Mechanical Prosthetic Heart Valves Research Articles

Cost-Effectiveness Analysis of Pharmacogenomics-Guided Versus Standard Dosing of Warfarin in Patients with Mechanical Prosthetic Heart Valve

Background: Warfarin is the only approved anticoagulant for antithrombotic treatment in patients with mechanical prosthetic heart valves (MPHV). However, dosing warfarin is challenging due to its narrow therapeutic window and highly variable clinical outcomes. Both low and high doses of warfarin can lead to thrombotic and bleeding events, respectively, with these complications being more severe in individuals with sensitive genetic polymorphisms. Incorporating genetic testing could enhance the accuracy of warfarin dosing and minimize its adverse events. Objectives: This study aims to evaluate the utilities and cost-effectiveness of pharmacogenomics-guided versus standard dosing of warfarin in patients with MPHV in Iran. Methods: In this economic evaluation study, a cost-effectiveness analysis was conducted to compare pharmacogenomics-guided versus standard warfarin dosing. Data related to quality of life (QoL) were collected through a cross-sectional study involving 105 randomly selected MPHV patients using the EuroQol-5D (EQ-5D) Questionnaire. Costs were calculated with input from clinical experts and a review of relevant guidelines. Additional clinical data were extracted from published literature. The pharmacoeconomic threshold set for medical interventions within Iran's healthcare system was $1,500. A decision tree model was designed from the perspective of Iran's healthcare system with a one-year study horizon. Sensitivity analyses were also performed to assess the uncertainty of input parameters. Results: The utility scores derived from the questionnaire for standard and pharmacogenomics-guided warfarin treatments were 0.68 and 0.76, respectively. Genotype-guided dosing of warfarin was more costly compared to the standard dosing ($246 vs $69), and the calculated incremental cost-effectiveness ratio (ICER) was $2474 per quality-adjusted life year (QALY) gained. One-way sensitivity analyses showed that our model is sensitive to the percentage of time in the therapeutic range (PTTR), the cost of genetic tests, and the utility of both pharmacogenomics-guided and standard dosing arms. However, the probabilistic sensitivity analysis demonstrates the robustness of our model. Conclusions: Warfarin dosing with pharmacogenomics testing is currently not cost-effective. However, if the cost of genotyping tests decreases to $118, the ICER would become cost-effective.

Effect of Ramadan Fasting on the International Normalized Ratio and Prosthetic valve function in Patients with Mechanical Prosthetic Heart Valves

Effect of Ramadan Fasting on the International Normalized Ratio and Prosthetic valve function in Patients with Mechanical Prosthetic Heart Valves

Role of multimodality imaging in the assessment of mechanical prosthetic heart valve dysfunction

Role of multimodality imaging in the assessment of mechanical prosthetic heart valve dysfunction

Etiology and predictors of heart failure in pregnancy. Newer Insights from the M-PAC registry

