Mechanical Valve Research Articles

Perioperative Management of Anticoagulation and Antithrombotic Therapy

The latest updates to the NCCN Guidelines for perioperative management of anticoagulation and antithrombotic therapies reflect significant changes in the use of bridging anticoagulation. For patients with low- to intermediate-risk atrial fibrillation, the standard of care has shifted toward reduced reliance on bridging anticoagulation. The rationale for this shift is based on the BRIDGE trial, which revealed a 3-fold greater risk of major bleeding without significant reduction in thrombotic outcomes in patients receiving bridging therapy. In patients with mechanical heart valves, findings from the PERIOP2 study led to similar conclusions. Both of these studies have contributed to a paradigm shift in perioperative anticoagulation management, pivoting toward personalized therapy based on patient-specific bleeding and thrombotic risks. For emergent or elective surgeries, the NCCN Guidelines provide a framework for more individualized decision-making, emphasizing the need for ongoing cooperation among physicians, surgeons, and patients.

Trend in mitral valve prostheses of choice and early outcomes in the United Kingdom

ObjectiveDespite the superiority of mitral valve repair, surgical mitral valve replacement (SMVR) remains an important intervention for patients with valve stenosis, infective endocarditis and complex mitral valve degeneration.There has been an increasing popularity in the worldwide use of biological valves due to the avoidance of long-term anti-coagulation and recent advancements in transcatheter techniques. We aim to evaluate the trend, early clinical outcomes and the choice of prostheses use in isolated SMVR over a 23 years period in the United Kingdom. MethodsAll patients (n = 13,147) who underwent elective or urgent isolated SMVR from March 1996 to April 2019 were identified from the National Adult Cardiac Surgery Audit database.Trends in clinical outcomes, predicted/observed mortality of patients and the utilization of biological prostheses across 5 different age groups: <50, 50–59, 60–69, 70–79 and ≥80 years old were investigated. Early clinical outcomes associated with the use of mechanical and biological mitral valve prostheses in patients between the age of 60–70 years old were analysed. ResultsThe number of isolated SMVR performed has remained stable with approximately 600 cases annually since 2010. The in-hospital/30-day mortality rate has decreased from 7.41% (1996) to 3.92% (2018), despite the EuroScore II increasing from 1.42% in 1996 to 2.43% in 2018.Biological prostheses usage increased across all age group, and particularly in the 60–69 and 70–79 group, from 17.86% and 53.85% in 1996 to 48.85% and 82.38% in 2018, respectively. The use of mechanical prostheses was reduced in patients between the age of 50–59 from 100% in 1996 to 80.65% in 2018. There were no differences in short term outcomes among patients aged 60–70 years who received either a biological or mechanical prostheses. ConclusionThere has been a significant reduction in surgical mitral valve replacement early in-hospital mortality, despite an observed increase in the risk profile of patients over 23 years. A shifting trend in valve replacement choices was observed with a rise in the use of biological prostheses, particularly within the 60–69 and 70–79 age group. Early in hospital outcomes for patients aged 60–70 were not determined by the implanted valve type.

A photo-triggered coating of prosthetic valve leaflet surface to realize antibacterial and thrombolysis on-demand

Thrombosis formation and bacterial infection pose significant challenges in the clinical application of long-term implanted prosthetic heart valves (PHV), and the two challenges generally occurred in the middle and late stages of implantation. So, it would be very valuable for PHV to realize antibacterial and thrombolysis “on-demand”. In this study, we constructed a photo-triggered coating to simultaneously address the above both challenges based on photodynamic therapy (PDT), which has been widely researched due to its advantage of spatiotemporal control. The photosensitizer chlorin e6 (Ce6) were grafted onto the polyethyleneimine (PEI) and introduced into the coating by layer-by-layer (LBL) technology. Under near-infrared (660 nm) irradiation, the coating could release reactive oxygen species (ROS), effectively destroy bacterial walls and disintegrating the fibrin three-dimensional network structure of formed thrombi. Therefore, the coating exhibited dual functionality of antibacterial and thrombolysis “on-demand”. Experimental results demonstrated that the coating effectively eradicated gram-positive and gram-negative bacteria both in vitro and in vivo, as well as causing thrombolysis under irradiation. These results highlight the potential of this coating in improving the anticoagulation and antibacterial properties of prosthetic heart valves and other long-term implanted devices.

