Thromboembolic and hemorrhagic complications in patients with prosthetic heart valves cared for in a tertiary care center. What have we learned?

BACKGROUND: Heart valve replacement surgery with mechanical or biological prostheses entails a risk of thromboembolism and bleeding complications. OBJECTIVE: To determine the complications related to complementary anticoagulation therapy and the probability of risk. METHODS: One-hundred and sixty-three patients who underwent heart valve replacement between 2002 and 2016 with either mechanical or biological prostheses, and who received vitamin K antagonists after hospital discharge, were studied. Anticoagulation therapy was categorized into optimal and non-optimal according to INR values prior to the development of complications. Patients with comorbidities and other risk factors for thrombosis and/or bleeding were excluded. RESULTS: In total, 68.7 % of patients received mechanical prostheses, and 31.3 %, biological prostheses (p ≤ 0.001); 25.2 % experienced the complications that motivated the study (p ≤ 0.001), which were hemorrhagic in 48.8 %, thromboembolic in 26.8 %, and of both types in 24.4 % (relative risk = 4.229). Among the patients with complications, 95.1 % received mechanical prostheses, and 4.9 %, biological (p = 0.005); non-optimal INR was identified in 49.7 % (p ≤ 0.001). CONCLUSIONS: Given the high risk of thromboembolic and hemorrhagic complications, valve prostheses must be carefully chosen, and care priorities should include prevention and follow-up, especially in those patients who require anticoagulation therapy.

ANTECEDENTES: El reemplazo valvular por prótesis mecánicas o biológicas implica riesgo de tromboembolismo y complicaciones hemorrágicas. OBJETIVO: Determinar las complicaciones relacionadas con la terapia de anticoagulación complementaria y la probabilidad de riesgo en pacientes portadores de prótesis valvulares del corazón. MÉTODOS: Se estudiaron 163 pacientes entre 2002 y 2016, portadores de prótesis mecánicas y biológicas, quienes recibieron antagonistas de la vitamina K posterior al egreso hospitalario. La terapia de anticoagulación se categorizó en óptima y no óptima conforme a los valores de INR previos a las complicaciones. Fueron excluidos los pacientes con comorbilidades y otros factores de riesgo de trombosis y/o sangrado. RESULTADOS: a 68.7 % de los pacientes se les colocó prótesis mecánica y a 31.3 %, biológica (p ≤ 0.001); 25.2 % presentó las complicaciones motivo de estudio (p ≤ 0.001), hemorrágicas en 48.8 %, tromboembólicas en 26.8 % y de ambos tipos en 24.4 % (riesgo relativo = 4.229); a 95.1 % de los pacientes con complicaciones se les colocó prótesis mecánica y a 4.9 %, biológica (p = 0.005); 49.7 % presentó INR no óptimo (p ≤ 0.001). CONCLUSIONES: Ante riesgo alto de complicaciones tromboembólicas y hemorrágicas, la elección de las prótesis valvulares, la prevención y el seguimiento son prioridades, principalmente en quienes requieren terapia de anticoagulación.

Absolute-Delay Multiphase Reconstruction Reduces Prosthetic Valve-Related and Atrial Fibrillation-Related Artifacts at Cardiac CT.

OBJECTIVE: The objective of our study was to compare the image quality of cardiac CT images of mechanical valves in patients with irregular heart rates (HRs) using absolute-delay multiphase reconstruction versus relative-delay multiphase reconstruction. MATERIALS AND METHODS: A total of 26 patients with 40 mechanical valves who had atrial fibrillation during CT were included. The image quality of the CT scans was assessed for the subvalvular and valvular regions on a 4-point scale. The paired t test or Wilcoxon signed rank test was used to compare image quality scores between the relative-delay and absolute-delay reconstruction techniques. The overall image quality score was determined as the mean of the valvular and subvalvular region scores. RESULTS: For valvular regions, the image quality scores were 2.93 ± 0.73 (mean ± SD) for the relative-delay reconstruction technique and 3.55 ± 0.60 for the absolute-delay reconstruction technique (p < 0.0001). For subvalvular regions, the image quality scores were 2.8 ± 2.80 ± 0.79 and 3.35 ± 0.66 for the relative- and absolute-delay reconstructions (p < 0.0001), respectively. The nondiagnostic image quality group consisted of relative-delay reconstruction images of three valves (7.5%); the image quality scores for the absolute-delay reconstruction images of all three valves were improved, and the absolute-delay reconstruction images of the three valves were of diagnostic quality (p < 0.0001). CONCLUSION: Absolute-delay multiphase reconstruction can improve CT image quality of mechanical valves in patients with an irregular HR compared with relative-delay reconstruction.