Abstract Background Women with heart disease undergoing pregnancy is on the increase, along with an increasing cardiac contribution to maternal mortality. Aim To identify the proposition of pregnant women with heart disease, who develop heart failure as a complication and to identify the predictors of heart failure in pregnancy Methods The Madras medical college Pregnancy And Cardiac (M-PAC) registry (1) is a single-centre prospective observational registry conducted at a tertiary care public hospital in Tamil Nadu, India from July 2016 to December 2019. Patient with new or worsening heart failure during pregnancy and up to 1 week post-delivery were included in the present analysis. When heart failure was the presenting symptom, it was considered as the primary event and when patient presented with failure symptoms secondary to another inciting event, heart failure was considered as secondary event. This cohort of patient were evaluated for the aetiology, predictors and outcome of heart failure and were placed on extended follow up. The accuracy of mWHO and CARPREG I score to predict heart failure were assessed. Results 1005 women with 1029 pregnancies were enrolled. Heart failure was observed in 127 (%) pregnancies, in 103 as primary event and in 24 as a secondary event. The common aetiologies of heart failure include rheumatic valvar heart diseases (n=45), peripartum cardiomyopathy (n=45) and congenital heart diseases (n=18). The univariable predictors of heart failure include, NYHA class at first visit, mWHO class of disease, first diagnosis of heart disease, during current pregnancy, pulmonary hypertension, left ventricular ejection fraction ≤ 45%, significant mitral stenosis, mechanical prosthetic heart valve and history of prior cardiac events. However, when peripartum cardiomyopathy was excluded from the analysis, current pregnancy diagnosis was no longer a predictor. Multivariable predictors of heart failure are shown in Figure-1. CARPREG-1 score was marginally more effective than modified World Health Organisation (mWHO) score (C-statistic of 0.820 vs 0.802) in predicting heart failure (Figure-2). Maternal death was 15.7% (20/127). Caesarean delivery was more common in patients with heart failure (53/119; 44.5%; vs 318/838; 38%) Patients with heart failure had significantly higher proportion of composite adverse fetal outcome (46.5% vs 31.9%, P<0.001), preterm birth (9.2% vs 4.5%, P=0.029) and low birth weight (41.2% vs 26%, P <0.001) Conclusion Heart failure is the commonest complication of pregnant women with heart disease. Mortality is very high in patients presenting with heart failure. Modified WHO classification and CARPREG 1 score have moderate accuracy to predict heart failure in pregnancy.Fig-1: Predictors of Heart FailueFig-2: Prediction by CARPREG-1 and mWHO

PB1529 Anticoagulation Protocol of Therapeutic Unfractionated Heparin Administration for Pregnant Women with Mechanical Prosthetic Heart Valves

PB1529 Anticoagulation Protocol of Therapeutic Unfractionated Heparin Administration for Pregnant Women with Mechanical Prosthetic Heart Valves

Optimization of anticoagulant therapy in patients undergoing mechanical heart valve replacement

Acquired heart defects have a high prevalence among patients of different age groups and represent a significant social problem. To date, surgery remains the only effective option to treat acquired heart disease, and replacement of the dysfunctional heart valves frequently relies on mechanical prosthetic heart valves which implantation requires lifelong anticoagulant therapy with vitamin K antagonists and constant monitoring of international normalised ratio. However, the optimal target range for international normalised ratio values remains poorly defined. Optimisation of the approaches to anticoagulant therapy for this category of patients is becoming increasingly important. This paper highlights the main problems and possible solutions for patients who have undergone implantation of mechanical heart valves and need constant intake of vitamin K antagonists.

Evolving technology: the TRIFLO tri-leaflet mechanical valve without oral anticoagulation: a potential major innovation in valve surgery.

The aortic valve is the most frequently diseased valve and aortic stenosis (AS) is the most prevalent valvular heart disease in developed countries. The diseased native aortic valve can be replaced by either a biological or mechanical valve prosthesis. The main concerns relate to durability, the need for oral anticoagulants and the incidence of complications related to this medication. Experimental, computational and biomolecular blood flow studies have demonstrated that the systolic forward flow but also the reverse flow phase at the end of the systole and leakage during the diastolic phase is mainly responsible for platelet activation and thrombosis. Better design of mechanical prosthetic heart valves must ensure smooth closing during flow deceleration and must eliminate high-shear hinge flow during diastole to prevent life-threatening thrombosis. A novel tri-leaflet valve should combine the favorable hemodynamics and the durability of existing mechanical heart valves and eliminate the less favorable characteristics, including the extremely rapid closing. In this paper, we discuss some issues of current mechanical heart valve prostheses and present a new valve design with the potential for significant innovation in the field. The TRIFLO Heart Valve, is a rigid, three-leaflet central flow heart valve prosthesis consisting of an alloyed titanium housing, and three rigid polymer (PEEK) cusps. This valve has a physiological operating mode. During the forward flow phase, the intraventricular pressure opens the leaflets so that blood can freely flow through with little obstruction, and with the deceleration of the blood flow, the leaflets close early and smoothly, minimizing blood flow regurgitation, blood cell damage, and activation of the coagulation cascade. Pre-clinical studies have shown pretty favorable results and a first-in-man study should start very soon.

