Mechanical Heart Valve Prostheses Research Articles

Comparative assessment of the effectiveness of mechanical and biological heart valve prostheses in reverse remodeling of the left ventricle after aortic valve surgery (propensity score matching analysis and clinical-experimental comparison)

Comparative assessment of the effectiveness of mechanical and biological heart valve prostheses in reverse remodeling of the left ventricle after aortic valve surgery (propensity score matching analysis and clinical-experimental comparison)

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.

Revisiting aortic valve prosthesis choice in patients younger than 50 years: 10 years results of the AUTHEARTVISIT study.

This population-based cohort study investigated mid-term outcome after surgical aortic valve replacement with a bioprosthetic or mechanical valve prosthesis in patients aged <50 years in a European social welfare state. We analysed patient data from the main social insurance carriers in Austria (2010-2020). Subsequent patient-level record linkage with national health data provided patient characteristics and clinical outcome. Survival, reoperation, myocardial infarction, heart failure, embolic stroke or intracerebral haemorrhage, bleeding other than intracerebral haemorrhage and major adverse cardiac events were evaluated as outcomes. A total of 991 patients were analysed. Regarding demographics, no major differences between groups were observed. Multivariable Cox regression revealed no significant difference in overall survival (P = 0.352) with a median follow-up time of 6.2 years. Reoperation-free survival was decreased (hazard ratio = 1.560 [95% CI: 1.076-2.262], P = 0.019) and the risk for reoperation was increased (hazard ratio = 2.770 [95% CI: 1.402-5.472], P = 0.003) in patients who received bioprostheses. Estimated probability of death after reoperation was 0.23 (CL: 0.08-0.35) after 2 years and 0.34 (CL: 0.06-0.53) after 10 years over both groups. Regarding further outcomes, no significant differences between the two groups were observed. In patients below 50 years of age receiving aortic valve replacement, implantation of bioprostheses when compared to mechanical heart valve prostheses was associated with a significantly higher rate of reoperations and reduced reoperation-free survival. Nevertheless, we could not observe a difference in overall survival. However, long-term follow-up has to evaluate that a significantly lower rate of reoperations may translate in consistently improved long-term survival.

In vivo performance of a tri-leaflet mechanical heart valve prosthesis in an ovine model.

We present the long-term results of a trileaflet (Triflo) versus bileaflet (On-X) mechanical valve in both aortic and pulmonary positions in a sheep model. The Triflo valve was implanted in 21 female sheep in aortic (n = 8) and pulmonary position (n = 13). The On-X valve was implanted in 7 female sheep in aortic (n = 1) and pulmonary (n = 6) positions. No antithrombotic medication of any kind was given postoperatively. In the aortic group, survival cohorts were 3 and 5 months. In the pulmonary group, survival cohorts were 10 and 20 weeks. Valve performance was assessed using haematology, echocardiography and acoustic measurements combined with post-mortem pathology analysis of the downstream organs. The mean gradients were lower for the Triflo valve in both pulmonary [4.30 mmHg (3.70-5.73) vs 6.80 mmHg (4.63-7.96), P = 0.012] and aortic [5.1 mmHg (4.2-7.7) vs 10.7 mmHg (8.7-12.9), P = 0.007] positions. Peak gradients were lower for the Triflo valve in both pulmonary [8.05 mmHg (6.75-10.23) vs 13.15 mmHg (9.20-14.76), P = 0.005] and aortic [8.7 mmHg (7.5-12.5) vs 16.5 mmHg (14.2-19.6), P = 0.009] positions. In both positions, leaflets and housing surface were free from any deposits macro- and microscopically and comparable to nonimplanted control valves. Peripheral organs showed no signs of thrombo-embolic damage. Biochemical and haematological were comparable to preoperative. The closing click sound pressure level of the Triflo was significantly lower in both aortic [108.4 sound pressure level (102.0-115.7) vs 111.7 sound pressure level (105.5-117.0), P < 0.001] and pulmonary [103.6 sound pressure level (99.1-108.9) vs 118.5 sound pressure level (116.7-120.2), P < 0.001] position. Preliminary in vivo results of the Triflo valve are promising in both aortic and pulmonary positions in an ovine model. Excellent haemodynamics, stable long-term function, low valve noise and no thrombo-embolic events in the absence of antithrombotic medication lay the foundation to a future clinical first-in-man trial.

