Incidence and risk factors for thromboembolism and major bleeding in patients with mechanical valve prosthesis: A nationwide population-based study

Natural biomaterials in the management of the aortic valve pathology. Biomedical and clinical aspects: A review

Heart valve diseases are a prevalent cardiovascular pathology worldwide, affecting nearly 2.5% of the population. Degenerative aortic stenosis is the most common form of heart valve disease. The treatment options include surgical or transcatheter procedures. There are two main categories of valve prostheses available: mechanical heart valves constructed from synthetic materials and bioprosthetic heart valves made from natural biomaterials. The choice of valve type depends on various factors, including the underlying medical condition, suitability for anticoagulation, valve durability, and the patient's age and preferences. Mechanical heart valves have the advantage of long-term durability. However, patients receiving mechanical implants are subjected to lifelong anticoagulation therapy with an increased risk of thromboembolism and bleeding. Natural biomaterials do not require long-term anticoagulation. However, they experience degenerative changes leading to structural valve deterioration that may require reoperation. The purpose of this article is to review the role of natural biological materials used for aortic valve replacement or repair, assess their biomedical and clinical advantages and limitations, and analyze the direction and perspectives of future development.

Prosthetic valve dysfunction in patients with mechanical heart valves: Results from the Emergency Salam Centre cohort

INTRODUCTION

Mechanical heart valve (MHV) replacement requires long-life anticoagulation due to the risk of Prosthetic Valve Dysfunction (PVD) and cardioembolism.

METHODS

We report data from a prospective observational study conducted on MHV patients in the Khartoum Salam Centre for Cardiac Surgery built by 'Emergency,' an Italian Non-Governmental Organization, to evaluate the occurrence of PVD and associated risk factors.

RESULTS

We prospectively followed 3647 patients, and 38 patients (rate 1.04 × 100 pt-years) had PVD during follow-up. The time in therapeutic range (TTR) among patients without PVD was 53 % (IQR 37-67), and it was 43 % (IQR 19-58) among patients with PVD (p = 0.04). Twenty-three over 38 patients (60.5 %) were symptomatic, 18 (47.4 %) had obstructive valvular stenosis, 24 patients (63.2 %) had INR <2.0 at diagnosis, and 21 patients (55.3 %) had been off warfarin for a long time: 3 patients for 1 week, 1 patient for 2 weeks, and 17 patients for >4 weeks (6 patients were off warfarin from 3 to 12 months). Ten were uncompliant to treatment, and 8 were pregnant women. Ten patients (26.3 %) with PVD had had a previous episode of PVD, and 14 patients (36.8 %) had 2 or more associated risk factors. Only in 6 cases were no associate risk factors found.

CONCLUSIONS

Among MHV patients on warfarin treatment with a sub-optimal quality of anticoagulation, the rate of PVD is 1.04 % pt-years, and the most frequent associated risk factor for PVD occurrence is warfarin withdrawal lasting more than one week.

Management of perioperative anticoagulation in patients with mechanical heart valve replacement undergoing laparoscopic cholecystectomy: a case report of postoperative cerebral embolism

Patients with mechanical heart valve replacement require lifelong anticoagulation therapy, and additional surgeries can pose a risk of bleeding and thromboembolic events due to the need for perioperative anticoagulation management. Here, we present a case report of a patient who underwent laparoscopic cholecystectomy (LC) and endoscopic retrograde cholangiopancreatography (ERCP) after mechanical heart valve replacement and experienced postoperative cerebral embolism. The management of perioperative anticoagulation in these patients is discussed, including strategies for minimizing the risks of bleeding and thromboembolic events during and after surgery.

