Edge-to-edge repair for tricuspid valve regurgitation. Preliminary echo-data from the Tricuspid Regurgitation IMAging (TRIMA) study

Background

The natural history of tricuspid valve regurgitation (TR) is characterized by dismal prognosis and high in-hospital mortality when treated with isolated surgery. We report preliminary procedural and echocardiographic results of our experience with the TriClip System in a cohort of “real-life” patients with functional tricuspid regurgitation.

Methods

From June 2020 to March 2022, 27 consecutive patients with > moderate TR have been screened, 12 underwent transcatheter TriClip repair. The anatomical feasibility was established through a complete transthoracic (TTE) and transesophageal echocardiogram (TEE), and a dedicated CT scan for the right cardiac chambers. The procedure was conducted under general anesthesia, guided by TEE and fluoroscopy.

Results

A total of 12 subjects (83% female) with significant comorbidities and at high surgical risk were included. The mean age was 82±4 years with an average EuroSCORE II of 8.5±4%. TR included functional (75%) and (25%) mixed etiology (lead-induced and functional) and all patients were classified as at least NYHA functional class III. Nine patients (75%) had severe, two patients (17%) massive and one patient (8%) torrential TR.

The implant and procedural success were achieved in all cases, implanting one device in 8 patients (67%) and two in 4 patients (33%). The device was positioned antero-septal in 83% (10of12) and postero-septal in 50% (6of12) of cases. A TR reduction of≥1 grade after procedure was achieved in all patients; 5 (42%) subjects had moderate, 6 (50%) mild, and one patient (8%) with previous torrential TR treated with two clips had severe post-procedural TR because of partial leaflet detachment 48-hours post-procedure. On TTE, significant reductions in effective regurgitant orifice area (0.61±0.28 to 0.31±0.22 cm2; p<0.001) and regurgitant volume (56.3±16.7 to 27.5±16.6ml; p<0.001) occurred between baseline and before hospital discharge. We also observed a significant reduction of tricuspid annulus diameter (43.8±5.6 to 39.8±4.2 mm; p<0.001), right ventricular basal diameter (47.2±6.8 to 42.9±4.5 mm; p=0.001), right atrial area (28.8±8.8 to 26.7±9.4 cm2; p=0.033). While 3 patients demonstrated a reduced TAPSE/PASP ratio (<0.31 mmHg) before the intervention, the overall ratio significantly improved after device placement (0.37±0.1 to 0.46±0.1 mmHg; p=0.011). At 30-days-follow-up, there was significant and sustained improvement in NYHA class with all patients reaching class II or less without additional reported hospitalizations.

Conclusion

In this single center experience, we have shown that treatment with the edge-to-edge TriClip device is safe and effective and is associated with marked clinical benefits and reduced rates of hospitalizations. The resulting echocardiographic improvements indicate leaflet grasping does not just significantly reduce the grade of TR, but also affects adjacent structures and improves right ventricular afterload adaptation.

Funding Acknowledgement

Type of funding sources: None.

Many hands make light work. Echocardiography and computed tomography results from the Tricuspid Regurgitation IMAging (TRIMA) study

Background

Anatomic knowledge of the tricuspid valve (TV) is the first step in the diagnostic algorithm of patients with tricuspid regurgitation (TR), who are candidates for transcatheter tricuspid valve intervention (TTVI). Currently, echocardiography and computed tomography (CT) are available instruments to study the TV anatomy, guide the decision-making process and support the development of novel transcatheter therapies.

Purpose

The Tricuspid Regurgitation IMAging (TRIMA) study aimed to correlate CT parameters to commonly used echocardiographic variables.

Methods

This prospective, single-center study enrolled 22 consecutive patients with TR equal to or greater than severe (≥3+). All patients underwent transthoracic echocardiogram (TTE), transesophageal echocardiogram (TEE) and cardiac CT study, in order to obtain anatomical dimensions of the tricuspid annulus and quantification of right-chambers remodeling and function. Novel CT scan measurements were analyzed. Correlation between measurements on echocardiography and CT imaging was assessed.