Starr–Edwards ball caged mechanical heart valves’ reverberations – Need for a Phoenix of analysis with a critical mindset

The mechanical heart valve prosthesis with a caged ball has been around for 60 years. It has since experienced changes and adjustments. The Starr–Edwards (SE) valve was a pioneer and was taken out of clinical use in the late 2000s. SE is reportedly close to or has reached the age of 50, according to numerous sources from around the globe. The author’s observations and review of the literature about thrombogenicity, pannus formation, left ventricular outflow tract obstructions, and infective endocarditis in the SE valves, which were reportedly higher before its clinical ending, were only an overestimation and were not supported by scientific data. However, it was less discussed in the article, along with potential benefits. The main reasons for its demise were its obtrusive size and unattractive shape. There have been several successful implantations of these valves in Asian nations and reports of fewer primary failures and unexpected cardiac fatalities. Therefore, there is a need for extensive data gathering, documentation, and more recent studies on these valves to prepare for a prospective revival of use with newer research, mainly when long-term durability is considered.

MarioHeart: Novel In-Vitro Flow Model for Testing Heart Valve Prostheses and Anticoagulant Therapies.

Mechanical heart valve (MHV) prostheses present a risk of thromboembolic complications despite antithrombotic therapy. Further steps in the development of more hemocompatible MHVs and new anticoagulants are impeded due to the lack of adequate in-vitro models. With the development of a novel in-vitro model (MarioHeart), a pulsatile flow similar to the arterial circulation is emulated. The MarioHeart design owns unique features as 1) a single MHV within a torus with low surface/volume ratio, 2) a closed loop system, and 3) a dedicated external control system driving the oscillating rotational motion of the torus. For verification purposes, a blood analog fluid seeded with particles was used to assess fluid velocity and flow rate using a speckle tracking method on high-speed video recordings of the rotating model. The flow rate resembled the physiological flow rate in the aortic root, in both shape and amplitude. Additional in-vitro runs with porcine blood showed thrombi on the MHV associated with the suture ring, which is similar to the in-vivo situation. MarioHeart is a simple design which induces well-defined fluid dynamics resulting in physiologically nonturbulent flow without stasis of the blood. MarioHeart seems suitable for testing the thrombogenicity of MHVs and the potential of new anticoagulants.

Dual versus triple antithrombotic therapy after percutaneous coronary intervention: the prospective multicentre WOEST 2 Study.

For patients on oral anticoagulants (OAC) undergoing percutaneous coronary intervention (PCI), European guidelines have recently changed their recommendations to dual antithrombotic therapy (DAT; P2Y12 inhibitor and OAC) without aspirin. The prospective WOEST 2 registry was designed to obtain contemporary real-world data on antithrombotic regimens and related outcomes after PCI in patients with an indication for OAC. In this analysis, we compare DAT (P2Y12 inhibitor and OAC) to triple antithrombotic therapy (TAT; aspirin, P2Y12 inhibitor, and OAC) on thrombotic and bleeding outcomes after one year. Clinically relevant bleeding was defined as Bleeding Academic Research Consortium classification (BARC) grade 2, 3, or 5; major bleeding as BARC grade 3 or 5. Major adverse cardiac and cerebrovascular events (MACCE) was defined as a composite of all-cause mortality, myocardial infarction, stent thrombosis, ischaemic stroke, and transient ischaemic attack. A total of 1,075 patients were included between 2014 and 2021. Patients used OAC for atrial fibrillation (93.6%) or mechanical heart valve prosthesis (4.7%). Non-vitamin K oral anticoagulants (NOAC) were prescribed in 53.1% and vitamin K antagonists in 46.9% of patients. At discharge, 60.9% received DAT, and 39.1% TAT. DAT was associated with less clinically relevant and similar major bleeding (16.8% vs 23.4%; p<0.01 and 7.6% vs 7.7%, not significant), compared to TAT. The difference in MACCE between the two groups was not statistically significant (12.4% vs 9.7%; p=0.17). Multivariable adjustment and propensity score matching confirmed these results. Dual antithrombotic therapy is associated with a substantially lower risk of clinically relevant bleeding without a statistically significant penalty in ischaemic events.