Perioperative Management of Valvular Heart Disease in Patients Undergoing Non-Cardiac Surgery

Postoperative cardiovascular complications (either in a hospital or within 30 days after the operation) are among the most common problems with non-cardiac surgeries (NCSs). Pre-existing cardiac comorbidities add significant risk to the development of such complications. Valvular heart disease (VHD), a rather frequent cardiac comorbidity (especially in the elderly population), can pose serious life-threatening peri-/postoperative complications. Being familiar with the recommended perioperative management of patients with VHD or an implanted prosthetic heart valve who are scheduled for NCS is of great importance in daily clinical practice. Although recently published guidelines by the European Society of Cardiology (ESC) and the American College of Cardiology and American Heart Association (ACC/AHA) for the management of VHD and perioperative management of patients undergoing NCS addresses the mentioned problem, a comprehensive review of the guidelines that provides an easy-to-use summary of the recommendations and their similarities and differences is missing in the published literature. In this review article, we summarize all of the relevant important information based on the latest data published in both guidelines needed for practical decision-making in the perioperative management of patients with VHD or after valvular repair (with prosthetic heart valve) who are scheduled for NCS.

Utility of a pharmacist-managed Anticoagulation Program in patients with congenital heart disease

BACKGROUND

Warfarin remains the preferred anticoagulant for many patients with CHD. The complexity of management led our centre to shift from a nurse-physician-managed model with many providers to a pharmacist-managed model with a centralized anticoagulation team. We aim to describe the patient cohort managed by our Anticoagulation Program and evaluate the impact of implementation of this consistent, pharmacist-managed model on time in therapeutic range, an evidence-based marker for clinical outcomes.

METHODS

A single-centre retrospective cohort study was conducted to evaluate the impact of the transition to a pharmacist-managed model to improve anticoagulation management at a tertiary pediatric heart centre. The percent time in therapeutic range for a cohort managed by both models was compared using a paired t-test. Patient characteristics and time in therapeutic range of the program were also described.

RESULTS

After implementing the pharmacist-managed model, the time in therapeutic range for a cohort of 58 patients increased from 65.7 to 80.2% (p < .001), and our Anticoagulation Program consistently maintained this improvement from 2013 to 2022. The cohort of patients managed by the Anticoagulation Program in 2022 included 119 patients with a median age of 24 years (range 19 months-69 years) with the most common indication for warfarin being mechanical valve replacement (n = 81, 68%).

CONCLUSIONS

Through a practice change incorporating a collaborative, centralized, pharmacist-managed model, this cohort of CHD patients on warfarin had a fifteen percent increase in time in therapeutic range, which was sustained for nine years.

Using machine learning to predict the bleeding risk for patients with cardiac valve replacement treated with warfarin in hospitalized

BACKGROUND

Distinguishing warfarin-related bleeding risk at the bedside remains challenging. Studies indicate that warfarin therapy should be suspended when international normalized ratio (INR) ≥ 4.5, or it may sharply increase the risk of bleeding. We aim to develop and validate a model to predict the high bleeding risk in valve replacement patients during hospitalization.

METHOD

Cardiac valve replacement patients from January 2016 to December 2021 across Nanjing First Hospital were collected. Five different machine-learning (ML) models were used to establish the prediction model. High bleeding risk was an INR ≥4.5. The area under the receiver operating characteristic curve (AUC) was used for evaluating the prediction performance of different models. The SHapley Additive exPlanations (SHAP) was used for interpreting the model. We also compared ML with ATRIA score and ORBIT score.

RESULTS

A total of 2376 patients were finally enrolled in this model, 131 (5.5%) of whom experienced the high bleeding risk after anticoagulation therapy of warfarin during hospitalization. The extreme gradient boosting (XGBoost) exhibited the best overall prediction performance (AUC: 0.882, confidence interval [CI] 0.817-0.946, Brier score, 0.158) compared to other prediction models. It also shows superior performance compared with ATRIA score and ORBIT score. The top 5 most influential features in XGBoost model were platelet, thyroid stimulation hormone, body surface area, serum creatinine and white blood cell.