In vitro assessment of the Lenz effect on heart valve prostheses at 1.5 T.

PURPOSE: Increasing numbers of patients with cardiac valve prostheses are being referred for magnetic resonance imaging (MRI) despite concerns about the potential for functional valve impedance due to Lenz forces. This study aims to determine, in vitro, the occurrence of Lenz forces on 9 heart valve prostheses at 1.5 T and assess the risk of impedance of valve function. MATERIALS AND METHODS: A specially designed hydro-pneumatic system was used to record pressure changes across the valve indicative of any MR induced alteration in leaflet performance. Nine cardiac valve prostheses were exposed to the B0 field at 1.5 T. Each valve was advanced through the B0 field and continuous signals from high frequency pressure transducers were recorded and pressure drops across the valve were assessed using time correction superimposition. The delta p across the valve was assessed as a marker of any MRI induced alteration in leaflet performance. RESULTS: All prostheses produced sinusoidal waveforms. Profiles were asymmetrical and there was no consistency in complex shape and valve type/sub-group. Irregularities in pressure profiles of 4 prostheses were detected indicating resistance of the occluder to the B0 field. CONCLUSION: This study provides empirical evidence of the Lenz Effect on cardiac valve prostheses exposed to the MR B0 field causing functional valve impedance and increasing the risk of valvular regurgitation and reduced cardiac output. Thus, it is essential to consider the potential for the Lenz Effect when scanning cardiac valve implant patients in order to safeguard their wellbeing.

Effective orifice diameter: a new sizing parameter of surgical valve prostheses to inform valve selection.

Background: The labeled sizes of surgical valve prostheses and their discordance with the physical internal valve orifice sizes has long been a controversy in the cardiac surgery community, leading many to believe it to be a contributing factor in prosthesis-patient mismatch following valvular replacement surgery. In an attempt to address this issue, the International Organization for Standardization (ISO) 5840-2:2021 standard for surgical valve prostheses recommends that a new sizing parameter, namely, the effective orifice diameter, be provided in labeling by all manufacturers as an indicator of the true flow-passing capacity of a prosthetic valve. Methods: The ISO Cardiac Valves Working Group conducted a multi-laboratory round-robin study to investigate whether the effective orifice diameter of a prosthetic surgical valve could be derived repeatably and reproducibly through steady forward-flow testing. A total of seven valve models, each with multiple sizes, were tested, including a mechanical heart valve and multiple biological heart valves. Results: The round-robin study confirmed that the steady forward-flow test had good intra-laboratory repeatability and inter-laboratory reproducibility in deriving the effective orifice diameters of surgical valve prostheses. On average, among the participating laboratories, the experimentally derived effective orifice diameter of a prosthetic heart valve was 3-12 mm smaller than its labeled size. Conclusions: The effective orifice diameter provides better characterization of the hydrodynamic characteristics of a surgical valve prosthesis and can be derived using a validated steady forward-flow test method. This new sizing parameter will soon be adopted by surgical valve manufacturers and provided in device labeling to inform valve selection by surgeons.

Comparison of the Early Results of Supra-Annular and Intra-Annular Aortic Valve Replacement in Isolated Aortic Valve Replacement.

Objectives: This study aims to compare the early results of patients who underwent isolated aortic valve replacement (AVR) with supra-annular and intra-annular AVR. Methods: Between 2013 and 2019, 113 patients (77 males; mean age 57.8±16.36 years) who underwent isolated AVR were evaluated. The patients were divided into two groups those who underwent supra-annular (n=59) and intra-annular (n=54) AVR. The most commonly used valves in surgeries St Jude Medical Masters (St. Jude Medical, Minneapolis, MN, USA), (n=35, 30.9%), Sorin Mitroflow (Sorin Group Inc., Mitroflow Division, Canada), (n=32, 28.3%, and Carbomedics Top Hat (Sulzer, Carbomedics, Austin, TX), (n=31, 27.4%). Results: The cross-clamp (XCL) and cardiopulmonary bypass (CPB) times of the patients who underwent supra-annular AVR were found to be significantly higher than the patients who underwent intra-annular AVR. However, there was no significant difference between the two groups in terms of postoperative adverse events. There was no significant difference between the two groups in the postoperative first-week transthoracic echocardiographic (TTE) findings. Conclusion: When comparing supra-annular and intra-annular valve positioning results in patients undergoing isolated AVR, no significant difference was found between the groups in terms of postoperative complications, gradient differences in postoperative TTE, and ejection fractions. Supra-annular valve positioning should be considered, especially in patients with small annulus, in the presence of suitable anatomical features. However, this issue needs to be investigated in future prospective studies with more patients.

