Impact of proportionate versus disproportionate mitral regurgitation on acute procedural changes and clinical outcomes following transcatheter mitral valve repair

Background

Transcatheter mitral edge-to-edge repair (TEER) with MitraClip offers a less invasive alternative for patients with severe, symptomatic mitral regurgitation (MR) who are considered high risk for surgery. However, patient selection for TEER remains challenging given the variability in underlying MR pathology and current discordance among studies regarding predictors of procedural efficacy and clinical outcomes.

Purpose

This study aimed to assess acute procedural changes and long-term outcomes in patients who underwent TEER according to the proportionality of MR, defined as the ratio of the effective regurgitant orifice area (EROA) and left ventricular end-diastolic volume (LVEDV).

Methods

We analyzed patients who underwent TEER at our institution between 2014 and 2020 with available biplane left ventricular volume measurement. Relevant clinical comorbidities, demographics, and anthropometrics, along with pertinent pre- and post-procedural echocardiogram measurements, were obtained by review of the electronic medical record. The EROA to LVEDV index was calculated for all patients who were then stratified by quartiles. Patients with an EROA/LVEDV index in the lowest quartile were defined as having the most proportionate MR and those with an index in the highest quartile were defined as the most disproportionate MR. Baseline and post-TEER parameters were used to assess acute procedural and longitudinal outcomes.

Results

Baseline clinical and echocardiographic parameters of the 230 subjects according to quartile are shown in the table. Following TEER, there was a larger reduction in the left ventricular end-diastolic diameter and increased MR reduction with increasingly disproportionate MR (p=0.03 and p=0.05, respectively). The change in ejection fraction pre- versus post-TEER did not significantly differ across groups (p=0.64). Median follow up time was 1.7 (0.7–3.5) years; mortality occurred in 77 patients (33.5%) and heart failure hospitalizations occurred in 20 patients (8.7%) during follow up. No significant difference in all-cause mortality or post-procedural heart failure hospitalizations was identified across groups.

Conclusions

In our series, patients with proportionate MR were similarly symptomatic to those with disproportionate MR but had less severe MR with increased comorbidities. Post-TEER MR grade was similar between groups. Longer-term follow up in larger groups of patients is needed to determine the clinical implications.

Funding Acknowledgement

Type of funding sources: None.

Tricuspid annulus dynamics in atrial fibrillation compared to sinus rhythm using 3-D echocardiography: relation with tricuspid regurgitation

Funding Acknowledgements

Type of funding sources: None.

Background

Atrial fibrillation (AF) is known to cause dilation in both the mitral (MA) and the tricuspid (TA) annuli. Few studies have investigated MA dynamics and function in AF compared to sinus rhythm (SR). However, no study addressed this issue in TA. Hence, we set forth to describe TA dynamics in AF and SR and its relationship with severity of tricuspid regurgitation (TR).

Methods

3D echocardiographic imaging data were acquired from adult patients in AF or SR with varying degrees of TR between 2018 and 2020. TA was automatically tracked throughout the cardiac cycle using a commercially available software (TomTec 4MV software; Figure 1) over 4-6 cardiac cycles per patient. Time to minimal area as percentage of the R-R interval was recorded in each of the cycles. Absolute change in TA area was calculated as the difference between maximal and minimal TA area in each cardiac cycle and was averaged over 4-6 cycles per patient. This measurement was used to reflect the dynamic range of TA deformation during the cardiac cycle. Right atrial (RA) and right ventricular (RV) volumes and longitudinal strain were also measured (speckle tracking, 4-ch view).

Results

A total of 70 patients were studied (35 AF; 35 SR; 54% males in each group). Patients with AF were older [median (IQR) of 81 (72-86) years vs. 69 (59-78) years in SR, p < 0.001], had larger maximal TA area and circumference (p < 0.001 for both), larger RA size (p < 0.001), lower RA reservoir strain  (p < 0.001) and RV free-wall strain (p < 0.001). Absolute change in TA area was significantly decreased in AF [2.3 (1.7-2.7) cm2] vs. 3.1 (2.3-3.5) cm2 in SR, p = 0.002. Patients with ≥ moderate TR (n = 41, 59%) had lower absolute change in TA area [2.4 (1.7-3.1) cm2 vs. 2.8 (2.2-3.5) cm2 in < moderate TR, p = 0.05]. Female sex was associated with lower absolute change in TA area [2.3 (1.7-3.2) cm2 vs. 2.7 (2.2-3.6) cm2 in males, p = 0.02] on univariate analysis. AF patients had more frequently ≥ moderate TR [28 AF vs. 13 SR, p < 0.001]. On multivariate analysis including sex, rhythm, TR severity, RA and RV strains, and averaged maximal TA area, independent factors associated with lower absolute change in TA area were AF, ≥ moderate TR, and larger maximal TA area (p < 0.05 for all).  Time to minimal TA size was achieved in (0-40%) of the R-R interval in 70% of patients in SR compared to only 41% of patients in AF (Figure 2) and in 73% in patients with < moderate TR compared to 43% in patients with ≥ moderate TR.