THE EFFECT OF BILEAFLET MECHANICAL HEART VALVE DESIGNS ON BIOMECHANICAL BEHAVIOURS – A FINITE ELEMENT ANALYSIS

Heart valve replacement is a popular treatment modality for patients with valvular heart disease. One of the prominent issues of mechanical heart valve is blood clotting around the valve that could lead to operation failure. Different valve design affects the valve structural behaviour differently which could be associated to the valve leaflet movement and its attachment to the housing. This study aimed to analyse the stress and total deformation of a fixed and expandable heart valve designs under a closed and opened leaflet conditions using three-dimensional (3-D) finite element analysis (FEA). Geometrical valve models were created in SolidWorks 2020 and then exported into Ansys 2022 R2. All models were assigned with linearly elastic, isotropic, and homogenous properties. A pressure of 16 kPa was applied on the top (closed condition) and bottom (opened condition) surfaces of the leaflets. The results exhibited that the expandable design recorded about 98% and 8.6% higher stress than the fixed design under the closed and opened conditions, respectively. The expandable valve was also observed to generate approximately 186% and 182% greater total deformation compared to the fixed valve under the closed and opened conditions, respectively. Of the valve designs evaluated, the fixed valve was found to be more satisfactory. However, the expandable valve could also be of interest with relevant modifications imposed if the adverse functionality impacts are concerned.

Electric-controlled pressure relief valve for enhanced safety in liquid-cooled lithium-ion battery packs

The liquid-cooled battery energy storage system (LCBESS) has gained significant attention due to its superior thermal management capacity. However, liquid-cooled battery pack (LCBP) usually has a high sealing level above IP65, which can trap flammable and explosive gases from battery thermal runaway and cause explosions. This poses serious safety risks and challenges for LCBESS. In this study, we tested overcharged battery inside a commercial LCBP and found that the conventionally mechanical pressure relief valve (PRV) on the LCBP had a delayed response and low-pressure relief efficiency. A realistic 20-foot model of an energy storage cabin was constructed using the Flacs finite element simulation software. Comparative studies were conducted to evaluate the pressure relief efficiency and the influence on neighboring battery packs in case of internal explosions, considering different sizes and installation positions of the PRV. Here, a newly developed electric-controlled PRV integrated with battery fault detection is introduced, capable of starting within 50 ms of the battery safety valve opening. Furthermore, the PRV was integrated with the battery management system and changed the battery charging and discharging strategy after the PRV was opened. Experimental tests confirmed the efficacy of this method in preventing explosions. This paper addresses the safety concerns associated with LCBPs and proposes an effective solution for explosion relief.

Surgical Treatment Methods for Tricuspid Valve Infective Endocarditis

Introduction: In recent years, there has been a significant increase in the incidence of tricuspid valve infective endocarditis (IE), which is associated with both the increased number of invasive examinations and procedures and the high rates of intravenous drug use. The initial treatment for tricuspid valve IE was surgical removal of the focus of infection and restoration of intracardiac hemodynamics.Reconstructive surgery aimed at preserving the valve is the preferred method of surgical treatment. If a valve-­preserving operation is not possible due to significant valvular apparatus destruction, implantation of artificial heart valves (both mechanical and biological) is the method of choice.Objective: To analyze the results of reconstructive valve-­preserving surgery and tricuspid valve replacement for tricuspid valve IE treatment.Materials and methods: In the Scientific Research Institute – Specialized Cardiac Surgery Clinical Hospital named after Academician B.A. Korolev (Nizhny Novgorod, Russian Federation) 110 patients underwent surgery for tricuspid valve IE. Primary surgery was performed in 97 patients, and 13 patients underwent repeated surgery. The patients were divided into 2 groups based on the chosen surgical method for correcting tricuspid valve disease. Group 1 included 62 patients who successfully underwent tricuspid valve replacement: mechanical prostheses in 10 patients and biological prostheses in 52 patients. Group 2 included 38 patients who underwent reconstructive valve­preserving surgery. All patients underwent De Vega annuloplasty. In 10 patients it was directly associated with bicuspidalization of the tricuspid valve and plastic surgery of intact leaflets. Two patients had suture annuloplasty of the tricuspid valve based on the modified technique. In 2 of 3 patients, an infected right atrial thrombus was removed. Three patients underwent removal of the left ventricular wall abscess and aortic valve replacement for critical stenosis. After translocation of the chords, triangular resection of the anterior leaflet was performed to separate the chord of the left side of the chest and the myxoma of the right and left chest.Results: In the early postoperative period, no valve­related complications were observed in group 1. The most common nonlethal complication was a third­-degree atrioventricular block. Multiple organ dysfunction syndrome occurred in 3 patients; cardiac tamponade was reported in 2 patients, and 1 patient had postoperative bleeding that required resternotomy for serous mediastinitis in the mid­term period and reosteosynthesis. At the hospital stage, 1 patient from group 1 died, whereas there were no deaths in group 2. In­-hospital mortality in the groups of operated patients was 0.9%.Functional ultrasound imaging findings in the postoperative period show that patients from group 1 had the peak gradient across the prosthetic tricuspid valve of 9.4 ± 1.8 mm Hg, while the mean gradient was 5.8 ± 1.75 mm Hg. There was a significant decrease in the estimated right ventricle pressure from 54.0 ± 16.2 to 35.0 ± 5.5 mm Hg. In group 2 tricuspid valve regurgitation was not observed in 27 patients, while mild and moderate regurgitation was reported in 8 and 3 patients, respectively. The peak gradient during the tricuspid valve reconstruction was 6.2 ± 1.7 mm Hg, while the mean gradient was 2.8 ± 0.75 mm Hg. The annulus fibrosus size during tricuspid valve annuloplasty averaged 30.8 ± 2.5 (28­33) mm. There was a decrease in the right ventricle pressure from 44.0 ± 18.4 to 32.0 ± 7.3 mm Hg. In the mid-­term follow­up, surviving patients were classified as NYHA classes I­-II. Of 110 patients discharged from the clinic, we were able to trace the fate of 69 patients, which accounted for 62.7%. In the long-­term period, 3 patients from group 1 died. Thus, long­term mortality in the general group was 2.72%.Conclusions: Reconstructive surgery has significant advantages over tricuspid valve replacement using various artificial heart valve models: lower rates of in-­hospital and long­-term mortality and specific complications, higher quality of life. Compliance with principles and methods of pathogenetic treatment of electrode­induced IE guarantees a success in the cohort of severe patients. The technique of reconstruction and restoration of tricuspid valve structures and functions in case of active tricuspid valve IE with detachment of the chords and destruction of the leaflets demonstrated high surgical efficiency.

