Asymptomatic Primary Mitral Regurgitation Research Articles

New atrio-ventricular indices derived from conventional cine MRI correlate with functional capacity in patients with asymptomatic primary mitral regurgitation

Mitral regurgitation (MR) is associated with morphological and functional alterations of left atrium (LA) and ventricle (LV), possibly inducing LA–LV misalignment. We aimed to: (1) characterize angulation between LA and mitral annulus from conventional cine MRI data and feature-tracking (FT) contours, (2) assess their associations with functional capacity in MR patients, as assessed by oxygen consumption (peak-VO2) and minute ventilation to carbon dioxide production (VE/VCO2) slope, in comparison with MRI LA/LV strain indices. Thirty-two asymptomatic primary MR patients (56 [40; 66] years, 12 women) underwent cardiac MRI resulting in LA/LV conventional FT-derived strain indices. Then, end-diastolic angles were derived from FT LA contours: (1) α, centered on the LA centre of mass and defined by mitral valve extremities, (2) γ, centered on the mitral ring anterior/lateral side, and defined by LA centre and the other extremity of the mitral ring. Cardiopulmonary exercise testing with simultaneous echocardiography were also performed; peak-VO2 and VE/VCO2 slope were measured. While peak-VO2 and VE/VCO2 slope were not correlated to LA/LV strains, they were significantly associated with angles (α: r = 0.50, p = 0.003 and r = − 0.52, p = 0.003; γ: r = − 0.53, p = 0.002 and r = 0.52, p = 0.003; respectively), independently of age and gender (R2 ≥ 0.29, p ≤ 0.03). In primary MR, the new LA/mitral annulus angles, computed directly from standard-of-care MRI, are better correlated to exercise tolerance than conventional LA/LV strain.

Timing of Surgery for Asymptomatic Primary Mitral Regurgitation: Possible Value of Early, Serial Measurements of Left Ventricular Sphericity.

Asymptomatic primary mitral regurgitation due to myxomatous degeneration of the mitral valve leaflets may remain so for long periods, even as left ventricular function progresses to a decompensated stage. During the early compensated stage, the ventricle's initial response to the volume overload is an asymmetric increase in the diastolic short axis dimension, accomplished by a diastolic shift of the interventricular septum into the right ventricular cavity, creating a more spherical left ventricular diastolic shape, increasing diastolic filling and stroke volume. Early valve repair is recommended to reduce postoperative left ventricular dysfunction. Early serial measurements of left ventricular sphericity index [LV-Si]. during the compensated stage of mitral regurgitation might identify subtle changes in left ventricular shape and assist in determining the optimal earliest timing for surgical intervention.

Kiosk 6R-TA-03 - CMR Left Atrial Flow Indices and Mitral Annulus Angulation in Patients with Asymptomatic Primary Mitral Regurgitation

Kiosk 6R-TA-03 - CMR Left Atrial Flow Indices and Mitral Annulus Angulation in Patients with Asymptomatic Primary Mitral Regurgitation

Left atrial size predicts outcome in severe but asymptomatic mitral regurgitation

Patients with severe asymptomatic primary mitral regurgitation (MR) can be safely managed with an active surveillance strategy. Left atrial (LA) size is affected by MR severity, left ventricular function and is also associated with the risk of atrial fibrillation and may be an integrative parameter for risk stratification. The present study sought to determine the predictive value of LA size in a large series of asymptomatic patients with severe MR. 280 consecutive patients (88 female, median age 58 years) with severe primary MR and no guideline-based indications for surgery were included in a follow-up program until criteria for mitral surgery were reached. Event-free survival was determined and potential predictors of outcome were assessed. Survival free of any indication for surgery was 78% at 2 years, 52% at 6 years, 35% at 10 years and 19% at 15 years, respectively. Left atrial (LA) diameter was the strongest independent echocardiographic predictor of event-free survival with incremental predictive value for the thresholds of 50, 60 and 70 mm, respectively. In a multivariable analysis that encompassed age at baseline, previous history of atrial fibrillation, left ventricular end systolic diameter), LA diameter, sPAP > 50 mmHg and year of inclusion, LA diameter was the strongest independent echocardiographic predictor of event-free survival (adjusted HR = 1.039, p < 0.001). LA size is a simple and reproducible predictor of outcome in asymptomatic severe primary MR. In particular, it may help to identify patients who may benefit from early elective valve surgery in heart valve centers of excellence.