Maternal and Fetal Outcomes in Pregnant Patients With Mechanical and Bioprosthetic Heart Valves.

Background Guidelines for choice of prosthetic heart valve in people of reproductive age are not well established. Although biologic heart valves (BHVs) have risk of deterioration, mechanical heart valves (MHVs) require lifelong anticoagulation. This study aimed to characterize the association of prosthetic valve type with maternal and fetal outcomes in pregnant patients. Methods and Results Using the 2008 to 2019 National Inpatient Sample, we identified all adult patients hospitalized for delivery with prior heart valve implantation. Multivariable regressions were used to analyze the primary outcome, major adverse cardiovascular events, and secondary outcomes, including maternal and fetal complications, length of stay, and costs. Among 39 871 862 birth hospitalizations, 4152 had MHVs and 874 had BHVs. Age, comorbidities, and cesarean birth rates were similar between patients with MHVs and BHVs. The presence of a prosthetic valve was associated with over 22-fold increase in likelihood of major adverse cardiovascular events (MHV: adjusted odds ratio, 22.1 [95% CI, 17.3-28.2]; BHV: adjusted odds ratio, 22.5 [95% CI, 13.9-36.5]) as well as increased duration of stay and hospitalization costs. However, patients with MHVs and BHVs had no significant difference in the odds of any maternal outcome, including major adverse cardiovascular events, hypertensive disease of pregnancy, and ante/postpartum hemorrhage. Similarly, fetal complications were more likely in patients with valve prostheses, including a 4-fold increase in odds of stillbirth, but remained comparable between MHVs and BHVs. Conclusions Patients hospitalized for delivery with prior valve replacement carry substantial risk of adverse maternal and fetal events, regardless of valve type. Our findings reveal comparable outcomes between MHVs and BHVs.

Impact of PPAR-gamma activation on the durability of biological heart valve prostheses in hypercholesterolaemic rats.

OBJECTIVES: Hypercholesterolaemia and obesity are risk factors for the development of calcified aortic valve disease and common comorbidities in respective patients. Peroxisome proliferator-activated receptor gamma activation has been shown to reduce the progression of native aortic valve sclerosis, while its effect on bioprosthetic valve degeneration is yet unknown. This project aims to analyse the impact of pioglitazone, a peroxisome proliferator-activated receptor gamma agonist, on the degeneration of biological aortic valve conduits in an implantation model in obese and hypercholesterolaemic rats. METHODS: Cryopreserved allogenic rat aortic valve conduits (n = 40) were infrarenally implanted into Wistar rats on high-fat (34.6%) diet. One cohort was treated with pioglitazone (75 mg/kg chow; n = 20, group PIO) and compared to untreated rats (n = 20, group control). After 4 or 12 weeks, conduits were explanted and analysed by (immuno-)histology and real-time polymerase chain reaction. RESULTS: A significantly decreased intima hyperplasia occurred in group PIO compared to control after 4 (P = 0.014) and 12 weeks (P = 0.045). Calcification of the intima was significantly decreased in PIO versus control at 12 weeks (P = 0.0001). No significant inter-group differences were shown for media calcification after 4 and 12 weeks. Echocardiographically, significantly lower regurgitation through the implanted aortic valve conduit was observed in PIO compared to control after 4 (P = 0.018) and 12 weeks (P = 0.0004). Inflammatory activity was comparable between both groups. CONCLUSIONS: Systemic peroxisome proliferator-activated receptor gamma activation decreases intima hyperplasia and subsequent intima calcification of cryopreserved allografts in obese, hypercholesterolaemic recipients. Additionally, it seems to inhibit functional impairment of the implanted aortic valve. Further preclinical studies are required to determine the long-term impact of peroxisome proliferator-activated receptor gamma agonists on graft durability.

Surgical aortic valve replacement in patients aged 50-69 years-insights from the German Aortic Valve Registry (GARY).

OBJECTIVES: The aim of this study was to analyse the outcome of patients between 50 and 69 years of age undergoing biological or mechanical aortic valve replacement. METHODS: Data were collected from the German Aortic Valve Registry. Data were analysed regarding baseline characteristics and outcome parameters such as 5-year survival, stroke and reintervention. RESULTS: In total.3046 patients undergoing isolated surgical aortic valve replacement between 2011 and 2012 were investigated and a propensity score matching was performed. Within this period, 2239 patients received a biological prostheses, while 807 patients received a mechanical prosthesis. Mean age in the biological group was 63.07 (±5.11) and 57.34 (±4.67) in the mechanical group (standardized mean difference 1.172). In the overall cohort, there were more female patients in the biological group (32.7% vs 28.4%) and log EuroSCORE I was higher (5.41% vs 4.26%). After propensity matching (610 pairs), there was no difference in the mortality at 5-year follow-up (12.1% biological vs 9.2% mechanical P = 0.05) nor for reoperation/reintervention (2.5% biological vs 2.0% mechanical, P = 0.546). Patients undergoing mechanical aortic valve replacement suffered from a higher stroke rate 3.3% vs 1.5% (P = 0.04) at 5-year follow-up. CONCLUSIONS: Aortic valve replacement with biological or mechanical prostheses showed similar 5-year outcomes for survival and reoperation in a propensity-matched cohort, but significantly increased stroke rate after mechanical aortic valve replacement. This could influence the choice of a mechanical valve in younger patients.

