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.

[Emergent Transcatheter Aortic Valve Implantation for Degenerated Surgical Aortic Valve Under Local Anesthesia:Report of a Case].

An 89-year-old man who had undergone aortic valve replacement with a 21 mm Mosaic bioprosthetic valve at another hospital 14 years ago was admitted to the emergency room for a sudden respiratory distress two days prior and was diagnosed with severe aortic regurgitation( AR) caused by valve insufficiency and acute heart failure secondary to low cardiac function. Upon admission, he was found to have severe hypoxia with PaO2 of 40 mmHg range, and transcatheter aortic valve replacement (TAVI, TAV in SAV) with a 20 mm SAPIEN3 was performed under local anesthesia for fear of hypotension while under general anesthesia. After confirming that AR had completely disappeared, the patient was intubated and discharged from the operating room on a mechanical ventilator. The patient was weaned from the ventilator on the second postoperative day and was transferred to the other hospital for rehabilitation, 48 days postoperatively. Although there is no report on the comparative study of anesthesia methods for emergency transcatheter aortic valve implantation( TAVI), TAVI under regional anesthesia is minimally invasive with a lower risk for hypotension than general anesthesia. Therefore, we believe it is useful for patients with acute heart failure and hypotension. In addition, it is important to use a balloon expandable valve with excellent implantability to complete the procedure in a short time.

Calcification of Various Bioprosthetic Materials in Rats: Is It Really Different?

The causes of heart valve bioprosthetic calcification are still not clear. In this paper, we compared the calcification in the porcine aorta (Ao) and the bovine jugular vein (Ve) walls, as well as the bovine pericardium (Pe). Biomaterials were crosslinked with glutaraldehyde (GA) and diepoxide (DE), after which they were implanted subcutaneously in young rats for 10, 20, and 30 days. Collagen, elastin, and fibrillin were visualized in non-implanted samples. Atomic absorption spectroscopy, histological methods, scanning electron microscopy, and Fourier-transform infrared spectroscopy were used to study the dynamics of calcification. By the 30th day, calcium accumulated most intensively in the collagen fibers of the GA-Pe. In elastin-rich materials, calcium deposits were associated with elastin fibers and localized differences in the walls of Ao and Ve. The DE-Pe did not calcify at all for 30 days. Alkaline phosphatase does not affect calcification since it was not found in the implant tissue. Fibrillin surrounds elastin fibers in the Ao and Ve, but its involvement in calcification is questionable. In the subcutaneous space of young rats, which are used to model the implants' calcification, the content of phosphorus was five times higher than in aging animals. We hypothesize that the centers of calcium phosphate nucleation are the positively charged nitrogen of the pyridinium rings, which is the main one in fresh elastin and appears in collagen as a result of GA preservation. Nucleation can be significantly accelerated at high concentrations of phosphorus in biological fluids. The hypothesis needs further experimental confirmation.

Single-cell RNA sequencing reveals the diversity and biology of valve cells in cardiac valve disease.

From highly aligned extracellular fibrils to the cells, a multilevel ordered hierarchy in valve leaflets is crucial for their biological function. Cardiac valve pathology most frequently involves a disruption in normal structure-function correlations through abnormal and complex interaction of cells, extracellular matrix, and their environment. At present, effective treatment for valve disease is limited and frequently ends with surgical repair or replacement with a mechanical or artificial biological cardiac valve, which comes with insuperable complications for many high-risk patients including aged and pediatric populations. Therefore, there is a critical need to fully appreciate the pathobiology of valve disease in order to develop better, alternative therapies. To date, the majority of studies have focused on delineating valve disease mechanisms at the cellular level. However, the cellular heterogeneity and function is still unclear. In this review, we summarize the body of work on valve cells, with a particular focus on the discoveries about valve cells heterogeneity and functions using single-cell RNA sequencing. We conclude by discussing state-of-the-art strategies for deciphering heterogeneity of these complex cell types, and argue this knowledge could translate into the improved personalized treatment of cardiac valve disease.

