Long-term outcomes of isolated mechanical versus bioprosthetic mitral valve replacement in different age groups of propensity-matched patients.

OBJECTIVES: Prothesis choice in isolated mitral valve replacement for patients aged 75 years or younger remains debated as most studies comparing prothesis type have included large proportions of combined operations and benefits are influenced by concomitant procedures. This study compared long-term outcomes of isolated mechanical versus bioprosthetic mitral valves in different age groups of propensity-matched populations. METHODS: This is a retrospective, multicentre, propensity-matched observational study. Baseline characteristics, operative details and long-term outcomes (mortality and freedom from surgical/transcatheter reintervention) were collected. RESULTS: Totally, 1536 isolated mitral valve replacements (806 mechanical, 730 bioprosthetic) were performed between 2000 and 2017. Over 90% of eligible patients successfully underwent propensity matching, yielding 226 each of mechanical and bioprosthetic valves in patients aged <65 years and 171 each of bioprosthetic and mechanical valves in patients aged 65-75 years with median follow-up of 13 years (maximum 20 years). In matched patients <65 years, 10-year survival was superior with mechanical valves versus bioprosthetic valves (78.2% vs 69.8%, P = 0.029), as was 10-year freedom from reintervention (96.2% vs 81.3%, P < 0.001). For matched patients between 65 and 75 years, there were no differences between mechanical and bioprosthetic valves in 10-year survival (64.6% vs 60.8%, P = 0.86) or 10-year freedom from reintervention (94.0% vs 97.2%, P = 0.23). Rates of post-operative stroke, gastrointestinal bleeding, renal failure and permanent pacemaker insertion were similar. CONCLUSIONS: In patients requiring isolated mitral valve replacement, mechanical valves confer significantly better long-term survival and freedom from reintervention for patients <65 years, while no benefit is observed at age 65-75 years compared to bioprosthetic valves.

Mitral Valve Replacement for Bulky, Calcified Mitral Annulus: A Case Report.

Calcification of the mitral valve annulus is common in patients on dialysis. The growing number of individuals receiving dialysis has been accompanied by an increase in cases necessitating surgical intervention for mitral valve annulus calcification. In this report, we present a severe case characterized by bulky calcification of the mitral annulus, which was managed with mechanical mitral valve replacement. A 61-year-old man on dialysis presented with chest pain upon exertion that had persisted for 3 months. Cardiac echocardiography revealed severe mitral stenosis and regurgitation, accompanied by cardiac dysfunction. During surgery, an ultrasonic aspiration system was employed to remove the calcification of the mitral valve annulus to the necessary extent. Subsequently, a mechanical mitral valve was sutured into the supra-annular position. To address the regurgitation, the area surrounding the valve was sewn to the wall of the left atrium. Postoperative assessments indicated an absence of perivalvular leak and demonstrated improved cardiac function. The patient was discharged on postoperative day 22. We describe a successful mitral mechanical valve replacement in a case of extensive circumferential mitral annular calcification. Even with severe calcification extending into the left ventricular myocardium, we were able to minimize the decalcification process. This approach enabled the performance of mitral mechanical valve replacement in a high-risk patient on dialysis, thus expanding the possibilities for cardiac surgery.

Twenty-year experience following aortic valve replacement in patients younger than 60 years of age.

OBJECTIVE: Reports on long-term outcomes of surgical aortic valve replacement (AVR) for patients aged < 60 years are scarce in Japan. Hence, we aimed to evaluate these outcomes in patients aged < 60 years. METHODS: Between March 2000 and December 2020, 1477 patients underwent aortic valve replacement. In total, 170 patients aged < 60 years who underwent aortic valve replacement were recruited. Patients aged < 18 years were excluded. Patient data collected from the operative records and follow-up assessments were reviewed. RESULTS: The mean age was 49 ± 9 years, and 64.1% of patients were male. One-hundred-and-fifty-two patients (89.4%) underwent aortic valve replacement with a mechanical valve and 18 (10.6%) with a bioprosthetic valve. The mean follow-up period was 8.1 ± 5.5 years. No operative mortality occurred, and in-hospital mortality occurred in one patient (0.6%). Ten late deaths occurred, with seven cardiac-related deaths. The overall survival rate was 95.4 ± 1.7%, 93.9 ± 2.3%, 90.6 ± 3.9%, and 73.2 ± 11.8% at 5, 10, 15, and 20 years, respectively. Freedom from major bleeding was 96.4 ± 1.6% at 5, 10, and 15 years, and 89.0 ± 7.3% at 20 years. Freedom from thromboembolic events was 98.7 ± 1.3%, 97.3 ± 1.9%, 90.5 ± 4.5%, and 79.0 ± 11.3% at 5, 10, 15, and 20 years, respectively. Freedom from valve-related reoperation was 99.4 ± 0.6% at 5 years, 97.8 ± 1.7% at 10 and 15 years, and 63.9 ± 14.5% at 20 years. CONCLUSIONS: Patients aged < 60 years undergoing aortic valve replacement with a high mechanical valve implantation rate had favorable long-term outcomes.

