Transcatheter or Surgical Replacement for Failed Bioprosthetic Aortic Valves.

Importance: The use of valve-in-valve (ViV) transcatheter aortic valve replacement (TAVR) has been rapidly expanding as an alternative treatment to redo surgical aortic valve replacement (SAVR) for failed bioprosthetic valves despite limited long-term data. Objective: To assess mortality and morbidity in patients undergoing intervention for failed bioprosthetic SAVR. Design, Setting, and Participants: This was a retrospective population-based cohort analysis conducted between January 1, 2015, and December 31, 2020, with a median (IQR) follow-up time of 2.3 (1.1-4.0) years. A total of 1771 patients with a history of bioprosthetic SAVR who underwent ViV-TAVR or redo SAVR in California, New York, and New Jersey were included. Data were obtained from the California Department of Health Care Access and Information, the New York Statewide Planning and Research Cooperative System, and the New Jersey Discharge Data Collection System. Exclusion criteria included undergoing TAVR or redo SAVR within 5 years from initial SAVR, as well as infective endocarditis, concomitant surgical procedures, and out-of-state residency. Propensity matching yielded 375 patient pairs. Data were analyzed from January to December 2023. Interventions: ViV-TAVR vs redo SAVR. Main Outcomes and Measurements: The primary outcome was all-cause mortality. Secondary outcomes were stroke, heart failure hospitalization, reoperation, major bleeding, acute kidney failure, new pacemaker insertion, and infective endocarditis. Results: From 2015 through 2020, the proportion of patients undergoing ViV-TAVR vs redo SAVR increased from 159 of 451 (35.3%) to 498 or 797 (62.5%). Of 1771 participants, 653 (36.9%) were female, and the mean (SD) age was 74.4 (11.3) years. Periprocedural mortality and stroke rates were similar between propensity-matched groups. The ViV-TAVR group had lower periprocedural rates of major bleeding (2.4% vs 5.1%; P = .05), acute kidney failure (1.3% vs 7.2%; P < .001), and new pacemaker implantations (3.5% vs 10.9%; P < .001). The 5-year all-cause mortality rate was 23.4% (95% CI, 15.7-34.1) in the ViV-TAVR group and 13.3% (95% CI, 9.2-18.9) in the redo SAVR group. In a landmark analysis, no difference in mortality was observed up to 2 years (hazard ratio, 1.03; 95% CI, 0.59-1.78), but after 2 years, ViV-TAVR was associated with higher mortality (hazard ratio, 2.97; 95% CI, 1.18-7.47) as well as with a higher incidence of heart failure hospitalization (hazard ratio, 3.81; 95% CI, 1.57-9.22). There were no differences in 5-year incidence of stroke, reoperation, major bleeding, or infective endocarditis. Conclusions and Relevance: Compared with redo SAVR, ViV-TAVR was associated with a lower incidence of periprocedural complications and a similar incidence of all-cause mortality through 2 years' follow-up. However, ViV-TAVR was associated with higher rates of late mortality and heart failure hospitalization. These findings may be influenced by residual confounding and require adjudication in a randomized clinical trial.

Permanent Pacemaker Implantation and Long-Term Outcomes of Patients Undergoing Concomitant Mitral and Tricuspid Valve Surgery.

BACKGROUND: Tricuspid valve annuloplasty (TA) during mitral valve repair (MVr) is associated with increased risk of permanent pacemaker (PPM) implantation, but the magnitude of risk and long-term clinical consequences have not been firmly established. OBJECTIVES: This study assesses the incidence rates of PPM implantation after isolated MVr and following MVr with TA as well as the associated long-term clinical consequences of PPM implantation. METHODS: State-mandated hospital discharge databases of New York and California were queried for patients undergoing MVr (isolated or with concomitant TA) between 2004 and 2019. Patients were stratified by whether or not they received a PPM within 90 days of index surgery. After weighting by propensity score, survival, heart failure hospitalizations (HFHs), endocarditis, stroke, and reoperation were compared between patients with or without PPM. RESULTS: A total of 32,736 patients underwent isolated MVr (n = 28,003) or MVr + TA (n = 4,733). Annual MVr + TA volumes increased throughout the study period (P < 0.001, trend), and PPM rates decreased (P < 0.001, trend). The incidence of PPM implantation <90 days after surgery was 7.7% for MVr and 14.0% for MVr + TA. In 90-day conditional landmark-weighted analyses, PPMs were associated with reduced long-term survival among MVr (HR: 1.96; 95% CI: 1.75-2.19; P < 0.001) and MVr + TA recipients (HR: 1.65; 95% CI: 1.28-2.14; P < 0.001). In both surgical groups, PPMs were also associated with an increased risk of HFH (HR: 1.56; 95% CI: 1.27-1.90; P < 0.001) and endocarditis (HR: 1.95; 95% CI: 1.52-2.51; P < 0.001), but not with stroke or reoperation. CONCLUSIONS: Compared to isolated MVr, adding TA to MVr was associated with a higher risk of 90-day PPM implantation. In both surgical groups, PPM implantation was associated with an increase in mortality, HFH, and endocarditis.