Abstract P2137: Comparative Effectiveness And Safety Of Rivaroxaban Versus Warfarin In Valvular Atrial Fibrillation: A Systematic Review And Meta-Analysis

Introduction: Patients with valvular atrial fibrillation (AF), which refers to moderate to severe mitral stenosis or mechanical prosthetic heart valves, have an increased risk of ischemic stroke and systemic embolism, which mandates the need for long-term anticoagulation. Still, there are no clear consensus guidelines on the indications of anticoagulation therapy in valvular AF. We aimed to compare the effectiveness of rivaroxaban, a common direct-acting oral anticoagulant (DOAC), to warfarin for preventing thromboembolism in valvular AF patients. Methods: We performed a systematic search of the following databases; PubMed, Cochrane Library, Google Scholar, and EMBASE from inception until February 06, 2023. Results: After screening 389 studies, 8 studies with 68,847 patients have been included in the final analysis. Our meta-analysis did not reveal a significant difference in the occurrence of all-cause mortality between patients who received rivaroxaban and those who received warfarin [RR, 0.97 (95% CI: 0.53-1.76]), p =0.91]. On analysis of the individual studies, rivaroxaban was non-inferior to warfarin with a lower risk of bleeding events [RR, 0. 80 (95% CI: 0.62-1.04), p =0.72], myocardial infarction [RR, 0.56 (95% CI: 0.13-2.47), p =0.44], and stroke/systemic embolism [RR, 0.54 (95% CI: 0. 11-2.55), p = 0.43]. But there was no statistically significant difference between the two groups. Conclusions: With a decreased risk for major adverse events, rivaroxaban appears to have a favorable safety profile, making them a promising alternative to warfarin in treating patients with valvular AF. However, more randomized clinical trials are imperative.

A rare case series of mechanical prosthetic heart valve structural deterioration presented as severe mitral regurgitation

A rare case series of mechanical prosthetic heart valve structural deterioration presented as severe mitral regurgitation

Endothelial Cell Behavior and Nitric Oxide Production on a-C:H:SiOx-Coated Ti-6Al-4V Substrate

This paper focuses on the surface modification of the Ti-6Al-4V alloy substrate via a-C:H:SiOx coating deposition. Research results concern the a-C:H:SiOx coating structure, investigated using transmission electron microscopy and in vitro endothelization to study the coating. Based on the analysis of the atomic radial distribution function, a model is proposed for the atomic short-range order structure of the a-C:H:SiOx coating, and chemical bonds (C-O, C-C, Si-C, Si-O, and Si-Si) are identified. It is shown that the a-C:H:SiOx coating does not possess prolonged cytotoxicity in relation to EA.hy926 endothelial cells. In vitro investigations showed that the adhesion, cell number, and nitric oxide production by EA.hy926 endothelial cells on the a-C:H:SiOx-coated Ti-6Al-4V substrate are significantly lower than those on the uncoated surface. The findings suggest that the a-C:H:SiOx coating can reduce the risk of endothelial cell hyperproliferation on implants and medical devices, including mechanical prosthetic heart valves, endovascular stents, and mechanical circulatory support devices.

Annals for Hospitalists - April 2023

Annals for Hospitalists - April 2023

Causes and treatment strategies of unilateral leaflet escape of bileaflet mechanical prosthetic heart valves after surgery: a case series