Sulfonated, oxidized pectin-based double crosslinked bioprosthetic valve leaflets for synergistically enhancing hemocompatibility and cytocompatibility and reducing calcification.

Clinically frequently-used glutaraldehyde (GA)-crosslinked bioprosthetic valve leaflets (BVLs) are still curbed by acute thrombosis, malignant immunoreaction, calcification, and poor durability. In this study, an anticoagulant heparin-like biomacromolecule, sulfonated, oxidized pectin (SAP) with a dialdehyde structure was first obtained by modifying citrus pectin with sulfonation of 3-amino-1-propane sulfonic acid and then oxidating with periodate. Notably, a novel crosslinking approach was established by doubly crosslinking BVLs with SAP and the nature-derived crosslinking agent quercetin (Que), which play a synergistic role in both crosslinking and bioactivity. The double crosslinked BVLs also presented enhanced mechanical properties and enzymatic degradation resistance owing to the double crosslinking networks formed via CN bonds and hydrogen bonds, respectively, and good HUVEC-cytocompatibility. The in vitro and ex vivo assay manifested that the double-crosslinked BVLs had excellent anticoagulant and antithrombotic properties, owing to the introduction of SAP. The subcutaneous implantation also demonstrated that the obtained BVLs showed a reduced inflammatory response and great resistance to calcification, which is attributed to quercetin with multiple physiological activities and depletion of aldehyde groups by hydroxyl aldehyde reaction. With excellent stability, hemocompatibility, anti-inflammatory, anti-calcification, and pro-endothelialization properties, the obtained double-crosslinked BVLs, SAP + Que-PP, would have great potential to substitute the current clinical GA-crosslinked BVLs.

Strict control of phosphorus concentration of hemodialysis patients may decrease structural valve deterioration after aortic valve replacement.

OBJECTIVES: The number of hemodialysis patients requiring aortic valve replacement (AVR) is increasing. Although bioprosthetic valves are increasingly popular, they are associated with a risk of structural valve deterioration (SVD). The aim of this study is to examine the outcomes of bioprosthetic valves in hemodialysis patients undergoing AVR and to identify treatment strategies that can decrease the risk of SVD. METHODS: Between February 2010 and November 2019, 61 patients on hemodialysis underwent AVR using bioprosthetic valves at our hospital. Five patients died while still in the hospital. Kaplan-Meier estimates of overall survival and univariate Cox proportional hazards regression analyses were performed for the remaining 56 patients. RESULTS: During follow-up, there were six SVD events (10.7%) related to the bioprosthetic valves. The survival rate was 67.9% at 3 years and 39.5% at 5 years. In all SVD cases, SVD was caused by aortic stenosis. The mean interval between AVR and the discovery of SVD was 41.5 months. The SVD-free rate was 88.6% at 3 years and 65.3% at 5 years. Preoperative phosphorus levels are associated with SVD risk. High preoperative phosphorus concentration is associated with elevated SVD risk. CONCLUSIONS: In this study, we determined that the risk of SVD can be influenced by preoperative phosphorus level. Strict control of the phosphorus concentration of hemodialysis patients may decrease structural valve deterioration after aortic valve replacement.

Dialdehyde pectin-crosslinked and hirudin-loaded decellularized porcine pericardium with improved matrix stability, enhanced anti-calcification and anticoagulant for bioprosthetic heart valves.

