2-Year Clinical and Echocardiography Follow-Up of Transcatheter Mitral Valve Replacement With the Transapical Intrepid System.

BACKGROUND: Thirty-day outcomes with the investigational Intrepid transapical (TA) transcatheter mitral valve replacement (TMVR) system have previously demonstrated good technical success, but longer-term outcomes in larger cohorts need to be evaluated. OBJECTIVES: The authors sought to evaluate the 2-year safety and performance of the Intrepid TA-TMVR system in patients with symptomatic, ≥moderate-severe mitral regurgitation (MR) and high surgical risk. METHODS: Patient eligibility was determined by local heart teams and approved by a central screening committee. Clinical events were adjudicated by an independent clinical events committee. Echocardiography was evaluated by an independent core laboratory. RESULTS: The cohort included 252 patients that were enrolled at 58 international sites before February 2021 as part of the global Pilot Study (n = 95) or APOLLO trial (primary cohort noneligible + TA roll-ins, n = 157). Mean age was 74.2 years, mean STS-PROM was 6.3%, 60.3% were male, and 80.6% were in NYHA functional class III/IV. Most presented with secondary MR (70.1%), and nearly all had ≥moderate-severe MR (98.4%). All-cause mortality was 13.1% (30-day), 27.3% (1-year), and 36.2% (2-year). The 30-day ≥major bleeding event rate was 22.3%. Heart failure rehospitalization was 9.6% (30-day) and 36.2% (2-year). At 2 years, >50% of patients were alive with improvement in NYHA functional class (82.1%, class I/II), and all patients with available echocardiograms had ≤mild MR. CONCLUSIONS: This analysis represents the largest reported TA-TMVR experience with the longest follow-up in high-risk ≥moderate-severe MR patients. Early mortality and heart failure rehospitalizations were significant, exacerbated by early TA-related bleeding events; however, meaningful improvements in clinical outcomes and marked reductions in MR severity were observed through 2 years.

Pulmonary Vein Flow Morphology After Transcatheter Mitral Valve Edge-to-Edge Repair as Predictor of Survival.

BACKGROUND: Data on the prognostic factors after mitral valve (MV) transcatheter edge-to-edge repair (TEER; MV-TEER) are limited. Pulsed-wave Doppler interrogation of pulmonary vein flow (PVF) is a convenient method to assess the hemodynamic burden of residual mitral regurgitation (MR), which could be of utility as a predictor of outcomes. METHODS: Patients that underwent MV-TEER between May 2014 and December 2021 at our institution were evaluated. Pulmonary vein flow patterns post-MV-TEER were reviewed on the procedural transesophageal echocardiogram and classified as normal (systolic dominant or codominant) or abnormal (systolic blunting or reversal). The PVF pattern was correlated with all-cause mortality at follow-up. RESULTS: Two-hundred sixty-five patients had diagnostic PVF post-MV-TEER, with 73 (27.5%) categorized as normal and 192 (72.5%) categorized as abnormal. Patients with abnormal PVF morphology were more likely to have atrial fibrillation (70% vs 42%, P < .001) and greater than moderate residual MR (16% vs 3%, P = .01) and had higher mean left atrial pressure (18.1 ± 5.0 vs 15.9 ± 4.2 mm Hg, P = .002) and left atrial V wave (26.6 ± 8.5 vs 21.4 ± 7.3 mm Hg, P < .001) postprocedure. In multivariable analysis, abnormal PVF morphology post-MV-TEER was independently associated with mortality at follow-up (hazard ratio = 1.70; 95% CI, 1.06-2.74; P = .03) after correction for end-stage renal disease, atrial fibrillation, and residual MR. Results were similar in subgroups of patients with moderate or less and those with mild or less residual MR. CONCLUSIONS: Pulmonary vein flow morphology is a simple and objective tool to assess MR severity immediately post-MV-TEER and offers important prognostic information to optimize procedural results. Additional studies are needed to determine whether patients with abnormal PVF pattern post-MV-TEER would benefit from more intensive goal-directed medical therapy postprocedure.

