Citations

Introduction: Unsupervised machine learning (ML) can provide insight into a dataset without significant expert time for annotation and labeling, but was never used to assess the heterogeneous MitraClip population. Hypothesis: We hypothesized that unsupervised k-means ML could identify prognostically-distinct phenogroups in MitraClip patients without a priori knowledge of the dataset. Methods: Patients who underwent MitraClip (June 2014-September 2020) at Mayo Clinic sites were identified from the Mayo institutional NCDR database for baseline and follow-up data. Variables with ≥ 50% missing data were excluded. A k-means algorithm was used for clustering analysis. Input variables were grouped according to 4 distinct k-means determined clusters. Kaplan-Meier survival analysis was used to assess the survival of each cluster. Results: A total of 389 consecutive patients were included in the final analysis, and 95 unique variables were used. The mean age was 80.3±8.7 years; 256 (65.8%) were male. The mean STS MV Replace score was 9.1±5.7. Fifty-five (14.5%) patients died during the mean follow duration (185 days). Kaplan-Meier analysis showed significant survival differences among clusters (Figure 1). The cluster (cluster 2, n=120) with best survival performance (all-cause mortality 3.3%) had features of non-calcified mitral leaflets, nonischemic cardiomyopathy, and less than moderate tricuspid regurgitation. Cluster 3 (n=66) had the worst survival performance (all-cause mortality 27.3%) and opposite features than cluster 2. Conclusions: Unsupervised ML can identify distinct phenotype clusters with prognostic significance in MitraClip patients. Patients with non-calcified mitral leaflets, nonischemic cardiomyopathy, and less than moderate tricuspid regurgitation are intrinsically different from other MitraClip patients and should be considered the potential optimal candidates.

Background/Introduction: More than moderate tricuspid regurgitation (TR) at baseline is associated with worse outcome in MitraClip patients. The presence of iatrogenic ASD (iASD) may cause right-sided volume overload and lead to adverse events. However, the real effects of iASD are not well-investigated in these patients who are vulnerable to right-sided volume overload. Methods: Patients with more than moderate TR who underwent a successful MitraClip procedure in the period from June 2014 to September 2020 were identified from the Mayo institutional NCDR database. Follow-up transthoracic echocardiography (TTE) at about 1 year after the procedure was used to determine the presence of iASD, and speckle-tracking strain analysis was done. Patients were grouped according to the presence of iASD (iASD+ group vs. iASD- group) for statistical analysis. Results: A total of 141 consecutive patients were included for the final analysis (iASD+ group n=44 and iASD- group n=97). The mean age was 79.3 ± 8.8 years, and 72.3% were male. Follow-up echocardiography and speckle-tracking strain data did not show a significant difference in either left or right ventricular function in conventional echocardiographic parameters and strain. LA reservoir strain (13.7 ± 6.9 vs 11.5±7.5, P=0.0418) was the only parameter with significant difference among the two groups. Details are summarized in Table 1 . Conclusion: The presence of iASD can decompress the left atrium, but does not affect left or right ventricular strain function in MitraClip patients with more than moderate baseline TR.

AbstractObjectivesTo assess the impact of pulmonary hypertension (PH) on outcomes of patients with severe mitral annular calcification (MAC) undergoing transcatheter mitral valve replacement (TMVR).BackgroundPH is associated with poor outcomes after mitral valve surgery. Whether the presence of PH in patients with MAC undergoing (TMVR) is associated with poor outcomes, is unknown.MethodsRetrospective evaluation of 116 patients from 51 centers in 11 countries who underwent TMVR with valve in mitral annular calcification (ViMAC) using balloon‐expandable aortic transcatheter valves (THVs) from September 2012 to March 2017. Pulmonary artery systolic blood pressure (PASP) by echocardiogram was available in 90 patients. The subjects were stratified based on PASP: No PH = PASP ≤35 mmHg (n = 11); mild to moderate PH = PASP 36–49 mmHg (n = 21) and severe PH = PASP ≥50 mmHg (n = 58). Clinical, procedural, and echocardiographic outcomes were assessed.ResultsMean age was 72.7 (±12.8) years, 59 (65.6%) were female, Society of Thoracic Surgeons score was 15.8 + 11.8% and 90.0% where in New York Heart Association (NYHA) class III–IV. There was no significant difference in all‐cause mortality at 30 days (no PH = 27.3%, mild–moderate PH = 19.0%, severe PH = 31.6%; p = 0.55) or at 1 year (no PH = 54.5%, mild–moderate PH = 38.1%, severe PH = 56.1%; p = 0.36). No difference in adverse events, NYHA class or amount of residual mitral regurgitation at 1 year were observed between the groups.ConclusionThis study suggests that the presence of PH in patients with predominantly mitral stenosis with MAC undergoing TMVR does not impact mortality or adverse events. Further studies are needed to fully understand the effect of PH in this group of patients.