CONCLUSION

A model for predicting high bleeding risk in valve replacement patients who treated with warfarin during hospitalization was successfully developed by using machine learning, which may well assist clinicians to identify patients at high risk of bleeding and allow timely adjust therapeutic strategies in evaluating individual patient.

Antithrombotic Medication and Major Complications After Mechanical Aortic Valve Replacement

Patients with mechanical aortic valve replacement (AVR) require lifelong vitamin K antagonist (VKA) therapy for stroke and systemic embolism prevention. However, VKA treatment predisposes patients to various types of bleeding. In the present study, we sought to assess the success of antithrombotic therapy and the occurrence and timing of strokes and bleeding events after mechanical AVR. A total of 308 patients who underwent isolated mechanical AVR were included in the study, and follow-up data were completed for 306 patients (99.4%). The median follow-up time was 7.3 (interquartile range 4.2 to 10.9) years. The risk for major bleeding was 5-fold compared with major stroke (6.2% vs 1.3% and 20.9% vs 4.0%, respectively; events rates 3.1 vs 0.5 per 100 patient-years, respectively) at 30-day and long-term follow-up, indicating good efficacy but inadequate safety of stroke prevention. At the time of the early postoperative major bleeding, the international normalized ratio was under the therapeutic range in 73.7% of the patients. However, most patients were on triple antithrombotic treatment consisting of subcutaneous enoxaparin, VKA, and a tail effect of discontinued aspirin. During the long-term follow-up, the most common site of bleeding was gastrointestinal (41.7%), followed by genitourinary bleeding (23.3%) and intracranial hemorrhage (18.3%). Furthermore, mortality was relatively high, with a 10-year survival estimate of 78.3%. In conclusion, although ischemic stroke is a well-identified adverse event after mechanical AVR, it seems that major bleeding is a frequent clinically relevant complication during perioperative and long-term follow-up. This finding underscores the recognition and management of modifiable bleeding risk factors.

Oral anticoagulant management of patients with mechanical heart valves at the Salam Centre of Khartoum: Observations on quality of anticoagulation and thrombotic risk

INTRODUCTION

Rheumatic heart disease with mechanical heart valve (MHV) replacement is common in Africa. However, MHV requires long-life anticoagulation and managing this can be challenging.

METHODS AND RESULTS

We report data of a prospective observational study conducted between August 2018 and September 2019 in MHV patients in the Salam Centre for Cardiac Surgery built in Khartoum, by Emergency, an Italian Non-Governmental Organization, to evaluate the quality of anticoagulation control and the risk of thrombotic complications.

RESULTS

We studied 3647 patients (median age 25.1 years; 53.9 % female). Median Time in Therapeutic Range (TTR) was 53 % (interquartile range 37 % to 67 %) and 70 thrombotic events (rate 1.8 × 100 pt-years [95 % CI 1.38-2.23]) were recorded. Among patients in the first quartile of TTR (≤37 %), we recorded 34/70 (48.6 %) of all thrombotic events (rate 3.7 × 100 pt-years [95 % CI 2.5-5.1]), with a high mortality rate (2.2 × 100 pt-years [95 % CI 1.3-3.3]). In patients with guideline-recommended TTR (≥65 %) the event rate was 0.8 × 100 pt-years for thrombotic events [95 % CI 0.3-1.5] and 0.4 × 100 pt-years for mortality [95 % CI 0.1-0.9]. Multivariable analysis showed that having a TTR in the lowest quartile (≤37 %) and being noncompliant are significantly associated with increased thrombotic risk. Aspirin use or different valve type did not influence the thrombotic risk. Almost 40 % of all thromboembolic complications could have been potentially prevented by further improving VKA management to obtain a TTR > 37 %.

CONCLUSION

The thrombotic risk of MHV patients on VKAs living in a low-income country like Sudan is associated with low quality of anticoagulation control. Efforts should be made to decrease the number of non-compliant patients and to reach a guideline-recommended TTR of ≥65 %.