To conveniently and effectively cure heart valve diseases or defects, combined with transcatheter valve technology, bioprosthetic heart valves (BHVs) originated from the decellularized porcine pericardium (D-PP) have been broadly used in clinics. Unfortunately, most clinically available BHVs crosslinked with glutaraldehyde (GA) were challenged in their long-term tolerance, degenerative structural changes, and even failure, owing to the synergistic impact of multitudinous elements (cytotoxicity, calcification, immune responses, etc.). In this work, dialdehyde pectin (AP) was prepared by oxidizing the o-dihydroxy of pectin with sodium periodate. Hereafter, the AP-fixed PP model was obtained by crosslinking D-PP with AP with high aldehyde content (6.85 mmol g-1), for acquiring excellent mechanical properties and outstanding biocompatibility. To further improve the hemocompatibility of the AP-fixed PP, a natural and specific inhibitor of thrombin (hirudin) was introduced to achieve surface modification of the AP-fixed PP. The feasibility of crosslinking and functionalizing AP-fixed PP, which was a potential leaflet material of BHVs, was exhaustively and systematically evaluated. In vitro studies found that hirudin-loaded and AP-fixed PP (AP + Hirudin-PP) had synchronously achieved effective fixation of collagen, highly effective anticoagulation, and good HUVECs-cytocompatibility. In vivo results revealed that the AP + Hirudin-PP specimens recruited the minimum immune cells in the implantation experiment, and also presented an excellent anti-calcification effect. Overall, AP + Hirudin-PP was endowed with competitive collagen stability (compared with GA-fixed PP), excellent hemocompatibility, good HUVECs-cytocompatibility, low immunogenicity and outstanding anti-calcification, suggesting that AP + Hirudin-PP might be a promising alternative to GA-fixed PP and exhibited a bright prospect in the clinical applications of BHVs.

Warfarin maintenance dose prediction for Chinese after heart valve replacement by a feedforward neural network with equal stratified sampling.

Patients requiring low-dose warfarin are more likely to suffer bleeding due to overdose. The goal of this work is to improve the feedforward neural network model's precision in predicting the low maintenance dose for Chinese in the aspect of training data construction. We built the model from a resampled dataset created by equal stratified sampling (maintaining the same sample number in three dose-groups with a total of 3639) and performed internal and external validations. Comparing to the model trained from the raw dataset of 19,060 eligible cases, we improved the low-dose group's ideal prediction percentage from 0.7 to 9.6% and maintained the overall performance (76.4% vs. 75.6%) in external validation. We further built neural network models on single-dose subsets to invest whether the subsets samples were sufficient and whether the selected factors were appropriate. The training set sizes were 1340 and 1478 for the low and high dose subsets; the corresponding ideal prediction percentages were 70.2% and 75.1%. The training set size for the intermediate dose varied and was 1553, 6214, and 12,429; the corresponding ideal prediction percentages were 95.6, 95.1%, and 95.3%. Our conclusion is that equal stratified sampling can be a considerable alternative approach in training data construction to build drug dosing models in the clinic.

Entelon (vitis vinifera seed extract) reduces degenerative changes in bovine pericardium valve leaflet in a dog intravascular implant model.

BACKGROUND AND AIMS: Inflammation and calcification are major factors responsible for degeneration of bioprosthetic valve and other substitute heart valve implantations. The objective of this study was to evaluate the anti-inflammatory and anti-calcification effects of Entelon150® (consisting of grape-seed extract) in a beagle dog model of intravascular bovine pericardium implantation. METHODS: In total, 8 healthy male beagle dogs were implanted with a bovine pericardium bilaterally in the external jugular veins and divided into two groups. Animals in the Entelon150® group (n = 4) were treated with 150 mg of Entelon150® twice daily for six weeks after surgery. The negative control (NC) group (n = 4) was treated with 5 ml of saline using the same method. After six weeks, we measured the calcium content, performed histological examination, and performed molecular analysis. RESULTS: The calcium content of implanted tissue in the Entelon150® group (0.56±0.14 mg/g) was significantly lower than that in the NC group (1.48±0.57 mg/g) (p < 0.05). Histopathological examination showed that infiltration of chronic inflammatory cells, such as fibroblasts and macrophages, occurred around the graft in all groups; however, the inflammation level of the implanted tissue in the Entelon150® group was s lower than that in the NC group. Both immunohistochemical and western blot analyses revealed that bone morphogenetic protein 2 expression was significantly attenuated in the Entelon150® group. CONCLUSIONS: Our results indicate that Entelon150® significantly attenuates post-implantation inflammation and degenerative calcification of the bovine pericardium in dogs. Therefore, Entelon150® may increase the longevity of the bovine pericardium after intravascular implantation.