Clinical Characteristics and Long-Term Outcome of Patients with Bio-Prosthetic Mitral Valve – Experience From a South Asian Country

Objectives: The aim of this study is to evaluate clinical characteristics and long-term outcome of the patients with bio-prosthetic mitral valve replacement at a tertiary care hospital of a South Asian country.&#x0D; Methodology: The study is a retrospective observational observational study involving patients who underwent bio-prosthetic mitral valve replacement at a tertiary care hospital in Karachi, Pakistan, between 2006 and 2020, and had at least two complete echocardiograms. Patients with incomplete clinical data, no electronic reports of echocardiograms, and mechanical mitral valve replacement were excluded.&#x0D; Results: This is a retrospective observational study, conducted at a tertiary care hospital. We included a total of 502 patients who underwent bio-prosthetic mitral valve replacement from the year 2006 to 2020. Patients were divided into two groups based on normal functioning bio-prosthetic mitral valve and bio-prosthetic mitral valve dysfunction (BMVD). Out of 502 patients, 322 (64%) were female, mean age at the time of surgery was 49.42 ± 14.56 years. Mitral regurgitation was more common, found in 279 (55.6%) patients followed by mitral stenosis in 188 (37.5%) patients. Mitral valve replacement was done as an elective procedure due to NYHA II to IV symptoms at the time of surgery in 446 (88.8%) patients. In the mean follow-up of 6.59 + 2.99 years, bio-prosthetic mitral valve dysfunction (BMVD) was observed in 183 (36.5%) patients. However, re-do mitral valve surgery was done in only 49 (9.8%) patients. Comparing the two groups, individuals with normal functioning bio-prosthetic mitral valve had a mean age of 51.6 + 14.27 years, while those with BMVD had a mean age of 45.639 + 14.33 years at the time of index surgery (p value=0.000). There were more long-term complications including heart failure (n = 16, 8.74%), atrial fibrillation (n = 11, 6.01%) and death (n = 6, 3.28%) in BMVD group which were statistically significant.&#x0D; Conclusion: This study is distinct because it demonstrates the outcomes of bio-prosthetic valve replacement in a relatively younger South Asian population. Due to rapid degeneration of bio-prosthetic valve in younger patients, a significant number of cases developed BMVD along with poor long-term clinical outcomes even at a short follow up period of less than ten years. These findings are like international data and signify that mechanical mitral valve replacement may be a more reasonable alternative in younger patients.

Evaluation of pliable bioresorbable, elastomeric aortic valve prostheses in sheep during 12 months post implantation

Pliable microfibrous, bioresorbable elastomeric heart valve prostheses are investigated in search of sustainable heart valve replacement. These cell-free implants recruit cells and trigger tissue formation on the valves in situ. Our aim is to investigate the behaviour of these heart valve prostheses when exposed to the high-pressure circulation. We conducted a 12-month follow-up study in sheep to evaluate the in vivo functionality and neo-tissue formation of these valves in the aortic position. All valves remained free from endocarditis, thrombotic complications and macroscopic calcifications. Cell colonisation in the leaflets was mainly restricted to the hinge area, while resorption of synthetic fibers was limited. Most valves were pliable and structurally intact (10/15), however, other valves (5/15) showed cusp thickening, retraction or holes in the leaflets. Further research is needed to assess whether in-situ heart valve tissue engineering in the aortic position is possible or whether non-resorbable synthetic pliable prostheses are preferred.