Significance of Left Ventricular Ejection Time in Primary Mitral Regurgitation

The optimal timing for mitral valve (MV) surgery in asymptomatic patients with primary mitral regurgitation (MR) remains controversial. We aimed at evaluating the relation between left ventricular ejection time (LVET) and outcome in patients with moderate or severe chronic primary MR because of prolapse. Clinical, Doppler echocardiographic, and outcome data prospectively collected from 302 patients (median age 61 [54 to 74] years, 34% women) with moderate or severe primary MR were analyzed. Patients were retrospectively stratified by quartiles of LVET. The primary end point of the study was the composite of need for MV surgery or all-cause mortality. During a median follow-up time of 66 (25th to 75th percentile, 33 to 95) months, 178 patients reached the primary end point. Patients in the lowest quartile of LVET (&lt;260 ms) were at high risk for adverse events compared with those in the other quartiles of LVET (global p=0.005), whereas the rate of events was similar for the other quartiles (p=NS for all). After adjustment for clinical predictors of outcome, including age, gender, history of atrial fibrillation, MR severity, and current recommended triggers for MV surgery in asymptomatic primary MR, LVET &lt;260 ms was associated with an increased risk of events (adjusted hazard ratio 1.49, 95% confidence interval 1.03 to 2.16, p=0.033). In conclusion, we observed that shorter LVET is associated with increased risk of adverse events in patients with moderate or severe primary MR because of prolapse. Further studies are required to investigate whether shorter LVET has a direct effect on outcomes or is solely a risk marker in primary MR.

Mitral regurgitation management: a systematic review of clinical practice guidelines and recommendations.

Multiple guidelines exist for the diagnosis and management of mitral regurgitation (MR), the second most common valvular heart disease in high-income countries, with recommendations that do not always match. We systematically reviewed guidelines on diagnosis and management of MR, highlighting similarities and differences to guide clinical decision-making. We searched national and international guidelines in MEDLINE and EMBASE (1 June 2010 to 1 September 2021), the Guidelines International Network, National Guideline Clearinghouse, National Library for Health Guidelines Finder, Canadian Medical Association Clinical Practice Guidelines Infobase, and websites of relevant organizations. Two reviewers independently screened the abstracts and identified articles of interest. Guidelines that were rigorously developed (as assessed with the Appraisal of Guidelines for Research and Evaluation II instrument) were retained for analysis. Five guidelines were retained. There was consensus on a multidisciplinary approach from the heart team and for the definition and grading of severe primary MR. There was general agreement on the thresholds for intervention in symptomatic and asymptomatic primary MR; however, discrepancies were present. There was agreement on optimization of medical therapy in severe secondary MR and intervention in patients symptomatic despite optimal medical therapy, but no consensus on the choice of intervention (surgical repair/replacement vs. transcatheter approach). Cut-offs for high-risk intervention in MR, risk stratification of progressive MR, and guidance on mixed valvular disease were sparse.

Myocardial efficiency in severe asymptomatic primary mitral regurgitation: relation to quantitative measures of regurgitation

Abstract Objectives To study the association of myocardial external efficiency (MEE) in mitral regurgitation (MR) towards routinely used quantitative indicators of disease severity and progression. Background Quantitative assessment of LV function and regurgitation in asymptomatic severe primary MR is crucial for management. MEE is a load-independent indicator of mechano-energetic coupling and can be measured non-invasively using 11C-acetate positron emission tomography (PET). The role of MEE in this setting has not been studied. Methods 48 asymptomatic patients with severe primary mitral regurgitation underwent PET, echo, and CMR on the same day. MEE was automatically derived from PET as the ratio of cardiac work (cardiac output * mean arterial pressure) and total left ventricular (LV) oxygen consumption (mean MVO2 * LV mass). LV function and mitral regurgitant volumes (RegVol) were measured by echo and CMR. MEE in MR was compared to healthy volunteers (n=9). MEE and parameters of regurgitation severity and of LV volumes and function were studied as predictors of outcome (valve surgery or death). Results MEE was reduced in MR (21.5±4.2%) vs healthy volunteers (32.0±5.6%, p&amp;lt;0.001) and showed weak but significant correlations (r2&amp;lt;0.25) with regurgitation severity and LV volumes. There were 23 cardiac events (valve surgery: 22; cardiovascular death: 1) during follow-up (median 2.7 years, IQR 1.9–3.2). Univariate Cox models showed that MEE, echocardiographic left atrial volume as well as RegVol and LV ventricular volumes from both echo and CMR were significant outcome predictors (all p&amp;lt;0.05), while LVEF and NT-pro-BNP were not (p&amp;gt;0.05). Prediction by MEE was not affected by age, sex or BMI. When categorically divided by the median MEE was a strong predictor in Kaplan-Meier analysis (log-rank p=0.0004, figure 1) and remained independently significant, compared to all other univariate predictors in bivariate Cox models. Conclusions This study suggests an important role of energetic insufficiency in progression of asymptomatic severe primary MR. Reduced MEE was linked to outcome independently of standard functional measures of regurgitation severity or left ventricular size and function. Strategies for improvement of myocardial energetics in MR are warranted. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Swedish Heart-Lung Foundation Figure 1