Treatment of valvular heart disease in young patients-"early evidence" versus"latest fashion".

Is the performance of locally manufactured mechanical valve prostheses relevant for modern cardiac surgery, in which mechanical valve replacement has become a rarity? This question comes to mind reading the article in this issue of the Journal demonstrating equal outcomes of the TTK Chitra tilting disk mechanical heart valve prostheses in comparison to the SJM bi-leaflet blockbuster. The evidence documenting efficacy of mechanical valve replacement stems from the early ages of cardiac surgery, but often demonstrates superior outcomes in terms of survival and hemodynamics. Yet, the latest fashion in the Western world consists biological choices in combination with new transcatheter techniques (valve in valve options) or the Ozaki or Ross procedures. As long-term results are often missing and documented advantages for mechanical valves stems from early evidence, the local emphasis of mechanical valve replacement may possibly result in superior individual prognoses compared to following the Western world's latest fashions. Individual patient information and decision making moves into focus.

Mechanical Prosthetic Valve Thrombus in a Term Pregnant Woman Presenting as Acute Heart Failure: Case Report and Review of Literature

Abstract Cardiovascular disease in pregnancy contributes to a significant proportion of death worldwide. Though pregnancy-associated myocardial infarction and aortic dissection are the common causes of adverse cardiac events in developed countries, rheumatic heart diseases continue to be the important reason for cardiovascular morbidity and mortality in developing countries. The risk of adverse cardiac outcome is dependent on the type and severity of valvular abnormality, functional status, left ventricular function, and pulmonary arterial pressure. Managing a pregnant woman with a mechanical heart valve prosthesis is challenging because of the difficulty in achieving optimal anticoagulation in the presence of hypercoagulability. Mitral valve thrombus is a life-threatening event and women can present with acute heart failure or thromboembolic events. We report successful management of a 26-year-old primigravida with rheumatic heart disease diagnosed to have huge thrombus on mechanical prosthetic mitral valve presented with acute heart failure at 36 weeks. She received multidisciplinary care and underwent concurrent cesarean section followed by thrombectomy under cardiopulmonary bypass. She had a good recovery following surgery and the complexity surrounds the management merit the presentation with a review of management strategies for a women with mechanical prosthetic heart valve in pregnancy.

Laser texturing of a St. Jude Medical RegentTM mechanical heart valve prosthesis: the proof of concept.

The liquid-solid interactions have attracted broad interest since solid surfaces can either repel or attract fluids, configuring a wide spectrum of wetting states (from superhydrophilicity to superhydrophobicity). Since the blood-artificial surface interaction of bileaflet mechanical heart valves essentially represents a liquid-solid interaction, we analysed the thrombogenicity of mechanical heart valve prostheses from innovative perspectives. The aim of the present study was to modify the surface wettability of standard St. Jude Medical Regent™ occluders. Four pyrolytic carbon occluders were irradiated by means of ultra-short pulse laser, to create 4 different nanotextures (A-D), the essential prerequisite to achieve superhydrophobicity. The static surface wettability of the occluders was qualified by the contact angle (θ) of 2 µl of purified water, using the sessile drop technique. The angle formed between the liquid-solid and the liquid-vapour interface was the contact angle and was obtained by analysing the droplet images captured by a camera. The morphology of the occluders was characterized and analysed by a scanning electron microscope at different magnifications. The scanning electron microscope analysis of the textures revealed 2 different configurations of the pillars since A and B showed well-rounded shaped tops and C and D flat tops. The measured highest contact angles were comprised between 108.1° and 112.7°, reflecting an improved hydrophobicity of the occluders. All the textures exhibited, to different extents, an orientation (horizontal or vertical), which was strictly related to the observed anisotropy. In this very early phase of our research, we were able to demonstrate that the intrinsic wettability of pyrolytic carbon occluders can be permanently modified, increasing the water repellency.

