Artificial intelligence-enhanced electrocardiogram left ventricular diastolic function assessment for prognostic assessment in mitral annulus calcification
Abstract Background Moderate-severe mitral annulus calcification (MAC) and left ventricular (LV) diastolic dysfunction are both linked to increased risks of heart failure and mortality. Assessing LV diastolic function (LVDF) in moderate-severe-MAC by echocardiography is frequently challenging and unreliable. We recently validated an AI-ECG model for LVDF. We aimed to determine if this tool can predict long-term mortality in patients with moderate-severe-MAC and whether it can help establish MAC-specific echocardiographic LVDF parameter cutoffs. Methods This retrospective study included all patients from the AI-ECG LVDF study test cohort who underwent comprehensive transthoracic echocardiography confirming moderate-severe-MAC and ECG within fourteen days of each other at Mayo Clinic between 09/2001 and 06/2022. AI-ECG LVDF was determined based on the index ECG. Patients were categorized based on AI-ECG into groups representing normal/grade-1 LVDF, grade-2 LVDF, or grade-3 LVDG (DF-1, DF-2, and DF-3, respectively). Results Of 2,506 patients with moderate-severe-MAC [mean age 77, 64.1% females], 709 (28.3%), 1,510 (60.3%), and 287 (11.5%) were classified as DF-1, DF-2, and DF-3, respectively. Worse LVDF grade was associated with older age, male sex, lower LV ejection fraction, and higher rates of noncardiovascular and cardiovascular comorbidities. Over a median follow-up of 2.8 years, 1,059 (42.3%) patients died. In multivariable survival analysis, DF-2 [adjusted hazard ratio (aHR) 1.43, 95% confidence interval (95%CI) 1.21-1.68] and DF-3 (aHR 1.54, 95%CI 1.22-1.93) were independently associated with a higher risk of death (figure). Findings were also consistent after adjusting to mitral inflow gradients. When comparing LVDF echocardiographic parameters in controls without MAC matched by age, sex, left ventricular ejection fraction, and AI-ECG DF grade, significant differences were observed. Patients with moderate to severe MAC generally exhibited lower e' velocities, higher TR velocities, elevated E/e' ratios, and increased LAVi. Interestingly, the E/A ratio between MAC patients and their matched controls across AI-ECG LVDF grades remained consistent. Conclusion AI-ECG LVDF predicts mortality risk in patients with moderate-severe-MAC, regardless of mitral inflow gradients. Utilizing AI-ECG LVDF might aid in the risk stratification of patients with significant MAC.
Impact of proportionate versus disproportionate mitral regurgitation on acute procedural changes and clinical outcomes following transcatheter mitral valve repair
Abstract 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.
Topological data analysis identified prognostically-distinct phenotypes in MitraClip patients
Abstract Background Topological data analysis (TDA) is the state-of-the-art unsupervised machine learning framework that can provide insight into the dataset and visualize condensed information via the topological network graph. This robust approach was never used to assess the heterogeneous MitraClip population. Purpose We aim to develop a TDA model that will identify prognostically-distinct phenogroups in MitraClip patients without a priori knowledge of the population and their outcomes. Method Patients who underwent MitraClip (June 2014-September 2020) at Mayo Clinic sites were identified from the institutional database for baseline and follow-up data. Thirteen variables were used for TDA. The topological network graph was created using the Python Scikit-TDA Kepler-Mapper package (v. 2.0.1), and clustering was performed at the graph level with Louvain's modularity method. Kaplan-Meier survival analysis was used to assess the all-cause mortality endpoint of each cluster identified in an unsupervised manner. The dataset with cluster labels was also used to train a Light Gradient Boosted Machine model, and SHapley Additive exPlanations (SHAP) analysis was applied to determine the feature importance. Results A total of 389 consecutive patients were included in the final analysis and two major clusters consisting of 384 patients were identified. The mean age was 80.3±8.7 years; 256 (65.8%) were male. The mean Society of Thoracic Surgeons Mitral Valve Replacement risk score was 9.6±6.9%. Fifty-five (14.5%) patients died during the mean follow duration (185 days). Kaplan-Meier analysis showed significant survival differences among the two clusters (HR: 2.38; 95% CI: 1.39–4.06, p=0.001; Figure 1). Clusters 1 (n=195) was associated with > mild residual mitral regurgitation and worse survival performance and was characterized with worse tricuspid regurgitation severity, a higher proportion of patients with atrial fibrillation/flutter, anterior leaflet prolapse, and mitral annular/leaflet calcification, as summarized in Table 1. Conclusion TDA can identify distinct phenotype clusters with prognostic significance in MitraClip patients based on mitral valve morphology and clinical risk factors. This simple model can facilitate clinical risk stratification for MitraClip patients regarding procedural success and survival performance. Funding Acknowledgement Type of funding sources: None.