Incidence of Severe Adverse Drug Reactions to Ultrasound Enhancement Agents in a Contemporary Echocardiography Practice.

OBJECTIVES: Prior data indicate a very rare risk of serious adverse drug reaction (ADR) to ultrasound enhancement agents (UEAs). We sought to evaluate the frequency of ADR to UEA administration in contemporary practice. METHODS: We retrospectively reviewed 4 US health systems to characterize the frequency and severity of ADR to UEA. Adverse drug reactions were considered severe when cardiopulmonary involvement was present and critical when there was loss of consciousness, loss of pulse, or ST-segment elevation. Rates of isolated back pain and headache were derived from the Mayo Clinic Rochester stress echocardiography database where systematic prospective reporting of ADR was performed. RESULTS: Among 26,539 Definity and 11,579 Lumason administrations in the Mayo Clinic Rochester stress echocardiography database, isolated back pain or headache was more frequent with Definity (0.49% vs 0.04%, P < .0001) but less common with Definity infusion versus bolus (0.08% vs 0.53%, P = .007). Among all sites there were 201,834 Definity and 84,943 Lumason administrations. Severe and critical ADR were more frequent with Lumason than with Definity (0.0848% vs 0.0114% and 0.0330% vs 0.0010%, respectively; P < .001 for each). Among the 3 health systems with >2,000 Lumason administrations, the frequency of severe ADR with Lumason ranged from 0.0755% to 0.1093% and the frequency of critical ADR ranged from 0.0293% to 0.0525%. Severe ADR rates with Definity were stable over time but increased in more recent years with Lumason (P = .02). Patients with an ADR to Lumason since the beginning of 2021 were more likely to have received a COVID-19 vaccination compared with matched controls (88% vs 75%; P = .05) and more likely to have received Moderna than Pfizer-Biotech (71% vs 26%, P < .001). CONCLUSION: Severe and critical ADR, while rare, were more frequent with Lumason, and the frequency has increased in more recent years. Additional work is needed to better understand factors, including associations with recently developed mRNA vaccines, which may be contributing to the increased rates of ADR to UEA since 2021.

Prognostic Significance of Elevated Left Ventricular Filling Pressures with Exercise: Insights from a Cohort of 14,338 Patients.

BACKGROUND: Exercise echocardiography can assess for cardiovascular causes of dyspnea other than coronary artery disease. However, the prevalence and prognostic significance of elevated left ventricular (LV) filling pressures with exercise is understudied. METHODS: We evaluated 14,338 patients referred for maximal symptom-limited treadmill echocardiography. In addition to assessment of LV regional wall motion abnormalities (RWMAs), we measured patients' early diastolic mitral inflow (E), septal mitral annulus relaxation (e'), and peak tricuspid regurgitation velocity before and immediately after exercise. RESULTS: Over a mean follow-up of 3.3 ± 3.4 years, patients with E/e' ≥15 with exercise (n = 1,323; 9.2%) had lower exercise capacity (7.3 ± 2.1 vs 9.1 ± 2.4 metabolic equivalents, P < .0001) and were more likely to have resting or inducible RWMAs (38% vs 18%, P < .0001). Approximately 6% (n = 837) had elevated LV filling pressures without RWMAs. Patients with a poststress E/e' ≥15 had a 2.71-fold increased mortality rate (2.28-3.21, P < .0001) compared with those with poststress E/e' ≤ 8. Those with an E/e' of 9 to 14, while at lower risk than the E/e' ≥15 cohort (hazard ratio [HR] = 0.58 [0.48-0.69]; P < .0001), had higher risk than if E/e' ≤8 (HR = 1.56 [1.37-1.78], P < .0001). On multivariable analysis, adjusting for age, sex, exercise capacity, LV ejection fraction, and presence of pulmonary hypertension with stress, patients with E/e' ≥15 had a 1.39-fold (95% CI, 1.18-1.65, P < .0001) increased risk of all-cause mortality compared with patients without elevated LV filling pressures. Compared with patients with E/e' ≤ 15 after exercise, patients with E/e' ≤15 at rest but elevated after exercise had a higher risk of cardiovascular death (HR = 8.99 [4.7-17.3], P < .0001). CONCLUSION: Patients with elevated LV filling pressures are at increased risk of death, irrespective of myocardial ischemia or LV systolic dysfunction. These findings support the routine incorporation of LV filling pressure assessment, both before and immediately following stress, into the evaluation of patients referred for exercise echocardiography.

