Bioprosthetic Mitral Valve Replacement Research Articles

Antithrombotic therapy after heart valve surgery: contemporary practice in the UK.

There is a lack of high-quality data informing the optimal antithrombotic drug strategy following bioprosthetic heart valve replacement or valve repair. Disparity in recommendations from international guidelines reflects this. This study aimed to document current patterns of antithrombotic prescribing after heart valve surgery in the UK. All UK consultant cardiac surgeons were e-mailed a custom-designed survey. The use of oral anticoagulant (OAC) and/or antiplatelet drugs following bioprosthetic aortic valve replacement or mitral valve replacement, or mitral valve repair (MVrep), for patients in sinus rhythm, without additional indications for antithrombotic medication, was assessed. Additionally, we evaluated anticoagulant choice following MVrep in patients with atrial fibrillation. We identified 260 UK consultant cardiac surgeons from 36 units, of whom 103 (40%) responded, with 33 units (92%) having at least 1 respondent. The greatest consensus was for patients undergoing bioprosthetic aortic valve replacement, in which 76% of surgeons favour initial antiplatelet therapy and 53% prescribe lifelong treatment. Only 8% recommend initial OAC. After bioprosthetic mitral valve replacement, 48% of surgeons use an initial OAC strategy (versus 42% antiplatelet), with 66% subsequently prescribing lifelong antiplatelet therapy. After MVrep, recommendations were lifelong antiplatelet agent alone (34%) or following 3 months OAC (20%), no antithrombotic agent (20%), or 3 months OAC (16%). After MVrep for patients with established atrial fibrillation, surgeons recommend warfarin (38%), a direct oral anticoagulant (37%) or have no preference between the 2 (25%). There is considerable variation in the use of antithrombotic drugs after heart valve surgery in the UK and a lack of high-quality evidence to guide practice, underscoring the need for randomized studies.

Long-Term Outcomes of Bioprosthetic Valves in the Mitral Position: A Pooled Meta-Analysis of Reconstructed Time-to-Event Individual Patient Data

ObjectivesBioprosthetic MVR use is on the rise, but data regarding long term durability is lacking. We sought to perform a reconstructed individual patient data meta-analysis from published Kaplan Meier curves to ascertain survival, freedom from valve degeneration and reoperation in studies published since 2010. We explored the effects of age and valve type (bovine pericardial or porcine valve) on outcomes. MethodsWe searched MEDLINE, OVID, Embase and Cochrane CENTRAL for studies reporting at least 3 years of follow-up after bMVR and published since 2010. The ROBINS-I tool was used to assess methodological quality. Kaplan Meier curves were digitized to extract individual patient data and reconstructed estimates for overall survival, freedom from SVD and freedom from re-operation. Results20 studies (16465 patients) were included. 9 studies reported on porcine valves, 6 on bovine and 7 did not specify the valve type. Overall survival after bMVR at 15 years was 40% (CI 38%-42%), freedom from re-operation at 15 years was 79% (CI 76%-82%) and freedom from structural valve degeneration at 15 years was 64% (58%-70%). Freedom from SVD was improved in the 70+ age group (93% up to 25 years, HR 6.6(2.5-17) for 18-59 VS >70, p<0.0001). There was no difference in valve durability or survival between bovine pericardial or porcine valves. ConclusionIn this meta-analysis patients of receiving bioprosthetic mitral valve replacement using newer generation valves, the inverse relationship between age and SVD was re-iterated in the 70+ age group. Prosthesis type made no difference in outcomes.

Mitral valve replacement in children: balancing durability and risk with mechanical and bioprosthetic valves.