Relation of Guideline Adherence to Outcomes in Patients With Asymptomatic Severe Primary Mitral Regurgitation

Current guidelines empirically recommend serial clinical evaluations for asymptomatic patients with severe mitral regurgitation (MR). However, there is a paucity of data on the effectiveness of such monitoring. This study sought to examine the potential benefit of guideline adherence among asymptomatic patients with severe primary MR. Asymptomatic patients with severe primary MR who had been evaluated in the Allina Health system between January 1, 2012 and May 30, 2018 were examined. The medical records were manually reviewed for demographics, comorbidities, echocardiographic data, subsequent interventions, and clinical outcomes. Patients were grouped according to occurrence of guideline adherence, which was defined as a serial clinical evaluation with echocardiography every 12 ± 1 month until mitral valve surgery, or death. Over the study period, 246 patients (67.3 ± 15.5 years, 61.4% men) with severe, asymptomatic primary MR were identified, including 154 patients (62.6%) with and 92 patients (37.4%) without guideline adherence. Overall, there were no differences in demographics, morbidities, MR severity, or left ventricular function between patient adherence groups. During follow-up (40.9; 21.2, 58.3 months), patients with adherence more frequently had surgery or transcatheter therapy performed (64.3% vs 18.5%; p <0.001) and the time to intervention was earlier (13.6 [3.9-22.7] vs 44.2[25.6-57.3] months; p <0.001). Compared to non-adherent patients, those with guideline adherence had a significantly higher five-year survival free from all-cause mortality (92.0% vs 74.3%, p=0.002), and freedom from death or hospitalization for heart failure (90.1% vs 69.3%, p=0.001). Adherent patients also had a significantly better survival free from combined endpoint of death, re-hospitalization for heart failure, myocardial infarction, and stroke (84.5% vs 63.2%, p=0.002). In patients with asymptomatic severe primary MR, guideline adherence with serial evaluations every 12 months or less is associated with earlier therapy and improved long-term outcomes. These data support educational efforts to promote guideline adherence.

Quantification of mitral regurgitation and biventricular assessment is feasible during continuous supine exercise cardiovascular magnetic resonance in primary mitral regurgitation patients