Structural evolution of mechanical heart valves (review)

Prosthetic heart valves are widely used biomedical devices. The need for these prostheses is increasing due to the increasing life expectancy of the general population and the consequent incidence of age-related degenerative valvular defects. However, even though mechanical prosthetic valves have been significantly modernized over the last decades, they are still associated with several life-threatening complications, the main one being thrombosis. Addressing this problem is challenging and requires collaboration between bioengineering and cardiothoracic surgery. Thus, the problem of creating the most adapted model of prosthetic heart valve (PHV) turns out to be at the confluence of sciences – medicine, biology, applied mechanics, mathematical modeling, etc. Today, it seems clear that the engineering ideas for hemodynamic adaptation of PHV models have been fully developed. However, research in the field of materials science, as well as a search for surface modification methods, remain a pressing bioengineering challenge.

Ross procedure or mechanical aortic valve, which is the best lifetime option for an 18-year-old? A decision analysis

Objective(s)Identifying the optimal solution for young adults requiring aortic valve replacement (AVR) is challenging, given the variety of options and their lifetime complication risks, impacts on quality of life, and costs. Decision analytic techniques make comparisons incorporating these measures. We evaluated lifetime valve-related outcomes of mechanical aortic valve replacement (mAVR) versus the Ross procedure (Ross) using decision tree microsimulations modeling. MethodsTransition probabilities, utilities, and costs derived from published reports were entered into a Markov model decision tree to explore progression between health states for hypothetical 18-year-old patients. In total, 20,000 Monte Carlo microsimulations were performed to model mortality, quality-adjusted-life-years (QALYs), and health care costs. The incremental cost-effectiveness ratio (ICER) was calculated. Sensitivity analyses was performed to identify transition probabilities at which the preferred strategy switched from baseline. ResultsFrom modeling, average 20-year mortality was 16.3% and 23.2% for Ross and mAVR, respectively. Average 20-year freedom from stroke and major bleeding was 98.6% and 94.6% for Ross, and 90.0% and 82.2% for mAVR, respectively. Average individual lifetime (60 postoperative years) utility (28.3 vs 23.5 QALYs) and cost ($54,233 vs $507,240) favored Ross over mAVR. The average ICER demonstrated that each QALY would cost $95,345 more for mAVR. Sensitivity analysis revealed late annual probabilities of autograft/left ventricular outflow tract disease and homograft/right ventricular outflow tract disease after Ross, and late death after mAVR, to be important ICER determinants. ConclusionsOur modeling suggests that Ross is preferred to mAVR, with superior freedom from valve-related morbidity and mortality, and improved cost-utility for young adults requiring aortic valve surgery.

Clinical risk factors and prediction model for infective endocarditis in patients with gram-positive bacteremia

Abstract Introduction Gram-positive bacteremia (GPB) is a common condition in clinical practice that potentially leads to infective endocarditis (IE), a high morbidity and mortality disease. Clinicians still encounter challenges in determining the likelihood of developing IE in GPB patients. Comprehensive and invasive cardiac investigations in every patient with GPB for IE could be unnecessary and potentially harmful while missing proper investigations might result in the delay or misdiagnosis of this fatal condition. Objective We aimed to determine the significant clinical risk factors and develop the prediction model for IE in patients with GPB. Methods Data were obtained from medical records of hospitalized adult patients with GPB in our hospital from January 2016 to December 2020. IE was defined by the ‘definite’ group according to modified Duke criteria. The cohort was divided into training (80%) and test (20%) sets. We identified the association between clinical risk factors and the development of IE by logistic regression analyses. Significantly associated clinical risk factors in multivariate analysis were used in the prediction model. The area under the receiver operating characteristic curve (AUROC) was utilized to evaluate model performances. Results A total of 794 patients with GPB were included in the study. IE was diagnosed in 89 patients (11.2%). Among 21 selected clinical risk factors from univariate analysis, 10 variables, including the unknown origin of bacteremia, mechanical and bioprosthetic heart valve, duration of symptoms more than 7 days, presence of Roth spot, neurological symptoms, murmur, heart failure, number of positive hemoculture more than 2 specimens, and Staphylococcus aureus septicemia, were significantly associated with IE in multivariate analysis (Figure 1) and were utilized in the prediction model. The AUROC of prediction models were 0.943 and 0.865 in training and test sets, respectively. Conclusions Our prediction model based on clinical risk factors can precisely predict IE in patients with GPB. Using this model allows clinicians to address patients at risk and guide decision-making in which cases need an urgent and comprehensive workup for IE or a wait-and-see strategy.Figure 1

Sex differences in characteristics, microbiology, management, and outcomes in infective endocarditis