To investigate if there is still a place for bioprosthetic mitral valve replacement in children by comparing the prosthetic durability and transplant-free survival after bioprosthetic and mechanical mitral valve replacement. We reviewed all mitral valve replacements in children between 1981 and 2020. Bioprosthetic mitral valve replacement cases were individually matched to mechanical mitral valve replacement cases. The incidence rate of a 2nd replacement was calculated using the cumulative incidence function that considered death or transplantation as a competing risk. The median age at implantation was 3.6 years (interquartile range 0.8-7.9) for the bioprosthetic valve cohort (n = 28) and 3 years (interquartile range 1.3-7.8) for the mechanical valve cohort (n = 28). Seven years after bioprosthetic mitral valve replacement, the cumulative incidence of death or transplantation was 17.9% [95% confidence interval (CI) 6.3-34.1] and the cumulative incidence of a 2nd replacement was 63.6% (95% CI 39.9-80.1). Seven years after mechanical mitral valve replacement, the cumulative incidence of death or transplantation was 28.6% (95% CI 13.3-46) and the cumulative incidence of a 2nd replacement was 10.7% (95% CI 2.6-25.5). Fifteen years after mechanical mitral valve replacement, the cumulative incidence of death or transplantation was 33.6% (95% CI 16.2-52.1) and the cumulative incidence of a 2nd replacement was 41.1% (95% CI 18.4-62.7). The cumulative incidence curves for bioprosthetic and mechanical mitral valve replacement were statistically different for a 2nd valve replacement (P < 0.001) but not for death or transplantation (P = 0.33). There is no difference in transplant-free survival after bioprosthetic and mechanical mitral valve replacement in children. The lifespan of bioprosthetic mitral valves remains limited in children because of structural valve failure due to calcification. After 15 years, 40% of mechanical valves were replaced, primarily because of patient-prosthesis mismatch related to somatic growth.

Transcatheter Arterial Embolization for Atraumatic Splenic Rupture in TEE-negative Endocarditis: A Case Report

Introduction: Spontaneous splenic rupture is an extremely rare complication of infective endocarditis.Case Report: We present a case of a 56-year-old immunocompetent female with porcine bioprosthetic mitral valve replacement, automated implanted cardioverter-defibrillator, and atrial fibrillation on apixaban who was found to have in-hospital atraumatic splenic rupture complicating infective endocarditis with Haemophilus parainfluenza. The rupture was treated successfully by endovascular embolization. Usual treatment with six weeks of antibiotics provided durable cure without further complication, and no surgical intervention was needed for either the valve or spleen.Conclusion: Transcatheter arterial embolization should be considered early in atraumatic splenic rupture. Relevant abdominal and cerebral imaging should be considered in all cases of suspected or confirmed infective endocarditis where unexplained symptoms are present.

Left atrial Thrombus formation after discontinuation of anticoagulation in patient with severe bioprosthetic mitral stenosis

BackgroundMitral valve stenosis can be a highly symptomatic condition with significant complications if left untreated. In such cases, mitral valve replacement with a bioprosthetic or mechanical valve may be a viable solution to prevent progressive disease. Current guidelines do not recommend continued anticoagulation beyond 6 months for patients who have undergone bioprosthetic valve replacement without a separate indication for anticoagulation. With this case discussion we aim to 1) Review the current indications for anticoagulation for bioprosthetic mitral valves in patients without atrial fibrillation and 2) Discuss the constellation of comorbidities that may affect the decision to begin anticoagulation therapy.Case presentationWe present a case describing a 55-year-old male with end-stage renal disease, coronary artery disease with coronary artery bypass graft surgery, and bioprosthetic mitral valve replacement 2 years prior with rapid degeneration of the replaced valve and on warfarin without a clear indication for anticoagulation. The patient was admitted for symptomatic, severe mitral stenosis and consideration of transcatheter mitral valve-in-valve replacement. During hospital admission, warfarin was discontinued and replaced with prophylactic anticoagulation. However, 8 days after warfarin cessation an intraoperative transesophageal echocardiography revealed a newly developed large left atrial thrombus leading to cancellation of the planned operation.ConclusionsThis patient developed a left atrial thrombus after discontinuing warfarin in the setting of rapidly deteriorating bioprosthetic valve stenosis and vascular comorbidities. The decision to discontinue warfarin was made in concordance with current guidelines, which do not indicate systemic anticoagulation post 3–6 months after bioprosthetic valve replacement without separate indication for anticoagulation. This case identifies the need to investigate rebound hypercoagulability and further risk stratify comorbidities which may independently increase the risk of clot formation in the setting of severe mitral valve stenosis.