Loss of Prosthetic Aortic Valve during TAVI Procedure: Endovascular Treatment in Emergent Setting.

BACKGROUND: Transcatheter aortic valve implantation (TAVI) has proven over the years to be a viable alternative to open surgery. A rare but severe complication is represented by the valve migration. We report a case of TAVI complication due to the loss of the prosthetic valve in the abdominal aorta treated by endovascular approach. METHODS: An 88-year-old patient with severe aortic valve stenosis, symptomatic for dyspnea was proposed for a TAVI because considered at high risk for surgery. During the TAVI procedure, the undeployed device (Edwards SAPIEN 3 - Edwards Lifesciences, Irvine, CA, USA) detached from its delivery system. Several attempts to withdraw the valve fluctuating in the aorta into its supporting system were performed without success. An emergency endovascular treatment was promptly planned to obtain the exclusion from the flow of the embolized valve. Under local anaesthesia, through the percutaneous femoral access already present, a tube aortic endograft (EndurantTM II, Medtronic, Santa Rosa, CA; ETTF2828C70EE) was successfully introduced and deployed in the infrarenal aorta without any related complications. The embolized valve was completely covered by the endgraft and thus fixed to the aortic wall. The first postoperative computer tomography angiography (CTA) confirmed the correct placement of the endograft, the exclusion of the valve from the flow and the patency of the great vessels. No perioperative or postoperative complications were recorded. The patient was discharged on the ninth postoperative day with the indication to a new attempt of TAVI, through transapical access. CONCLUSIONS: In case of intraprocedural loss of an undeplyed valve during TAVI, the valve fixing through endograft deployment in infrarenal aorta is a possible solution.

Aortic Valve Neocuspidalization May Be a Viable Alternative to Ross Operation in Pediatric Patients.

The aim of the study was to evaluate the medium-term results of aortic valve neocuspidalization according to Ozaki compared to Ross procedure for treatment of isolated aortic valve disease in pediatric age. Thirty-eight consecutive patients with congenital or acquired aortic valve disease underwent either Ozaki (n = 22) or Ross (n = 16) operation between 01/2015 and 05/2020. The primary outcome was progression of aortic valve disease and aortic ring and root dimension, whereas secondary outcome was freedom from reintervention or death by type of operation. Median age was 12.4 (8.8-15.8) years and the prevailing lesion was stenosis in 20 cases (52%) and incompetence in 18 (48%). One death occurred in the Ross group in the early postoperative period, while there were no deaths in the Ozaki group. Effective treatment of aortic valve stenosis or regurgitation occurred in both groups and remained stable over a median follow-up of 18.2 (5-32) months. In Ozaki group, 3 patients required aortic valve replacement at 4.9, 3.5, and 33 months, respectively. In Ross group, 1 patient required Melody pulmonary valve replacement, whereas none required aortic valve surgery. Finally, significantly higher aortic transvalvular gradient at follow-up was recorded in Ozaki group compared to Ross group. Overall, there was no significant difference in freedom from reoperation or death between the two groups. The medium-term outcome of Ozaki and Ross in pediatric patients is similar, despite an increased tendency of the former to develop aortic transvalvular gradient in the follow-up. Future larger multicenter studies with longer follow-up are warranted to confirm these results.

Percutaneous mitral valve repair in recurrent severe mitral valve regurgitation after mitral annuloplasty : MitraClip-in-the-ring as a complementary strategy.