Aortic valve replacement in sheep with a novel trileaflet mechanical heart valve prosthesis without anticoagulation

BackgroundEven after decades of intensive research, an ideal heart valve prosthesis remains elusive. Shortcomings of conventional devices include reduced durability of bioprostheses and the thrombogenicity of mechanical substitutes, necessitating anticoagulation and resulting in imperfect hemodynamics. Here we present in vivo results of a novel mechanical heart valve prosthesis aiming for freedom from anticoagulation. MethodsFour female sheep had their aortic valves replaced using the novel mechanical heart valve (size 21 mm), with no postoperative anticoagulation treatment. This trileaflet heart valve was designed with the pivots in the systolic central flow. Hemodynamics, biochemistry, hematology, and macroscopy and microscopy were studied at 90 days in 2 sheep and at 1 year in the other 2 sheep. ResultsMean (<6 mm Hg) and peak (<10 mm Hg) aortic transvalvular gradients remained low during the study period. Aortic regurgitation was trivial, and central traces were only rarely observed. The rate of thrombotic events was very low, with none macroscopically and microscopically visible thrombotic material on the device. Biochemistry and hemotology were unchanged without hemolysis. In 3 sheep, the fibrous pannus and mitral leaflet were partially folded over the edge of the annular body. Apart from organic/inorganic deposits on the leaflets after 1 year, the ultrastructurally evaluated leaflets were similar to those of nonimplanted controls. ConclusionsThe preliminary in vivo results of this novel anticoagulation-free aortic mechanical heart valve are promising with excellent hemodynamics and a very low risk of thrombotic events.

Impact of an oral anticoagulation self-monitoring and self-management program in patients with mechanical heart valve prosthesis.

Objective: To analyze impact of implementation of an oral anticoagulation self-monitoring and self-management program among patients with mechanical valve prosthesis. Materials & methods: Observational and retrospective study performed in Hospital Moises Broggi, Barcelona, Spain. The program started on June 2019. The study compared 6-month period before and after the implementation of the program. Results: The study included 44 patients. There was a numerical increase of time in therapeutic range from 53.6±21.3% to 57.1±15.7% (p = 0.30). Proportion of patients withinternational normalized ratio (INR) >5 significantly decreased from 3.9to 2.0% (p = 0.04). No significant differences were observed in thromboembolic or bleeding complications. Visits to emergency department decreased from (29.5to 22.7%; p = 0.41). Conclusion: Oral anticoagulation self-monitoring and self-management program seems an appropriate approach that could provide additional benefits in selected patients with mechanical valve prosthesis.

Effects of a Personalized Nurse-Led Educational Program for New Patients Receiving Oral Anticoagulant Therapy after Mechanical Heart Valve Prosthesis Implantation on Adherence to Treatment.

BackgroundLife-long anticoagulant therapy is mandatory for patients who undergo heart valve replacement with implantation of a mechanical prosthesis. The aim of this study was to investigate the effects of a nurse-led patient educational program concerning oral anticoagulant therapy intake after heart valve replacement surgery on patients’ knowledge of important parameters of anticoagulant administration.MethodsIn this single-center study, 200 patients who underwent surgical implantation of a mechanical prosthesis were divided into 2 groups. The control group received the basic education concerning oral anticoagulants, while the intervention group received a personalized educational program.ResultsPersonalized education was correlated with a better regulation of therapeutic international normalized ratio (INR) levels and adequate knowledge among patients. Therapeutic levels of INR were achieved in 45% of the patients during the first month, 71% in the third month, and 89% in the sixth month after discharge in the intervention group, compared to 25%, 47%, and 76% in the control group, respectively. Patients’ satisfaction with the information was higher in the intervention group than in the control group. The percentage of satisfaction reached 80% for the intervention group versus 37% for the patients of the control group.ConclusionThe implementation of the nurse-led educational programs was associated with improved clinical results and increased adherence to oral anticoagulant treatment.