Outcomes after bioprosthetic versus mechanical mitral valve replacement for infective endocarditis in the United States

ObjectiveIn patients who underwent mitral valve replacement for infectious endocarditis, we evaluated the association of prosthesis choice with readmission rates and causes (the primary outcomes), as well as with in-hospital mortality, cost, and length of stay (the secondary outcomes). MethodsPatients with infectious endocarditis who underwent isolated mitral valve replacement from January 2016 to December 2018 were identified in the United States Nationwide Readmissions Database and stratified by valve type. Propensity score matching was used to compare adjusted outcomes. ResultsA weighted total of 4206 patients with infectious endocarditis underwent bioprosthetic mitral valve replacement (n = 3132) and mechanical mitral valve replacement (n = 1074) during the study period. Patients in the bioprosthetic mitral valve replacement group were older than those in the mechanical mitral valve replacement group (median 57 vs 46 y, P < .001). After propensity matching, the bioprosthetic mitral valve replacement group (n = 1068) had similar in-hospital mortality, length of stay, and costs compared with the mechanical mitral valve replacement group (n = 1056). Overall, 90-day readmission rates were high (28.9%) and comparable for bioprosthetic mitral valve replacement (30.5%) and mechanical mitral valve replacement (27.5%, P = .4). Likewise, there was no difference in readmissions over a calendar year by prosthesis type. Readmissions for infection and bleeding were common for both bioprosthetic mitral valve replacement and mechanical mitral valve replacement groups. ConclusionsOutcomes and readmission rates were similar for mechanical mitral valve replacement and bioprosthetic mitral valve replacement in infectious endocarditis, suggesting that valve choice should not be determined by endocarditis status. Additionally, strategies to mitigate readmission for infection and bleeding are needed for both groups.

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

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

Abstract 13931: Direct Oral Anticoagulants in Atrial Fibrillation Patients With Rheumatic Heart Disease After Mitral Valve Replacement With Bioprosthesis

Background: We sought to investigate the outcomes of direct oral anticoagulants (DOACs) versus warfarin in patients with atrial fibrillation and bioprosthetic mitral valve replacement (bMVR) due to rheumatic heart disease. Methods: We performed a retrospective study using the TriNetX global database to identify patients with atrial fibrillation and bMVR due to rheumatic heart disease from 2010 to 2020. Patients who had mechanical mitral or aortic valve replacement were excluded. Patients were stratified into 2 groups: DOAC group and Warfarin group. 1:1 propensity-score matching to control for baseline differences between the two groups was performed. The primary endpoint was ischemic stroke and secondary endpoints were all-cause mortality, major bleeding, myocardial infarction, and all-cause hospitalization over a mean follow-up of 3 years. Results: A total of 2,011 patients were identified and 586 were included after propensity-score matching (293 patients in each group). Patients in the DOAC group, compared to the warfarin group aged 68.9 ± 11.2 vs 68.2 ± 11 years (P=0.41) and 63.4% vs 63.8% were females (P=0.93). There was no significant difference between the two groups in ischemic stroke, all-cause mortality, major bleeding, myocardial infarction, and all-cause hospitalization. (Table 1, figure 1). Conclusion: In patients with atrial fibrillation and bMVR due to rheumatic heart disease, DOACs use was associated with similar rates of ischemic stroke, mortality, major bleeding, myocardial infarction, or hospitalization compared to warfarin.