Abstract Background Infective endocarditis affects male patients more frequently, yet female sex has been associated with higher mortality rate in prior smaller studies. Unselected nationwide studies on sex differences in infective endocarditis are sparse and may help identify sex-related and universal prophylactic strategies. Purpose To investigate sex related differences in patient characteristics, practice patterns and outcomes in patients with infective endocarditis. Methods Between 2010–2020, we identified and characterized all patients with infective endocarditis according to sex. We used data from the Danish national registries including microbiological data, and outcome. Frailty was assessed by the sum of cardiovascular and non-cardiovascular comorbidities in each patient using the Hospital Frailty Risk Score. Mortality was compared in unadjusted analyses using Kaplan-Meier estimates for 90-day mortality following hospital admission and 5-year mortality following hospital discharge. In adjusted analyses, Cox regression was used for comparison of 90-day and 5-year mortality. Results We identified 6,259 patients with infective endocarditis including 2,047 (32.7%) female patients and 4,212 (67.3%) male patients. Female patients were older (median age 75.0 years (IQR 64.3–82.2 vs. 71.7 years (IQR 61.7–78.9) and more frail (Intermediate frailty: 36.5% vs. 33.1%, High frailty: 11.4% vs. 9.2%, p&amp;lt;0.001). Female patients had lower education level, lower income and were more likely to live alone. Female patients had less cardiovascular comorbidity than male patients such as ischemic heart disease (25.2% vs. 34.8%), congestive heart failure (20.3% vs. 24.0%), prior myocardial infarction (7.8% vs. 14.3%), prosthetic heart valve (16.5% vs. 20.3%), and CIED (12.2% vs. 18.7%) (p&amp;lt;0.01). Staphylococcus aureus was the most common microorganism in both sexes (34.6% vs. 28.8%), but fewer female patients had Enterococcus species than male patients (10.5% vs. 18.1%). Female patients were less often surgically treated (14.0% vs. 21.2%). The cumulative 90-day incidences of mortality from hospital admission were 30.9% (95% CI 28.9%–32.9%) in females and 23.6% (95% CI 22.3%–24.9%) in males (Figure 1). The cumulative 5-year incidences of mortality from hospital discharge were 59.8% (95% CI 57.4%–62.0%) in female patients and 53.0% (95% CI 51.3%–54.6%) in male patients. In adjusted analysis, female sex was associated with increased 90-day mortality (adj. HR 1.22, 95% CI 1.10–1.36), but no difference was found in 5-year mortality (adj. HR 1.02, 95% CI 0.93–1.12). Conclusion In infective endocarditis, female sex is associated with an increased 90-day mortality despite adjusting for age and frailty. However, this association is not found in long-term mortality. Female patients differ from male patients with lower prevalence of Enterococcus infective endocarditis and lower rates of surgery. Further research is needed to understand why these differences persist.

Trends in newly diagnosed atrial fibrillation and oral anticoagulant use after cardiac surgery: a population-based analysis from Ontario, Canada

Abstract Background Post-operative atrial fibrillation after cardiac surgery is associated with an increased risk of death and ischemic cardiovascular outcomes. In the non-surgical setting, oral anticoagulation (OAC) is beneficial among patients with AF in reducing their risk of thromboembolism. The use of OAC for patients with post-operative AF after cardiac surgery is not well-defined in contemporary clinical practice - at a time when direct oral anticoagulants (DOAC) are commonly prescribed in the non-surgical setting. Purpose To examine trends in OAC use among patients with post-operative atrial fibrillation after cardiac surgery at a time when DOAC is commonly prescribed in clinical practice. Methods The study cohort consisted of consecutive patients (&amp;gt;65 years) who experienced post-operative AF within 90 days after coronary artery bypass grafting (CABG), isolated left-sided non-mechanical heart valve surgery (iValve), and combined CABG + valve surgery between 2008 and 2021, identified by a mandatory provincial registry of all patients undergoing cardiac surgery in Ontario, Canada. Key exclusion criteria included: patients with pre-existing AF, end-stage renal disease requiring dialysis, mechanical heart valves, left atrial appendage ligation, and those who required anticoagulation for non-AF indications. Prescription of OAC (warfarin or DOAC) within 90 days after discharge from surgery was collected via linkage with the Ontario Drug Benefits Plan. Results The overall cohort consisted of 45,571 patients, in whom 14,572 (32.0%) developed POAF after cardiac surgery. Rates of POAF were highest among patients who underwent combined CABG + valve surgery (44.3% in 2008 to 34.2% in 2021), followed by iValve (42.6% in 2008 to 37.3% in 2021), then followed by isolated CABG (27.6% in 2008 to 24.2% in 2021). Over the study period, there was a decrease in the rates of POAF among patients who underwent all three types of cardiac surgery (P[trend] &amp;lt;0.01). In 2021, rates of oral anticoagulation were highest among patients who underwent combined CABG + valve surgery (61.1%), followed by iValve (59.2%) and isolated CABG (42.0%). Among patients who underwent isolated CABG, there was a 9% increase in the rates of OAC use during the study period (P[trend] &amp;lt;0.001). On the other hand, rates of OAC use remained largely unchanged (Figure A) among patients who underwent iValve and combined CABG + valve surgery (P[trend] 0.24 and 0.26, respectively). Since 2018, DOAC accounted for 60-70% of all OAC prescriptions (Figure B). Conclusions Despite advances in surgical techniques and post-operative care, the rates of post-operative atrial fibrillation after cardiac surgery remain substantial. Prescription rates for OAC remain modest over the past decade, but DOAC is increasingly more commonly prescribed in this patient population. Randomized trials are needed to assess the risks and benefits of OAC, specifically DOAC, in this high-risk patient population.Figure AFigure B