Management of Life-Threatening Bleeding in Patients With Mechanical Heart Valves

Valvular heart disease is common in the United States, with a number of patients undergoing valve replacement procedures every year. The two types of valve prostheses include mechanical and bioprosthetic valves. Mechanical heart valves require lifelong anticoagulation with vitamin K antagonists like warfarin. The clinicians are often faced with the dilemma of major bleeding episodes such as intracranial hemorrhage or gastrointestinal bleeding in these patients. The management includes reversing warfarin-induced coagulopathy with vitamin K supplementation, fresh frozen plasma, or prothrombin complex concentrate (PCC), with PCC being the treatment of choice. With regard to the safe resumption of anticoagulation, guidelines are silent, and data is limited to case reports/series. This article reviews the present literature for the management of bleeding in patients with mechanical heart valves and the safe duration for holding off anticoagulation with minimal risk of valve thrombosis/thromboembolism.

Safety of low intensity oral anticoagulant therapy in patients with bileaflet mechanical aortic valve prosthesis: A propensity weighted study

BACKGROUND

Scarce data are available on the long-term outcomes of different regimens of oral anticoagulation in an all comer population of patients undergoing aortic valve replacement with a bileaflet mechanical heart valve.

METHODS

Outcomes of 88 patients discharged with a target INR of 2.0 (LOW-INR) were compared to 147 contemporary patients who have been recommended a target INR of 2.5 (CONV). Primary outcome was the composite of any thromboembolic or haemorrhagic events. Secondary outcomes were the individual components of the primary outcome, cardiovascular mortality and stroke. To reduce selection bias, a propensity weighted analysis was performed.

RESULTS

After inverse probability of treatment weighting, the primary endpoint occurred in 0.7% of patient in the LOW-INR group and in 7.0% in the CONV group (p = .0255). Linearized event rate were significantly lower in the LOW-INR group (primary endpoint: rate difference - 12.0 per 1000 patient/years, p = .0052; haemorrhage: -5.8 per 1000 patient/years, p = .0330; neurological events: -7.6 per 1000 patient/years, p = .0140). Conventional target INR was associated with an increased hazard of the composite endpoint (HR 11.193, 95% CI 1.424-88.003, p = .0217).

CONCLUSIONS

Lowering the intensity of oral anticoagulation resulted in a relevant clinical benefit of reduced rates of haemorrhagic and neurological adverse events in the mid-term follow-up. This report confirms the safety profile of the low INR regimen in an all comer population undergoing aortic valve replacement with an Abbott mechanical valve.

Acute Stroke During Pregnancy and Puerperium

BACKGROUND

Acute stroke during pregnancy or within 6 weeks of childbirth is devastating for the mother and her family, yet data regarding incidence and contemporary trends are very limited.

OBJECTIVES

This study sought to investigate the incidence and outcomes of acute stroke and transient ischemic attack during pregnancy or within 6 weeks of childbirth in a large database.

METHODS

The National Inpatient Sample was queried to identify women age ≥18 years in the United States with pregnancy-related hospitalizations from January 1, 2007, to September 30, 2015. Temporal trends in acute stroke (ischemic and hemorrhagic)/transient ischemic attack incidence and in-hospital mortality were extracted.

RESULTS

Among 37,360,772 pregnancy-related hospitalizations, 16,694 (0.045%) women had an acute stroke. The rates of acute stroke did not change (42.8 per 100,000 hospitalizations in 2007 vs. 42.2 per 100,000 hospitalizations in 2015; ptrends = 0.10). Among those with acute stroke, there were increases in prevalence of obesity, smoking, hyperlipidemia, migraine, and gestational hypertension. Importantly, in-hospital mortality rates were almost 385-fold higher among those who had a stroke (42.1 per 1,000 pregnancy-related hospitalizations vs. 0.11 per 1,000 pregnancy-related hospitalizations; p < 0.0001). The rates of in-hospital mortality among pregnant women with acute stroke decreased (5.5% in 2007 vs. 2.7% in 2015; ptrends < 0.001).