Abstract 14162: Long-Term Outcomes for Contemporary Mechanical versus Bioprosthetic Surgical Mitral Valve Replacement in Patients Aged 50 to 70 Years

Background: Guidelines are still unclear regarding whether mechanical or bioprosthetic valves should be selected for mitral valve replacement (MVR) in patients aged 50-70 years. Aims: To assess long-term outcomes in patients aged 50-70 years undergoing MVR using contemporary mechanical and bioprosthetic valves. Methods: We performed a retrospective study using the TriNetX global database to identify patients aged 50 to 70 years who had primary isolated surgical MVR from 2014 to 2020. Patients who had concomitant or prior cardiac surgeries were excluded. Patients were stratified into 2 groups: mechanical and bioprosthetic, and a 1:1 propensity-score matching to control for baseline differences between the two groups was performed. The primary endpoint was all-cause mortality and secondary endpoints were stroke, major bleeding, and reoperation over a follow-up period of 8 years. Results: Propensity-score matching yielded 1,130 patients in each group. There were significantly higher rates of all-cause mortality, stroke, and major bleeding events in the mechanical group compared to the bioprosthetic valve. There was no significant difference between the two groups regarding reoperation (Table 1 and Figure 1). Conclusion: At an 8-year follow-up, the use of contemporary bioprosthetic valves for MVR in patients aged 50-70 years shows favorable all-cause mortality and lower rates of strokes and major bleeding with similar reoperation rates compared to mechanical valves.

Should mitral valve replacement age guidelines be lowered due to better bioprosthetic mitral valve durability?

ObjectiveGuideline recommendations for mechanical or bioprosthetic valve for mitral valve replacement by age remains controversial. We sought to determine bovine pericardial valve durability by age and risk of reintervention. MethodsThis retrospective study between 2 large university-based cardiac surgery programs examined patients who underwent bioprosthetic mitral valve replacement from 2004 to 2020. Follow-up was obtained through June 2022. Durability outcomes involving structural valve deterioration were compared by age decile. ResultsOf 1544 available patients, mean age was 66 ± 13 years and 652 (42%) were aged less than 65 years. Indications for mitral valve replacement were as follows: mitral regurgitation greater than 2+ in 53% (n = 813), mitral stenosis in 44% (n = 650), endocarditis in 18% (n = 277), and reoperation in 39% (n = 602). Concomitant procedures were aortic valve replacement in 28% (n = 426), tricuspid valve in 36% (n = 550), and coronary artery bypass in 19% (n = 290). Thirty-day mortality was 5.4%. In follow-up (clinical: median [interquartile range] 75 [25-129] months), reoperation for endocarditis and new stroke were low (0.30 and 1.06 per 100 patient/years, respectively). The cumulative incidence of mitral valve reintervention for structural valve deterioration among all patients was 6.2% at 10 years and 9.0% at 12 years with no statistical difference in structural valve deterioration in patients aged 40 to 70 years (P = .1). In 90 patients with mitral valve reintervention, 30-day mortality after reintervention was 4.7% (n = 2) for 43 with mitral valve-in-valve and 6.4% (n = 3) for 47 with reoperation. ConclusionsBovine pericardial mitral valve replacement is a durable option for younger patients. The opportunity to avoid anticoagulation and the associated risks with mechanical mitral valve replacement may be of benefit to patients. These insights may provide data needed to revise the current guidelines.

Long-Term Outcomes of Bovine versus Porcine Mitral Valve Replacement: A Multicenter Analysis.

