anticoagulants (DOACs) has led to a change in the management of non-valvular atrial fibrillation (NVAF) in recent years. The objectives of this study are to determine the level of therapeutic control of anticoagulation with vitamin K antagonists (VKA) and its possible involvement in major adverse cardiovascular events (MACE) and to evaluate differences between the group on VKA with respect to the group on DOACs. Patients and methods: Prospective cohort study that included consecutive patients diagnosed with NVAF in Cardiology Consultations with a clinical follow-up of 18 months. Demographic, clinical and analytical differences between groups were analyzed, including the level of therapeutic control of anticoagulation on the VKA group and its association with MACE. Results: Overall, 273 patients were included: 46.5% on VKA, 42.5% on DOACs, 11% without antithrombotic treatment. Patients on VKA spent 62.1% of their time within therapeutic range (TTR by the Rosendaal formule). There were no differences in MACE depending on anticoagulation control. The DOACs group presented lesser MACE rate than the VKA group (13.4 vs. 4.3%; 0.90; HR 0.90; 0.83-0.98 p = 0.01) with lower cardiovascular mortality (0.0 vs. 5.5%; HR, 0.94; 0.90-0.98; p = 0.01) and total mortality (0.9 vs. 12.6%; HR, 0.88; 0.82-0.94; p less 0.01) although without significant differences in hemorrhagic (0.9 vs. 4.7 %; p = 0.07), or ischemic events (2.6 vs. 0.8%, p = 0.27). Conclusions: Patients on VKA have a different clinical profile than those who receive DOACs. Patients on VKA have an inadequate control of the anticoagulation in quite the half of the cases. The VKA group presented more MACE than the DOACs group.

Eficacia y seguridad del tratamiento anticoagulante oral con antagonistas de vitamina k en pacientes con prótesis valvulares cardíacas / Safety and efficacy of anticoagulation with vitamin k antagonists in patients with prosthetic heart valves

Introducción: Los pacientes con válvulas mecánicas cardíacas (VMC) representan una proporción significativa del total de pacientes que requieren anticoagulación. Sin embargo, hay pocos estudios que comparen la efectividad de la anticoagulación con distintos antagonistas de vitamina K (AVK). Objetivo: Comparar la efectividad y seguridad del tratamiento con warfarina y acenocumarol en pacientes con VMC. Métodos: Estudio observacional de pacientes en po-liclínico de anticoagulación UC sometidos a recambio valvular entre los años 2005 y 2013. Se estandarizó las dosis de AVK con software Isaza Hytwin Biostac 2.0. Se evaluaron registros de hemorragia mayor y menor (seguridad) y accidentes vasculares y embolías sistémicas (efectividad). La efectividad se analizó mediante el tiempo en rango terapéutico (TTR) con método de Ro-sendaal. Resultados: Se incluyó 365 pacientes con edad promedio de 64,1 +/- 13,2 años, 53,9 por ciento de sexo femenino. El seguimiento promedio fue de 33,3 +/- 18 meses; La mortalidad registrada fue 2,1 por ciento. El promedio de TTR fue 68 +/- 13,3 por ciento (recambio aórtico TTR 66,1 +/- 12,6 por ciento, recambio mitral TTR 65,8 +/- 13,8 por ciento y recambio mitro-aórtico TTR 61,2 +/- 12 por ciento). Acenocumarol presentó un TTR menor que warfarina (65,1 +/- 13,1 vs. 71,2 +/- 13,6, p = 0,001), sin aumento del riesgo de complicaciones. Conclusión: Aunque warfarina ofrece un mejor perfil de TTR, no existen diferencias significativas en la eficacia o seguridad al compararla con acenocumarol.

Background: Patients with cardiac mechanical valves (MHV) represent a significant proportion of all patients requiring anticoagulation. However, there are few studies comparing safety and efficacy of different vitamin K antagonists (VKA). Aim: To compare the efficacy and safety of warfarin and acenocoumarol in patients with MHV. Methods: Observational study of patients who had a mitral and /or aortic valve replacement between 2005 and 2013, followed at the Catholic University anticoagulation clinics. VKA dose adjustments were performed using the Isaza Hytwin Biostac 2.0 software. Major and minor bleeding (safety) and stroke and systemic embolism (effectiveness) were evaluated. The efficacy was estimated by the time in therapeutic range (TTR) with the Rosendaal method. Results: 365 patients were included with a mean age of 64.1 +/- 13.2 years, 53.9 percent of them were females. Mean follow-up was 33.3 +/- 18 months Overall mortality rate was 2.1 percent, which is similar to that of patients treated with VKA for other reasons. The average TTR was 68 +/- 13.3 percent (66,1 +/- 12,6 percent for aortic valves, 65,8 +/- 13,8 percent for mitral valves and 61,2 +/- 12 percent for aortic and mitral valves). TTR was lower with acenocoumarol compared to warfarin (65.1 +/- 13.1 vs. 71.2 +/- 13.6 , p = 0.001 ), However, the risk of complications was not different between groups. Conclusions: Although warfarin provides a better profile of TTR , there were no significant differences in efficacy or safety when compared with acenocoumarol.

The risk of bleeding of triple therapy with vitamin K-antagonists, aspirin and clopidogrel after coronary stent implantation: Facts and questions / 老年心脏病学杂志（英文版）

BackgroundTriple therapy (TT) with vitamin K-antagonists (VKA),aspirin and clopidogrel is the recommended antithrombotic treatment following percutaneous coronary intervention with stent implantation (PCI-S) in patients with an indication for oral anticoagulation.TT is associated with an increased risk of bleeding,but available evidence is flawed by important limitations,including the limited size and the retrospective design of most of the studies,as well as the rare reporting of the incidence of in-hospital bleeding and the treatment which was actually ongoing at the time of bleeding.Since the perceived high bleeding risk of TT may deny patients effective strategies,the determination of the true safety profile of TT is of paramount importance.MethodsAll the 27 published studies where the incidence of bleeding at various time points during follow-up has been reported separately for patients on TT were reviewed,and the weakness of the data was analyzed.ResultsThe absolute incidence of major bleeding upon discharge at in-hospital,＜ 1 month,6 months,12 months and ≥ 12months was: 3.3％ ± 1.9％,5.1％ ± 6.7％,8.0％ ± 5.2％,9.0％ ± 8.0,and 6.2％ ± 7.8％,respectively,and not substantially different from that observed in previous studies with prolonged dual antiplatelet treatment with aspirin and clopidogrel.ConclusionsWhile waiting for the ongoing,large-scale,registries and clinical trials to clarify the few facts and to answer the many questions regarding the risk of bleeding of TT,this treatment should not be denied to patients with an indication for VKA undergoing PCI-S provided that the proper measures and cautions are implemented.