Complications of TAVR From an Anesthesia Perspective.

Description Transcatheter aortic valve replacement (TAVR) has become the predominant technique for aortic valve replacement in the United States. Initially approved for high surgical risk patients, TAVR is now approved for most patients requiring valve therapy, including younger, lower-risk patients. The procedure is ideally performed in a hybrid operating room equipped with fluoroscopic equipment and transesophageal echocardiogram (TEE) imaging that can be viewed simultaneously by the operating team. The operating room should also be equipped to allow initiation of cardiopulmonary bypass, if necessary. Cardiac anesthesia teams are often involved with the management of these patients. This mini-review is designed to summarize potential complications that anesthesiologists may contend with during TAVR.

Possible Early Generation of Physiological Helical Flow Could Benefit the Triflo Trileaflet Heart Valve Prosthesis Compared to Bileaflet Valves.

Background-Physiological helical flow in the ascending aorta has been well documented in the last two decades, accompanied by discussions on possible physiological benefits of such axial swirl. Recent 4D-MRI studies on healthy volunteers have found indications of early generation of helical flow, early in the systole and close to the valve plane. Objectives-Firstly, the aim of the study is to investigate the hypothesis of premature swirl existence in the ventricular outflow tract leading to helical flow in the valve plane, and second to investigate the possible impact of two different mechanical valve designs on the preservation of this early helical flow and its subsequent hemodynamic consequences. Methods-We use a pulse duplicator with an aortic arch and High-Speed Particle Image Velocimetry to document the flow evolution in the systolic cycle. The pulse-duplicator is modified with a swirl-generating insert to generate early helical flow in the valve plane. Special focus is paid to the interaction of such helical flow with different designs of mechanical prosthetic heart valves, comparing a classical bileaflet mechanical heart valve, the St. Jude Medical Regent valve (SJM Regent BMHV), with the Triflo trileaflet mechanical heart valve T2B version (Triflo TMHV). Results-When the swirl-generator is inserted, a vortex is generated in the core flow, demonstrating early helical flow in the valve plane, similar to the observations reported in the recent 4D-MRI study taken for comparison. For the Triflo trileaflet valve, the early helical flow is not obstructed in the central orifice, similar as in the case of the natural valve. Conservation of angular momentum leads to radial expansion of the core flow and flattening of the axial flow profile downstream in the arch. Furthermore, the early helical flow helps to overcome separation at the outer and inner curvature. In contrast, the two parallel leaflets for the bileaflet valve impose a flow straightener effect, annihilating the angular momentum, which has a negative impact on kinetic energy of the flow. Conclusion-The results imply better hemodynamics for the Triflo trileaflet valve based on hydrodynamic arguments under the discussed hypothesis. In addition, it makes the Triflo valve a better candidate for valve replacements in patients with a pathological generation of nonaxial velocity in the ventricle outflow tract.

Time in therapeutic range and risk of thromboembolism and bleeding in patients with a mechanical heart valve prosthesis.

OBJECTIVE: Oral anticoagulation with vitamin K antagonists is recommended after mechanical heart valve replacement. However, data regarding the association between the quality of vitamin K antagonist treatment and the risk of complications are sparse. METHODS: Patients undergoing mechanical heart valve replacement (1997-2012) with available data on international normalized ratio values were identified in Danish registries. The quality of vitamin K antagonist treatment between discharge after valve replacement and 6 months postdischarge (ie, index) was assessed as time in therapeutic range (TTR) ≥70% or <70% reflecting the percentage of time in therapeutic international normalized ratio interval. Patients were followed from index until occurrence of an outcome of interest (ie, thromboembolism and bleeding), death, or end of study (December 31, 2012), whichever came first. The risk of outcomes according to quality of vitamin K antagonist treatment was estimated with multivariable Cox regression. RESULTS: In total, 659 patients undergoing mechanical heart valve replacement were included in the study. Median number of international normalized ratio measurements in the 6-month period after surgery was 13 (interquartile range, 8-19). Median TTR was 54.9% (interquartile range, 39.0%-72.9%) and 29.1% of patients had a TTR ≥70%. Median follow-up was 6.1 years. The risk of thromboembolism was significantly lower in the group with TTR ≥70% compared with TTR <70% (hazard ratio, 0.44; 95% confidence interval, 0.22-0.85), whereas no significant difference concerning risk of bleeding among groups was found (hazard ratio, 0.63; 95% confidence interval 0.36-1.08). CONCLUSIONS: In patients undergoing mechanical heart valve replacement, TTR <70% in the 6-month period after surgery was associated with an increased risk of thromboembolic events but not bleeding compared with TTR ≥70%.