BACKGROUND: Patients with reduced left ventricular (LV) function undergoing coronary artery bypass graft surgery or/and aortic valve replacement occasionally show severe mitral valve (MV) regurgitation and thus also undergo surgical mitral annuloplasty. Over time, further deterioration of LV function and additional ischemic events cause recurrence of severe MV regurgitation due to the Carpentier IIIb morphology of the MV that is not adequately addressed by the previously implanted annuloplasty ring. METHODS: Seven patients (Society of Thoracic Surgeons score: 7.5 ± 1.5%) with Carpentier type-IIIb recurrent severe MV regurgitation, having undergone prior cardiothoracic surgery (median: 40 months) including mitral annuloplasty, were treated with the MitraClip device. RESULTS: MitraClip implantation resulted in significantly reduced MV regurgitation and improved New York Heart Association functional state, translating into an increased exercise capability and improved cardiac biomarkers. The morphology of the MV was adequately addressed without causing relevant MV stenosis, while the MV annulus area remained unaltered. The procedure was safe with a 30-day mortality rate of 0%. CONCLUSION: MitraClip-in-the-ring is feasible and in principle safe for treating Carpentier type IIIb severe MV regurgitation after surgical MV repair using mitral annuloplasty. MitraClip-in-the-ring resulted in immediate amelioration of clinical symptoms and increased physical exercise capacity.

Simplified Trans-Axillary Aortic Valve Replacement Under Local Anesthesia - A Single-Center Early Experience.

BACKGROUND: The axillary artery is an alternative route for patients with comorbidities and unfavorable femoral arteries who need transcatheter aortic valve replacement (TAVR). Simplified trans-axillary transcatheter aortic valve replacement (TAx-TAVR) implies a completely percutaneous approach under local anesthesia and arteriotomy closure with vascular closure techniques. Herein, we report on early experience with simplified TAx-TAVR under local anesthesia. METHODS: We enrolled all consecutive patients who underwent simplified TAx-TAVR in our center. Main study parameter was the incidence of axillary access related major vascular complications within 30 days. Secondary parameters included a composite early safety endpoint, axillary access-site related vascular/bleeding complications and short-term mortality. Post TAVR axillary stent patency was evaluated during follow-up by CT-analysis. RESULTS: Between July 2018 and April 2020, Tax-TAVR was attempted in 35 patients with a mean age of 79 years. Local anesthesia and conscious sedation were used in 91.4% (n = 32) and 8.6% (n = 3) respectively. A covered stent was needed for complete axillary hemostasis in 44.1% (n = 15). Device success was achieved in 91.2% (n = 31/34). The 30-day axillary artery major vascular and ≥major bleeding complication rates were 14% (n = 5) and 11% (n = 4). The early safety endpoint was reached in 22.9% (n = 8). Mortality rates at 30 days and six months were 2.9% and 11.6%. Computed tomography (CT) confirmed axillary stent patency during follow-up in 82% (n = 9/11). CONCLUSIONS: In patients with high/prohibitive surgical risk and unsuitable femoral access, simplified TAx-TAVR under local anesthesia offers a valuable alternative for transfemoral TAVR but requires advanced access site management techniques including covered stents. Our data suggest an unmet clinical need for dedicated TAx closure devices.

Rivaroxaban Versus Warfarin in Patients with Mechanical Heart Valves: Open-Label, Proof-of-Concept trial-The RIWA study.