Conclusion

AF is associated with blunted TA dynamics resulting in lower decrease in TA size and with a heterogenous timing of minimal TA size throughout the cardiac cycle. The blunted and discoordinated annular contraction may reduce systolic tricuspid valve competence and be involved in the pathophysiology of functional TR. Future studies are needed to confirm this hypothesis and evaluate the effect of restoration of SR on TA dynamics and time to minimal TA size. Abstract Figure 1Abstract Figure 2

Intraoperative finding of immobile leaflet(s) following freshly implanted bioprosthetic valves: clinical characteristics and impact on outcomes

Funding Acknowledgements

Type of funding sources: None.

BACKGROUND

Detection of immobile leaflets immediately following bioprosthetic valve implantation is a rare but important intraoperative finding. Restriction of leaflet movement can occur in the closed or open position, leading to abnormal prosthesis function. We sought to determine the clinical implications of immobile leaflets seen on intraoperative echocardiography.

METHODS

Patients with immobile leaflets identified on intra-operative/procedure echocardiography immediately post implantation between 2009-2020 were identified from an institutional database. All echocardiograms were reviewed de-novo to confirm immobile leaflets in the immediate post-implantation period. Identified cases were matched 1:2 to controls for age; sex; prosthesis position, model and size; and implantation approach (surgical vs. transcatheter).  Nominal logistic regression and proportional hazards were used to analyze outcomes.

RESULTS

Thirty patients with immobile leaflets immediately post-bioprosthesis implantation were included. Clinical characteristics are summarized in the Table. Immobile leaflets were documented in procedural reports in only 18 (60%) patients. Moderate stenosis was present intraoperatively in 1 patient, none demonstrated ≥moderate regurgitation, and none resulted in immediate corrective action. In 3 (10%), valve re-intervention was required within 30 days due to symptomatic prosthesis dysfunction. Presence of restricted leaflet motion was associated with higher need for post-operative extracorporeal membrane oxygenation use (odds-ratio 7.3, p = 0.02) and composite end-point of death, valve re-replacement, prosthesis thrombosis, or cardiac hospitalizations (risk ratio 2.1, p = 0.03, Figure).

CONCLUSION

Immobile leaflet(s) immediately post-bioprosthetic valve implantation is an uncommon, under-reported, and under-treated phenomenon. Even in the absence of significant prosthetic valve dysfunction, it can be associated with worse post-operative course as well as worse outcomes.

Baseline characteristics Age 76 (67-84) Sex, male 10 (33%) Surgical approach 25 (83%) Aortic 5 (17%) Mitral 12 (40%) Tricuspid 12 (40%) Pulmonary 1 (3%) Re-intervention within 10 days 3 (10%) Numbers are presented as median (interquartile range) or number (percentage). Abstract Figure. Clinical outcome of stuck leaflets

Beat-to-beat variability in the tricuspid annulus dimensions and dynamics is markedly increased in atrial fibrillation

Background

Atrial fibrillation (Afib) leads to beat-to-beat variability in cycle length; however, whether there is associated beat-to-beat variability in the tricuspid annulus (TA) dimensions or variability in the time in cardiac cycle when TA reaches maximal size is unknown.

Purpose

We aim to assess the beat-to-beat variability in the TA dimensions in Afib compared with sinus rhythm (SR).

Methods

Images were obtained from 58 patients (29 in Afib, 29 in SR) undergoing either 3D TTE or TEE examination. We measured TA in 3–6 cardiac cycles per patient using commercially available software (TomTec 4MV).

Results

Median absolute difference in maximal TA area over 3–6 cardiac cycles was 1.60 cm2 (range 0.35 cm2 to 4.08 cm2) in Afib vs. 1.17 cm2 (range 0.32 cm2 to 2.19 cm2) in SR, p=0.0063. Median absolute difference in the maximal circumference was 0.79 cm (range 0.09 cm to 2.2 cm) in Afib vs 0.54 cm (range 0.12 cm to 1.43 cm) in SR, p=0.0175. A total of 118 cardiac cycles were analyzed in patients in SR and 147 in Afib. Timing of maximal TA area was most commonly recorded at end-diastole (80–100% of the R-R interval) in 62% of cycles in SR; however, it was distributed over a broad range in Afib, p<0.0001, [Figure].