BackgroundDuring the eleven years from 2010 to 2021, preliminary statistics have shown that Fuwai Hospital completed 23,571 mechanical valve replacements for various types of valves, and 1139 mechanical valve replacements were performed in Guangyuan First People's Hospital. Only two patients developed valve leaflet escape, so valve leaflet escape is a rare postoperative complication.Case presentationIn 2010 and 2021, two patients were selected after they had unilateral leaflet escape after having mechanical valve replacements in Fuwai Hospital of Chinese Academy of Medical Sciences and Guangyuan First People's Hospital. Both patients underwent reoperations with the classic operation and the new bileaflet mechanical prosthetic heart valve was sutured. The treatment of detached single lobe and distal vessel was comprehensively determined, and the condition was treated according to the patient's symptoms, CT results, ultrasound results and other test results, as well as whether this detached lobe caused any abnormal hemodynamics of the distal vessel. The patient with mechanical aortic valve escape completed the 10-year follow-up, and patient with mechanical mitral valve escape completed the 3-month follow-up. there was no thrombosis or hematoma at the embolic site; the patient had no lower limb symptoms.ConclusionsThe reason for the leaflet escape may be related to the valve design and the leaflet material. If the detached leaflets are damaged and if the distal blood vessels are affected, simultaneous surgical treatment is required. Those patients whose vessels were not damaged by the valve lobe should be carefully monitored.

Is there still room for warfarin after the appearance of direct oral anticoagulants?

After the appearance of direct oral anticoagulants (DOAC), the use of vitamin K antagonists (VKA) has become more rare, but nevertheless, there are diseases in which they remain indispensable drugs. This review is devoted to VKA and the diseases in which these drugs can be used. The article compares the mechanism of action of VKA and DOAC, discusses methods of monitoring VKA therapy. Among the diseases of non-alternative use of VKA, mechanical prosthetic heart valves, atrial fibrillation in patients with moderate and severe mitral stenosis, antiphospholipid syndrome should be mentioned. Another indication for the appointment of anticoagulants is thrombosis of the left ventricle. In patients who have survived a myocardial infarction complicated by left ventricular thrombosis, anticoagulant treatment should be continued for up to 6 months with repeated imaging control. For this purpose, warfarin is successfully used. Currently, there is insufficient data to recommend the routine use of DOAC in patients with KrCl less than 25–30 ml/min, and in routine practice, warfarin remains the main anticoagulant in such patients. Direct oral anticoagulants have practically not been studied in the so-called special groups of patients: patients with congenital thrombophilia and rare localizations of thrombosis. There were practically no such patients in randomized trials and very little is known about the effectiveness of DOAC, so today warfarin remains the main drug for their treatment. Despite the fact that DOAC has displaced VKA in patients with non-valvular AF, we should not forget that it is VKA that we are obliged to prove the effectiveness of anticoagulants in patients with AF. The article discusses the pharmacogenetics of warfarin in relation to the data of the Russian Federation, as well as the practically important question of the possibility of resuming anticoagulants in patients with bleeding, the results of their own research are presented.

Unique tissue mitral valve replacement with lateral thoracotomy which survived more than expected: a case report

Background: Mechanical prosthetic heart valves have been used for many decades to replace damaged native valves. Unlike sternotomy incision, the right lateral thoracotomy seems to be favorable regarding resource-related outcomes. Case Presentation: We present the case of a 57-year-old female who underwent mechanical mitral valve (MV) replacement (MVR) in 2006. However, this patient has been well since the surgery, and there were no complications of the MV. The reported case has no complications after 17 years of MVR. Based on our information, she may be the only patient who has not shown signs of MVR surgery on X-ray and has been well after 17 years of MVR. Conclusion: To our knowledge, this is the first report of a unique tissue MVR which survived for more than 17 years.

Role of multimodality imaging in the assessment of mechanical prosthetic heart valve dysfunction

Role of multimodality imaging in the assessment of mechanical prosthetic heart valve dysfunction

A clinical conundrum: review of anticoagulation in pregnant women with mechanical prosthetic heart valves.