Abstract Funding Acknowledgements Type of funding sources: None. Background Biventricular volume and great vessel flow assessment during continuous supine free-breathing exercise cardiovascular magnetic resonance (Ex-CMR) is feasible in healthy volunteers using Compressed SENSEx3 (CS3) sequences1. Exercise transthoracic echocardiography (TTE) provides prognostic information in primary mitral regurgitation (MR). Resting CMR offers reference standard biventricular assessment and MR quantification with superior reproducibility to TTE. Ex-CMR assessment of biventricular volumes and quantitated MR may offer additional prognostic information. Purpose Determine the feasibility of biventricular assessment and MR quantification in primary MR patients during continuous supine Ex-CMR using the recently validated protocol1. Methods 10 asymptomatic patients with at least moderate primary MR on TTE (8 male, median age 62, 55-67years interquartile range) underwent continuous in-scanner (1.5T Philips Ingenia) supine cycle ergometer (Lode BV) Ex-CMR. Target heart rates (THR) were individually prescribed using heart rate reserve (HRR) and age predicted maximal heart rate model. Participants exercised for 2-minutes at no resistance, then an increase of 25-Watts every 2-minutes until THR achieved at low (30-39% HRR), then moderate (40-59% HRR) stages. CMR imaging: free-breathing CS3 respiratory navigated short axis cine imaging and free-breathing CS3 aortic phase-contrast magnetic-resonance at rest, low and moderate exercise stages. MR was quantified indirectly from left ventricular (LV) and aortic stroke volumes. Intra/inter-observer reproducibility was assessed by coefficient of variance (CV). Results All patients completed the Ex-CMR protocol without complication. During exercise, no statistically significant changes occurred in LV volumes, global left ventricular ejection fraction (LVEF), right ventricular end-diastolic or systolic volumes (Table 1). From rest to low and moderate exercise: right ventricular ejection fraction increased (55 ± 5.4% to 60 ± 6.0% and 63 ± 6.6% respectively, p = 0.001) and MR fraction decreased (40 ± 14% to 36 ± 11% and 30 ± 15% respectively, p = 0.006) allowing effective forward LVEF (aortic stroke volume/ left ventricular end-diastolic volume) to increase (38 ± 9.3% to 43 ± 9.3% and 46 ± 11% respectively, p = 0.004). Intra-observer reproducibility (Table 2) was excellent (CV &amp;lt;10%), except right ventricular stroke volumes (RVSV) during low, MR volumes and fraction during moderate and right ventricular end-systolic volumes (RVESV) during both exercise stages, which were good (CV10-20%). Inter-observer reproducibility (Table 2) was excellent (CV &amp;lt; 10%), except RVESV and MR volumes at all stages, LV end-systolic volumes during low and MR fraction during moderate exercise, which were good (CV 10-20%). Conclusion Biventricular assessment and MR quantification during continuous supine Ex-CMR is feasible in asymptomatic primary MR patients, further research assessing the techniques prognostic ability is now warranted.

Prognostic Value of Peak Exercise Systolic Pulmonary Arterial Pressure in Asymptomatic Primary Mitral Valve Regurgitation

The contribution of exercise echocardiography in primary asymptomatic mitral regurgitation (MR) remains debated. The aim of this study was to gain evidence regarding its usefulness in this setting and to investigate the prognostic value of peak exercise systolic pulmonary artery pressure (SPAP). One hundred seventy-seven patients (mean age, 56±13years; 69% men) with moderate to severe (grade 3+) or severe (grade 4+) degenerative MR and preserved left ventricular ejection fraction, in sinus rhythm, referred for clinically indicated exercise echocardiography were identified. The end point, MR-related events, was a composite of all-cause death or occurrence of symptoms, heart failure, atrial fibrillation, left ventricular ejection fraction < 60%, left ventricular end-systolic diameter ≥ 45mm, or resting SPAP > 50mm Hg. At rest, effective regurgitant orifice area was 48±16mm2, regurgitant volume 74±26mL, and SPAP 32±7mm Hg, and MR was severe in 138 patients (78%). Peak exercise SPAP was 55±10mm Hg. Positive results on exercise testing motivated surgery in 26 patients, 11 underwent prophylactic surgery, 10 were lost to follow-up, and 130 were included in the outcome analysis. During a follow-up period of 19±7months, 31 MR-related events (24%) were reported. Peak exercise SPAP was predictive of outcomes in univariate analysis (P=.01) and after adjustment for age, gender, MR severity, and resting SPAP (P<.05). Peak exercise SPAP ≥ 50mm Hg was associated with worse event-free survival (hazard ratio, 5.24; 95% CI, 1.77-15.53; P=.003), but not the threshold of ≥60mm Hg proposed in previous guidelines (hazard ratio, 1.70; 95% CI, 0.71-4.03; P=.24). The present findings support the use of exercise echocardiography for risk stratification in patients with asymptomatic primary MR and suggest a lower peak exercise SPAP threshold (50mm Hg) than previously recommended to define the timing of intervention. Prospective studies are needed to confirm these findings.

Progress in Research of Asymptomatic Primary Mitral Regurgitation Examination Methods: A Review of Literature.

Mitral regurgitation (MR) is a common valvular heart disease, which can be classified into primary and secondary, according to the cause. Primary mitral regurgitation (PMR) is caused by rheumatic fever, degenerative changes, valve prolapse, etc. The appearance of clinical symptoms has always been the best indicator of surgical intervention in patients with severe PMR, but for asymptomatic patients, the best treatment has been controversial. The choice of follow-up observation or early surgery has different results in different randomized studies. Two-dimensional echocardiography is the most commonly used detection method for evaluating MR, but its evaluation of the degree of reflux may be inaccurate, and there are differences in the outcomes of patients with asymptomatic PMR. Recent studies have shown that three-dimensional echocardiography, cardiac magnetic resonance, speckle-tracking echocardiography, brain natriuretic peptide, and exercise stress test can optimize the timing of surgery for asymptomatic patients and judge the asymptomatic of PMR.