1-Year Outcomes Following Transfemoral Transseptal Transcatheter Mitral Valve Replacement: Intrepid TMVR Early Feasibility Study Results.

BACKGROUND: High surgical risk may preclude mitral valve replacement in many patients. Transcatheter mitral valve replacement (TMVR) using transfemoral transseptal access is a novel technology for the treatment of mitral regurgitation (MR) in high-risk surgical patients. OBJECTIVES: This analysis evaluates 30-day and 1-year outcomes of the Intrepid TMVR Early Feasibility Study in patients with ≥moderate-severe MR. METHODS: The Intrepid TMVR Early Feasibility Study is a multicenter, prospective, single-arm study. Clinical events were adjudicated by a clinical events committee; endpoints were defined according to Mitral Valve Academic Research Consortium criteria. RESULTS: A total of 33 patients, enrolled at 9 U.S. sites between February 2020 and August 2022, were included. The median age was 80 years, 63.6% of patients were men, and mean Society of Thoracic Surgeons Predicted Risk of Mortality for mitral valve replacement was 5.3%. Thirty-one (93.9%) patients were successfully implanted. Median postprocedural hospitalization length of stay was 5 days, and 87.9% of patients were discharged to home. At 30 days, there were no deaths or strokes, 8 (24.2%) patients had major vascular complications and none required surgical intervention, there were 4 cases of venous thromboembolism all successfully treated without sequelae, and 1 patient had mitral valve reintervention for severe left ventricular outflow tract obstruction. At 1 year, the Kaplan-Meier all-cause mortality rate was 6.7%, echocardiography showed ≤mild valvular MR, there was no/trace paravalvular leak in all patients, median mitral valve mean gradient was 4.6 mm Hg (Q1-Q3: 3.9-5.3 mm Hg), and 91.7% of survivors were in NYHA functional class I/II with a median 11.4-point improvement in Kansas City Cardiomyopathy Questionnaire overall summary scores. CONCLUSIONS: The early benefits of the Intrepid transfemoral transseptal TMVR system were maintained up to 1 year with low mortality, low reintervention, and near complete elimination of MR, demonstrating a favorable safety profile and durable valve function.

Impact of atrial fibrillation on outcomes in asymptomatic severe aortic stenosis: a propensity-matched analysis.