Percutaneous Coronary Intervention Versus Coronary Artery Bypass Grafting in Patients With Left Main Disease With and Without Diabetes: Findings From a Pooled Analysis of 4 Randomized Clinical Trials.

BACKGROUND: Diabetes may be associated with differential outcomes in patients undergoing left main coronary revascularization with percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG). The aim of this study was to investigate outcomes in patients with left main disease with and without diabetes randomized to PCI versus CABG. METHODS: Individual patient data were pooled from 4 trials (SYNTAX [Synergy Between PCI With Taxus and Cardiac Surgery], PRECOMBAT [Premier of Randomized Comparison of Bypass Surgery Versus Angioplasty Using Sirolimus-Eluting Stent in Patients With Left Main Coronary Artery Disease], NOBLE [Nordic-Baltic-British Left Main Revascularisation Study], and EXCEL [Evaluation of XIENCE Versus Coronary Artery Bypass Surgery for Effectiveness of Left Main Revascularization]) that randomized patients with left main disease to PCI or CABG. Patients were considered suitable for either approach. Patients were categorized by diabetes status. Kaplan-Meier event rates, Cox model hazard ratios, and interactions were assessed. RESULTS: Among 4393 patients, 1104 (25.1%) had diabetes. Patients with diabetes experienced higher rates of 5-year death (158/1104 [Kaplan-Meier rate, 14.7%] versus 297/3289 [9.3%]; P<0.001), spontaneous myocardial infarction (MI; 67/1104 [6.7%] versus 114/3289 [3.7%]; P<0.001), and repeat revascularization (189/1104 [18.5%] versus 410/3289 [13.2%]; P<0.001). Rates of all-cause mortality did not differ after PCI versus CABG in those with (84/563 [15.3%] versus 74/541 [14.1%]; hazard ratio, 1.11 [95% CI, 0.82-1.52]) or without (155/1634 [9.7%] versus 142/1655 [8.9%]; hazard ratio, 1.08 [95% CI, 0.86-1.36; PintHR=0.87) diabetes. Rates of stroke within 1 year were lower with PCI versus CABG in the entire population, with no heterogeneity based on diabetes status (PintHR=0.51). The 5-year rates of spontaneous MI and repeat coronary revascularization were higher after PCI regardless of diabetes status (spontaneous MI: 45/563 [8.9%] versus 22/541 [4.4%] in diabetes and 82/1634 [5.3%] versus 32/1655 [2.1%] in no diabetes, PintHR=0.47; repeat revascularization: 127/563 [24.5%] versus 62/541 [12.4%] in diabetes and 254/1634 [16.3%] versus 156/1655 [10.1%] in no diabetes, PintHR=0.18). For spontaneous MI and repeat revascularization, there were greater absolute risk differences beyond 1 year in patients with diabetes (4.9% and 9.9%) compared with those without (2.1% and 4.3%; PintARD=0.047 and 0.016). CONCLUSIONS: In patients with left main disease considered equally suitable for PCI or CABG and with largely low to intermediate SYNTAX scores, diabetes was associated with higher rates of death and cardiovascular events through 5 years. Compared with CABG, PCI resulted in no difference in the risk of death and a lower risk of early stroke regardless of diabetes status, and a higher risk of spontaneous MI and repeat coronary revascularization, with larger late absolute excess risks in patients with diabetes. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifiers: NCT01205776, NCT0146651, NCT00422968, and NCT00114972.

Prospective Study of Risk Factors for Postoperative Atrial Fibrillation After Cardiac Surgery.