Left atrial filling index in prediction of exercise induced pulmonary hypertension in patients with asymptomatic primary mitral regurgitation

Abstract Funding Acknowledgements Type of funding sources: None. Introduction. In patients with chronic mitral regurgitation (MR), left atrium (LA) is one of the first cardiac structures, that are affected by progressive volume overload. Previous studies have shown that higher LA filling index (FI) could be a potential negative prognostic marker and it may provide additional information in cases where surgical valve correction is considered. Purpose. The aim of this study was to evaluate the connection between the LA FI and exercise–induced pulmonary hypertension (EIPH) in patients with asymptomatic primary moderate to severe MR. Methods. The study sample consisted of 50 patients (age 61.88 ± 12.88 years) with asymptomatic primary moderate to severe MR and preserved left ventricular (LV) ejection fraction (EF) (&amp;gt;60%). All of the patients underwent resting and stress (bicycle–ergometry as per protocol 25 + 25W every 3 minutes) echocardiography. The ratio of the early–diastolic mitral inflow peak velocity (E) and LA reservoir strain was calculated as the LA FI. EIPH was considered as systolic pulmonary artery pressure (SPAP) ≥60 mmHg during peak stress. Results. EIPH was identified in 13 (26%) patients with primary asymptomatic MR. LA FI at rest, during initial and peak stress was higher in patients with EIPH (p = 0.041, p = 0.023 and p = 0.036, respectively). LA FI at rest (r = 0.334; p = 0.044), during initial (25W) stress (r = 0.371; p = 0.037) and during recovery phase (r = 0.408; p = 0.023), weakly correlated with SPAP during maximal achieved workload. In univariate logistic regression analysis, LA FI during initial and peak stress was significantly related to EIPH (Table 1). According to ROC analysis, LA FI &amp;gt;6.46 during initial stress could predict EIPH with 70.0% sensitivity and 75.0% specificity (p = 0.023). LA FI &amp;gt;9.59 during peak stress could distinguish the possibility of underlying EIPH with 60.0% sensitivity and 94.3% specificity (p = 0.036). Conclusions. Resting and exercise LA FI was higher in subjects with EIPH. LA FI during stress could be the potential predictor of EIPH in patients with asymptomatic primary MR and preserved LV EF. Table 1 Parameter β Chi-Square Odds ratio Standard error 95% CI p value LA FI at rest 1.21 3.549 3.271 0.106 0.984 - 1.489 0.071 LA FI during initial (25 W) stress 1.535 6.056 4.812 0.195 1.047 - 2.250 0.028 LA FI during peak stress 1.662 7.364 4.646 0.236 1.047 - 2.638 0.031 LA FI during recovery phase 1.257 3.998 3.139 0.129 0.976 - 1.619 0.076 LA - left atrium FI - filling index Abstract Figure. Picture 1

Parameters of left atrial during stress in patients with asymptomatic primary mitral regurgitation

Abstract Introduction Progressive volume overload caused by chronic mitral regurgitation (MR) leads to left atrium (LA) and left ventricle (LV) remodeling. Despite these structural changes, most of MR patients may remain asymptomatic for a long time. LA enlargement and reduced LA deformation parameters in asymptomatic MR patients predict a worse prognosis and may provide additional information to guide for earlier surgery. Purpose The aim of the study was to evaluate changes of LA size and deformation parameters in patients with asymptomatic primary MR during stress. Methods 84 asymptomatic patients (age 59.87±13.47 years) with sinus rhythm and preserved left ventricle (LV) ejection fraction (EF) (&amp;gt;50%) at rest were included in the study. Resting and stress (veloergometry as per protocol 25 + 25 W every 3 minutes) echocardiography and speckle tracking off-line analyses were performed to 52 (61.9%) patients with moderate MR (MR group) and 32 (38.1%) patients without significant heart valves disease (control group). Statistical analyses were performed using the SPSS 20.0 software. The value of p&amp;lt;0.05 was considered as statistically significant. Results Volume index of LA was significantly higher in subjects with MR (picture 1). LA area was similar in MR and control groups at rest. However, during stress LA area became significantly larger in MR group (picture 1). LA myocardial deformation parameters were calculated during 3 phases of LA cycle: reservoir phase strain (LASr), conduit phase strain (LAScd), contraction phase strain (LASct). At rest, during peak stress and at recovery phase all of them were higher in controls but difference was not significant. During initial stress (25 W) LAScd was significantly higher in MR group (−16.86±−8.06% vs. −11.33 ±−6.26% p=0.034), while healthy subjects had a tendency to lower LASr (20.32±10.53% vs. 22.7±10.89%, p=0.535) (picture 1). Better LV EF at rest was related to smaller LA area (p=0.003, r – 0.390) and volume index (p=0.020, r – 0.308) during peak stress. Conclusions Stress provokes significant increase of LA size (volume and area) and LAScd in patients with primary mitral regurgitation. Other myocardial deformation parameters of LA were not significantly related to MR. LV EF at rest correlates with LA parameters during peak stress. Changes of LA parameters during stress Funding Acknowledgement Type of funding source: None