Rate of transesophageal echocardiography related complications during 1229 TEE-guided structural heart disease procedures
Abstract Funding Acknowledgements Type of funding sources: None. Background/Introduction: Transesophageal echocardiography (TEE) has long provided excellent diagnostic imaging of left-sided valvular pathology with an excellent safety profile; however, recent data has suggested an increased risk of injury related to TEE guidance. Purpose This study aims to evaluate the incidence and nature of TEE-related oropharyngeal or esophageal complications in patients undergoing TEE-guided structural heart procedures and identify associated risk factors. Methods We reviewed consecutive patients undergoing TEE-guided structural heart procedures from 2005-2020. All procedures were performed under general anesthesia. TEE-related oropharyngeal or esophageal complications were defined as those occurring within 30 days of the procedure resulting in i) persistent dysphagia, odynophagia, or upper gastrointestinal bleeding requiring prolonged endotracheal intubation, therapeutic endoscopic or surgical intervention, or diagnostic imaging that demonstrated oropharyngeal or esophageal injury. ii) upper gastrointestinal bleed requiring transfusion, hemodynamic compromise warranting mechanical or pharmacologic support; or iii) oropharyngeal or esophageal complications leading to death. For multivariate analysis, all variables with a p < 0.15 at univariate analysis were included in the model. Results Among 1229 adult patients undergoing TEE-guided structural heart procedures between 2005-2020, 274 underwent a transcatheter aortic valve replacement (TAVR) with the remaining 955 undergoing either mitral valve transcatheter edge-to-edge repair (mTEER, n = 278), mitral paravalvular leak closure (PVLC, n = 354), mitral valve-in-valve replacement (VIV, n = 41), or left atrial appendage closure (LAAO, n = 282). Of these, 6 (0.5 %) had TEE-related complications; 0% TAVR, 0% VIV, 0.36% LAAO, 0.28% PVLC, 1.41% mTEER (p = 0.14). Of the six patients with complications 3 required at least one day of prolonged tracheal intubation and one a blood transfusion. None required surgical repair. Factors associated with increased complication risk (Table) included a prior history of gastrointestinal bleed (Odds ratio 5.44 [0.98-30.04; p = 0.05]) and longer procedural time (OR per 30 min 1.15 [1.01-1.31, p = 0.03]). Patients undergoing mTEER had an increased risk of complication (OR 6.76 [1.23-37.1 p = 0.03]) and longer procedural time (OR per 30 mins 1.15[1.01-1.31, p = 0.04]) compared to other all other procedures. Conclusion(s): In a large series of patients undergoing cardiac structural interventions under general anesthesia with TEE-guidance, rates of TEE-induced injury were low. Risk of oropharyngeal or esophageal complications was increased with longer procedure times, prior gastrointestinal bleeding history, increased age, increased pre-procedural creatinine, procedural type being mTEER and in male patients, lower height. Abstract Table
Beat-to-beat variability in the tricuspid annulus dimensions and dynamics is markedly increased in atrial fibrillation
Abstract 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
P339 Gradient adjusted cardiac power index does not improve prediction of survival post transcatheter aortic valve replacement compared to cardiac power index alone
Abstract Funding Acknowledgements None Background Cardiac Power Index (CPI) is an integrative hemodynamic measure of cardiac pumping capability and is the product of the simultaneously measured mean arterial pressure (MAP) and cardiac output (CO). In patients with aortic stenosis (AS), MAP is not reflective of mean systolic left ventricular (LV) pressure due to the transvalvular gradient. Non-invasive assessment of mean systolic LV pressure is challenging in severe aortic stenosis. CPI assessed using systemic MAP was previously shown to predict survival post transcatheter aortic valve replacement (TAVR). Purpose We evaluated the utility of a gradient adjusted CPI in predicting survival post TAVR compared to CPI alone Methods A retrospective study was performed including patients undergoing TAVR with 1 year follow-up. Baseline demographics, clinical, and echocardiographic data were abstracted from a cohort of 1,011 patients. CPI was calculated, (CO x MAP)/ (451 x BSA) Watts/m2. Gradient adjusted CPI was calculated using an augmented MAP i) adding aortic valve mean gradient(AVMG) to systolic blood pressure (CPI1); ii) adding aortic valve maximal instantaneous gradient to systolic blood pressure (CPI2) and iii) adding AVMG to MAP (CPI3). Patient survival score was calculated using a step up technique to identify the cut off value for CPI and gradient adjusted CPI to identify, where the maximum difference in mortality occurred. Multivariate cox-regression analysis was performed to adjust for baseline covariates. Receiver operator curves(ROC) for CPI and gradient adjusted CPI were calculated to predict survival post TAVR. Results The mortality rate at 1 yr was 16%. Mean age and AVMG of survivors was 81 +/- 9 yrs and 43 +/-14 mmHg vs 80 +/-9 yrs and 42 +/- 13 mmHg in the deceased group. Proportion of female patients was similar in both groups (p = 0.7). Patients in the deceased group at baseline had a higher prevalence of chronic lung disease, atrial fibrillation, heart failure within 2-weeks of procedure, higher STS-PROM score, lower serum albumin level, higher prevalence of moderate to severe tricuspid regurgitation, higher right ventricular systolic pressure and higher prevalence of dialysis. Both CPI and gradient adjusted CPI were independently associated with survival at 1 year. The area under ROC for CP, CP1, CP2 and CP3 were 0.67 (95% confidence interval [CI] 0.62 - 0.72), 0.65 (95% CI 0.60 – 0.70), 0.66 (95% CI 0.61 – 0.71) and 0.63 (95% CI 0.58 – 0.68) respectively. Conclusion Gradient adjusted CPI did not improve accuracy of predicting post TAVR survival at 1 year compared to CPI alone. Abstract P339 Figure. Area under ROC