Assessing the Thrombogenic Potential of Heart Valve Prostheses: An Approach for a Standardized In-Vitro Method.

PURPOSE: Thrombogenic complications are still a main issue in the general performance of cardiovascular implants, especially heart valves. To date, the thrombogenic potential of those prostheses is pre-clinically assessed in time consuming animal studies with questionable evidence. METHODS: In this study, we present a new in-vitro method to assess and compare deficiencies of heart valve substitutes concerning their thrombogenic performance and locate initial clot formation under physiological conditions using porcine blood. Therefore, an athrombogenic pulse duplicator (THIA3) was developed that simulates the anatomic and hemodynamic conditions in the vicinity of the aortic valve. Validation of this tester was carried out with regard to hemodynamics, reproducibility and using positive and negative control valves and by comparison of clot locations with literature data from chronic animal trials with sheep using a St. Jude bileaflet valve. RESULTS: Validation of the tester showed quasi-physiological hemodynamics and reproducible clot formation. Identical clot formations were found comparing findings in vitro with chronic animal trials. CONCLUSION: The THIA 3 has proven its suitability for valid, reproducible evaluation of thrombogenic potential of heart valves in a short period of time.

Durabilidad de prótesis valvulares aórticas biológicas: deterioro estructural e incidencia de eventos en el seguimiento alejado / Durability of Bioprosthetic Aortic Valves: Structural Deterioration and Incidence of Events at Long-Term Follow-Up

RESUMEN Introducción: En el tratamiento de la estenosis aórtica grave ha habido un cambio en la elección del tipo de prótesis valvular, con priorización de la utilización de válvulas biológicas. En la actualidad, a nivel mundial, en el 80% de los recambios valvulares aórticos se utilizan prótesis biológicas, cuya menor durabilidad alejada representa su mayor limitación. No contamos con evaluación reciente en nuestro medio de la durabilidad de las válvulas biológicas y la incidencia de eventos a largo plazo. Objetivos: Evaluar el comportamiento alejado de las prótesis valvulares aórticas biológicas, respecto de su sobrevida e incidencia ecocardiográfica de deterioro valvular estructural (DVE). Material y Métodos: Estudio retrospectivo sobre 2365 pacientes operados entre enero de 2003 y diciembre de 2023. Se evaluó la sobrevida alejada y la incidencia de DVE de acuerdo con las modificaciones del gradiente medio transprotésico (GMt) según la edad (dicotomizada en 60 años) y el tamaño de la prótesis utilizada (dicotomizado en 23 mm). Resultados: La edad promedio fue de 73 ± 3,05 años (105 pacientes < 60 años y 2530 pacientes ≥60 años). Sexo masculino en 63,4 %. Seguimiento alejado en el 92 % de los pacientes, media de 5,9 ± 3,2 años. Sobrevida a 5 y 10 años según edad: en < 60 años: 98,3 y 91,7 % vs. ≥ 60 años: 81,7 y 65,7 % (p=0,007) respectivamente. Seguimiento ecocardiográfico global en 1399 (59,7 %) pacientes. Valores del GMt basal, y a 5 y 10 años: a) según edad: en < 60 años: 16 ±3 mmHg, 16 ± 6 mmHg y 19 ± 5 mmHg, vs. en ≥ 60 años: 15 ± 5 mmHg, 16 ± 7 mmHg y 18± 7 mmHg (p=NS); b) según tamaño de la prótesis: en < 23 mm: 17±6 mmHg, 19±7 mmHg y 22± 7 mmHg, vs. en ≥ 23 mm: 15± 5 mmHg, 16± 6 mmHg y 18± 6 mmHg (p= 0,001). Conclusiones: Los pacientes con prótesis valvulares biológicas presentaron una elevada sobrevida alejada con diferencias según el grupo etario. Se registraron en el seguimiento diferencias del GMt (<10 mmHg) en las válvulas < 23 mm, demostrando baja incidencia de DVE grave.