Recent national guidelines recommending mitral valve replacement (MVR) for severe secondary mitral regurgitation have resulted in an increased utilization of mitral bioprosthesis. There is a paucity of data on how longitudinal clinical outcomes vary by prosthesis type. We examined long-term survival and risk of reoperation between patients having bovine vs. porcine MVR. Study Design. A retrospective analysis of MVR or MVR + coronary artery bypass graft (CABG) from 2001 to 2017 among seven hospitals reporting to a prospectively maintained clinical registry was conducted. The analytic cohort included 1,284 patients undergoing MVR (801 bovine and 483 porcine). Baseline comorbidities were balanced using 1 : 1 propensity score matching with 432 patients in each group. The primary end point was all-cause mortality. Secondary end points included in-hospital morbidity, 30-day mortality, length of stay, and risk of reoperation. In the overall cohort, patients receiving porcine valves were more likely to have diabetes (19% bovine vs. 29% porcine; p < 0.001), COPD (20% bovine vs. 27% porcine; p=0.008), dialysis or creatinine >2 mg/dL (4% bovine vs. 7% porcine; p=0.03), and coronary artery disease (65% bovine vs. 77% porcine; p < 0.001). There was no difference in stroke, acute kidney injury, mediastinitis, pneumonia, length of stay, in-hospital morbidity, or 30-day mortality. In the overall cohort, there was a difference in long-term survival (porcine HR 1.17 (95% CI: 1.00-1.37; p=050)). However, there was no difference in reoperation (porcine HR 0.56 (95% CI: 0.23-1.32; p=0.185)). In the propensity-matched cohort, patients were matched on all baseline characteristics. There was no difference in postoperative complications or in-hospital morbidity and 30-day mortality. After 1 : 1 propensity score matching, there was no difference in long-term survival (porcine HR 0.97 (95% CI: 0.81-1.17; p=0.756)) or risk of reoperation (porcine HR 0.54 (95% CI: 0.20-1.47; p=0.225)). In this multicenter analysis of patients undergoing bioprosthetic MVR, there was no difference in perioperative complications and risk of reoperation of long-term survival after matching.

COMPARISON OF PROPENSITY SCORES FOR SURGICAL TREATMENT OF BIOPROSTHETIC MITRAL VALVE DYSFUNCTION USING TRADITIONAL AND “VALVE-IN-VALVE” METHODS

HighlightsThe article describes the first conducted pseudorandomized comparative study of mitral valve replacement using either traditional or “valve-in-valve” techniques. AbstractAim. To compare short-term (perioperative) and medium-term (6 months) outcomes of surgical treatment of bioprosthetic mitral valve dysfunction using traditional and “valve-in-valve” methods.Methods. The study included 18 patients undergoing “valve-in-valve” replacement and 18 patients undergoing traditional mitral valve replacement (open mitral valve replacement) chosen according to the following criteria: heart disease type, predominant type of defect, age, gender, severity of the disease and the presence of concomitant pathology and using 1:1 matching on the propensity score.Results. No perioperative mortality was noted in both groups. The cardiopulmonary bypass and cross-clamping of the aorta time was significantly lower in the “valve-in-valve” group. Comparison of echocardiographic parameters revealed a decrease in the mean pulmonary arterial pressure gradient, and a decrease in the size of the heart chambers in both groups. The peak and mean transvalvular gradient were lower in the “traditional” group. There were no cases of patient-prosthesis mismatch. In the mid-term period, patients in both groups presented with a lower functional class of heart failure.Conclusion. Bioprosthetic mitral valve replacement using the “valve-in-valve” technique provides comparable clinical and hemodynamic results compared to the “traditional” technique in short-term and mid-term periods, and significantly reduces cardiopulmonary bypass and aortic cross clamping time.

Long-term Outcomes and Anticoagulation in Mitral Valve Surgery—A Report From The Society of Thoracic Surgeons Database

BackgroundAnticoagulation after bioprosthetic mitral valve (MV) replacement (BMVR) and repair (MVrep) is controversial. We explore outcomes among BMVR and MVrep patients in The Society of Thoracic Surgeons Adult Cardiac Surgery Database based on discharge anticoagulation status. MethodsBMVR and MVrep patients aged ≥65 years in The Society of Thoracic Surgeons Adult Cardiac Surgery Database were linked to the Centers for Medicare and Medicaid Services claims database. Long-term mortality, ischemic stroke, bleeding, and a composite of the primary end points were compared as a function of anticoagulation. Hazard ratios (HRs) were calculated using multivariable Cox regression. ResultsA total of 26,199 BMVR and MVrep patients were linked to the Centers for Medicare and Medicaid Services database; of these, 44%, 4%, and 52% were discharged on warfarin, non-vitamin K–dependent anticoagulant (NOAC), and no anticoagulation (no-AC; reference), respectively. Warfarin was associated with increased bleeding in the overall study cohort (HR, 1.38; 95% CI 1.26-1.52) and in the BMVR (HR, 1.32; 95% CI, 1.13-1.55) and MVrep subcohorts (HR, 1.42; 95% CI, 1.26-1.60). Warfarin was associated with decreased mortality only among BMVR patients (HR, 0.87; 95% CI, 0.79-0.96). Stroke and the composite outcome did not differ across cohorts with warfarin. NOAC use was associated with increased mortality (HR, 1.33; 95% CI 1.11-1.59), bleeding (HR, 1.37; 95% CI, 1.07-1.74), and the composite outcome (HR, 1.26; 95% CI, 1.08-1.47). ConclusionsAnticoagulation was used in fewer than half of mitral valve operations. In MVrep patients, warfarin was associated with increased bleeding and was not protective against stroke or mortality. In BMVR patients, warfarin was associated with a modest survival benefit, increased bleeding, and equivalent stroke risk. NOAC was associated with increased adverse outcomes.