INTRODUCTION: To examine risk factors for new-onset postoperative atrial fibrillation (POAF) after cardiac surgery. METHODS: Patients enrolled in the Cardiothoracic Surgical Trials Network multicenter, randomized trial of rate control versus rhythm control for POAF were included. Predictors of POAF were determined using multivariable logistic regression. RESULTS: Among the 2104 patients who were enrolled preoperatively, 695 developed POAF (33.0%). Rates of POAF were 28.1% after isolated coronary artery bypass grafting (CABG), 33.7% after isolated valve repair or replacement, and 47.3% after CABG plus valve repair or replacement. Baseline characteristics associated with an increased risk of POAF identified on multivariable analysis included older age (odds ratio [OR] 1.57; 95% confidence interval [CI] 1.42-1.73, per 10 y), White race or non-Hispanic ethnicity (OR 1.52; CI: 1.11-2.07), history of heart failure (OR 1.55; CI: 1.16-2.08), and history of hypothyroidism (OR 1.42; CI 1.04-1.94). The type of cardiac procedure was associated with an increased risk of POAF with both isolated valve repair or replacement (OR 1.33, CI 1.08-1.64) and combined CABG plus valve repair or replacement (OR 1.64, CI 1.24-2.17) having increased risk of POAF compared to isolated CABG. No preoperative cardiac medication was associated with POAF. CONCLUSIONS: In this prospective cohort of patients, older age, a history of hypothyroidism, a history of heart failure, and valve repair or replacement, with or without CABG, and White non-Hispanic race were associated with an increased risk of POAF.

Imaging Methods for Evaluation of Chronic Aortic Regurgitation in Adults: JACC State-of-the-Art Review.

A global multidisciplinary workshop was convened to discuss the multimodality diagnostic evaluation of aortic regurgitation (AR). Specifically, the focus was on assessment tools for AR severity and analyzing evolving data on the optimal timing of aortic valve intervention. The key concepts from this expert panel are summarized as: 1) echocardiography is the primary imaging modality for assessment of AR severity; however, when data is incongruent or incomplete, cardiac magnetic resonance may be helpful; 2) assessment of left ventricular size and function is crucial in determining the timing of intervention; 3) recent evidence suggests current cutpoints for intervention in asymptomatic severe AR patients requires further scrutiny; 4) left ventricular end-systolic volume index has emerged as an additional parameter that has promise in guiding timing of intervention; and 5) the role of additional factors (including global longitudinal strain, regurgitant fraction, and myocardial extracellular volume) is worthy of future investigation.

Heart failure medical therapy prior to mitral transcatheter edge-to-edge repair: the STS/ACC Transcatheter Valve Therapy Registry.

BACKGROUND AND AIMS: Guideline-directed medical therapy (GDMT) is recommended before mitral valve transcatheter edge-to-edge repair (MTEER) in patients with heart failure (HF) and severe functional mitral regurgitation (FMR). Whether MTEER is being performed on the background of optimal GDMT in clinical practice is unknown. METHODS: Patients with left ventricular ejection fraction (LVEF) < 50% who underwent MTEER for FMR from 23 July 2019 to 31 March 2022 in the Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapy Registry were identified. Pre-procedure GDMT utilization was assessed. Cox proportional hazards models were constructed to evaluate associations between pre-MTEER therapy (no/single, double, or triple therapy) and risk of 1-year mortality or HF hospitalization (HFH). RESULTS: Among 4199 patients across 449 sites, beta-blockers, angiotensin-converting enzyme inhibitors/angiotensin receptor blockers, mineralocorticoid receptor antagonists, and angiotensin receptor-neprilysin inhibitors were used in 85.1%, 44.4%, 28.6%, and 19.9% before MTEER, respectively. Triple therapy was prescribed for 19.2%, double therapy for 38.2%, single therapy for 36.0%, and 6.5% were on no GDMT. Significant centre-level variation in the proportion of patients on pre-intervention triple therapy was observed (0%-61%; adjusted median odds ratio 1.48 [95% confidence interval (CI) 1.25-3.88]; P < .001). In patients eligible for 1-year follow-up (n = 2014; 341 sites), the composite rate of 1-year mortality or HFH was lowest in patients prescribed triple therapy (23.0%) compared with double (24.8%), single (35.7%), and no (41.1%) therapy (P < .01 comparing across groups). Associations persisted after accounting for relevant clinical characteristics, with lower risk in patients prescribed triple therapy [adjusted hazard ratio (aHR) 0.73, 95% CI .55-.97] and double therapy (aHR 0.69, 95% CI .56-.86) before MTEER compared with no/single therapy. CONCLUSIONS: Under one-fifth of patients with LVEF <50% who underwent MTEER for FMR in this US nationwide registry were prescribed comprehensive GDMT, with substantial variation across sites. Compared with no/single therapy, triple and double therapy before MTEER were independently associated with reduced risk of mortality or HFH 1 year after intervention.