Challenges Faced and Lessons Learned: The Journey of a 22-Year-Old Male with a Mechanical Heart Valve Complicated by Ischemic Stroke in a Developing Country: A Sub-Saharan Africa Prospect.

This report reviews an Ethiopian patient who underwent cardiac surgery and had a mechanical heart valve implanted on the mitral valve with tricuspid valve repair for rheumatic heart disease via a local non-profit organization donation later complicated by cardio-embolic stroke, and aims to describe the challenges faced by patients from rural Ethiopia who require cardiac surgery for rheumatic heart disease and narrate the importance of careful follow-up. The lessons to be drawn from this case are that careful follow-up and adherence to prescribed Vitamin K antagonists after surgery for mechanical heart valves are critical and, when such patients are lost to follow-up as was witnessed in this case, it can induce lifelong morbidity. Morbidity that could have been avoided with strict and meticulous follow-up and with standardized patient tracing or contact systems. When patients are lost to follow-up it needs to be top priority to trace them after cardiac surgery and this report highlights the pivotal role of the health education in such populations. Unless we utilize this opportunity to unlock the door and embrace a systemic approach to reforming our risk assessment, referral chain system, and integration of various healthcare professionals in patient follow-up, as well as enhancing health education among our patients in rural Ethiopia and other low-income countries, the consequences could prove to be significant. Preventing such fatal complications is far superior to managing them afterwards, as it not only saves on expenses but also saves lives and enhances quality-of-life.

Evaluation and Management of Mechanical Heart Valve Dysfunction and Thrombosis.

PURPOSE OF REVIEW: Dysfunction and thrombosis of mechanical heart valves, although uncommon, represents a challenge that requires multidisciplinary expertise for diagnosis and management. The aim of this review is to summarize strengths and weaknesses of diagnostic methods and therapeutic strategies for this uncommon but potentially life-threatening pathology. RECENT FINDINGS: Expeditious diagnosis of mechanical valve thrombosis and exclusion of other diagnostic considerations, often with incorporation of multimodality imaging, can inform the best treatment strategy. Presentation of mechanical valve thrombosis can be asymptomatic or can include heart failure, life-threatening embolic events, or cardiogenic shock. Echocardiography, fluoroscopy and computed tomography are important in the evaluation of mechanical valve dysfunction. Therapeutic strategies for thrombosis include anticoagulation, systemic thrombolysis, and surgery. Choice of treatment depends on multiple factors including thrombus size, degree of valve dysfunction, clinical presentation, and available surgical expertise.

A case report of entrapment of PentaRay catheter in the mechanical mitral valve: a known complication experienced anew.

Background: Complex atrial tachycardia (AT) is commonly observed in patients with cardiac surgery. High-density mapping is widely adopted for catheter ablation of complex AT in patients with cardiac surgery. Several case reports have described that PentaRay mapping catheter can be trapped in the mechanical valve and sheared off and successful retrieval of the spline by a snare system. We described a rare case in which PentaRay mapping catheter spline was successfully retrieved from the distal anterior tibial artery by direct syringe suction via the diagnostic catheter following entrapment in the mechanical mitral valve (MV) and rupture of the spline. Case summary: A 70-year-old female with mechanical bileaflet MV underwent catheter ablation for AT. During mapping in left atrium, the catheter was entrapped in mechanical MV and sheared off. We attempted to release the entrapped the spline by advancing the ablation catheter towards the stuck disc and pushing on the hinge portion of the disc with the catheter tip. The stuck and closed disc was opened, and the deeply entrapped spline was released. However, the entrapped PentaRay spline floated through the Valsalva sinus and strayed into the distal left anterior tibial artery. Fortunately, we successfully retrieved the spline from the distal anterior tibial artery by direct syringe suction instead of a snare system. Discussion: The possibility of the entrapment and subsequent rupture of the spline should always be considered during mapping the site close to mechanical valve. A rapid retrieval of embolized material should be carried out. If the spline strays into the distal and small artery in which the snare system is difficult to advance, a direct syringe suction via the diagnostic catheter may be attempted.