Conclusion

Afib leads to significant beat-to-beat variability in the maximal TA area, minimal TA area, maximal TA circumference, and in the time of maximal TA area. These findings suggest that accurate assessment of TA dimensions should be based on continuous tracking of the TA over several cardiac cycles, especially in patients with Afib. These observations have significant implications for device sizing in percutaneous tricuspid valve interventions.

Timing of Maximal TA Area

Funding Acknowledgement

Type of funding source: None

1049 High single-beat Doppler signals in low-gradient aortic stenosis are associated with higher aortic valve calcium

Funding Acknowledgements

Mayo Clinic

Background

Variability in Doppler signals is common in patients with atrial fibrillation (AF) and AF is common in low-gradient AS (LGAS). Presence of high single beat Doppler signals (peak velocity ≥4m/s or mean gradient ≥40mmHg) is not factored into decision-making in low-gradient aortic stenosis (LGAS).

Objective

Determine prevalence of at least one high Doppler signal in AF LGAS and its relationship to computed tomography aortic valve calcium score (AVCS) versus sinus rhythm (SR) high-gradient aortic stenosis (HGAS).

Methods

Consecutive patients with aortic valve area ≤1cm2 and left ventricular ejection fraction ≥50% during echo were identified (January 1, 2012-December 31, 2016). At least three consecutive Doppler signals were averaged in sinus rhythm (SR) and five in atrial fibrillation (AF).

Results

Of 1,854 patients, age 76± 11 years, male 52%, 301/1,854 (16%) were in AF and LGAS was present in 122/301 (41%). At least one high Doppler signal in AF LGAS was present in 43/122 (35%). AVCS within 1 year of echo was available for 36% of patient with SR HGAS and 34% of AS LGAS. Median AVCS was not different in SR HGAS 2424 (IQR 1623, 3445) vs AF LGAS with at least one high Doppler signal 2509 [IQR1547, 3119], p =0.10 AVCS threshold for severe AS (men >2000 women >1200) was met in 80% SR HGAS vs 86% AF LGAS with high signals.

Conclusions

High Doppler signals in AF LGAS are associated with high AVCS more frequently exceeding thresholds for severe AS. Single-beat high Doppler signals instead of the average correlate better with AVCS and classic HGAS.

6098The role of diastolic function in risk stratification of patients with moderate aortic stenosis

Background

Currently data on the risk stratification of patients with moderate aortic stenosis (AS) are very limited.

Method

Patients diagnosed with moderate AS in 2012 (aortic valve area [AVA]: >1 and ≤1.5cm2) were identified. Patients were stratifying by LV diastolic function (normal vs high filling pressure), left ventricular ejection fraction (LVEF ≥50 vs <50%) and stroke volume index (SVI ≥35 vs <35 ml/m2). High filling pressure was defined as average E/e' ≥14 or septal E/e' ≥11 when atrial fibrillation was present. The prognosis was compared to age- and sex-matched general population.

Results

898 patients were included (age 74 years, 58% male, AVA 1.25 cm2). During a median follow-up of 2.9 years, there were 346 deaths. In patients with moderate AS, mortality was higher than expected (P<0.001, Fig 1A). LV high filling pressure, LVEF<50% and SVI<35ml/m2 were present in 416 (55%), 140 (17%) and 81 (9%) patients, respectively. Those with normal filling pressure had similar prognosis when compared to controls (Fig 1C, P=0.35); whereas mortality rates remained higher than reference even when LVEF≥50% or SVI≥35ml/m2 (Fig 1E, 1G, P<0.001). Amongst all groups, mortality rates were the highest in patients with LVEF <50% or SVI <35 ml/m2 (Fig 1D, 1F, P<0.001); mortality ratios were 3.78 (95% CI 3.01–4.67) and 6.91 (95% CI 5.13–9.11), respectively. Noteworthy, high filling pressure allowed further risk stratification when LVEF or SVI was preserved (Fig 2, P<0.001).

Figures 1 & 2

Conclusions

Patients with moderate AS showed poor survival. A clinical trial examining role of aortic valve replacement would be beneficial not only in patients with reduced LVEF or SVI but also in those with high LV filling pressures.