Twenty-five years of observations from the International Registry of Acute Aortic Dissection (IRAD) and its impact on the cardiovascular scientific community.

OBJECTIVE: The International Registry of Acute Aortic Dissection (IRAD) celebrated its 25th anniversary in January 2021. This study evaluated IRAD's role in promoting the understanding and management of acute aortic dissection (AD) over these years. METHODS: IRAD studies were identified, analyzed, and ranked according to their citations per year (c/y) to determine the most-cited IRAD studies and topics. A systematic search of the literature identified cardiovascular guidelines on the diagnosis and management of acute AD. Consequently, IRAD's presence and impact were quantified using these documents. RESULTS: Ninety-seven IRAD studies were identified, of which 82 obtained more than 10 cumulative citations. The median c/y index was 7.33 (25th-75th percentile, 4.01-16.65). Forty-two studies had a greater than median c/y index and were considered most impactful. Of these studies, most investigated both type A and type B AD (n = 17, 40.5%) and short-term outcomes (n = 26, 61.9%). Nineteen guideline documents were identified from 26 cardiovascular societies located in Northern America, Europe, and Japan. Sixty-nine IRAD studies were cited by these guidelines, including 38 of the 42 most-impactful IRAD studies. Among them, partial thrombosis of the false lumen as a predictor of postdischarge mortality and aortic diameters as a predictor of type A occurrence were determined as most-impactful specific IRAD topics by their c/y index. CONCLUSIONS: IRAD has had and continues to have an important role in providing observations, credible knowledge, and research questions to improve the outcomes of patients with acute AD.

2022 ACC/AHA guideline for the diagnosis and management of aortic disease: A report of the American Heart Association/American College of Cardiology Joint Committee on Clinical Practice Guidelines.

AIM: The "2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease" provides recommendations to guide clinicians in the diagnosis, genetic evaluation and family screening, medical therapy, endovascular and surgical treatment, and long-term surveillance of patients with aortic disease across its multiple clinical presentation subsets (ie, asymptomatic, stable symptomatic, and acute aortic syndromes). METHODS: A comprehensive literature search was conducted from January 2021 to April 2021, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, CINHL Complete, and other selected databases relevant to this guideline. Additional relevant studies, published through June 2022 during the guideline writing process, were also considered by the writing committee, where appropriate. STRUCTURE: Recommendations from previously published AHA/ACC guidelines on thoracic aortic disease, peripheral artery disease, and bicuspid aortic valve disease have been updated with new evidence to guide clinicians. In addition, new recommendations addressing comprehensive care for patients with aortic disease have been developed. There is added emphasis on the role of shared decision making, especially in the management of patients with aortic disease both before and during pregnancy. The is also an increased emphasis on the importance of institutional interventional volume and multidisciplinary aortic team expertise in the care of patients with aortic disease.

Percutaneous Coronary Intervention vs Coronary Artery Bypass Graft Surgery for Left Main Disease in Patients With and Without Acute Coronary Syndromes: A Pooled Analysis of 4 Randomized Clinical Trials.