A parametric study on pulse duplicator design and valve hemodynamics.

BACKGROUND: In vitro assessment is mandatory for artificial heart valve development. This study aims to investigate the effects of pulse duplicator features on valve responsiveness, conduct a sensitivity analysis across valve prosthesis types, and contribute on the development of versatile pulse duplicator systems able to perform reliable prosthetic aortic valve assessment under physiologic hemodynamic conditions. METHODS: A reference pulse duplicator was established based on literature. Further optimization process led to new designs that underwent a parametric study, also involving different aortic valve prostheses. These designs were evaluated on criteria such as mean pressure differential and pulse pressure (assessed from high-fidelity pressure measurements), valve opening and closing behavior, flow, and regurgitation. Finally, the resulting optimized setup was tested under five different hemodynamic settings simulating a range of physiologic and pathologic conditions. RESULTS: The results show that both, pulse duplicator design and valve type significantly influence aortic and ventricular pressure, flow, and valve kinematic response. The optimal design comprised key features such as a compliance chamber and restrictor for diastolic pressure maintenance and narrow pulse pressure. Additionally, an atrial reservoir was included to prevent atrial-aortic interference, and a bioprosthetic valve was used in mitral position to avoid delayed valve closing effects. CONCLUSION: This study showed that individual pulse duplicator features can have a significant effect on valve's responsiveness. The optimized versatile pulse duplicator replicated physiologic and pathologic aortic valve hemodynamic conditions, serving as a reliable characterization tool for assessing and optimizing aortic valve performance.

Mechanical versus Bioprosthetic Aortic Valve Replacement in Patients Aged 50 to 70 Years.

Background: This study compared the outcomes of surgical aortic valve replacement (AVR) in patients aged 50 to 70 years based on the type of prosthetic valve used. Methods: We compared patients who underwent mechanical AVR to those who underwent bioprosthetic AVR at our institution between January 2000 and March 2019. Competing risk analysis and the inverse probability of treatment weighting (IPTW) method based on propensity score were employed for comparisons. Results: A total of 1,580 patients (984 patients with mechanical AVR; 596 patients with bioprosthetic AVR) were enrolled. There was no significant difference in early mortality between the mechanical AVR and bioprosthetic AVR groups (0.9% vs. 1.7%, p=0.177). After IPTW adjustment, the risk of all-cause mortality was significantly higher in the bioprosthetic AVR group than in the mechanical AVR group (hazard ratio [HR], 1.39; 95% confidence interval [CI], 1.07-1.80; p=0.014). Competing risk analysis revealed lower risks of stroke (sub-distributional hazard ratio [sHR], 0.44; 95% CI, 0.28-0.67; p<0.001) and anticoagulation- related bleeding (sHR, 0.35; 95% CI, 0.23-0.53; p<0.001) in the bioprosthetic AVR group. Conversely, the risk of aortic valve (AV) reintervention was higher in the bioprosthetic AVR group (sHR, 6.14; 95% CI, 3.17-11.93; p<0.001). Conclusion: Among patients aged 50 to 70 years who underwent surgical AVR, those receiving mechanical valves showed better survival than those with bioprosthetic valves. The mechanical AVR group exhibited a higher risk of stroke and anticoagulation-related bleeding, while the bioprosthetic AVR group showed a higher risk of AV reintervention.

Long-Term Outcomes of Mechanical Aortic Valve Replacement in Children.

