Abstract
Background
An expanded tricuspid regurgitation scale has been shown to be incrementally useful in understanding the response to transcatheter therapies. A similar approach to mitral regurgitation (MR) has not been evaluated. The purpose of this study was to investigate how an expanded MR grading system that includes categories of massive and torrential would regrade patients undergoing transcatheter edge-to-edge repair (TEER) for MR and evaluate procedural outcomes.
Methods
We retrospectively identified 142 consecutive patients with severe MR who underwent TEER. Transesophageal echocardiography was used to assess the quantitative severity of MR and reclassify regurgitation into severe, massive, and torrential grades. Similarly, residual MR was assessed postprocedurally.
Results
In the expanded scale, 59% of patients were regraded as severe, 23% as massive, and 18% as torrential, with respective median effective regurgitant orifice area (cm 2 ) of 0.45 [0.39, 0.50], 0.68 [0.65, 0.75], and 0.95 [0.85, 1.20]. Ninety-three percent of the entire cohort and 93% of severe, 94% of massive, and 96% of torrential patients, achieved moderate or less MR post-TEER ( p = 0.850) with corresponding improvements in New York Heart Association Functional Classification and 12-item Kansas City Cardiomyopathy Questionnaire scores.
Conclusions
An expanded grading system demonstrated that patients with massive and torrential MR still achieve adequate procedural success with reduction in regurgitation and improvement in health status. Further evaluation of how an expanded MR grading scale may be useful is warranted.
Introduction
Recent studies have examined the impact of an expanded grading system in tricuspid regurgitation (TR) beyond severe to include massive and torrential. Some patients with TR may experience significantly more regurgitation by quantitative measurements, such as effective regurgitant orifice area (EROA), yet still be classified as “severe” under conventional valvular heart disease grading. Often, these patients may still be graded with “severe” TR after transcatheter intervention, despite quantitative TR improvement with corresponding improvement in quality of life and forward stroke volume. Patients with “massive” or “torrential” TR may also experience worsened mortality compared to patients with “severe” TR and may have worse outcomes after transcatheter tricuspid valve interventions. , Similarly, worsened mortality has been demonstrated in patients with higher quantitative mitral regurgitation (MR) by EROA. The purpose of this study was to investigate how a similar expanded MR grading system that includes categories of massive and torrential would regrade patients undergoing transcatheter edge-to-edge repair (TEER) for MR and to further evaluate procedural and quality of life outcomes under an expanded MR grading system.
Materials and Methods
Study Population and Echocardiographic Acquisition
We retrospectively identified 225 patients who completed TEER for MR between July 2014 and March 2021. Forty-eight patients were excluded for preprocedural MR that was moderate-severe. A further 35 patients were excluded for unquantifiable EROA by flow convergence on retrospective review of transesophageal echocardiography images. Most of the unquantifiable studies had either a lack of quantitative imaging or inadequate proximal isovelocity surface areas (PISAs). Only patients with quantifiable pre-TEER EROA who completed TEER for severe MR were included in the final cohort ( Figure 1 ). The preprocedural transesophageal echocardiography was reviewed by two echocardiographers independently to assess severity of MR via 2D EROA and regurgitant volume according to the American Society of Echocardiography/European Association of Cardiovascular Imaging standards. , MR was regraded according to preprocedural EROA as follows: severe (0.40-0.59 cm 2 ), massive (0.60-0.79 cm 2 ), and torrential (≥0.80 cm 2 ). Similarly, post-TEER, residual MR was assessed. Pre- and post-transthoracic echocardiograms were reviewed to assess periprocedural echocardiographic changes. Residual MR using both the conventional and expanded grading systems was subsequently compared. Post-TEER residual MR was assessed qualitatively when a PISA was not measurable (usually when MR was mild or less).
Measurement of Health Status
Patient health status was assessed with Kansas City Cardiomyopathy Questionnaire-12 (KCCQ-12) scores pre-TEER and at 30 days postprocedurally. New York Heart Association (NYHA) Functional Classification was also recorded at the same encounters.
Statistical Analysis
Baseline characteristics for the analytic cohort are presented as percentages for categorical variables and medians with interquartile ranges or means with SDs for continuous variables. The Society of Thoracic Surgeons Predicted Risk of Operative Mortality score for mitral valve replacement was used to estimate patient mortality risk. Baseline characteristics, echocardiographic parameters, and health status were compared by expanded MR grade. Continuous variables were compared using analysis of variance, and categorical variables were compared using χ 2 tests. P -values <0.05 were considered statistically significant. The median KCCQ Summary Score (KCCQ-OS) at baseline and at 30 days post-TEER were compared across expanded MR grades using analysis of variance. Similarly, intraoperative and post-TEER echocardiographic parameters were compared across expanded MR grades using analysis of variance. The frequency of NYHA III/IV at baseline and at 30 days post-TEER was compared across expanded MR grades using χ 2 tests. The post-TEER qualitative MR grade frequencies were also compared across expanded grades using χ 2 tests.