Factors associated with delayed treatment initiation of oral anticoagulants among Medicare patients with atrial fibrillation

Abstract Background Atrial fibrillation (AF) is the most prevalent cardiac arrhythmia in the United States (US) and is associated with increased risk of stroke.1 Oral anticoagulants (OACs) are the primary treatment to reduce stroke risk in patients with AF.2,3 However, there is recent evidence of underuse of OAC in AF patients.4 Purpose To identify factors associated with delayed OAC treatment initiation among AF patients in the US clinical practice. Methods Medicare beneficiaries aged ≥65 years with a new diagnosis of AF without moderate-to-severe mitral stenosis or a mechanical heart valve after 1 Oct 2015 were included. Additional inclusion criteria included ≥1 claim for an OAC on or after 1st diagnosis of AF, ≥12 months of continuous Medicare Parts A, and D enrollment, and CHA2DS2-VASc score of ≥2 for males/≥3 for females. Time from 1st AF diagnosis to OAC initiation (index OAC), and demographic, sociodemographic, clinical and index OAC formulary characteristics were described. Delayed initiation was defined as OAC initiation &amp;gt;3 months after and early initiation as OAC initiation 0-3 months after 1st AF diagnosis. Factors associated with delayed OAC initiation were assessed using multivariable logistic regressions. Results A total of 446,441 patients met the inclusion criteria. Time from 1st AF diagnosis to OAC initiation was &amp;lt;1 month for 52.4% of patients, 1–≤3 months for 18.1%, &amp;gt;3–≤6 months for 7.1%, &amp;gt;6–≤12 months for 6.8%, and &amp;gt;12 months for 15.7%. Accordingly, 30% had delayed vs. 70% had early OAC initiation. Median age was 78 years (both), 48% and 47% were male, 87% and 89% were White, and median CHA2DS2-VASc score was 4 (both), respectively, for the delayed and early OAC initiation cohorts (Table 1). Factors associated with delayed OAC initiation included Black race (odds ratio [OR]: 1.29, 95% confidence interval [CI]: 1.25–1.33), South and West US census regions (OR: 1.22, 95%CI: 1.19–1.24 and OR: 1.29, 95%CI: 1.26–1.32, respectively), dementia (OR: 1.27, 95%CI: 1.23–1.30), congestive heart failure (OR: 1.20, 95%CI: 1.26–1.32), bleeding hospitalization ≤3 months before 1st AF diagnosis (OR: 1.22, 95%CI: 1.18–1.27), prior authorization (OR: 1.69, 95%CI: 1.66–1.71), and tier 4 formulary for index OAC at AF diagnosis (OR: 1.26, 95%CI: 1.22–1.30). Additionally, having low-income subsidy or dual eligibility (for Medicare and Medicaid) was associated with increased odds of delayed OAC initiation (OR: 1.06, 95%CI: 1.02–1.10 and OR: 1.09, 95%CI: 1.05–1.14, respectively; Figure 1). Conclusions In this study on Medicare patients with AF, Black race, low-income subsidy, and dual eligibility were found to be associated with delayed OAC initiation, suggesting potential disparities in the care of AF with timely OAC treatment. Moreover, OAC requiring prior authorization (the strongest predictor) or being on formulary tier 4 were associated with delayed initiation, indicating formulary restrictions may create barriers to timely OAC access for AF patients.Table 1.Patient characteristicsFigure 1.Factors of delayed initiation