BACKGROUND AND PURPOSE: To date, vitamin K antagonists are the only available oral anticoagulants in patients with mechanical heart valves. In this way, we developed a pilot trial with rivaroxaban. METHODS:  The RIWA study was a proof-of-concept, open-label, randomized clinical trial and was designed to assess the incidence of thromboembolic and bleeding events of the rivaroxaban-based strategy (15 mg twice daily) in comparison to dose-adjusted warfarin. Patients were randomly assigned in a 1:1 ratio and were followed prospectively for 90 days. RESULTS:  A total of 72 patients were enrolled in the present study. Of these, 44 patients were randomized: 23 patients were allocated to the rivaroxaban group and 21 to the warfarin group. After 90 days of follow-up, the primary outcome occurred in one patient (4.3%) in the rivaroxaban group and three patients (14.3%) in the warfarin group (risk ratio [RR] 0.27; 95% confidence interval [CI] 0.02-2.85; P = 0.25). Minor bleeding (without discontinuation of medical therapy) occurred in six patients (26.1%) in the rivaroxaban group versus six patients (28.6%) in the warfarin group (RR 0.88; 95% CI 0.23-3.32; P = 0.85). One patient in the warfarin group died from myocardial infarction. No cases of hemorrhagic stroke, valve thrombosis, peripheral embolic events, or new intracardiac thrombus were related in both groups. CONCLUSIONS: In this pilot study, rivaroxaban 15 mg twice daily had thromboembolic and bleeding events similar to warfarin in patients with mechanical heart valves. These data confirm the authors' proof-of-concept and suggest that a larger trial with a similar design is not unreasonable. CLINICALTRIAL. GOV IDENTIFIER: NCT03566303.

Surgery without Scars: Right Lateral Access for Minimally Invasive Aortic Valve Replacement.

As part of an institutionally driven holistic concept, named the "360-degree approach," all established surgical access routes -full sternotomy, partial upper sternotomy, and right anterolateral thoracotomy using the second interspace-are supported. The surgical toolbox now is completed by adding a further approach: through a 5- to7-cm skin incision in the right anterior axillary line, the third interspace is used for a minimally invasive aortic valve surgery providing striking exposition of the aortic valve and resulting in superior cosmetics with nearly no visible scars. The choice for the one or other method is institutionally driven and based on risk profiles, as well as anatomical and physiognomic considerations.

The Safety and Efficacy of Transcatheter Pulmonary Valve Replacement Combined with Electrophysiology Procedures.

The objective of this study was to evaluate the safety and efficacy of combining transcatheter pulmonary valve replacement (TPVR) and electrophysiology (EP) procedures. A retrospective review was undertaken to identify TPVR and EP procedures that were concomitantly performed in the cardiac catheterization laboratory at University of Iowa Stead Family Children's Hospital from January 2011 to October 2019. Procedural and follow-up data were compared between patients who underwent TPVR and EP procedures in the same setting to those who received TPVR or EP procedure separately and that were similar in age and cardiac anatomy. A total of 8 patients underwent combined TPVR and EP procedures. One patient was excluded due to lack of adequate control, leaving seven study subjects (57% female; median age at time of procedure 16 years). The median follow-up time was 11.5 months (range 2-36 months). Patients who received combined TPVR and EP had shorter recovery times (combined: median 18.9 h; IQR 18.35-19.5 vs separate: median 27.98 h; IQR 21.42-39.25; p-value 0.031), shorter hospital length of stay (combined: median 27.5 h; IQR 26.47-31.4 vs separate: median 38.4 h; IQR 33.42-51.50; p-value 0.016), and a 51% reduction in total hospital charges (combined: median $171,640; IQR 135.43-219.22 vs separate: median $333,560 IQR 263.20-400.98; p-value 0.016). There were no significant differences in radiation dose or procedure time between the combined and control groups. The median radiation time for those who had the combination procedure was 30.5 min [IQR 29.6-47.9], and the median dose area product was 215 mGy [IQR 158-935]. In conclusion, combining TPVR and EP procedures is feasible, safe, and economically advantageous.

A randomized clinical trial to evaluate the efficacy and safety of rivaroxaban in patients with bioprosthetic mitral valve and atrial fibrillation or flutter: Rationale and design of the RIVER trial.