ABSTRACT Background: In the treatment of severe aortic stenosis there has been a shift in the choice of the valve prosthesis type toward the use of biological valves. At present, bioprosthetic valves are used in 80% of aortic valve replacements worldwide. Their main limitation is their reduced long-term durability. No assessment has been yet performed in our setting regarding the durability of bioprosthetic valves and the incidence of long-term events. Objectives: To evaluate the long-term performance of bioprosthetic aortic valves related to survival and echocardiographic incidence of structural valve deterioration (SVD). Methods: A retrospective study of 2365 patients undergoing aortic valve replacement with biological prosthesis between January 2003 and December 2023. We analyzed the long-term survival and the incidence of SVD pursuant to changes in the mean transprosthetic gradient (mTPG) according to age (< or ≥60 years) and prosthetic valve size (< or ≥ 23 mm). Results: Mean age was 73±3.05 years (105 patients <60 years and 2530 patients ≥60 years). A total of 63.4% was male. Of patients, 92% completed a long-term follow-up, mean 5.9±3.2 years. Survival at 5 and 10 years according to age was: in patients <60 years: 98.3 and 91.7% vs. patients ≥60 years: 81.7 and 65.7% (p=0.007), respectively. A total of 1399 (59.7%) patients had an overall echocardiographic follow-up. The values of mTPG at baseline, 5 and 10 years were: a) according to age: in patients <60 years: 16±3 mmHg, 16±6 mmHg and 19±5 mmHg, vs. in patients ≥60 years: 15±5 mmHg, 16±7 mmHg and 18±7 mmHg (p=NS); b) according to prosthesis size: <23 mm: 17±6 mmHg, 19±7mmHg and 22±7 mmHg, vs. ≥23 mm: 15±5 mmHg, 16±6 mmHg and 18±6 mmHg (p= 0.001). Conclusions: Patients with bioprosthetic valves experienced high long-term survival with some differences according to age group. At follow-up, differences in mTPG (<10 mmHg) were observed in prosthetic valve sizes <23 mm, showing low incidence of severe SVD.

Early-onset prosthetic valve endocarditis definition revisited: Prospective study and literature review.

OBJECTIVE: To determine the annual incidence of prosthetic valve endocarditis (PVE) and to evaluate its current classification based on the epidemiological distribution of agents identified and their sensitivity profiles. METHODS: Consecutive cases of PVE occurring within the first year of valve surgery during the period 1997-2014 were included in this prospective cohort study. Incidence, demographic, clinical, microbiological, and in-hospital mortality data of these PVE patients were recorded. RESULTS: One hundred and seventy-two cases of PVE were included, and the global annual incidence of PVE was 1.7%. Most PVE cases occurred within 120days after surgery (76.7%). After this period, there was a reduction in resistant microorganisms (64.4% vs. 32.3%, respectively; p=0.007) and an increase in the incidence of Streptococcus spp (1.9% vs. 23.5%; p=0.007). A literature review revealed 646 cases of PVE with an identified etiology, of which 264 (41%) were caused by coagulase-negative staphylococci and 43 (7%) by Streptococcus spp. This is in agreement with the current study findings. CONCLUSIONS: Most PVE cases occurred within 120days after valve surgery, and the same etiological agents were identified in this period. The current cut-off level of 365days for the classification of early-onset PVE should be revisited.

Degenerative Aortic Stenosis in Women: Challenges and Perspectives

Abstract Degenerative aortic stenosis is currently a public health problem. Affecting the elderly population, this pathology has been showing an increasing prevalence as a direct result of the population aging. In this context, women have a greater life expectancy, corresponding to most of the population with degenerative aortic stenosis. Specific characteristics of this pathology in females are present in the diagnosis, pathophysiology, anatomical aspects, imaging and in therapeutic approach. Women present a more severe disease with less valve calcification than men, more concentric ventricular remodeling, higher transvalvular gradients, and less myocardial fibrosis. Less evident symptoms mean that these patients are referred later for surgical or percutaneous therapeutic treatment. The greater comorbidity presented by females and possibly due to the smaller body surface, bring specific aspects that affect the surgery results, leading to higher mortality rates and, more often, the prosthesis-patient mismatch. Percutaneous valve implantation is a good alternative, with better results in females, when compared to surgery, both in the treatment of native valves and in the treatment of a previously implanted bioprosthesis' dysfunction. The challenges encountered for the treatment of aortic stenosis in women and their possible solutions are described in this article, focusing on the observed difference of aortic stenosis in females and their possible solutions.

Complicaciones tromboembólicas y hemorrágicas en pacientes portadores de prótesis valvulares del corazón en un centro de tercer nivel. ¿Qué hemos aprendido? / Thromboembolic and hemorrhagic complications in patients with prosthetic heart valves at third level care center. What have we learned?