Background: Atrial fibrillation (AF) portends poor prognosis in patients with aortic stenosis (AS). Objectives: This study aimed to study the association of AF vs. sinus rhythm (SR) with outcomes in asymptomatic severe AS during routine clinical practice. Methods: We identified 909 asymptomatic patients from 3,208 consecutive patients with aortic valve area ≤1.0 cm2 and left ventricular ejection fraction ≥50% at a tertiary academic center. Patients were grouped by rhythm at the time of transthoracic echocardiogram [SR: 820/909 (90%) and AF: 89/909 (10%)]. Propensity-matched analyses (2 SR:1 AF) matching 174 SR to 89 AF patients by age, sex, and clinical comorbidities were used to compare outcomes. Results: In the propensity-matched cohort, median age (82 ± 8 vs. 81 ± 9 years, p = 0.31), sex distribution (male 58% vs. 52%, p = 0.30), and Charlson comorbidity index (4.0 vs. 3.0, p = 0.26) were not different in AF vs. SR. Median follow-up duration was 2.6 (IQR: 1.0-4.4) years. The 1-year rate of aortic valve replacement (AVR) was not different (AF: 32% vs. SR: 37%, p = 0.31). All-cause mortality was higher in AF [hazard ratio (HR): 1.68 (1.13-2.50), p = 0.009]. Independent predictors of mortality were age [HR: 1.92 (1.40-2.62), p < 0.001], Charlson comorbidity index [1.09 (1.03-1.15), p = 0.002], aortic valve peak velocity [HR: 1.87 (1.20-2.94), p = 0.006], stroke volume index [HR: 0.75 (0.60-0.93), p = 0.01], moderate or more mitral regurgitation [HR: 2.97 (1.43-6.19), p = 0.004], right ventricular systolic dysfunction [HR: 2.39 (1.29-4.43), p = 0.006], and time-dependent AVR [HR: 0.36 (0.19-0.65), p = 0.0008]. There was no significant interaction of AVR and rhythm (p = 0.57). Conclusions: Lower forward flow, right ventricular systolic dysfunction, and mitral regurgitation identified increased risk of subsequent mortality in asymptomatic patients with AF and AS. Additional studies of risk stratification of asymptomatic AS in AF vs. SR are needed.

Cerebral and Retinal Infarction in Bicuspid Aortic Valve.

Background Description of cerebral and retinal infarction in patients with bicuspid aortic valve (BAV) is limited to case reports. We aimed to characterize cerebral and retinal infarction and examine outcomes in patients with BAV. Methods and Results Consecutive patients from 1975 to 2015 with BAV (n=5401) were retrospectively identified from the institutional database; those with confirmed cerebral or retinal infarction were analyzed. Infarction occurring after aortic valve replacement was not included. Patients were grouped according to infarction pathogenesis: embolism from a degenerative calcific BAV (BAVi); non-BAV, large artery atherosclerotic or lacunar infarction (LAi); and non-BAV, non-large artery embolic infarction (nLAi). There were 83/5401 (1.5%) patients, mean age 54±12 years and 28% female, with confirmed cerebral or retinal infarction (LAi 23/83 [28%]; nLAi 30/83 [36%]; BAVi 26/83 [31%]; other 4/83 [5%]). Infarction was embolic in 72/83 (87%), and 35/72 (49%) were cardioembolic. CHA2DS2-VASc score was 1.4±1.2 in BAVi (P=0.188 versus nLAi) and 2.3±1.2 in LAi (P=0.005). Recurrent infarction occurred in 41% overall (50% BAVi, P=0.164 and 0.803 versus LAi and nLAi). BAVi was more commonly retinal (39% BAVi versus 13% LAi, P=0.044 versus 0% nLAi, P=0.002). Patients with BAVi and LAi were more likely to have moderate-to-severe aortic stenosis and undergo aortic valve replacement compared with patients with nLAi. Conclusions Cardioembolism, often from degenerative calcification of the aortic valve, is a predominant cause of cerebral and retinal infarction in patients with BAV and is frequently recurrent. Cerebral and retinal infarction should be regarded as a complication of BAV.

Right ventricular systolic strain in patients with pulmonary hypertension: clinical feasibility, reproducibility, and correlation with ejection fraction.