Pharmacogenetic testing in the management of patients with prosthetic heart valves

Abstract Background This study examined clinical, demographic, anthropometric, and inheritance factors that influence individual sensitivity to warfarin therapy after heart valve surgery. The clinical significance of the pharmacogenetic approach was assessed using the individual time frame and time spent in the INR therapeutic range. Purpose To study the influence of the preemptive panel-based pharmacogenetic testing on the effectiveness and safety of anticoagulant therapy in patients with prosthetic heart valves. Materials and methods The study included 928 patients (519 men and 409 female) (mean age 56±10 years) living in Western Siberia, Russia. Mainly there were patients with rheumatic heart disease, heart failure III NYHA and atrial fibrillation in 35% of cases. Mechanical heart valve prostheses were used in 70% of cardiac surgery cases. Real-time polymerase chain reaction was used for molecular genetic testing for polymorphisms VKORC, CYP2C9*2, CYP2C9*3, and CYP4F2. Results The frequencies of alleles and genotypes of CYP2C9 and VKORC1 in the study population of patients with heart valves prosthetic correspond to the distribution in Caucasian populations. Correlation between the calculated and actual therapeutic doses of warfarin was found according to the B.F Gage algorithm. In analyzing the dependence of the actual therapeutic dose of warfarin on polymorphic variants of the CYP2C9 and VKORC1 genes, it was shown that all the studied variants were associated with a therapeutic dose of warfarin, which was significantly different in carriers of different genotypes. Genotypes A/A CYP2C9*3 and G/G VKORC1 were associated with the largest deviations of the actual therapeutic dose from the calculated one. The clinical effectiveness of the pharmacogenetic approach was assessed according to the prevalence of the studied polymorphic variants of the CYP2C9 and VKORC1 genes in patients with prosthetic heart valves in the Kemerovo region. As a result, two groups of patients were formed using the “copy pair” method, without statistically significant differences in genetic, clinical, demographic, and anthropometric data. Usage of the pharmacogenetic testing at the beginning of warfarin therapy twice reduced time required to select a therapeutic dose of the anticoagulant, while the time within therapeutic INR range was increased by 20.2%. Conclusion The use of the panel-based pharmacogenetic approach at the beginning of warfarin therapy in patients with prosthetic heart valves increases the effectiveness and safety of anticoagulant therapy in the early postoperative period. Funding Acknowledgement Type of funding source: None

Incidence and risk factors for thromboembolism and major bleeding in patients with mechanical heart valves: a tertiary hospital-based study in Botswana.

Mechanical heart valve (MHV) prostheses increase the risk of thromboembolic complications. While warfarin anticoagulation reduces this risk, its use increases the risk of bleeding. We sought to estimate the rate of thromboembolic and bleeding complications among patients with MHVs at a tertiary hospital in Botswana. Factors associated with bleeding and thromboembolic complications are also described. This retrospective cohort study involved a cohort of patients with MHV at Princess Marina Hospital who were operated on before September 2017. The study documented bleeding and thromboembolic events since the valve replacement, patients' demographic information, co-existing medical conditions, drug history and details of valve replacement. Using the recent international normalised ratio (INR) results, each patient's time in therapeutic range (TTR) was calculated to assess the level of anticoagulation control. The study enrolled 142 patients with a mean (SD) age of 42 (12) years and a median (IQR) duration since valve replacement of four years (1.8-10.0). The median (IQR) TTR was 29.8% (14.1-51.0) and only 14.8% of the patients had an optimal anticoagulation control. The rates of major bleeding and thromboembolic complications were 1.5 per 100 person-years and 2.80 per 100 person-years, respectively. A longer duration of warfarin use was associated with an increased risk of both bleeding (p = 0.008) and thromboembolic complications (p = 0.01). Bleeding and thromboembolic complications were common in MHV prosthesis patients in this study. Long duration of anticoagulation, albeit sub-optimal control, was a risk factor for bleeding and thromboembolic complications in these patients. Therefore, long-term efforts are necessary to address these complications and possibly improve the quality of life of these patients.

Shear stress evaluation on blood cells using computational fluid dynamics.

Thrombus formation and hemolysis are important factors in developing blood pumps and mechanical heart valve prostheses. These phenomena are induced by flow properties. High shear stress induces platelet and red cell damage. Computational fluid dynamics (CFD) analysis calculates shear stress of fluid and particle pathlines of blood cells. We studied blood cell damage in a blood pump by using CFD analysis and proposed a method for estimating blood damage. We analyzed a pulsatile blood pump that was developed as a totally implantable left ventricular assist system at Tokai University. Shear stress on blood cells throughout pulsatile blood pumps were analyzed using CFD software. Based on the assumption that the effect of shear stress on platelets is accumulated along the trace, we proposed a method for estimating blood damage using the damage parameter D. Platelet damage parameter is calculated regardless of the division time 𝛥t which is dependent on the calculation time step. The results of the simulations are in good agreement with Giersiepen's equation obtained from the experiments. The history of shear stress on a particle was calculated using CFD analysis. The new damage parameter D yields a value close to that of Giersiepen's equation with small errors.