Clinical outcomes of isolated tricuspid valve surgery: a systematic review

Abstract Background/Introduction Patients with isolated tricuspid valve (ITV) disease have a poor prognosis with no consensus on their management. Transcatheter ITV intervention is emerging as a valid option in patients with prohibitive surgical risk. Purpose We aimed to analyse the characteristics and clinical outcomes of patients who underwent ITV surgery to inform the clinical decision making in patients undergoing transcatheter ITV intervention and to advance the development of future technologies. Methods Digital databases were searched from inception through to 2022 for studies reporting clinical outcomes on ITV surgeries, namely ITV repair, ITV replacement with a bioprosthetic valve (ITVR-B), or ITV replacement with a mechanical valve (ITVR-M). Overall estimates of treatment effect were calculated with a random-effects model. Results Twenty-seven studies involving 10,478 patients (4,931 ITV repair, 3,821 ITVR-B, 1,713 ITVR-M) were included. Overall, early mortality occurred in 9.0% of patients and did not differ between different ITV surgical approaches. Late mortality was 27.1% at a median follow-up of 3.9 (3.0-6.0) years and was significantly higher for all ITV replacement surgeries (30.2% vs. 24.7%, RR 1.18, 95% CI 1.05-1.31, P=0.004) compared to ITV repair. Late mortality did not differ between ITVR-B and ITVR-M. Early and late clinical outcomes after ITV surgery differed according to the surgery performed. Compared to all ITV replacement surgeries and despite its favourable late mortality outcomes, ITV repair was observed to have a relatively higher risk of cerebrovascular accidents or need for permanent pacemaker implantation in the post-operative period, as well as TV regurgitation recurrence after 1 year. Conclusions Amongst ITV surgeries, ITV repair has favourable long-term mortality compared to ITV replacements. This supports the development and refinement of transcatheter ITV repair approaches in suitable patients.

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&amp;lt;0.001), preterm birth (9.2% vs 4.5%, P=0.029) and low birth weight (41.2% vs 26%, P &amp;lt;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

Quality of anticoagulation and outcomes after mechanical aortic valve replacement in patients with atrial fibrillation: a nationwide cohort study

Abstract Background Mechanical aortic valve replacement (AVR) remains predominant treatment approach for younger patients in need of aortic valve operation. However, little is known about the success of the required Vitamin K Antagonist (VKA) treatment and its relation to adverse events. Purpose We assessed the quality of VKA treatment prior to ischemic events and major bleeding episodes after mechanical AVR in AF patients. Methods The registry-based FinACAF study combining data from several Finnish health care registers covers all patients diagnosed with atrial fibrillation (AF) during 2007–2018 in Finland. In the present study, we included patients undergoing mechanical AVR before or after the AF diagnosis. Hazard ratios (HR) of first-ever ischemic stroke, any bleeding, intracranial bleeding, and myocardial infarction (MI) after AVR were estimated with Fine-Gray model adjusted for known bleeding and stroke risk factors. Results We identified 1086 patients (27.1% female, median age 62.8 (IQR 56.2–68.3) years) with mechanical AVR and AF diagnosis, either before (58.8%) or after (41.2%) the operation, and without prior bleeding episode, ischemic stroke, or MI. Cumulative incidence estimates at 10 years after AVR were 12.8% for ischemic stroke, 27.9% for significant bleeding, 5.8% for intracranial hemorrhage (ICH), and 7.2% for MI. International Normalized Ratio (INR) was &amp;lt;2.0 during 27.9–33.9% of ischemic events and lower mean Time in Therapeutic Range (TTR) with INR target ≥2.0 was associated with subsequent higher stroke occurrence (standardized adjusted HR 1.23 (1.03–1.49) for lower TTR, p=0.030, Figure 1). INR was &amp;gt;3.5 during 23.4–24.3% of major bleeding events and lower mean TTR (INR target 2.0–3.5) was associated with subsequent bleeding episode (adjusted HR 1.20 (1.03–1.41), p=0.021, Figure 2). Mortality was high (10-year estimated survival 71.1%), and lower mean TTR (INR target 2.0–3.5) was associated with higher mortality (adjusted HR 1.56 (1.39–1.72), p&amp;lt;0.001). Conclusions Adverse events after mechanical AVR are frequent in AF patients and mortality is high. Suboptimal mean TTR appears to identify the patients at high risk for both bleeding episodes and ischemic stroke.Figure 1.Figure 2.

Risk factors for serious adverse events related to vitamin K antagonists in children with congenital or acquired heart disease: a prospective cohort study

ObjectivesTo assess the occurrence of thrombosis and major bleeding in children with congenital or acquired heart disease (CAHD) treated with VKA and to identify risk factors for these serious adverse events (SAE). Study designAll children enrolled in our VKA dedicated educational program between 2008 and 2022 were prospectively included. The time in therapeutic range (TTR) was calculated to evaluate the stability of anticoagulation. Statistical analysis included Cox proportional hazard models. ResultsWe included 405 patients. Median follow-up was 18.7 (9.3–49.4) months. The median TTR was 83.1 % (74.4 %–95.3 %). No deaths occurred because of bleeding or thrombotic events. The incidences of thrombotic and major bleeding events were 0.9 % (CI95 % [0.1–1.8]) and 2.3 % (CI95 % [0.9–3.8]) per patient year, respectively. At 1 and 5 years, 98.3 % (CI95 % [96.2 %–99.2 %]) and 88.7 % (CI95 % [81.9 % 93.1 %]) of patients were free of any SAE, respectively. Although the mechanical mitral valve (MMV) was associated to major bleeding events (HR = 3.1 CI95 % [1.2–8.2], p = 0.02) in univariate analysis, only recurrent minor bleeding events (HR = 4.3 CI95 % [1.6–11.7], p < 0.01) and global TTR under 70 % (HR = 4.7 CI95 % [1.5–15.1], p < 0.01) were independent risk factors in multivariable analysis. In multivariable analysis, giant coronary aneurysms after Kawasaki disease (HR = 7.8 [1.9–32.0], p = 0.005) was the only risk factor for thrombotic events. ConclusionOverall, VKA therapy appears to be safe in children with CAHD. Suboptimal TTR, regardless of the indication for VKA initiation, was associated with bleeding events.