Background: Several studies have evaluated preprocedural imaging predictors of left ventricular outflow tract obstruction (LVOTO) after transcatheter mitral valve replacement. The patient cohorts in these studies were heterogeneous and included patients with transcatheter mitral valve replacement in failed bioprostheses, annuloplasty rings, and severe mitral annular calcification (MAC). The goal of this study was to evaluate predictors of LVOTO specific to patients undergoing valve-in-MAC. Methods: This study included patients with severe MAC who underwent valve-in-MAC and had optimal quality preprocedural multidetector row computed tomography scans eligible for retrospective analysis. Baseline demographic, echocardiographic, and procedural data on these patients were collected. multidetector row computed tomography parameters were analyzed for association with LVOTO, defined as increase in mean LVOT gradient by ≥10 mm Hg with accompanying hemodynamic instability. Results: Seventy-one patients with optimal preprocedural computed tomography scans were included in this study (mean age, 72.5±13.5 years), 9 of which developed LVOTO (all female). Baseline mean LVOT area, neo-LVOT area (145.3 versus 270.9 mm 2 ; P =0.006), indexed neo-LVOT area (90.1 versus 157.4; P =0.05), and virtual transcatheter heart valve to septum distance (3.1 versus 6.9 mm; P =0.002) were lower in the LVOTO group. Expected % LVOT area reduction was higher in the latter group (58.3 versus 42.7%; P =0.008). In the univariable analysis, the baseline mean LVOT area, neo-LVOT area, indexed neo-LVOT area, and valve to septum distance were all significantly associated with LVOTO. Conclusions: The systolic mean LVOT area, neo-LVOT area, indexed neo-LVOT, expected percentage LVOT area reduction, and the valve to septum distance were associated with LVOTO after valve-in-MAC.

AbstractBackgroundChange in left atrial pressure (LAP) has been shown to be associated with symptom improvement post‐MitraClip; however, the association between acute procedural changes in transmitral diastolic mean gradient (MG) compared to LAP and symptom improvement is not well established.Methods164 consecutive patients undergoing MitraClip at Mayo Clinic between June 2014 and May 2018 were included. Preclip and postclip MG and LAP were recorded. Baseline demographics, clinical, and echocardiographic outcomes, including 30‐day New York Heart Association (NYHA) functional status were obtained from patient charts.ResultsMedian age was 81.5 years (IQR: 76.3, 87), 34% were female and 94.5% had NYHA class III and IV functional status at baseline. At baseline, median MG was 4 mmHg (IQR: 3, 5) and LAP was 19 mmHg (IQR: 16, 23.5). Following MitraClip deployment, the median MG was 4 mmHg (IQR: 3, 6) and the median LAP was 17 mmHg (IQR: 14, 21), 69.5% of patients had less than moderate MR. There was no statistically significant association between change in MG and NYHA functional class at 30 days (OR = 0.95, 95% CI: 0.76–1.20). However, a reduction in LAP following MitraClip deployment was significantly associated with improvement in NYHA functional status at 30 days following adjustments for age and sex (aOR 3.36, 95% CI: 1.34–8.65). There was no significant correlation between change in mean LAP and change in MG (p = .98).ConclusionUnlike change in left atrial pressure, change in MG post‐MitraClip was not associated with patient reported outcomes at 30 days and did not correlate with change in left atrial pressure. Long‐term follow up is needed to evaluate the impact of LA pressure on symptoms.