Non-physiologic closing of bi-leaflet mechanical heart prostheses requires a new tri-leaflet valve design

Mechanical heart valve prostheses are based on older designs without changes during the last 40 years. Today, there is an unmet need for less thrombogenic mechanical prostheses. Analysis of the relationship between flow characteristics and thromboembolic complications is possible using numerical and biomolecular flow studies that have shown that the reverse rather than the forward flow is responsible for local platelet activation and thrombosis. After peak flow, leaflets experience flow deceleration and the leaflets are still widely open when the flow becomes zero. The closure of the valve starts with the onset of reverse flow. Therefore, the valve closes extremely fast with most of the leaflet traveling angle occurring in <10 ms with excessively high reverse flow velocities. The pivoting spaces, so-called “Hot Spots” should be eliminated to prevent pathologic shear stress that result in thrombosis. A novel tri-leaflet valve combines favorable hemodynamics with the durability of mechanical heart valve. This valve closes within 60 ms, much slower than bi-leaflet valves and similar to the closing mode of a tissue valve. Micro-particle image velocimetry did not show critical regions of flow stagnation and zones of excessive shear in the pivoting region suggesting low potential for thrombogenic events that should allow to avoid long-term anticoagulation.

Stroke in patients with mechanical heart valve prosthesis: Challenge of resumption of anticoagulation

Patients with mechanical valvular prostheses are at high risk of embolism and excessive risk of bleeding by Warfarin, the vast majority of whom are cerebral. A sudden neurological deficit in a patient with a prosthetic valve requires brain imaging to determine whether it is an ischemic or haemorrhagic stroke. The decision to restart anticoagulation should be multidisciplinary to counterbalance the risk of cerebral hemorrhage and thrombosis of the prosthetic valve. The objective is to study the clinical and radiological evolution of patients with mechanical heart valve prostheses complicated by a cerebrovascular accident. A retrospective study spread over one year (November 2017 to November 2018) on 21 cases in the Cardiology Department of Ibn Rochd Casablanca Teaching Hospital. We report 21 observations of patients with cardiac mechanical prostheses placed under warfarin, hospitalized for stroke. Including 14 men and 7 women with an average age of 35 years. Of which 11 patients had mitral prostheses, 3 had aortic prostheses and 7 mitro-aortic prostheses. Of these patients, 15 had ischemic stroke and 6 hemorrhagic stroke (4 cases with ventricular flood). Radiological monitoring by brain CT from J0 and unfractionated heparin by self-injecting syringe was the method of choice for resuming anticoagulation in 17 patients in agreement with neurologists. The evolution was favorable in 13 patients (61, 9%) with a good relay to warfarin (10 AVCI and 3 AVCH), a haemorrhagic transformation in 5 patients with. We had death of 3 patients who had hemorrhagic stroke. The prognosis can be put into play after the occurrence of stroke in patients with mechanical heart valves, a risk of cerebral hemorrhage in case of early resumption of anticoagulants and thrombotic risk of prostheses in case of a delayed recovery.

Optimal oral anticoagulant therapy in Chinese patients with mechanical heart valves

