Accuracy and Efficacy of Artificial Intelligence-Derived Automatic Measurements of Transthoracic Echocardiography in Routine Clinical Practice.

Background: Transthoracic echocardiography (TTE) is the gold standard modality for evaluating cardiac morphology, function, and hemodynamics in clinical practice. While artificial intelligence (AI) is expected to contribute to improved accuracy and is being applied clinically, its impact on daily clinical practice has not been fully evaluated. Methods: We retrospectively examined 30 consecutive patients who underwent AI-equipped TTE at a single institution. All patients underwent manual and automatic measurements of TTE parameters using the AI-equipped TTE. Measurements were performed by three sonographers with varying experience levels: beginner, intermediate, and expert. Results: A comparison between the manual and automatic measurements assessed by the experts showed extremely high agreement in the left ventricular (LV) filling velocities (E wave: r = 0.998, A wave: r = 0.996; both p < 0.001). The automated measurements of LV end-diastolic and end-systolic diameters were slightly smaller (-2.41 mm and -1.19 mm) than the manual measurements, although without significant differences, and both methods showing high agreement (r = 0.942 and 0.977, both p < 0.001). However, LV wall thickness showed low agreement between the automated and manual measurements (septum: r = 0.670, posterior: r = 0.561; both p < 0.01), with automated measurements tending to be larger. Regarding interobserver variabilities, statistically significant agreement was observed among the measurements of expert, intermediate, and beginner sonographers for all the measurements. In terms of measurement time, automatic measurement significantly reduced measurement time compared to manual measurement (p < 0.001). Conclusions: This preliminary study confirms the accuracy and efficacy of AI-equipped TTE in routine clinical practice. A multicenter study with a larger sample size is warranted.

CORRIGENDUM: Preprocedural Controlling Nutritional Status Score as a Predictor of Mortality in Patients Undergoing Transcatheter Mitral Valve Repair　- A Single Center Experience in Japan.

[This corrects the article DOI: 10.1253/circrep.CR-23-0055.].

Impact of Renal Congestion in Patients With Secondary Mitral Regurgitation After Mitral Transcatheter Edge-to-Edge Repair.

BACKGROUND: Renal congestion is a potential prognostic factor in patients with heart failure and recently, assessment has become possible with intrarenal Doppler ultrasonography (IRD). The association between renal congestion assessed by IRD and outcomes after mitral transcatheter edge-to-edge repair (TEER) is unknown, so we aimed to clarify renal congestion and its prognostic implications in patients with mitral regurgitation (MR) who underwent TEER using MitraClip system.Methods and Results: Patients with secondary MR who underwent TEER and were assessed for intrarenal venous flow (IRVF) by IRD were classified according to their IRVF pattern as continuous or discontinuous. Of the 105 patients included, 78 patients (74%) formed the continuous group and 27 (26%) were the discontinuous group. Kaplan-Meier analysis revealed significant prognostic power of the IRVF pattern for predicting the composite outcome of all-cause death and heart failure rehospitalization (log-rank P=0.0257). On multivariate Cox regression analysis, the composite endpoint was independently associated with the discontinuous IRVF pattern (hazard ratio, 3.240; 95% confidence interval, 1.300-8.076; P=0.012) adjusted using inverse probability of treatment weighting. CONCLUSIONS: IRVF patterns strongly correlated with clinical outcomes without changes in renal function. Thus, they may be useful for risk stratification after mitral TEER for patients with secondary MR.

Impact of the MitraClip G4 System on Routine Practice and Outcomes in Patients With Secondary Mitral Regurgitation.

BACKGROUND: The MitraClip G4 system is a new iteration of the transcatheter edge-to-edge repair system. We assessed the impact of the G4 system on routine practice and outcomes in secondary mitral regurgitation (2°MR).Methods and Results: Consecutive patients with 2°MR treated with either the MitraClip G2 (n=89) or G4 (n=63) system between 2018 and 2021 were included. Baseline characteristics, procedures, and outcomes were compared. Inverse probability of treatment weighting and Cox regression were used to adjust for baseline differences. Baseline characteristics were similar, except for a lower surgical risk in the G4 group (Society of Thoracic Surgeons Predicted Risk of Mortality ≥8: 38.1% vs. 56.2%; P=0.03). In the G4 group, more patients had short (≤2 mm) coaptation length (83.7% vs. 54.0%; P<0.001) and fewer clips were used (17.5% vs. 36.0%; P=0.02). Acceptable MR reduction was observed in nearly all patients, with no difference between the G4 and G2 groups (100% vs. 97.8%, respectively; P=0.51). The G4 group had fewer patients with high transmitral gradients (>5mmHg; 3.3% vs. 13.6%; P=0.03). At 1 year, there was no significant difference between groups in the composite endpoint (death or heart failure rehospitalization) after baseline adjustment (10.5% vs. 20.2%; hazard ratio 0.39; 95% confidence interval 0.11-1.32; P=0.13). CONCLUSIONS: The G4 system achieved comparable device outcomes to the early-generation G2, despite treating more challenging 2°MR with fewer clips.

Changes in exercise stress echocardiographic parameters before and after transcatheter mitral valve edge-to-edge repair.