In South Africa, maternal mortality from cardiovascular disease remains high. The recent Saving Mothers report 2017-2019 from the Confidential Enquiries into Maternal Deaths revealed that indirect maternal death from medical and surgical disorders is the fourth commonest cause of maternal death, accounting for 16.9% of deaths, with cardiac disease accounting for one-third of this. The burden of rheumatic heart disease (RHD) is a significant contributor to maternal morbidity and mortality. The true burden is unknown due to limited data. The natural history of RHD confers additional risk as many cases may remain undiagnosed, with first presentation occurring during pregnancy. This undiagnosed subset of women may be the result of poor accessibility to healthcare facilities and primary healthcare interventions for acute rheumatic fever. RHD causes progressive damage to the heart valves, especially the left-sided valves, which eventually require surgical correction with mechanical prosthetic valves.

Use of SAMe-TT2R2 in a racially diverse anticoagulation clinic: prediction of optimal anticoagulation.

The SAMe-TT2R2 score predicts optimal long-term oral Vitamin K Antagonist (VKA) anticoagulation for homogenous Caucasian and homogenous Asian populations for non-valvular atrial fibrillation but at different score thresholds. The score that predicts optimal VKA anticoagulation in significantly diverse populations for multiple indications for systemic anticoagulation has not been reported. We determined whether optimal VKA anticoagulation is predicted by SAMe-TT2R2 score in a diverse inner-city population for non-valvular atrial fibrillation (NVAF), unprovoked venous and pulmonary thromboembolic disease (VTE), mechanical prosthetic heart valves and all other indications. All patients on long term VKA's that attended an inner-city anticoagulation clinic between February 2016 and October 2017 were included in this study. Eligible patients were grouped according to oral anticoagulation indication: (1) NVAF, (2) VTE, (3) prosthetic valves and (4) other indications. Each patient's SAMe-TT2R2 score and percent time of INR in the therapeutic range (TTR) was calculated with optimal international normalized ratio (INR) control defined as TTR ≥ 65%. The correlation between SAMe-TT2R2 score and TTR was determined by logistic regression for each oral anticoagulant indication. Receiver operating characteristic curves were then used to identify the best cutoff for prediction of ≥ 65% TTR. Of 316 patients meeting study criteria, 54% were non-Caucasian and there was a significant negative correlation between the SAMe-TT2R2 score and TTR (coefficient - 0.35, P < 0.0001) for all patients. A SAMe-TT2R2 score < 4 was identified as the best threshold for predicting optimal TTR (Youden's J-statistics = 0.238) with accuracy and positive likelihood ratio of 63.4% and 1.73, respectively. The SAMe-TT2R2 score predicts optimal VKA anticoagulation for systemic anticoagulation for multiple indications in a diverse urban population at a higher score than the original report for non-valvular atrial fibrillation of a cohort where < 10% non-Caucasians.

Lessons Learned From Intermittent Dysfunction of Mechanical Heart Valve.

Background:Intermittent malfunction is a rare but potentially serious complication of prosthetic heart valve replacement. This study aimed to describe the clinical features and etiologic causes of patients with intermittent mechanical prosthetic heart valve dysfunction.Methods:Between 2010 and 2021, 16 patients who were evaluated in the echocardiography laboratory of Koşuyolu Training and Research Hospital with the diagnosis of intermittent malfunction of prosthetic valves were included in the study.Results:The evaluated patients consisted of 12 bi-leaflet mitral valve replacements and 2 mono-leaflet mitral valve replacements. The underlying causes of intermittent malfunction were classified as follows: residual chord (n = 4), obstructive thrombus (n = 2), non-obstructive thrombus (n = 2), vegetation (n = 2), pannus and obstructive thrombus coexistence (n = 1), and solely pannus (n = 1). One of the patients with mono-leaflet mitral valve replacements had pannus and obstructive thrombus. In the other patient with mono-leaflet mitral valve replacement, a stuck valve was observed in 1 of 12 beats secondary to arrhythmia. There were also 2 patients with aortic valve replacements. One patient had moderate aortic regurgitation due to prominent calcification and the other had moderate obstruction due to pannus. In the patient with pannus, a stuck leaflet was observed in 1 of 6 beats and moderate aortic regurgitation arose in 1 of 2 beats in the patient with calcification.Conclusions:The intermittent stuck valve may have catastrophic outcomes. When making a treatment decision in these patients, assessing the degree of regurgitation or stenosis is essential. In particular, the frequency of entrapment should be taken into consideration when deciding the optimal therapy for intermittent prosthetic heart valve dysfunction.