P293 Assessment of right ventricle parameters during stress in patients with asymptomatic primary mitral regurgitation

Abstract Background Evaluation of right ventricle (RV) function and pulmonary artery pressure (PAP) during stress, plays an important role in identifying worse prognosis for patients with chronic mitral regurgitation (MR) and may help to optimise the time of surgical interventions. Purpose The aim of the study was to evaluate changes of RV function and systolic PAP in patients with asymptomatic primary MR during stress echocardiography. Methods Resting and stress (veloergometry as per protocol 25 + 25 W every 3 minutes) echocardiography were performed in 63 asymptomatic patients (age 56.12 ± 13.97 years) with preserved left ventricle (LV) ejection fraction (EF) (&amp;gt;50%) at rest. 39 (61.9%) patients with moderate (grade 2-3) MR (MR group) and 24 (38.1%) patients without significant heart valves disease (control group) were included in the study. Statistical analyses were performed using the SPSS 20.0 software. The value of p &amp;lt; 0.05 was considered as statistically significant. Results Anthropometric and clinical characteristics, LV EF (64.96 ± 9.14% vs. 64.87 ± 6.46%, p = 0.97) and LV global longitudinal strain (GLS) (-19.24± 3.12% vs. -19.28 ± 3.36%, p = 0.055) at rest were not significantly different between MR and control groups. Diameter of RV was larger in MR group (36.07 ± 5.34 mm vs. 33.13 ± 3.48 mm) however difference was not significant (p = 0.971). Parameters of RV function (longitudinal myocardial velocity - S’, fractional area change (FAC) and tricuspid annular plane systolic excursion (TAPSE)) were similar in both groups at rest, during stress and at recovery phase (Picture 1). However TAPSE and S’ at rest (p = 0.037 and p = 0.205, respectively) and minimal stress (p = 0.006 and p = 0.035, respectively) were significantly lower in patients with MR who had highly increased (&amp;gt;60 mmHg) systolic PAP during stress. Also TAPSE (p = 0.002) and S’ (p = 0.017) during recovery phase were significantly lower in subjects with reduced LV contractile reserve (whom LV EF increased &amp;lt;4% or GLS &amp;lt;1.9% during stress). Systolic PAP during stress was growing much faster in patients with MR (Picture 1). Conclusions Patients with asymptomatic moderate primary mitral regurgitation had higher systolic PAP during stress even though at rest it was similar as in controls. Prominent severe pulmonary hypertension during stress was related to worsening parameters of RV function. Abstract P293 Figure. Parameters of RV during stress

P1779Quantitation of severe degenerative mitral regurgitation by echocardiography and CMR with acetate PET for external reference for left ventricular volumes