Surgery for mitral annular caseous calcification-related calcified amorphous tumor: a case report

BackgroundA calcified amorphous tumor (a non-neoplastic tumor) with caseous calcification of the mitral annulus is a rare pathology that causes severe embolic events. We present a rare case of mitral valve surgery for a mitral annular caseous calcification-related calcified amorphous tumor found in cerebral infarction.Case presentationA 69-year-old man was diagnosed with a mitral valve calcified amorphous tumor with mitral annular caseous calcification found in cerebral infarction. He was admitted because of acute multiple embolic cerebral infarctions. A search for the embolic source through transesophageal echocardiography revealed a mitral valve tumor raised from the posterior mitral valve leaflet on the side of the left ventricle. Computed tomographic cardiac angiography revealed a calcified mitral valve tumor invading the posterior mitral valve annulus and left ventricular muscle. Intraoperative findings revealed a mitral annular calcification-related calcified amorphous tumor with caseous calcification of the posterior leaflet and annulus, which was suspected. Therefore, we performed radical debridement of the mitral annular calcification and bioprosthetic mitral valve replacement with patch repair of the posterior mitral valve annulus 2 weeks after the onset of cerebral infarction. The patient recovered well post operation, without any embolic events.ConclusionsA calcified amorphous tumor with caseous mitral annulus calcification may be highly associated with embolic events. In this case, mitral valve replacement with annular patch repair may be a favorable procedure for preventing embolic events.

Bovine pericardial versus porcine bioprosthetic mitral valves: results from a Korean Nationwide Cohort Study.

Comparisons of long-term clinical outcomes of mitral valve replacement (MVR) between bovine pericardial and porcine bioprostheses are conflicting, with limited research in large-scale real-world clinical settings. This study examined clinical outcomes in MVR according to bioprosthesis type using a national administrative claims database. This study included adult patients undergoing bioprosthetic MVR between 2003 and 2018 using administrative health care data from the Korean National Health Insurance Service database. Propensity score matching with competing risk analysis was used to compare the clinical outcomes according to the type of bioprosthesis. The end points were death, cardiac death, and valve-related events, including the incidence of reoperation, endocarditis, systemic thromboembolism, and major bleeding. A total of 3151 patients underwent bioprosthetic MVR with bovine pericardial (n = 1628, 51.7%) or porcine (n = 1523, 48.3%) bioprostheses. After matching, 1170 pairs were included in the final analysis. During follow-up (median 4.49 years, interquartile range 1.87 -8.75 years), death occurred in 1178 patients (6.8%/patient-year), comprising 730 (4.3%/patient-year) cardiac death. No significant differences were noted between the bovine and porcine groups in the cumulative incidences of death from any cause [adjusted hazard ratio (aHR), 1.00; 95% confidence interval (CI), 0.87-1.14], cardiac mortality (aHR, 0.96; 95% CI, 0.81-1.14), or reoperation (aHR, 1.01; 95% CI, 0.72-1.41). This study on a nationwide comparison between bovine and porcine bioprostheses in MVR found no significant differences in clinical outcomes including mortality, and valve-related reoperation.