Results

Severe TR (3+) was present in 27.4% patients, massive (4+) in 4.8% and torrential (5+) in 3.2%. The mean right ventricle (RV) length, RV mid diameter, and right atrium area were 60.81±9.11 mm, 41.27±7.67 mm and 31.72±9.66 cm2, respectively. Tricuspid annular plane excursion, fractional area change, longitudinal myocardial velocity (S') were 16.09±3.25 mm, 33.36±9.47% and 9.18±1.94 cm/sec, respectively. The annular dimensions obtained by CT scan were generally observed to reduce from diastole to systole, except for eccentricity, angles and distance between the postero-septal and antero-posterior commissure and distance between centroid and antero-posterior commissure. A Kruskal-Wallis test showed a stepwise increase in the tricuspid anatomical regurgitant orifice area (AROA) values by CT across the expanded TR grades by TEE, χ2(2)=6,466, p=0.039. Using the Pearson correlation coefficient, we found a relationship between the AROA and TR grade (r=0.593; p<0.004), as well as ARO-perimeter and TR grade (r=0.470; p<0.027). Additionally, a significant correlation was found between septal lateral annulus diameter obtained by TEE and CT (r=0.637; p=0.001). Anyway, no correlations were found between novel CT variables and TR grade or RV function assessed by echocardiogram, as well as between CT systo-diastolic annulus variability and RV function.

Conclusions

Standard echocardiographic study provide invaluable information about the anatomy and function of the right-chambers, as well as an accurate grade of TR. Conventional and novel variables derived by CT scan may step up the anatomical assessment of the complex morphology of the TV apparatus, thanks to the high spatial resolution of the technique. Therefore, an integrated multimodality assessment is the key point of the screening process of TR candidates for TTVI.

Funding Acknowledgement

Type of funding sources: None.

P318Positive left ventricular remodeling after TAVI assessed by high resolution electrocardiography

Introduction

Transcatheter aortic valve replacement (TAVI) is a novel treatment method for sever aortic stenosis that has a positive impact on reverse left ventricular (LV) remodeling. The morphology and function of the LV can be assessed by transthoracic echocardiography (TTE) and high resolution electrocardiography (HR-ECG). 

Purpose

 

The purpose of our study was to investigate whether morphological and functional myocardial changes after TAVI seen on TTE can be tracked by advanced ECG parameters using HR-ECG.

Methods

Consecutive TAVI patients with transfemoral approach were included in this pilot prospective study. A 5 minute HR-ECG and TTE were performed before and one year after TAVI. Spatial QRS vector amplitude (3D_QRSm), total 12-lead QRS amplitude (12leadV), spatial QRS-T angle (QRST_aM) and spatial ventricular gradient (SVG) were measured using HR-ECG and interventricular septum diastolic diameter (IVSd), left posterior wall diameter (LVPWd), left ventricular ejection fraction (LVEF) and tissue Doppler peak septal systolic velocity (Sm) were obtained by TTE. Student"s test was used for pairs to analyze the differences in sets of variables before and after TAVI and Pearson correlation coefficient to analyze the relationship between TTE and HR-ECG parameters. 

Results

15 patients (5 male; 33.3%) were included in the study. At one year follow-up we found statistically significant reduction in LV wall thickness and increase in LVEF (61.6 ± 6.50 % vs. 66.9 ± 7.84 %, p = 0.043). In the subgroup with narrow QRS (8 patients), we found a statistically significant correlation between change of left posterior wall thickness (deltaLVPW) and spatial QRS vector amplitude (delta3D_QRSm) (r = 0.795; p = 0.018), and between change of left ventricular ejection fraction (deltaLVEF) and spatial QRS-T angle (deltaQRST_aM) (r = 0.604; p = 0.038). No significant correlations were found in the subgroup of patients with wide QRS complex. 

Conclusions

Our pilot study showed that morphological and functional myocardial changes after TAVI in patients with narrow QRS complex can be followed with advanced ECG parameters using HR-ECG. HR-ECG could prove to be a simple and inexpensive method of follow-up after TAVI in patients with narrow QRS. To ascertain the usefulness and reliability of HR-ECG, a study on a larger number of patients would be required.

Synthesis of Wild Type and Mutant Human Hemoglobins in Saccharomyces cerevisiae

We have expressed human alpha and beta-globin cDNA clones from separate, synthetic galactose-regulated hybrid promoters contained on a single plasmid in Saccharomyces cerevisiae. Co-expression of the alpha and beta-globin chains in S. cerevisiae results in the assembly of these proteins into soluble tetrameric hemoglobin that accumulates to 3-5 percent of the total cell protein. Endogenously produced heme is incorporated into the tetramer and the protein produced is functionally and structurally indistinguishable from human Ao hemoglobin. This expression system has been used to produce both wild type hemoglobin and a low O2-affinity hemoglobin mutant that has oxygen binding and dissociation characteristics similar to human whole blood. The yeast expression system we describe may be suitable for the production of a recombinant hemoglobin based blood substitute as well as for detailed structure-activity studies of human hemoglobin.