Importance: Patients with left main coronary artery disease presenting with an acute coronary syndrome (ACS) represent a high-risk and understudied subgroup of patients with atherosclerosis. Objective: To assess clinical outcomes after PCI vs CABG in patients with left main disease with vs without ACS. Design, Setting, and Participants: Data were pooled from 4 trials comparing PCI with drug-eluting stents vs CABG in patients with left main disease who were considered equally suitable candidates for either strategy (SYNTAX, PRECOMBAT, NOBLE, and EXCEL). Patients were categorized as presenting with or without ACS. Kaplan-Meier event rates through 5 years and Cox model hazard ratios were generated, and interactions were tested. Patients were enrolled in the individual trials from 2004 through 2015. Individual patient data from the trials were pooled and reconciled from 2020 to 2021, and the analyses pertaining to the ACS subgroup were performed from March 2022 through February 2023. Main Outcomes and Measures: The primary outcome was death through 5 years. Secondary outcomes included cardiovascular death, spontaneous myocardial infarction (MI), procedural MI, stroke, and repeat revascularization. Results: Among 4394 patients (median [IQR] age, 66 [59-73] years; 3371 [76.7%] male and 1022 [23.3%] female) randomized to receive PCI or CABG, 1466 (33%) had ACS. Patients with ACS were more likely to have diabetes, prior MI, left ventricular ejection fraction less than 50%, and higher SYNTAX scores. At 30 days, patients with ACS had higher all-cause death (hazard ratio [HR], 3.40; 95% CI, 1.81-6.37; P < .001) and cardiovascular death (HR, 3.21; 95% CI, 1.69-6.08; P < .001) compared with those without ACS. Patients with ACS also had higher rates of spontaneous MI (HR, 1.70; 95% CI, 1.25-2.31; P < .001) through 5 years. The rates of all-cause mortality through 5 years with PCI vs CABG were 10.9% vs 11.5% (HR, 0.93; 95% CI, 0.68-1.27) in patients with ACS and 11.3% vs 9.6% (HR, 1.19; 95% CI, 0.95-1.50) in patients without ACS (P = .22 for interaction). The risk of early stroke was lower with PCI vs CABG (ACS: HR, 0.39; 95% CI, 0.12-1.25; no ACS: HR, 0.35; 95% CI, 0.16-0.75), whereas the 5-year risks of spontaneous MI and repeat revascularization were higher with PCI vs CABG (spontaneous MI: ACS: HR, 1.74; 95% CI, 1.09-2.77; no ACS: HR, 3.03; 95% CI, 1.94-4.72; repeat revascularization: ACS: HR, 1.57; 95% CI, 1.19-2.09; no ACS: HR, 1.90; 95% CI, 1.54-2.33), regardless of ACS status. Conclusion and Relevance: Among largely stable patients undergoing left main revascularization and with predominantly low to intermediate coronary anatomical complexity, those with ACS had higher rates of early death. Nonetheless, rates of all-cause mortality through 5 years were similar with PCI vs CABG in this high-risk subgroup. The relative advantages and disadvantages of PCI vs CABG in terms of early stroke and long-term spontaneous MI and repeat revascularization were consistent regardless of ACS status. Trial Registration: ClinicalTrials.gov Identifiers: NCT00114972, NCT00422968, NCT01496651, NCT01205776.

Transcatheter Mitral Valve Repair for Degenerative Mitral Regurgitation.

Importance: There are limited data on the outcomes of transcatheter edge-to-edge mitral valve repair for degenerative mitral regurgitation (MR) in a real-world setting. Objective: To evaluate the outcomes of transcatheter mitral valve repair for degenerative MR. Design, Setting, and Participants: Cohort study of consecutive patients in the Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapies Registry who underwent nonemergent transcatheter mitral valve repair for degenerative MR in the US from 2014 through 2022. Exposure: Transcatheter edge-to-edge mitral valve repair with the MitraClip device (Abbott). Main Outcomes and Measures: The primary end point was MR success, defined as moderate or less residual MR and a mean mitral gradient of less than 10 mm Hg. Clinical outcomes were evaluated based on the degree of residual MR (mild or less MR or moderate MR) and mitral valve gradients (≤5 mm Hg or >5 to <10 mm Hg). Results: A total of 19 088 patients with isolated moderate to severe or severe degenerative MR who underwent transcatheter mitral valve repair were analyzed (median age, 82 years; 48% women; median Society of Thoracic Surgeons predicted risk of mortality with surgical mitral valve repair, 4.6%). MR success was achieved in 88.9% of patients. At 30 days, the incidence of death was 2.7%; stroke, 1.2%; and mitral valve reintervention, 0.97%. MR success compared with an unsuccessful procedure was associated with significantly lower mortality (14.0% vs 26.7%; adjusted hazard ratio, 0.49; 95% CI, 0.42-0.56; P < .001) and heart failure readmission (8.4% vs 16.9%; adjusted hazard ratio, 0.47; 95% CI, 0.41-0.54; P < .001) at 1 year. Among patients with MR success, the lowest mortality was observed in patients who had both mild or less residual MR and mean mitral gradients of 5 mm Hg or less compared with those with an unsuccessful procedure (11.4% vs 26.7%; adjusted hazard ratio, 0.40; 95% CI, 0.34-0.47; P < .001). Conclusions and Relevance: In this registry-based study of patients with degenerative MR undergoing transcatheter mitral valve repair, the procedure was safe and resulted in successful repair in 88.9% of patients. The lowest mortality was observed in patients with mild or less residual MR and low mitral gradients.

Endocarditis, invasive dental procedures, and antibiotic prophylaxis efficacy in US Medicaid patients.