CONCLUSIONS

In this contemporary analysis of pregnancy-related hospitalizations, acute stroke occurred in 1 of every 2,222 hospitalizations, and these rates did not decrease over approximately 9 years. The prevalence of most stroke risk factors has increased. Acute stroke during pregnancy and puerperium was associated with high maternal mortality, although it appears to be trending downward. Future studies to better identify mechanisms and approaches to prevention and management of acute stroke during pregnancy and puerperium are warranted.

Robotic mitral valve replacements with bioprosthetic valves in 52 patients: experience from a tertiary referral hospital

OBJECTIVES

Robotic mitral valve replacement (MVR) emerged in the late 1990s as an alternative approach to conventional sternotomy. With the increased use of bioprosthetic valves worldwide and strong patient desire for minimally invasive procedures, the safety and feasibility of robotic MVRs with bioprosthetic valves require investigation.

METHODS

Between January 2013 and May 2017, 52 consecutive patients underwent robotic MVRs using the da Vinci Si surgical system (Intuitive Surgical Inc., Sunnyvale, CA, USA). Their mean age was 55.1 ± 13.8 years, and mean EuroSCORE II was 2.25% ± 1.25%. Among the enrolled patients, 32 (61.5%) patients presented with preoperative atrial fibrillation, 6 (11.5%) patients had experienced embolic stroke and 5 (9.6%) patients had undergone previous cardiac surgery. The operations were performed using cardiopulmonary bypass (CPB) under an arrested heart status.

RESULTS

Five porcine valves and 47 bovine valves were implanted. A total of 38 (73.1%) patients received concomitant cardiac procedures, including 26 Cox-maze IV procedures, 12 tricuspid valve repairs and 5 atrial septal defect repairs. The mean aortic cross-clamp and CPB times were 141.3 ± 34.3 min and 217.1 ± 42.0 min, respectively. There was no operative mortality. During the mean follow-up of 29 ± 15 months, no prosthesis degeneration was noted. The average left atrial dimension exhibited a significant decrease from 51.4 ± 11.5 mm to 42.6 ± 10.1 mm.

CONCLUSIONS

Robotic MVR with bioprosthetic valves is safe, feasible and reproducible. Mid-term results are encouraging. Both aortic cross-clamp and CPB times can be improved with experience.

Mechanical prosthetic heart valves: Quality of anticoagulation and thromboembolic risk. The observational multicenter PLECTRUM study

BACKGROUND

Patients with a mechanical prosthetic heart valve implantation need to be treated with a vitamin K antagonist (VKA) due to a substantially high risk of thromboembolism. In this study we report data on patients with mechanical heart valves (MV), with the aim of evaluating the thromboembolic risk in relation to the type and site of implantation, quality of anticoagulation and risk factors associated with thromboembolism.

METHODS

Observational retrospective multicenter study among Centers affiliated to the Italian Federation of Anticoagulation Clinics (FCSA) on patients with MV implanted after 1990 and followed for the management of anticoagulation.

RESULTS

We analyzed 2357 patients with mechanical heart valves (55.2% males), followed for 24,081 years. During the follow-up, 164 thromboembolic events (0.67/100 pt-yrs) and 243 major bleedings (1.0/100 pt-yrs) occurred. The median Time in Therapeutic Range (TTR), calculated in all intended INR classes, was 60% (IQR 47-74%). The rates of thrombotic events were significantly higher in patients intended to stay at therapeutic ranges >INR 2.0-3.0. The presence of atrial fibrillation, history of thromboembolism and of mitral prosthesis were independently associated with thromboembolism. However, a bad quality of anticoagulation (TTR <47%, 25°percentile of our population) was not correlated with thromboembolism.