Abstract Background Quantitative echocardiographic assessment of severity of primary mitral regurgitation (MR) is challenging. CMR is recommended if MR severity cannot be clearly determined, since quantitation of regurgitation as well as of left ventricular (LV) volumes and function is crucial for the indication for surgery especially in asymptomatic patients. Purpose We aimed to compare volumetric measurements obtained from transthoracic echo (TTE) and cardiovascular magnetic resonance (CMR) using ECG-gated [(11)C]acetate PET as reference for assessment of LV volumes. Methods A total of 51 asymptomatic patients with severe primary mitral regurgitation underwent TTE, CMR and PET on the same day. Mitral regurgitant volumes (RVol) were measured by TTE using proximal convergence (PISA) method and by CMR, subtracting aortic forward flow volume from LV stroke volume. LV volumes were measured by TTE, CMR and PET. Results Despite a fair correlation between regurgitant volumes measured by TTE and CMR (r=0.53, p&lt;0.001), PISA method heavily overestimated regurgitant volumes on TTE as compared to CMR (103±60ml vs. 78±35ml, p&lt;0.001). TTE systematically underestimated LV volumes as compared to CMR (see table) despite a good correlation (r=0.81, 0.67 and 0.76 respective for LV EDV, ESV and SV, p&lt;0.001 for all). There was no difference in LV EF between the methods. LV volumes obtained by CMR and PET showed a strong correlation (r=0.92, 0.79 and 0.89 respective for LV EDV, ESV and SV, p&lt;0.001 for all) and agreement (see table). Comparison of TTE, CMR and PET TTE CMR PET PET TTEvs.CMR PET CMRvs.PET F-test LV EDV, ml 145±34 241±57 234±51 &lt;0.001 0.004 &lt;0.001 LV ESV, ml 47±11 76±22 81±23 &lt;0.001 0.067 &lt;0.001L LV SV, ml 99±26 164±38 152±34 &lt;0.001 &lt;0.001 &lt;0.001 LV EF, % 68±5 69±5 65±6 0.236 &lt;0.001 &lt;0.001 Conclusions As compared to CMR, PISA method used by TTE substantially overestimates regurgitant volumes in patients with asymptomatic primary mitral regurgitation. Conversely, LV volumes in spite of good correlation are heavily underestimated by TTE in comparison with CMR. A strong correlation and agreement between LV volumes measured by CMR and PET confirms the accuracy of the former method which is considered as a golden standard for assessment of ventricular function and volumes. Thus, even so-called quantitative echo measures should be understoas essentially semi-quantitative indicators of severity.

P1483Left atrial size is a powerful predictor of outcome in severe asymptomatic primary mitral regurgitation

P1483Left atrial size is a powerful predictor of outcome in severe asymptomatic primary mitral regurgitation

Long-Term Outcome of Active Surveillance in Severe But Asymptomatic Primary Mitral Regurgitation

ObjectivesThis study sought to assess the long-term outcome of active surveillance in these patients. BackgroundThe optimal timing of mitral valve surgery in asymptomatic primary mitral regurgitation (MR) remains controversial. MethodsBetween 1997 and 2015, 280 consecutive patients with severe asymptomatic primary MR were enrolled in our heart valve clinic follow-up program. They were prospectively followed up every 6 months clinical and echocardiographical examinations until surgical criteria were reached. Event-free survival and overall survival as compared with the age- and gender-matched general population were assessed. ResultsDuring a median potential follow-up of 93.4 (quartiles 55.3 to 152.9) months, 161 patients developed an indication for surgery and 13 patients died. Event-free survival rates were 78.0% (95% confidence interval [CI]: 73.2% to 83.2%) at 2 years, 52.2% (95% CI: 46.3% to 59.0%) at 6 years, 35.5% (95% CI: 29.3% to 43.1%) at 10 years, and 18.7% (95% CI: 12.3% to 28.5%) at 15 years. Overall survival rate was 99.6% (95% CI: 98.9% to 100%) at 2 years, 94.6% (95% CI: 91.7% to 97.6%) at 6 years, 85.6% (95% CI: 80.3% to 91.2%) at 10 years, and 74.5% (95% CI: 66.6% to 83.4%) at 15 years. Overall survival of patients managed according to an active surveillance strategy was comparable with the expected cumulative survival and early survival rates were even better in the study population (standardized mortality ratio: 0.667; 95% CI: 0.463 to 0.963; p = 0.013). ConclusionsPatients with severe asymptomatic primary MR may remain free of indications for surgery for extensive periods of time. In such patients, active surveillance performed in experienced centers is associated with a favorable prognosis, resulting in timely referral to surgery, excellent long-term survival, and good surgical outcomes.