The safety and feasibility are still not well known for exercise-induced mitral regurgitation (MR). This study is aimed to assess and compare the hemodynamic and symptomatic changes in patients with significant secondary MR during exercise stress echocardiography (ESE) before and after transcatheter edge-to-edge repair (TEER). The study included a total of 15 patients with secondary MR who underwent ESE before and after TEER using the MitraClip system (Abbott, Abbott Park, IL, USA). Echocardiographic data of ESE were collected both before the procedure and during the follow-up visit at 3 months. During the one-year postoperative observation period, the rate of readmission due to heart failure was 13% (n = 2), with no recorded fatalities. Although no significant differences of ESE data were observed in exercise-induced pulmonary hypertension or cardiac output before and after the repair, the severity of MR was significantly improved after the procedure, both at rest (2 [2-3] vs. 1 [1-2], p = 0.0125) and during ESE (3 [3-3] vs. 1 [1-1], p < 0.0001). Furthermore, the New York Heart Association Functional Classification was improved (3 [3-3] vs. 1 [1-1], p < 0.0001) after treatment. For a supplemental analysis, MR during ESE was significantly improved not only in cases with atrial secondary MR but also in ventricular secondary MR. Transcatheter edge-to-edge repair for exercise-induced MR resulted in a significant improvement in postoperative MR severity and subjective symptoms. These results are novel, as they have not been extensively reported previously, particularly among Japanese patients.

Preprocedural Controlling Nutritional Status Score as a Predictor of Mortality in Patients Undergoing Transcatheter Mitral Valve Repair　- A Single Center Experience in Japan.

Background: A high score for controlling nutritional status (CONUT) due to poor nutritional status has been associated with adverse outcomes in patients with chronic heart failure. However, because little is known about the effect of CONUT score on mortality rates after transcatheter mitral valve repair, we evaluated nutrition screening tools for prognosis prediction in patients undergoing transcatheter mitral valve repair using the MitraClipTM system. Methods and Results: We retrospectively analyzed 148 patients with severe mitral regurgitation (MR) who underwent MitraClipTM implantation between April 2018 and April 2021. The preprocedural CONUT scores were assessed at the time of hospitalization, the primary outcome was all-cause death, and the analysis was of the mortality and incidence rates of cardiac events 1 year post-operation. Functional MR was of ischemic origin in the majority of patients (69.6%), with a mean left ventricular ejection fraction of 48.9±15.8%. Kaplan-Meier curves indicated that all-cause death was significantly worse in the high-CONUT score group than in the low-CONUT score group. Cox hazard analysis showed a significant association between all-cause death and CONUT score, as well as MitraScore. Conclusions: Preprocedural CONUT score, as well as MitraScore, in patients undergoing transcatheter edge-to-edge mitral valve repair may predict an increased risk of all-cause death. This knowledge should allow the heart team to accurately assess the clinical implications and prognostic benefits of the procedure in individual patients.

Additive value of the right parasternal view for the assessment of aortic stenosis.

BACKGROUND: Although Doppler evaluation using a multiplanar method is recommended to assess the severity of aortic stenosis (AS) with transthoracic echocardiography, evidence on the diagnostic significance of a non-apical method is limited. This study aimed to compare the use of the apical with the use of the right parasternal view (RPV) method to evaluate AS severity and to examine the diagnostic significance of performing the RPV method in addition to the apical method during the evaluation. METHODS: This retrospective observational study included 276 consecutive patients (mean age: 79 ± 10 years; women, 56%) with severe AS (aortic valve area [AVA] ≤1.0cm2 ). The severity of AS according to the apical method and that according to the RPV for all subjects were compared, and the significance of performing the RPV method in addition to the apical method was examined. Furthermore, we compared the concordance group, in which the apical and RPV methods indicated matching in severity, and the discordant group, in which the apical and RPV methods did not indicate matching severity. RESULTS: Peak velocity (Vmax ), mean pressure gradient (MG) were significantly higher and the AVA, AVAi, and Doppler velocity index (DVI) were significantly smaller when the RPV was added to the apical view. Performing the RPV method in addition to the apical method significantly decreased the number of low PG AS cases (MG < 40 mmHg) from 69.9% to 65.0% and it increased the number of very severe AS cases (Vmax ≥ 5 m/s) from 8.7% to 14.5%. Deviation of Doppler angle was significantly greater in the discordant group compared to the concordant group (22.5 ± .6 vs. 31.8 ± 1.7, p < .001). CONCLUSIONS: By performing the RPV method in addition to the apical method to determine AS severity, the diagnosis of AS to be resolved in approximately 10% of cases. These results suggest that AS severity may be underestimated by using the apical method alone.

Usefulness of Intra-Aortic Balloon Pump Off Test With Echocardiography for Decision Making in Secondary Ischemic Mitral Regurgitation: A Case Report.

Our patient was a 60-year-old male with myocardial infarction. Urgent percutaneous coronary intervention was performed with intra-aortic balloon pump (IABP) support. Despite successful revascularization, the patient suffered from cardiogenic shock and heart failure. Secondary mitral regurgitation (MR) was mild and seemed unlikely to be the cause of heart failure. However, when IABP was temporarily stopped (IABP-OFF), secondary MR was aggravated; therefore, we decided to perform transcatheter mitral valve repair. Thereafter, only mild residual MR was observed after IABP removal, and hemodynamic stability was achieved. This case presents IABP-OFF test with echocardiography as a useful method to assess secondary MR.