Background: The oral administration of anticoagulants is an effective means of preventing thromboembolic complications in patients implanted with mechanical valves. This treatment strategy, however, entails a dose-dependent in the risk of hemorrhage that is a cause for concern in China. As such, in this study, we sought to better determine what the ideal oral anticoagulant therapy intensity is in a Chinese population of patients implanted with mechanical valves.Methods: In the present observational cohort study, we observed the outcomes of eligible enrolled patients that had been implanted with St. Jude Medical prosthetic valves and who had been treated at our institution from 2013 onwards. All enrolled patients were followed for between 1 and 6 years through outpatient visits or telephone interviews following discharge. Study endpoints included instances of thromboembolism and major hemorrhage. We calculated the international normalized ratio (INR)-specific incidence of such adverse events as a means of determining optimal anticoagulant therapeutic intensity in patients with these bileaflet mechanical valve prostheses.Results: In total this study enrolled 3176 patients, of whom 3017 were followed for 12,746.08 total person-years (4.22 mean years per patient), while the remaining 159 patients (5%) were lost during follow-up. A total of 182 patients suffered from adverse events, with a roughly 1.43% annual incidence rate of such adverse events (95% confidence interval [CI], 1.22–1.64). Of these, 54 patients suffered from episodes of major bleeding (0.42% per patient-year, 95% CI, 0.31–0.53), while 131 suffered from thromboembolism (1.03% per patient-year, 95% CI, 0.85–1.21). Based on these analyses, we determined that the ideal low-intensity anticoagulant treatment regimen for patients with bileaflet mechanical heart valve prostheses was an INR between 1.5 and 2.5. In those patients that had undergone aortic valve replacement (AVR), the optimal INR was between 1.5 and 2.0 regardless of any thromboembolism risk factors in these patients. In contrast, in patients that had undergone mitral valve replacement (MVR) who were not at risk for thromboembolism, the optimal INR was between 1.5 and 2.0, whereas in those at risk of thromboembolism the optimal INR was between 2.0 and 2.5. The ideal anticoagulant intensity in patients undergoing both AVR and MVR (DVR) was the same as in patients undergoing MVR alone.Conclusions: In order to achieve optimal outcomes by maintaining effective anticoagulant dosing while entailing minimal risk in Chinese patients that have undergone a bileaflet mechanical valve replacement, the target INR range should be between 1.5 and 2.5, with the final intensity of this anticoagulant regimen being determined based on a given patient's risk of thromboembolism.

Midterm Results of Mitral Valve Replacement for Heart Disease in Females in Child Bearing Period - Mechanical Versus Tissue Valves

Abstract Background: Current guidelines limit mitral valve replace-ment to irrepairable valve pathology that will result in poor durability outcomes, especially in patients unlikely to tolerate future reinterventions. There are two basic types of prosthetic heart valves used in current clinical practice: Mechanical and bioprosthetic valves. Young women planning pregnancy are considered high risk patients who require careful selection of the optimal prosthetic heart valve. Some authors advocate that mechanical heart valve prostheses, which require lifelong anticoagulant therapy (warfarin), are not appropriate because of the teratogenic potential of anticoagulants. However, the main issue with bioprosthetic heart valves is their finite lifespan and high risk of reoperation in the future. Aim of Study: To primary outcome: To compare midterm results of post-operative outcome between mechanical versus tissue valves in the terms of morbidity in females in the childbearing period. Hence guide future choice of prosthetic valves in females in childbearing period. Secondary outcome: To discuss the rate maternal complication for both types of valves during pregnancy. Patients and Methods: This study was conducted at the Cardiothoracic Surgery Department, Souad Kafafi University Hospital and Ain Shams University Hospitals. The study period starting between 2013 to 2018. Results: Our results showed that the pre-operative Left Ventricular End Diastolic Diameter (LVEDD), Left Ventricular End Systolic Diameter (LVESD) were significantly lower in the mechanical group and the Ejection Fraction (EF) was significantly lower in tissue group. The MVA was significantly lower and the pressure gradient was significantly higher in tissue group than mechanical group. Post-operatively, the LVEDD and LVESD remained significantly lower in mechan-ical group; however, the EF was comparable between both groups. Although, the post-operative pressure gradient was higher in tissue group, but it is not reflected on the durability of the valve at this age group regarding the midterm results of our study, and there were no statistically significant differ-ences between both groups in terms of MVA, incidence of new regurge, or paravalvular leak.Conclusion: Tissue valves appear to be the preferred option for women in childbearing period with MVD with better mid-term results than mechanical valves. The present study demonstrated that women with mechanical valves had a high rate of pregnancy loss. The risk of cardiovascular complications is higher in mechanical valves, as the main risks are related to the need of anticoagulation therapy (hem-orrhagic and thromboembolic complication) additional risks related to ventricular and valvular dysfunction as well. Fur-thermore the rate of reoperation is much higher in mechanical valves. However the risk of complications is lower in tissue valves, it can be significant in the presence of bioprosthetic dysfunctions. So, large-scale, studies are still needed to confirm our findings.