When the options of aortic valve repair or the Ross procedure are not feasible or have been exhausted, mechanical aortic valve replacement (AVR) may provide a reliable and structurally durable alternative, but with the limitations of long-term anticoagulation, thrombosis risk and lack of valve growth potential. In this article, we review the longitudinal outcomes of mechanical AVR in children in our institution and compare them to those recently reported by others. From 1978 to 2020, 62 patients underwent mechanical AVR at a median age of 12.4 years (interquartile range (IQR): 8.6-16.8 years). The most common underlying diagnoses were: conotruncal anomalies (40%, 25/62), congenital aortic stenosis (16%, 10/62), rheumatic valve disease (16%, 10/62), connective tissue disease (8.1%, 5/62) and infective endocarditis (6.5%, 4/62). Thirty-two patients (52%, 32/62) had at least 1 prior aortic valve surgery prior to mechanical AVR. Early death was 3.2% (2/62). Median follow-up was 14.4 years (IQR: 8.4-28.2 years). Kaplan-Meier survival was 96.8%, 91.9%, 86.3%, and 81.9% at 1, 5, 10, and 20 years. On competing risk analysis, the proportion of patients alive without aortic valve reoperation at 1, 5, 10, and 20 years was 95.2%, 87.0%, 75.5% and 55.4%, respectively, while the proportion of patients that had aortic valve reoperation (with death as a competing event) at 1, 5, 10, and 20 years was 1.6%, 4.9%, 12.8%, and 28.5%, respectively. In conclusion, when the options of aortic valve repair or the Ross procedure are not feasible in children, mechanical AVR is an alternative, yet the long-term rates of mortality and need for aortic valve reoperation are of concern.

Long-Term Outcomes of Mechanical Versus Bioprosthetic Aortic Valve Replacement: A Systematic Review and Meta-Analysis.

This study aimed to investigate the safety and efficacy of bioprosthetic (BV) versus mechanical valves (MV) on long-term outcomes in 50- to 70-year-old aortic stenosis (AS) patients. A literature search for articles published until April 2023 yielded 13 eligible studies, with 15,320 patients divided into BV (n = 7,320) and MV (n = 8,000) cohorts. The review was registered prospectively with PROSPERO (CRD42021278777). MV demonstrated a favorable hazard ratio (HR: 1.12, 95% CI: 1.00-1.25, I2 = 60%) and higher survival rates at 5 (OR:1.13, 95% CI: 1.02-1.25, I2 = 42%) and 10 years (OR: 1.13, 95% CI: 1.05-1.23, I2 = 0%). At 15 years, stroke incidence was comparable (OR: 1.12, 95% CI: 0.98-1.27, I2 = 4%). BV showed lower bleeding events (OR: 1.7, 95% CI: 1.18-2.46, I2 = 88%), but MV replacement showed lower reoperation incidence (OR: 0.27, 95% CI: 0.18-0.42, I2 = 85%). MV appears favorable for the long-term approach in AS management compared to BV.

Impact of explanted valve type on aortic valve reoperations: nationwide UK experience.

OBJECTIVES: This nationwide retrospective cohort study assessed the impact of the explanted valve type on reoperative outcomes in aortic valve surgery within the UK over a 23-year period. METHODS: Data were sourced from the National Institute for Cardiovascular Outcomes Research (NICOR) database. All patients undergoing first-time isolated reoperative aortic valve replacement between 1996 and 2019 in the UK were included. Concomitant procedures, homograft implantation or aortic root enlargement were excluded. Propensity score matching was utilized to compare outcomes and risk factors for in-hospital mortality was evaluated through multivariable logistic regression. Final model selection was conducted using Akaike Information Criterion through bootstrapping. The primary end point was in-hospital mortality, and secondary end points included postoperative morbidities. RESULTS: Out of 2371 patients, 24.9% had mechanical and 75% had bioprosthetic valves implanted during the primary procedure. Propensity matched groups of 324 patients each, were compared. In-hospital mortality for mechanical and bioprosthetic valve explants was 7.1% and 5.9%, respectively (P = 0.632). On multivariable logistic regression analysis, valve type was not a risk factor for mortality [odds ratio (OR) 0.62, 95% confidence interval (CI) 0.37-1.05; P = 0.1]. Age (OR 1.03, 95% CI 1.01-1.05; P < 0.05), left ventricular ejection fraction (OR 1.62, 95% CI 1.08-2.42; P < 0.05), creatinine ≥ 200 mg/dl (OR 2.21, 95% CI 1.17-4.04; P < 0.05) and endocarditis (OR 2.66, 95% CI 1.71-4.14; P < 0.05) emerged as risk factors for mortality. CONCLUSIONS: The type of valve initially implanted (mechanical or bioprosthetic) did not determine mortality. Instead, age, left ventricular ejection fraction, renal impairment and endocarditis were significant risk factors for in-hospital mortality.

Experimental observation on a new chimney-shaped mechanical valve completely implanted above the mitral annulus in animals.