CONCLUSIONS

A low rate of bleeding and thromboembolic events in patients with mechanical heart valves were found, despite the sub-optimal anticoagulation control. The thromboembolic risk was not associated with the low TTR.

Risk of reoperation in bioprosthetic valve patients with indication for long-term anticoagulation. Results from the observational retrospective multicentre PLECTRUM study

Objective

Several factors should be considered when a prosthetic heart valve, bioprosthetic valve (BV) or mechanical valve is to be implanted: thrombogenicity, life expectancy and the risk of reoperation.

Methods

We conducted an observational retrospective multicentre study among Italian Thrombosis Centers on patients with BV on long-term vitamin K antagonist (VKA) treatment to evaluate the risk of reoperation and the rate of bleeding and thrombotic events.

Results

We analysed 612 patients (median age 71.8 years) with BV on long-term VKA treatment for the presence of atrial fibrillation (AF) (78.4%) or other indications (21.6%). Thirty-four major bleeding events (rate 1.1×100 patient-years) and 29 thromboembolic events (rate 0.9×100 patient-years) were recorded, and 46 patients (rate 1.5×100 patient-years) underwent reoperation. The rate of reoperation was higher among younger patients: 32.9% in patients <60 years and 3.9% in patients ≥60 years (relative risk (RR) 3.8, 95% CI 2.1 to 7.2; p=0.0001). When patients were analysed according to age <65 or ≥65 years and <75 or ≥70 years, younger patients still were at higher risk for reoperation (RR 3.1, 95% CI 1.7 to 6.0 and 3.7, 95% CI 1.7 to 8.6, respectively).

Conclusions

Our findings suggest that the threshold of 65 years for implanting a BV should be carefully evaluated, considering the high risk for reoperation and the high risk of AF occurrence with persisting need for long-term anticoagulation. The high risk for reoperation of young patients implanted with BV and the availability of a safer and easier way to conduct VKA treatment, such as the use of point-of-care devices, should be considered when the type of valve must be chosen.

Vitamin K antagonist therapy: changes in the treated populations and in management results in Italian anticoagulation clinics compared with those recorded 20 years ago

Vitamin K antagonists (VKA) are the most widely used anticoagulants in the world. An appropriate management of treated patients is crucial for their efficacy and safety. The prospective, observational, multicenter, inception-cohort FCSA-START Register, a branch of START Register (NCT02219984) included VKA-treated patients managed by centers of Italian Federation of anticoagulation clinics (AC). Baseline patient characteristics and data during treatment were analyzed and compared with those of ISCOAT study, performed by the Federation and published in 1996/7. 5707 naïve patients [53% males, mean age 73.0 years (28.1% >80 years)], 61.6% treated for atrial fibrillation (AF), and 28.0% for venous thromboembolism were included. During the 8906 patient-years (pt-yrs) of observation, 123 patients had major bleeding (MB) (1.38% pt-yrs; fatal: 0.11% pt-yrs), while non-major clinically relevant bleeds were 144 (1.62% pt-yrs). Bleeding was more frequent in elderly (≥70 years; p = 0.04), and during initial 3-month therapy (p = 0.02). Bleeding rate was 2.5% pt-yrs for temporally related INR results <3.0, increasing to 12.5% for INR ≥ 4.5. Thrombotic events were 47 (0.53% pt-yrs; 4 fatal 0.04% pt-yrs). Compared with ISCOAT-1996/7 results, patients older than 80 y are increased from 8 to 28% (p < 0.01), and those treated for AF are increased from 17 to 61%. The quality of anticoagulation control and incidence of MB are not different. However, thrombotic complications fell drastically from 3.5 to 0.53% pt-yrs (p < 0.01), with lower mortality (p = 0.01). VKA-treated patients monitored in Italian AC have good clinical results, with low bleeding and thrombotic complications rates. Important changes in the treated population and improvement in thrombotic complications are detected compared with the ISCOAT-1996/7 study.