P3539Long term outcome of watchful waiting in severe but asymptomatic primary mitral regurgitation

P3539Long term outcome of watchful waiting in severe but asymptomatic primary mitral regurgitation

Strain Echocardiography and Functional Capacity in Asymptomatic Primary Mitral Regurgitation With Preserved Ejection Fraction

BackgroundThe potential additive utility of baseline resting left ventricular global longitudinal strain (LV-GLS) and exercise stress testing in risk stratification of patients with significant mitral regurgitation (MR) has not been studied. ObjectivesThe goal of this study was to determine whether resting LV-GLS and exercise testing provide incremental prognostic utility in asymptomatic patients with ≥3+ primary MR and preserved left ventricular ejection fraction. MethodsBetween 2000 and 2011, resting and exercise echocardiography data, Society of Thoracic Surgeons (STS) scores, and death were recorded in 737 patients (mean age 58 ± 13 years; 68% men). ResultsCoronary artery disease and flail leaflet were seen in 10% and 28% of patients, respectively. STS score, resting left ventricular ejection fraction, mitral effective regurgitant orifice, resting right ventricular systolic pressure (RVSP), exercise metabolic equivalents (METs), and percentage of age-/sex-predicted METs were 1.5 ± 1%, 62 ± 2%, 0.45 ± 0.2 cm2, 31 ± 12 mm Hg, 9.8 ± 3, and 115 ± 27, respectively. Median LV-GLS was –21.7%. Within 3 months (interquartile range: 1 to 15 months), 65% underwent mitral valve surgery. At 8.3 ± 3 years, 64 (9%) patients died (0% 30-day post-operative deaths). On multivariable Cox survival analysis, higher STS score (hazard ratio [HR]: 1.14), more abnormal resting LV-GLS (HR: 1.60), higher baseline RVSP (HR: 1.35), and lower percentage of age-/sex-predicted METs (HR: 1.13) were associated with higher mortality, whereas mitral valve surgery (HR: 0.82) was associated with improved survival (all p < 0.01). Addition of predicted METs and resting LV-GLS to STS, resting RVSP, left ventricular end-systolic dimension, and mitral effective regurgitant orifice increased the C-statistic for longer-term mortality from 0.61 to 0.69 and 0.78, respectively (all p < 0.01). On quadratic spline analysis, the risk of death progressively increased as resting LV-GLS worsened below –21%. ConclusionsReduced exercise capacity and worsening resting LV-GLS were associated with mortality, providing additive prognostic utility.

Abstract 15062: Incremental Prognostic Utility of LV Global Longitudinal Strain and Functional Capacity in Asymptomatic Patients With Significant Primary Mitral Regurgitation and Preserved Left Ventricular Ejection Fraction Undergoing Rest-Stress Echocardiography

Background: Outcomes after mitral valve (MV) surgery for primary mitral regurgitation (PMR) are excellent; however surgical timing in asymptomatic PMR &amp; preserved left ventricular ejection fraction (LVEF) remains challenging. We assessed the incremental utility of resting LV-global longitudinal strain (LV-GLS) &amp; exercise variables in asymptomatic patients with ≥3+ PMR &amp; preserved LVEF (≥60%) who underwent rest-stress echocardiography. Methods: We included 737 such patients (58±13 years, 68% men) between 2000-11. Clinical, resting (including LV-GLS using Velocity Vector Imaging &amp; right ventricular systolic pressure or RVSP) &amp; exercise stress echo (metabolic equivalents or METs) data were recorded. Society of Thoracic Surgeons (STS) score was calculated. Primary events were death &amp; heart failure admission. Results: Hypertension, atrial fibrillation (AF) and coronary artery disease were seen in 48%, 13% &amp; 10% patients. Posterior, anterior &amp; bileaflet prolapse were noted in 46%, 9% &amp; 45% (20% had flail). Mean STS score, resting LVEF, resting RVSP, exercise MET’s &amp; % age-gender predicted MET’s were 1.5±1, 62±2%, 31±12 mmHg, 9.8±3 &amp; 115±27 respectively. 65% underwent MV surgery with mean time to surgery 13±22 months. At 6.2±3 years, events occurred in 61 (8%) patients (death in 33 patients). On multivariable Cox survival analysis, higher rest RVSP (Hazard ratio or HR 1.04), lower % age-gender predicted METS (HR 1.11), lower LV-GLS (HR 1.42), higher STS score (HR 1.12) &amp; AF (HR 2.23) were significantly associated with events (all p&lt;0.05). Association of MV surgery (time-dependent covariate) with outcomes was not significant (HR 0.63 [0.38-1.07, p=0.1). Figure 1a shows an incremental model with association to outcomes &amp; 1b shows survival curves, based on LV-GLS better/worse than median (-21.7%). Conclusions: In asymptomatic patients with ≥3+ PMR &amp; preserved LVEF, lower baseline LV-GLS &amp; %age-gender predicted METs are associated with long-term adverse events.