Current commercially available prosthetic valves suffer from limited size, high requirements for implantation technique, subvalvular structural destruction, and valve dysfunction due to proliferation of fibrous endothelial tissue. This study aims to perform the preclinical large animal experiments for surgically implanting a chimney-shaped artificial mechanical heart valve with zero left ventricular occupancy, which fully accommodates the movement of the valve leaflets in the valve frame and realizes completely supra-annular surgical implantation. A total of 7 sheep underwent the replacement of artificial valve, and 5 sheep survived normally until anatomical examination. The mechanical properties of these artificial mitral valves remain functionally normal. There was no obvious thromboembolism around the artificial valve and in the important organs. The tissue layer of suture ring was completely organized and endothelialized, and the thickness of tissue layer was about 0.6-1.0 mm. The follow-up of echocardiography showed that the left ventricular ejection fraction was normal (60-70%) before and 6 months after operation. The results of transvalvular pressure gradient and blood flow velocity of artificial valve were normal. Left ventricular retrograde angiography showed that the artificial valve was completely located in the left atrium with good position and normal opening and closing. There was no obvious perivalvular leakage and other abnormalities. At 3 and 6 months, there were no obvious abnormalities in blood routine test, liver and kidney function, and other indexes. The new chimney-shaped artificial mechanical valve implanted completely above the mitral annulus had good wear resistance, histocompatibility, and antithrombotic and hemodynamic performance.

Heart Team Approach for Cardiogenic Shock Management in Pregnancy Complicated by Mechanical Mitral Valve Thrombosis.

A 27-year-old pregnant woman at 24 weeks of gestation was admitted with cardiogenic shock due to mechanical mitral valve thrombosis. Following discussion with the heart team, thrombolysis was achieved with tissue plasminogen activator therapy followed by heparin infusion. Ultimately, the patient required mitral valve replacement for persistently elevated gradients.

The association between perception of noise from a mechanical heart valve and symptoms of anxiety and depression.

AIM: Patients with symptomatic aortic valve stenosis are efficiently treated by aortic valve replacement (AVR), using a biological or mechanical valve. For some patients with mechanical valves, the metallic clicking sound may be problematic. The aim of this study was to investigate the perceived disturbance from the sound of a mechanical valve and the association between noise perception and symptoms of anxiety and depression. METHODS: and results: The study had a cross-sectional design. In April 2013, all patients who had undergone AVR at one university hospital during the period 2000-2012 were invited by post to participate. The primary variables were assessed using a valve-specific questionnaire and the Hospital Anxiety and Depression Scale (HADS).Of the 912 (77%) respondents, 245 had mechanical valves. Of these, fifty-nine (24%) were women, the mean (standard deviation: SD) age was 61 (11) years, and the mean time since surgery was 7 (3) years. The valve-specific questionnaire showed that 84% of the patients could sometimes or often hear the valve sound. A moderate positive correlation was found between valve prosthesis noise disturbance and anxiety, r = 0.35 (p = 0.001), and depression, r = 0.27 (p = 0.001). In a multiple linear regression analysis, valve noise perception was only significantly associated with anxiety among several other biopsychosocial factors. CONCLUSION: This study shows an association between valve noise disturbance and symptoms of anxiety, and highlights the importance of preparing all patients for the sound from the mechanical valves that arises after surgery.

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

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

DOACs in the Anticoagulation of Mechanical Valves: A Systematic Review and Future Perspectives.

Valvular heart disease is a common disease often necessitating valve replacement. Mechanical heart valves (MHVs) are often used in younger patients because of their longer durability. Their main disadvantage is the need for lifelong anticoagulation. Warfarin is considered a standard treatment, but it is far from perfect. Direct oral anticoagulants (DOACs) are a new and more patient-friendly alternative to warfarin when anticoagulation is required, but have not yet been approved for the indication of mechanical valves. EVIDENCE ACQUISITION: A literature search of Pubmed, Embase, Web of Science (Core Collection), and Cochrane Library (from inception to May 2023) was performed using a search string that was well defined and not modified during the study. An extensive overview of the search terms used in each database can be found in the Appendix. Only prospective clinical trials were included in this review. A total of 10 publications were included in this review. RELEVANCE TO CLINICAL PRACTICE: This systematic review summarizes the different types of DOACs and their possible use in the anticoagulation of mechanical valves. We aim to propose future directions in anticoagulation research for mechanical valves. CONCLUSIONS: DOAC use in MHVs has been halted due to the failure of both dabigatran and apixaban in two major clinical trials. However, rivaroxaban was successful in two small clinical trials. Ample research is still needed to explore new valve designs as well as new anticoagulation targets.