Resumen Antecedentes: El reemplazo valvular por prótesis mecánicas o biológicas implica riesgo de tromboembolismo y complicaciones hemorrágicas. Objetivo: Determinar las complicaciones relacionadas con la terapia de anticoagulación complementaria y la probabilidad de riesgo en pacientes portadores de prótesis valvulares del corazón. Métodos: Se estudiaron 163 pacientes entre 2002 y 2016, portadores de prótesis mecánicas y biológicas, quienes recibieron antagonistas de la vitamina K posterior al egreso hospitalario. La terapia de anticoagulación se categorizó en óptima y no óptima conforme a los valores de INR previos a las complicaciones. Fueron excluidos los pacientes con comorbilidades y otros factores de riesgo de trombosis y/o sangrado. Resultados: a 68.7 % de los pacientes se les colocó prótesis mecánica y a 31.3 %, biológica (p ≤ 0.001); 25.2 % presentó las complicaciones motivo de estudio (p ≤ 0.001), hemorrágicas en 48.8 %, tromboembólicas en 26.8 % y de ambos tipos en 24.4 % (riesgo relativo = 4.229); a 95.1 % de los pacientes con complicaciones se les colocó prótesis mecánica y a 4.9 %, biológica (p = 0.005); 49.7 % presentó INR no óptimo (p ≤ 0.001). Conclusiones: Ante riesgo alto de complicaciones tromboembólicas y hemorrágicas, la elección de las prótesis valvulares, la prevención y el seguimiento son prioridades, principalmente en quienes requieren terapia de anticoagulación.

Abstract Background: Heart valve replacement surgery with mechanical or biological prostheses entails a risk of thromboembolism and bleeding complications. Objective: To determine the complications related to complementary anticoagulation therapy and the probability of risk. Methods: One-hundred and sixty-three patients who underwent heart valve replacement between 2002 and 2016 with either mechanical or biological prostheses, and who received vitamin K antagonists after hospital discharge, were studied. Anticoagulation therapy was categorized into optimal and non-optimal according to INR values prior to the development of complications. Patients with comorbidities and other risk factors for thrombosis and/or bleeding were excluded. Results: In total, 68.7 % of patients received mechanical prostheses, and 31.3 %, biological prostheses (p ≤ 0.001); 25.2 % experienced the complications that motivated the study (p ≤ 0.001), which were hemorrhagic in 48.8 %, thromboembolic in 26.8 %, and of both types in 24.4 % (relative risk = 4.229). Among the patients with complications, 95.1 % received mechanical prostheses, and 4.9 %, biological (p = 0.005); non-optimal INR was identified in 49.7 % (p ≤ 0.001). Conclusions: Given the high risk of thromboembolic and hemorrhagic complications, valve prostheses must be carefully chosen, and care priorities should include prevention and follow-up, especially in those patients who require anticoagulation therapy.

A whole-heart motion-correction algorithm: Effects on CT image quality and diagnostic accuracy of mechanical valve prosthesis abnormalities.

BACKGROUND: We aimed to determine the effect of a whole-heart motion-correction algorithm (new-generation snapshot freeze, NG SSF) on the image quality of cardiac computed tomography (CT) images in patients with mechanical valve prostheses compared to standard images without motion correction and to compare the diagnostic accuracy of NG SSF and standard CT image sets for the detection of prosthetic valve abnormalities. METHODS: A total of 20 patients with 32 mechanical valves who underwent wide-coverage detector cardiac CT with single-heartbeat acquisition were included. The CT image quality for subvalvular (below the prosthesis) and valvular regions (valve leaflets) of mechanical valves was assessed by two observers on a four-point scale (1 = poor, 2 = fair, 3 = good, and 4 = excellent). Paired t-tests or Wilcoxon signed rank tests were used to compare image quality scores and the number of diagnostic phases (image quality score≥3) between the standard image sets and NG SSF image sets. Diagnostic performance for detection of prosthetic valve abnormalities was compared between two image sets with the final diagnosis set by re-operation or clinical findings as the standard reference. RESULTS: NG SSF image sets had better image quality scores than standard image sets for both valvular and subvalvular regions (P < 0.05 for both). The number of phases that were of diagnostic image quality per patient was significantly greater in the NG SSF image set than standard image set for both valvular and subvalvular regions (P < 0.0001). Diagnostic performance of NG SSF image sets for the detection of prosthetic abnormalities (20 pannus and two paravalvular leaks) was greater than that of standard image sets (P < 0.05). CONCLUSION: Application of NG SSF can improve CT image quality and diagnostic accuracy in patients with mechanical valves compared to standard images.

Effect of heart rate on the hemodynamics of bileaflet mechanical heart valves' prostheses (St. Jude Medical) in the aortic position and in the opening phase: A computational study.