AbstractBackgroundTranscatheter aortic valve‐in‐valve replacement (ViV) has been widely accepted as a less invasive alternative to treat failed aortic surgical or transcatheter bioprosthetic valves. Angulated aortas present an additional challenge, particularly when using self‐expanding transcatheter heart valves (SE‐THV).MethodsTwo patients with failed surgical bioprosthetic aortic valves and one patient with a failed transcatheter bioprosthetic aortic valve underwent transcatheter aortic ViV using SE‐THV. All were deemed high‐risk for surgical aortic valve replacement by a heart team. All three patients had initial failed SE‐THV delivery using a conventional approach with subsequent successful delivery using the endovascular snare technique.ResultsIn Cases 1 and 2, the SE‐THV was biased towards the greater curve of the angulated aorta and behind the outer frame of the bioprosthetic valve frame. An endovascular snare was deployed through a secondary left femoral artery access, and the valve delivery system was advanced through the snare in the ascending aorta. The snare was tightened around the SE‐THV capsule proximal to the hat‐marker, allowing deflection of the SE‐THV and successful delivery. In Case 3, the SE‐THV interacted with the tall frame of a failed SE‐THV. A snare via the left femoral artery was deployed in the descending artery. The SE‐THV was advanced through the snare, and both the snare and SE‐THV were advanced together to the ascending aorta where the SE‐THV was deflected and successfully delivered.ConclusionsThe endovascular snare technique is a feasible option for successful delivery of SE‐THV during transcatheter aortic ViV in failed transcatheter or surgical bioprosthetic valves in angulated aortas.

Abstract Background Older adults with severe aortic stenosis (AS) are at high risk of mortality unless surgical or transcatheter aortic valve replacement (AVR) is performed. Risk stratification often becomes complicated in frail elders with multi-morbidity, and time constraints limit thorough evaluation of geriatric comorbidities in the outpatient clinic setting. Purpose Utilization of an automated administratively-derived electronic health record (EHR) tool may aid in risk stratification of AS patients undergoing AVR. Methods We reviewed patients with severe AS undergoing AVR at our hospital program and cross-referenced with the Elder Risk Assessment (ERA) score. The ERA score is an administratively abstracted score derived on adults >60 years old followed by general medicine clinic. It contains the following variables: marital status, age, hospitalized days in preceding 2 years, diabetes, coronary disease, heart failure, stroke, pulmonary disease, cancer, and dementia; higher scores indicate greater risk for adverse outcomes. Kaplan-Meier method was used to estimate survival by ERA score tertile. Cox regression was used to test the association of ERA with survival. Results There were 97 patients with severe AS undergoing AVR with ERA scores. Mean age was 80.6 (±6.6) years, 37% were female, average Society of Thoracic Surgery (STS) score was 3.6% (± 2.6), and 7% had transcatheter AVR. Co-morbidities were prevalent and included atrial fibrillation (41%), chronic renal failure (16%), stroke (14%), and diabetes (35%). Over a mean follow-up of 68 months (± 37.9 months), there were 62 deaths. Elevated ERA score was associated with worse long term survival (p=0.016 by log-rank) (Figure 1), with only 49% surviving at 5 years in the highest ERA tertile vs 68% in the lowest ERA tertile. Cox regression demonstrated that the relative risk of death per 6 unit increase in ERA score was 1.54 (95% CI 1.21–1.96, P<0.001) in single variable analysis and 1.43 (95% CI 1.11–1.84, P=0.006) after adjusting for STS score. Conclusions Patients undergoing AVR for severe AS are often co-morbid older adults. An automated EHR derived ERA score was independently associated with survival after accounting for STS score and may streamline and improve risk assessment in these patients. Figure 1 Funding Acknowledgement Type of funding source: Foundation. Main funding source(s): Mayo Clinic