Results
Study Sample
The median age of the entire cohort was 81 [72, 86] years with a median Society of Thoracic Surgeons score of 6% [4, 9]. Forty-six percent of the cohort was female; the etiology of MR was 77% primary, 14% secondary, and 9% mixed. Baseline patient characteristics are available in Table 1 . Notably, higher frequencies of primary MR were observed with greater severity of MR (68% in severe, 82% in massive, 100% in torrential; p = 0.008) ( Table 2 ).
| Variable | Severe | Massive | Torrential | Total | P -value | ||||
|---|---|---|---|---|---|---|---|---|---|
| N | Median (Q1, Q3) | N | Median (Q1, Q3) | N | Median (Q1, Q3) | N | Median (Q1, Q3) | ||
| Age | 84 | 80 (71, 85) | 33 | 84 (74, 87) | 25 | 84 (78, 87) | 142 | 81 (72, 86) | 0.169 |
| STS score | 70 | 6 (5, 9) | 30 | 6 (4, 10) | 22 | 7 (5, 9) | 122 | 6 (4, 9) | 0.863 |
| Variable | N | Percentage | N | Percentage | N | Percentage | N | Percentage | P -value |
|---|---|---|---|---|---|---|---|---|---|
| Female | 41 | 41/84 (49%) | 13 | 13/33 (39%) | 12 | 12/25 (48%) | 66 | 66/142 (46%) | 0.646 |
| Diabetes | 13 | 13/84 (15%) | 7 | 7/33 (21%) | 2 | 2/25 (8%) | 22 | 22/142 (15%) | 0.387 |
| Dyslipidemia | 46 | 46/84 (55%) | 22 | 22/33 (67%) | 17 | 17/25 (68%) | 85 | 85/142 (60%) | 0.327 |
| Hypertension | 58 | 58/84 (69%) | 25 | 25/33 (76%) | 16 | 16/25 (64%) | 99 | 99/142 (70%) | 0.614 |
| CKD | 21 | 21/84 (25%) | 10 | 10/33 (30%) | 5 | 5/25 (20%) | 36 | 36/142 (25%) | 0.575 |
| CVD | 12 | 12/84 (14%) | 11 | 11/33 (33%) | 3 | 3/25 (12%) | 26 | 26/142 (18%) | 0.038 |
| Prior MI | 16 | 16/84 (19%) | 3 | 3/33 (9%) | 2 | 2/25 (8%) | 21 | 21/142 (15%) | 0.226 |
| Prior CABG | 26 | 26/84 (31%) | 5 | 5/33 (15%) | 6 | 6/25 (24%) | 37 | 37/142 (26%) | 0.208 |
| Prior PCI | 21 | 21/84 (25%) | 9 | 9/33 (27%) | 5 | 5/25 (20%) | 35 | 35/142 (25%) | 0.811 |
| Afib/Aflutter | 55 | 55/84 (66%) | 18 | 18/33 (55%) | 11 | 11/25 (44%) | 84 | 84/142 (59%) | 0.132 |
| Variable | Severe | Massive | Torrential | Total | P -value | ||||
|---|---|---|---|---|---|---|---|---|---|
| N | Percentage | N | Percentage | N | Percentage | N | Percentage | ||
| Primary | 57 | 57/84 (68%) | 27 | 27/33 (82%) | 25 | 25/25 (100%) | 109 | 109/142 (77%) | 0.008 |
| Mixed | 18 | 18/84 (21%) | 2 | 2/33 (6%) | 0 | 0/25 (0%) | 20 | 20/142 (14%) | |
| Secondary | 9 | 9/84 (11%) | 4 | 4/33 (12%) | 0 | 0/25 (0%) | 13 | 13/142 (9%) | |
Periprocedural Echocardiographic Features and Echocardiographic Outcomes
In the expanded scale, 59% of patients were regraded as severe, 23% as massive, and 18% as torrential. At baseline, median EROA (cm 2 ) was 0.45 [0.39, 0.50], 0.68 [0.65, 0.75], and 0.95 [0.85, 1.20], and median regurgitant volume (mL) was 72 [64, 85], 95 [83, 112], and 117 [97, 158] in the severe, massive, and torrential groups, respectively ( Table 3 ). Severity of MR correlated with left ventricular ejection fraction (LVEF) (median LVEF 56% [45%, 62%] in severe, 60% [54%, 67%] in massive, and 69% [63%, 74%] in torrential; p < 0.001). Post-TEER, median EROA (cm 2 ) was 0.14 [0.10, 0.25] in the entire cohort, 0.12 [0.08, 0.19] in the severe group, 0.24 [0.15, 0.29] in the massive group, and 0.14 [0.10, 0.17] in the torrential group among patients with quantifiable PISA ( p = 0.025). Table 3 further summarizes transthoracic echocardiogram features post-TEER (median 28 days postimplantation).