BACKGROUND: Right ventricular (RV) systolic function is the major determinant of prognosis in patients with pulmonary hypertension (PH) with quantitative assessment by speckle-tracking strain echocardiography emerging as a viable candidate measure. METHOD: We evaluated a prospective cohort of 231 patients with known or suspected PH referred for clinical echocardiography. All underwent measurement of RV free-wall systolic strain by sonographer staff. Digital images were recorded for blinded offline assessment by an expert echocardiographer. Reproducibility was assessed using the analysis methods of Bland-Altman and the Cohen's-Kappa coefficient. RESULTS: RV strain was feasible in 213 (92%). The average RV systolic pressure was 59 ± 22 mmHg. RV systolic strain correlated with functional class, NT-proBNP, and the degree of RV enlargement. The average free-wall systolic strain was - 20 ± 7% (range - 2 to - 37%). The RV strain measures (clinical practice versus blinded expert) had an excellent correlation with a normal distribution (R2 0.87, p < 0.0001). By Bland-Altman analysis, the mean difference in measurement was - 1.7% (95% CI - 1.4 to - 2.1) with a correlation of 0.93, p value of < 0.0001. The reproducibility of RV strain for clinically relevant thresholds was also excellent (Kappa coefficients 0.68-0.83). There was no effect on the variability of strain measures across body mass, pulmonary pressures, or rhythm. RV strain correlated with RV diastolic volumes and ejection fraction with RV free wall strain being the best echo predictor for a reduction in ejection fraction. CONCLUSION: Here RV systolic strain was found to be highly feasible and reproducible in clinical practice with excellent levels of agreement for clinically relevant thresholds.

Impact of Atrial Fibrillation on Outcomes in Very Severe Aortic Valve Stenosis.

The prevalence and impact of atrial fibrillation (AF) versus sinus rhythm (SR) on outcomes in very severe aortic stenosis (vsAS) of the native valve is unknown. The aim of the study was to determine the prognostic significance of AF in vsAS. A total of 563 patients with vsAS (transaortic valve peak velocity ≥5 m/s) and left ventricular ejection fraction ≥50% were identified retrospectively. Patients were divided by rhythm at the time of index transthoracic echocardiogram (AF: n = 50 [9%] vs SR: n = 513 [91%]). Patients with AF were older (83.1 ± 7.5 vs 72.5 ± 12.2 y, p <0.001) and had no difference in gender distribution (p = 0.49) but had a higher Charlson co-morbidity index (2 [1,3] vs 1 [0,2], p = 0.01). There was no difference in transaortic peak velocity (5.3 ± 0.3 m/s vs 5.4 ± 0.4 m/s, p = 0.13) and left ventricular ejection fraction was comparable (63 ± 7 vs 66 ± 7%, p = 0.01). Age-, gender-, Charlson co-morbidity index-, and time-dependent aortic valve replacement (AVR)-adjusted overall mortality at 5 years was significantly higher in patients with AF than patients with SR (hazard ratio [HR] 1.88 [1.23 to 2.85], p = 0.003). AVR was associated with improved survival (HR = 0.30 [0.22 to 0.42], p <0.001), with no statistically significant interaction of AVR and rhythm (p = 0.36). Outcomes were also compared in the 2 SR:1 AF propensity-matched analyses (100 SR: 50 AF), with matching done according to age, gender, clinical co-morbidities, and year of echocardiogram. In the propensity-matched analysis, age-, gender-, and time-dependent AVR-adjusted all-cause mortality was higher in AF (HR 2.32 [1.41 to 3.82], p <0.001). In conclusion, AF was not uncommon in vsAS and identified a subset of patients at a much higher risk of mortality without AVR.

Underestimation of Aortic Stenosis Severity by Doppler Mean Gradient during Atrial Fibrillation: Insights from Aortic Valve Weight.