Abstract 9744: Declining Relative Use of Mitral Valve Repair in Australia Despite Superior Outcomes: A Statewide Population-linkage Study

Introduction: Mitral valve (MV) repair (MVr) has superior survival outcomes to MV replacement (MVR) for primary MV diseases. MVr cases has increased in other developed nations but is unknown in Australia. We assessed temporal trends in the total and relative MVr volume and compared MVr and MVR outcomes over 17 years. Method: Patients who had isolated MV surgery (MVSx) between 2001-2017 were identified from the New South Wales statewide Admitted Patient Data Collection registry. Mortality outcome was tracked to Dec 2018. Results: A total of 5693 patients (MVr: n=2020 [35%]; mechanical MVR: n=1656 [29%]; bioprosthetic MVR: n=2017 [35%]) were identified; median age [interquartile range] were 67y [59-75y] vs 64y [55-71y] vs 75y [68-80y], respectively (all P&lt;0.001). Median follow-up for the cohort was 6.3yrs. Annual MVSx cases increased over the study period but relative use of MVr declined from 44% (110/252 MVSx) in 2002 to 27% (165/601 MVSx) in 2017 (Fig1). Crude in-hospital and 1-yr mortality steadily declined for all groups between 2001 and 2017. MVr had the best outcome, with 1.2% in-hospital, 2.5% 1-yr, and 21.6% total cumulative mortality. Compared to MVr, after adjusting for age, sex, referral source, and comorbidities, the adjusted hazard ratios for long-term mortality were 1.41 (95% confidence interval [CI]=1.24-1.61) for mechanical MVR and 1.73 (95% CI=1.53-1.95) for bioprosthetic MVR (Fig 2). Conclusion: In this statewide Australian cohort study, relative use of MVr decreased over 17 years and are lower than reported by other international studies, despite having superior outcome compared to MVR. Factors driving the relatively low use of MVr should be explored.

Abstract 14522: Infective Mitral Valve Endocarditis in an Immunocompetent Patient Caused by Lactobacillus Species Transmitted by Intranasal Cocaine Use

A 59-year-old male with controlled DM2, HTN, tobacco abuse, and remote MSSA bacteremia secondary to longstanding intranasal cocaine use (never IV drug user) presented to the ER with acute onset of left leg pain. He was in extreme distress and examination showed a cold left leg with absent extremity pulses. Cardiac assessment was notable for an apical systolic murmur. Magnetic resonance angiography (MRA) of the leg revealed a thrombotic occlusion of the left common femoral artery extending into the popliteal artery prompting emergent successful femoral artery thrombectomy and compartment fasciotomy. An intraoperative TEE revealed mobile echodensities on the anterior and posterior MV leaflets with severe eccentric mitral regurgitation (MR) [Figure1]. Blood and thrombectomy debris cultures yielded Lactobacillus acidophilus vs. gasseri species. Further workup showed multiple small embolic infarcts on MRA head and chronic sinusitis on CT sinuses, while CT chest, abdomen and pelvis were unremarkable. He received IV ampicillin for 1 week with bacterial clearance, followed by bioprosthetic mitral valve replacement. Gram stain of the mitral valve revealed gram positive rods, cultures grew Lactobacillus species, and histopathology confirmed the presence of infective endocarditis. The patient completed 7 weeks of penicillin G intravenously with clinical recovery. Lactobacillus acidophilus and gasseri are normal flora of the human oral cavity, gastrointestinal and genitourinary tracts. Lactobacillus endocarditis is rare and has been identified in only 0.05-0.4% of endocarditis cases. Infections primarily affect the immunocompromised, but to the best of our knowledge this is the first case of Lactobacillus mitral valve endocarditis presenting with concomitant acute limb ischemia with infected thromboembolic debris in an immunocompetent individual with the suspected inciting event being intranasal cocaine use causing trauma to the nasal vasculature.