OBJECTIVE: Antibiotic prophylaxis is recommended before invasive dental procedures to prevent endocarditis in those at high risk, but supporting data are sparse. We therefore investigated any association between invasive dental procedures and endocarditis, and any antibiotic prophylaxis effect on endocarditis incidence. SUBJECTS AND METHODS: Cohort and case-crossover studies were performed on 1,678,190 Medicaid patients with linked medical, dental, and prescription data. RESULTS: The cohort study identified increased endocarditis incidence within 30 days of invasive dental procedures in those at high risk, particularly after extractions (OR 14.17, 95% CI 5.40-52.11, p < 0.0001) or oral surgery (OR 29.98, 95% CI 9.62-119.34, p < 0.0001). Furthermore, antibiotic prophylaxis significantly reduced endocarditis incidence following invasive dental procedures (OR 0.20, 95% CI 0.06-0.53, p < 0.0001). Case-crossover analysis confirmed the association between invasive dental procedures and endocarditis in those at high risk, particularly following extractions (OR 3.74, 95% CI 2.65-5.27, p < 0.005) and oral surgery (OR 10.66, 95% CI 5.18-21.92, p < 0.0001). The number of invasive procedures, extractions, or surgical procedures needing antibiotic prophylaxis to prevent one endocarditis case was 244, 143 and 71, respectively. CONCLUSIONS: Invasive dental procedures (particularly extractions and oral surgery) were significantly associated with endocarditis in high-risk individuals, but AP significantly reduced endocarditis incidence following these procedures, thereby supporting current guideline recommendations.

Oral hygiene and infective endocarditis: a case control study.

OBJECTIVE: To determine if oral hygiene is associated with infective endocarditis (IE) among those at moderate risk for IE. STUDY DESIGN: This is a case control study of oral hygiene among hospitalized patients with IE (cases) and outpatients with heart valve disease but without IE (controls). The primary outcome was the mean dental calculus index. Secondary outcomes included other measures of oral hygiene and periodontal disease (e.g., dental plaque, gingivitis) and categorization of blood culture bacterial species in case participants. RESULTS: The 62 case participants had 53% greater mean dental calculus index than the 119 control participants (0.84, 0.55, respectively; difference = 0.29, 95% CI: 0.11, 0.48; P = .002) and 26% greater mean dental plaque index (0.88, 0.70, respectively; difference = 0.18, 95% CI: 0.01.0.36; P = .043). Overall, cases reported fewer dentist and dental hygiene visits (P = .013) and fewer dental visits in the 12 weeks before enrollment than controls (P = .007). Common oral bacteria were identified from blood cultures in 27 of 62 cases (44%). CONCLUSIONS: These data provide evidence to support and strengthen current American Heart Association guidance that those at risk for IE can reduce potential sources of IE-related bacteremia by maintaining optimal oral health through regular professional dental care and oral hygiene procedures.

Risk of Surgical Mitral Valve Repair for Primary Mitral Regurgitation.

BACKGROUND: Risk estimation for surgical intervention is an essential component of heart team shared decision-making. However, current mitral valve (MV) surgery risk models used in practice lack etiologic or procedural specificity. OBJECTIVES: The purpose of this study was to establish a comprehensive method for assessment of operative risk of MV repair of primary mitral regurgitation (MR). METHODS: A novel etiology and procedure-specific algorithm identified 53,462 consecutive (July 2014 to June 2020) intention-to-treat MV repair patients with primary MR from The Society of Thoracic Surgeons Adult Cardiac Surgery Database. Risk models were fit for 30-day operative mortality, mortality and/or major morbidity, and conversion-to-replacement (CONV). As-treated mortality and morbidity models were derived separately. RESULTS: Event rates for mortality (n = 619; 1.16%), mortality plus morbidity (n = 4,746; 8.88%), and CONV (n = 3,399; 6.36%) were low. Mortality was higher in CONV patients vs repair (3.18% vs 1.02%). All event rates were lower with increasing program volumes. The mortality risk model had excellent discrimination (AUC: 0.807) and calibration and confirmed very low mortality risk for isolated MV repair for primary MR, with mean mortality risk of 1.16% and median of 0.55% (IQR: 0.30%-1.17%) with 90th and 95th percentiles 2.48% and 3.99%, respectively. The mortality risk was <0.5% in patients <65 years of age, with 97% of the total population across age groups having a risk of <3%. Only 1 in 4 patients age 75 or older had >3% estimated risk of mortality. CONCLUSIONS: This etiologic and procedure-specific risk model establishes that the contemporary mortality risk of MV repair for primary MR is <1% for the vast majority of patients.