Abstract 12810: Short-Term Hospital Outcomes of Elderly Patients With Mechanical vs. Bioprosthetic Heart Valves Admitted for NSTEMI

Introduction: Valvular heart disease(VHD) is a significant cause of morbidity and mortality among the elderly. While the use, merits, and demerits of mechanical heart valves (MHV) and bioprosthetic heart valves(BHV) to treat VHD are well-documented in the literature, there needs to be more data on the outcomes following events of NSTEMI. Methods: We explored the 2016-2020 National Inpatient Sample for patients ages≥60 years hospitalized for a primary diagnosis of NSTEMI via their ICD-10 codes. We further retained those with a presence of MHV or BHV, and differences in outcomes between the two groups were evaluated. Results: Our study found 32775 adults of age 60 and more hospitalized with NSTEMI, which included 23670 (72.2%) cases with MHV, while 9105 (27.8%) patients had a BHV. No differences in mean Charlson Comorbidity Index (CCI) scores were found between the two groups (mean CCI in MHV patients: 4.14 vs. 4.22 in those with BHV, p=0.233). Compared to cases with BHV, those with MHV showed higher odds of acute kidney injury (aOR 1.108, p&lt;0.01), atrial fibrillation (aOR 1.110, p&lt;0.01), supraventricular tachycardia (aOR 1.46, p&lt;0.01), and use of CABG (aOR 1.289, p=0.031). However, patients with MHV were less likely to undergo PCI for NSTEMI than those with BHV (aOR 0.781, p&lt;0.01). No differences between the two cohorts were found for events of ventricular tachycardia (aOR 0.907, p=0.072), ventricular fibrillation (aOR 1.021, p=0.80), cardiogenic shock (aOR 1.012, p=0.876), or death (aOR 0.928, p=0.187). Finally, those with MHV reported a slightly more extended stay (mean length of stay 4.41 days) than those with BHV (mean length of stay 4.02 days, p&lt;0.01). Conclusions: Patients with MHV showed higher odds of complications such as AKI, Atrial fibrillation, supraventricular tachycardia, and use of CABG following NSTEMI while reporting lower odds of PCI use than those with BHV.

Abstract 16373: Pyridoxamine (Vitamin B6) Mitigation of Protein Glycation and Deleterious Platelet-Material Interactions in Bioprosthetic Heart Valve Leaflets

Introduction: Though bioprosthetic heart valves (BHV) most often do not require anticoagulation, it has been reported that 12% of BHVs have significant leaflet thrombosis. We identified Vitamin B6 (pyridoxamine, abbr. PYR) as a pretreatment agent to reduce advanced glycation end-product (AGE) accumulation within bovine pericardial (BP) BHVs. AGEs contribute to valvular degeneration through collagen crosslinking and immune signaling. PYR is also known to inhibit platelet aggregation. Hypothesis: PYR pretreatment and supplementation mitigate BHV thrombosis. Methods: Glutaraldehyde fixed collagen coated (GFC) PVC tubing was used as a leaflet surface model and methylglyoxal (MGO) pretreatment to simulate glycation. PYR pretreated collagen surfaces and perfusate PYR supplementation were compared to untreated controls. These studies were repeated with glycated GFC. Fresh citrated human whole blood from healthy donors was perfused over the surfaces for 4 hours at 37 °C and arterial shear using the Chandler loop apparatus. Post perfusion platelet activation (CD62P expression via flow cytometry) and nitric oxide synthase (NOS) activity were measured. Platelets adhered to the tubing sections were visualized and quantitated via scanning electron microscopy. Results: PYR pretreatment of GFC surfaces reduced platelet activation after perfusion compared to the control (Fig1a). Surface glycation with MGO resulted in increased platelet activation, but PYR pretreatment of the glycated surface mitigated the effect of glycation on platelet activation (Fig1b). NOS activity was impaired by surface glycation and PYR treatment appears to rescue function in glycated environments (Fig1c). Platelet adhesion to GFC was increased by glycation (Fig1d-f). Conclusions: Glycated surfaces, even in euglycemia, are prothrombotic when compared to non-glycated surfaces. Vitamin B6 reduces platelet activation and adhesion in both glycated and non-glycated environments.