Enoxaparin versus Unfractionated Heparin for the Perioperative Anticoagulant Therapy in Patients with Mechanical Prosthetic Heart Valve Undergoing Non-Cardiac Surgery.

Background and Objectives: Immediate postoperative anticoagulation regimens in patients with mechanical prosthetic valves undergoing non-cardiac surgery are clear only for unfractionated heparin (UH), whereas the few low-molecular-weight heparin (LMWH) trials available to date concern the use of Enoxaparin in general/orthopedic surgery. We performed a single-center real-world data study comparing the efficacy and safety of LMWH—Enoxaparin (E)— and UH during the perioperative period in non-cardiac surgical procedures in patients with mechanical prosthetic valve replacement in the mitral, aortic, or tricuspid positions. Materials and Methods: We enrolled 380 patients, who received E or UH together with oral anticoagulation with antivitamin K (acenocoumarol) until they achieved an optimal International Normalized Ratio (INR). Objective assessment of E efficacy included the following: normal value for all the parameters of ultrasound prosthetic functioning, no early thrombosis of the prosthesis, and rapid achievement of target INR with a decreased period of subcutaneous anticoagulation. Subjective assessment included the following: clinical improvement with decreased immobilization and in-hospital stay, fewer gluteal ulcerations, and fewer postoperative depression and anxiety episodes. Results: Comparing with UH, anticoagulation with E was more effective (p < 0.0001 and p = 0.02). The probability of death was smaller in the E group compared with the UH group. No major hemorrhagic event was reported. Mild bleeding episodes and thrombocytopenia were more common in the UH group. Patient’s compliance and quality of life were better with E due to shortened hospitalization, decreased need for testing of coagulation (every 6 h for UH), better dosing (SC every 12 h for E versus continuous infusion for UH), shortened immobilization during the immediate postoperative period with subsequent improvement in the psychological status, as well as due to lack of significant side effects. Conclusions: Taking into consideration the improved efficiency and safety, as well as all the supplementary advantages, such as no need for anticoagulation monitoring, the ease of administration, and reduced duration of hospitalization, E should be seen as an attractive alternative for anticoagulation which deserves further investigation.

Major bleedings in mechanical prosthetic heart valves patients on Vitamin K antagonist treatment. Data from the PLECTRUM Study

Patients with mechanical prosthetic heart valves (MHV) need vitamin K antagonist (VKA) treatment, due to the high thrombotic risk. The need to evaluate the bleeding risk of these patients is of great clinical relevance. This is an observational retrospective multicenter study among Centers affiliated to the Italian Federation of Anticoagulation Clinics on MHV patients, with the aim to evaluate the risk of major bleeding (MB) and associated risk factors. 2357 patients with MHV were included in the study, patients were followed for 24.081 pt-years; 246 patients had MB (rate 1.0 ×100 pt-yrs), 54 were intracranial hemorrhage (rate 0.22 ×100 pt-yrs). Patients with MB were significantly older, more affected by peripheral obstructive arterial disease (POAD) and atrial fibrillation (AF), and presented a history of previous MB, with respect to patients who did not bleed. Patients with MB showed a trend for lower time in therapeutic range (TTR), and a significant number of patients had a TTR in the lower quartile. Patients with MB had a higher mortality rate with respect to patients who did not bleed (p=0.001). The history of previous bleeding, the presence of POAD or of AF, and a TTR in the lowest quartile, were significantly associated with MB. MHV patients treated with VKAs followed by Anticoagulation Clinics, showed a low bleeding risk. Risk factors associated with major bleeding are older age, the presence of POAD or AF, the history of previous bleeding, and poor quality of anticoagulation. Patients who experienced MB during anticoagulation are at high risk of death.