The efficacy and safety of rivaroxaban in patients with bioprosthetic mitral valves and atrial fibrillation or flutter remain uncertain. DESIGN: RIVER was an academic-led, multicenter, open-label, randomized, non-inferiority trial with blinded outcome adjudication that enrolled 1005 patients from 49 sites in Brazil. Patients with a bioprosthetic mitral valve and atrial fibrillation or flutter were randomly assigned (1:1) to rivaroxaban 20 mg once daily (15 mg in those with creatinine clearance <50 mL/min) or dose-adjusted warfarin (target international normalized ratio 2.0-30.); the follow-up period was 12 months. The primary outcome was a composite of all-cause mortality, stroke, transient ischemic attack, major bleeding, valve thrombosis, systemic embolism, or hospitalization for heart failure. Secondary outcomes included individual components of the primary composite outcome, bleeding events, and venous thromboembolism. SUMMARY: RIVER represents the largest trial specifically designed to assess the efficacy and safety of a direct oral anticoagulant in patients with bioprosthetic mitral valves and atrial fibrillation or flutter. The results of this trial can inform clinical practice and international guidelines.

Khat Chewing Effect on the International Normalized Ratio in Patients with Mechanical Heart Valves under Warfarin Therapy.

BACKGROUND AND OBJECTIVE: Khat is a plant that contains the alkaloids cathine and cathinone which have some amphetamine-like properties. It is cultivated and it's leaves chewed for their euphoric effect. This study intended to elucidate the effect of khat chewing on blood coagulation by using the International Normalized Ratio (INR) value as a calculable benchmark. MATERIALS AND METHODS: In this cohort study, 146 patients with Mechanical Heart Valves (MHV) were assessed for two consecutive visits at one-month intervals. For each visit, the date of surgery, the patient's compliance, the dose of warfarin and the INR reading were assessed by the researcher. RESULTS: Out of 146 patients with MHV, the mean age was 33.72±12.43 years (range, 14-65 years); 82 (56.2%) were female and 64 (43.8%) were male. The results revealed that the mean of absolute INR readings was lower in khat-chewers than non-chewers by average 0.2 on the first and second visits (p = 0.038 and 0.002, respectively). CONCLUSION: Khat chewing has a significant coagulant effect. There was a significant decrease in the value of INR for khat chewers patients with MHV when compared to non-khat chewers.

Early Experience With a Novel Transfemoral Mitral Valve Implantation System in Complex Degenerative Mitral Regurgitation.

OBJECTIVES: The aim of this study was to evaluate the feasibility, procedural results, and 6-month outcomes of a novel transfemoral transcatheter mitral valve implantation (TMVI) system (Cephea) in patients with complex primary mitral regurgitation (MR). BACKGROUND: TMVI is emerging as an alternative to surgery in patients with severe MR. To date, the great majority of TMVI systems use the transapical surgical approach. METHODS: This study included consecutive patients undergoing transfemoral TMVI with the Cephea valve system. All patients were suboptimal candidates for catheter-based repair for anatomic reasons. Patients underwent clinical, echocardiographic, and computed tomographic angiographic follow-up at 6 months. Main outcomes were procedural success, peri-procedural complications, and valve hemodynamic status early and at 6-month follow-up. RESULTS: Three patients with severe primary MR (2 women, mean age 79 ± 3 years) at prohibitive surgical risk (mean European System for Cardiac Operative Risk Evaluation II score 13.8 ± 2.4%) were included. The valves were successfully implanted in all patients, with no procedural complications. Post-procedural echocardiography showed normal valve function in all patients (mean transvalvular gradient 3 mm Hg; range: 2 to 4 mm Hg), no moderate to severe valvular or paravalvular leak, and no clinically significant left ventricular outflow tract obstruction. At 6 months, all patients had improved quality of life (mean improvement vs. baseline 16.4 ± 12 points). All valve hemodynamic parameters were maintained. Computed tomographic angiography confirmed annular stability, proper valve geometry and no structural failure. CONCLUSIONS: The transfemoral delivery of a purposely designed mitral prosthesis (Cephea valve) was safe and feasible in prohibitive risk patients. Valve performance was sustained, and clinical outcomes improved at 6 months. Larger clinical studies are required.