BACKGROUND: Doppler mean gradient (MG) can underestimate aortic stenosis (AS) severity when obtained during atrial fibrillation (AF) compared with sinus rhythm (SR). Aortic valve weight (AVW) is a flow-independent measure of AS severity. The objective of this study was to determine whether AVW or AVW/MG ratio was increased in AF versus SR in patients with AS. METHODS: Excised native aortic valves from 495 consecutive patients (median age, 77 years; interquartile range [IQR], 71-82 years; 40% women), with left ventricular ejection fractions ≥50% who underwent surgical aortic valve replacement for native valve severe AS (aortic valve area ≤ 1 cm2 or indexed aortic valve area ≤ 0.6 cm2/m2) were weighed. Excised AVW/MG ratios were compared in AF versus SR in patients with high-gradient AS (aortic peak velocity ≥ 4 m/sec or MG ≥ 40 mm Hg) and low-gradient AS (aortic peak velocity < 4 m/sec and MG < 40 mm Hg) in sex-specific analyses. RESULTS: AF was present in 51 patients (10%; 11 of 51 [22%] had low-gradient AS) and SR in 444 (90%; 23 of 444 [5%] had low-gradient AS). There was no difference in sex distribution between AF and SR. Aortic valve area was not different, but forward stroke volume index and transaortic valve flow rate were lower in AF (P ≤ .002 for all); MG was lower in AF versus SR (median, 46 mm Hg [IQR, 37-50 mm Hg] vs 50 mm Hg [IQR, 44-61 mm Hg]; P < .0001). Overall AVW was not different (median, 2,290 mg [IQR, 1,830-3,063 mg] vs 2,140 mg [IQR, 1,530-2,958 mg]; P = .31), but overall AVW/MG ratio was higher in AF (median, 55 [IQR, 41-67] vs 42 [IQR, 30-55]; P = .001). In sex- and MG-specific analyses, the AVW/MG ratio was higher in AF compared with SR in men with high-gradient AS (median, 58 [IQR, 41-75] vs 51 [IQR, 39-61]; P = .03), but the differences were not statistically significant between AF and SR in other groups. CONCLUSIONS: AVW was discordant to Doppler MG in AF compared with SR in men with high-gradient AS. Additional studies of the relationship of MG to other measures of AS severity, such as leaflet fibrosis, are needed.

Characterization of myocardial mechanics and its prognostic significance in patients with severe aortic stenosis undergoing aortic valve replacement.

Aims: Aortic stenosis (AS) induces characteristic changes in left ventricular (LV) mechanics that can be reversed after aortic valve replacement (AVR). We aimed to comprehensively characterize LV mechanics before and after AVR in patients with severe AS and identify predictors of short-term functional recovery and long-term survival. Methods and results: We prospectively performed comprehensive strain analysis by 2D speckle-tracking echocardiography in 88 patients with severe AS and LV ejection fraction ≥50% (mean age 71 ± 12 years, 42% female) prior to and within 7 days after AVR. Patients were followed for up to 5.2 years until death from any cause or last encounter. Within days after AVR, we observed an absolute increase in global longitudinal strain (GLS) (-16.0 ± 2.0% vs. -18.5 ± 2.1%, P<0.0001) and a decrease in apical rotation (10.5 ± 4.0° vs. 8.3 ± 2.8°, P = 0.0002) and peak systolic twist (18.2 ± 5.0° vs. 15.5 ± 3.8°, P = 0.0008). A baseline GLS is less negative than -16.2% was 90% sensitive and 67% specific in predicting a ≥ 20% relative increase in GLS. During a median follow-up of 3.8 years, a global circumferential systolic strain rate (GCSRs) less negative than -1.9% independently predicted lower survival. Conclusion: In patients with severe AS, a reversal in GLS, apical rotation, and peak systolic twist abnormalities towards normal occurs within days of AVR. Baseline GLS is the strongest predictor of GLS recovery but neither was associated with long-term survival. In contrast, abnormal baseline GCSRs are associated with worse outcomes.

Impact of Managing Provider Type on Severe Aortic Stenosis Management and Mortality.