LONG-TERM OUTCOMES OF ISOLATED MECHANICAL VERSUS BIOPROSTHETIC MITRAL VALVE REPLACEMENT IN PROPENSITY MATCHED PATIENTS

Prosthesis choice in mitral valve replacement (MVR) is often associated with age. Because of long-term durability, young patients often receive mechanical prostheses, whereas older patients often receive bioprostheses. However, in patients aged 55-75 years, optimal valve choice has not been definitively clarified. Previous studies comparing mechanical and bioprosthetic MVR have included large proportions of combined operations, wherein risks and benefits are influenced by concomitant procedures.

Readmission After Bioprosthetic vs Mechanical Mitral Valve Replacement in the United States

BackgroundChoosing between a bioprosthetic and a mechanical mitral valve is an important decision for both patients and surgeons. We compared patient outcomes and readmission rates after bioprosthetic mitral valve replacement (Bio-MVR) vs mechanical mitral valve replacement (Mech-MVR). MethodsThe Nationwide Readmissions Database was queried to identify 31 474 patients who underwent isolated MVR (22 998 Bio-MVR, 8476 Mech-MVR) between January 1, 2016, and December 31, 2018. Propensity score matching by age, sex, elective status, and comorbidities was used to compare outcomes between matched cohorts by prosthesis type. Freedom from readmission within the first calendar year was estimated by Kaplan-Meier analysis and compared between matched cohorts. ResultsBio-MVR patients were older (median age, 69 vs 57 years; P < .001) and had more comorbidities (median Elixhauser score, 14 vs 11; P < .001) compared with Mech-MVR patients. After propensity score matching (n = 15 549), Bio-MVR patients had similar operative mortality (3.5% vs 3.4%; P = .97) and costs ($50 958 vs $49 782; P = .16) but shorter lengths of stay (8 vs 9 days; P < .001) and fewer 30-day (16.0% vs 18.1%; P = .04) and 90-day (23.8% vs 26.8%; P = .01) readmissions compared with Mech-MVR patients. The difference in readmissions persisted at 1 year (P = .045). Readmission for bleeding or coagulopathy complications was less common with Bio-MVR (5.7% vs 10.1%; P < .001). ConclusionsReadmission was more common after Mech-MVR than after Bio-MVR. Identifying and closely observing patients at high risk for bleeding complications may bridge the readmissions gap between Bio-MVR and Mech-MVR.

Mechanical or biologic prostheses for mitral valve replacement: A systematic review and meta-analysis.

Either a mechanical or bioprosthetic valve is used in patients undergoing mitral valve replacement (MVR). However, the optimal mitral prosthesis remains controversial. The aim of this meta‐analysis was thus to compare outcomes between mechanical mitral valve replacement (MVRm) and bioprosthetic mitral valve replacement (MVRb) for MVR patients. We searched Embase, PubMed, Web of Science, and Cochrane Library databases from January 1, 2000 to October 31, 2021 for studies that directly compared surgical outcomes of MVRm and MVRb. A total of 22 studies with 35 903 patients were included in the meta‐analysis (n = 23 868 MVRm and n = 12 035 MVRb). The MVRm group displayed lower long‐term all causes mortality (HR, 0.84; 95% confidence interval [CI]: 0.77−0.91; p < .0001; I² = 51%), and fewer mitral reoperation (hazard ratio [HR]: 0.34; 95% CI: 0.23−0.50; p < .00001; I² = 74%) than MVRb group. However, the MVRm group was associated with a greater risk of major bleeding events (HR: 1.21; 95% CI: 1.14−1.29; p < .00001; I² = 0%), stroke and systemic embolism (HR: 1.20; 95% CI: 1.10−1.32; p < .0001; I² = 0%) in matched or adjusted data. No significant difference was observed between MVRm and MVRb on operative mortality in matched/adjusted group (risk ratios: 0.83; 95% CI: 0.66−1.05; p = .12; I² = 0%). The results were consistent with patients aged under 70 years old. Patients who received a MVRm is associated with 16% lower risk of long‐term mortality and 66% lower risk of mitral reoperation, but 20% greater risk of stroke or systemic embolism, 21% greater risk of major bleeding compared with MVRb in matched/adjusted studies group, which were consistent to patients younger than the age of 70 years who underwent MVR.