To date, to the best of the authors' knowledge, in almost all of the studies performed around the hemodynamics of bileaflet mechanical heart valves, a heart rate of 70-72 beats/min has been considered. In fact, the heart rate of ~72 beats/min does not represent the entire normal physiological conditions under which the aortic or prosthetic valves function. The heart rates of 120 or 50 beats/min may lead to hemodynamic complications, such as plaque formation and/or thromboembolism in patients. In this study, the hemodynamic performance of the bileaflet mechanical heart valves in a wide range of normal and physiological heart rates, that is, 60-150 beats/min, was studied in the opening phase. The model considered in this study was a St. Jude Medical bileaflet mechanical heart valve with the inner diameter of 27 mm in the aortic position. The hemodynamics of the native valve and the St. Jude Medical valve were studied in a variety of heart rates in the opening phase and the results were carefully compared. The results indicate that peak values of the velocity profile downstream of the valve increase as heart rate increases, as well as the location of the maximum velocity changes with heart rate in the St. Jude Medical valve model. Also, the maximum values of shear stress and wall shear stresses downstream of the valve are proportional to heart rate in both models. Interestingly, the maximum shear stress and wall shear stress values in both models are in the same range when heart rate is <90 beats/min; however, these values significantly increase in the St. Jude Medical valve model when heart rate is >90 beats/min (up to ~40% growth compared to that of the native valve). The findings of this study may be of importance in the hemodynamic performance of bileaflet mechanical heart valves. They may also play an important role in design improvement of conventional prosthetic heart valves and the design of the next generation of prosthetic valves, such as percutaneous valves.

INR variability and outcomes in patients with mechanical heart valve prosthesis.

BACKGROUND: The quality of treatment with warfarin is mainly assessed by the time in therapeutic range (TTR) in patients with mechanical heart valve prosthesis (MHV). Our aim was to evaluate if International Normalized Ratio (INR) variability predicted a combined endpoint of thromboembolism, major bleeding and death better than TTR. METHODS AND RESULTS: We included 394 patients at one center with MHV during 2008-2011 with adverse events and death followed prospectively. TTR 2.0-4.0 and log-transformed INR variability was calculated for all patients. In order to make comparisons between the measures, the gradient of the risk per one standard deviation (SD) was assessed. INR variability performed equal as TTR 2.0-4.0 per one SD unit adjusted for covariates, hazard ratio (HR) 1.30 (95% CI 1.1-1.5) and 0.71 (95% CI 0.6-0.8) respectively for the combined endpoint, and performed better for mortality HR 1.47 (95% CI 1.1-1.9) and 0.70 (95% CI 0.6-0.8). INR variability was categorized into high and low group and TTR into tertiles. High variability within the low and high TTR, had a HR 2.0 (95% CI 1.7-3.6) and 2.2 (95% CI 1.1-4.1) respectively, of the combined endpoint compared to the low variability/high TTR group. INR values <2.0 greatly increased the rate of thromboembolism whereas the rate of major bleeding increased moderately between INR 3.0 and 4.0 and increased substantially after INR >4.0. CONCLUSION: The INR variability is an equal predictor as TTR of the combined endpoint of thromboembolism, major bleeding and death, and adds important information on top of TTR in patients with MHV.

A novel computational model for the hemodynamics of bileaflet mechanical valves in the opening phase.

A powerful alternative means to study the hemodynamics of bileaflet mechanical heart valves is the computational fluid dynamics method. It is well recognized that computational fluid dynamics allows reliable physiological blood flow simulation and measurements of flow parameters. To date, in almost all of the modeling studies on the hemodynamics of bileaflet mechanical heart valves, a velocity (mass flow)-based boundary condition and an axisymmetric geometry for the aortic root have been assigned, which, to some extent, are erroneous. Also, there have been contradictory reports of the profile of velocity in downstream of leaflets, that is, in some studies, it is suggested that the maximum blood velocity occurs in the lateral orifice, and in some other studies, it is postulated that the maximum velocities in the main and lateral orifices are identical. The reported values for the peak velocities range from 1 to 3 m/s, which highly depend on the model assumptions. The objective of this study is to demonstrate the importance of the exact anatomical model of the aortic root and the realistic boundary conditions in the hemodynamics of the bileaflet mechanical heart valves. The model considered in this study is based on the St Jude Medical valve in a novel modeling platform. Through a more realistic geometrical model for the aortic root and the St Jude Medical valve, we have developed a new set of boundary conditions in order to be used for the assessment of the hemodynamics of aortic bileaflet mechanical heart valves. The results of this study are significant for the design improvement of conventional bileaflet mechanical heart valves and for the design of the next generation of prosthetic valves.