Background Many patients with symptomatic severe aortic stenosis do not undergo aortic valve replacement (AVR) despite clinical guidelines. This study analyzed the association of managing provider type with cardiac specialist follow-up, AVR, and mortality for patients with newly diagnosed severe aortic stenosis (sAS). Methods and Results We identified adults with newly diagnosed sAS per echocardiography performed between January 2017 and March 2019 using Optum electronic health record data. We then selected from those meeting all eligibility criteria patients managed by a primary care provider (n=1707 [25%]) or cardiac specialist (n=5039 [75%]). We evaluated the association of managing provider type with cardiac specialist follow-up, AVR, and mortality, as well as the independent association of cardiac specialist follow-up and AVR with mortality, within 1 year of echocardiography detecting sAS. A subgroup analysis was limited to patients with symptomatic sAS. Patient characteristics and comorbidities at baseline were used for covariate-adjusted cause-specific and multivariable Cox proportional hazard models assessing group differences in outcomes by managing provider type. An adjusted Cox proportional hazard model with additional time-dependent covariates for follow-up and AVR was used to assess these practices' association with mortality. Within 1 year of echocardiography detecting sAS, data revealed that primary care provider management was associated with lower rates of cardiac specialist follow-up (hazard ratio [HR], 0.47 [95% CI, 0.43-0.50], P<0.0001) and AVR (HR, 0.58 [95% CI, 0.53-0.64], P<0.0001) and with higher 1-year mortality (HR, 1.45 [95% CI, 1.26-1.66], P<0.0001). Cardiac specialist follow-up and AVR were independently associated with lower mortality (follow-up: HR, 0.55 [95% CI, 0.48-0.63], P<0.0001; AVR: HR, 0.70 [95% CI, 0.60-0.83], P<0.0001). Results were similar for patients with symptomatic sAS. All analyses were adjusted for baseline patient characteristics and comorbidities. Conclusions For patients newly diagnosed with sAS, we observed differences in rates of cardiac specialist follow-up and AVR and risk of mortality between primary care provider- versus cardiologist-managed patients with sAS. In addition, a lower likelihood of receiving follow-up and AVR was independently associated with higher mortality.

Atrial mitral regurgitation: Characteristics and outcomes of transcatheter mitral valve edge-to-edge repair.

BACKGROUND: Mitral transcatheter edge-to-edge repair (MTEER) is an established therapeutic approach for mitral regurgitation (MR). Functional mitral regurgitation originating from atrial myopathy (A-FMR) has been described. OBJECTIVES: We sought to assess the clinical, echocardiographic and hemodynamic considerations in A-FMR patients undergoing MTEER. METHODS: From 2014 to 2020, patients undergoing MTEER for degenerative MR (DMR), functional MR (FMR), and mixed MR were assessed. A-FMR was defined by the presence of MR > moderate in severity; left ventricular (LV) ejection fraction (LVEF) ≥ 50%; and severe left atrial (LA) enlargement in the absence of LV dysfunction, leaflet pathology, or LV tethering. The diagnosis of A-FMR (vs. ventricular-FMR [V-FMR]) was confirmed by three independent echocardiographers. Baseline characteristics, procedural outcomes as well as clinical and echocardiographic follow-up are reported. Device success was defined as final MR grade ≤ moderate; MR reduction ≥1 grade; and final transmitral gradient <5 mmHg. RESULTS: 306 patients underwent MTEER, including DMR (62%), FMR (19%), and mixed MR (19%). FMR cases included 37 (63.8%) V-FMR and 21 (36.2%) A-FMR. Tricuspid regurgitation (≥ moderate) was higher in A-FMR (80.1%) compared to V-FMR (54%) and DMR (42%). Device success did not significantly differ between A-FMR and V-FMR (57% vs. 73%, p = 0.34) or DMR (57% vs. 64%, p = 1.0). The A-FMR cohort was less likely to achieve ≥3 grades of MR reduction compared to V-FMR (19% vs. 54%, p = 0.01) and DMR (19% vs. 49.7%, p = 0.01). Patients with V-FMR and DMR demonstrated significant reductions in mean left atrial pressure (LAP) and peak LA V-wave, though A-FMR did not (LAP -0.24 ± 4.9, p = 0.83; peak V-wave -1.76 ± 9.1, p = 0.39). In follow-up, echocardiographic and clinical outcomes were similar. CONCLUSIONS: In patients undergoing MTEER, A-FMR represents one-third of FMR cases. A-FMR demonstrates similar procedural success but blunted acute hemodynamic responses compared with DMR and V-FMR following MTEER. Dedicated studies specifically considering A-FMR are needed to discern the optimal therapeutic approaches.