Carboxyl-terminal sequences in APOA5 are important for suppressing ANGPTL3/8 activity.

Apolipoprotein AV (APOA5) lowers plasma triglyceride (TG) levels by binding to the angiopoietin-like protein 3/8 complex (ANGPTL3/8) and suppressing its capacity to inhibit lipoprotein lipase (LPL) catalytic activity and its ability to detach LPL from binding sites within capillaries. However, the sequences in APOA5 that are required for suppressing ANGPTL3/8 activity have never been defined. A clue to the identity of those sequences was the presence of severe hypertriglyceridemia in two patients harboring an APOA5 mutation that truncates APOA5 by 35 residues ("APOA5Δ35"). We found that wild-type (WT) human APOA5, but not APOA5Δ35, suppressed ANGPTL3/8's ability to inhibit LPL catalytic activity. To pursue that finding, we prepared a mutant mouse APOA5 protein lacking 40 C-terminal amino acids ("APOA5Δ40"). Mouse WT-APOA5, but not APOA5Δ40, suppressed ANGPTL3/8's capacity to inhibit LPL catalytic activity and sharply reduced plasma TG levels in mice. WT-APOA5, but not APOA5Δ40, increased intracapillary LPL levels and reduced plasma TG levels in Apoa5-/- mice (where TG levels are high and intravascular LPL levels are low). Also, WT-APOA5, but not APOA5Δ40, blocked the ability of ANGPTL3/8 to detach LPL from cultured cells. Finally, an antibody against a synthetic peptide corresponding to the last 26 amino acids of mouse APOA5 reduced intracapillary LPL levels and increased plasma TG levels in WT mice. We conclude that C-terminal sequences in APOA5 are crucial for suppressing ANGPTL3/8 activity in vitro and for regulating intracapillary LPL levels and plasma TG levels in vivo.

Deep learning evaluation of echocardiograms to identify occult atrial fibrillation.

Atrial fibrillation (AF) often escapes detection, given its frequent paroxysmal and asymptomatic presentation. Deep learning of transthoracic echocardiograms (TTEs), which have structural information, could help identify occult AF. We created a two-stage deep learning algorithm using a video-based convolutional neural network model that (1) distinguished whether TTEs were in sinus rhythm or AF and then (2) predicted which of the TTEs in sinus rhythm were in patients who had experienced AF within 90 days. Our model, trained on 111,319 TTE videos, distinguished TTEs in AF from those in sinus rhythm with high accuracy in a held-out test cohort (AUC 0.96 (0.95-0.96), AUPRC 0.91 (0.90-0.92)). Among TTEs in sinus rhythm, the model predicted the presence of concurrent paroxysmal AF (AUC 0.74 (0.71-0.77), AUPRC 0.19 (0.16-0.23)). Model discrimination remained similar in an external cohort of 10,203 TTEs (AUC of 0.69 (0.67-0.70), AUPRC 0.34 (0.31-0.36)). Performance held across patients who were women (AUC 0.76 (0.72-0.81)), older than 65 years (0.73 (0.69-0.76)), or had a CHA2DS2VASc ≥2 (0.73 (0.79-0.77)). The model performed better than using clinical risk factors (AUC 0.64 (0.62-0.67)), TTE measurements (0.64 (0.62-0.67)), left atrial size (0.63 (0.62-0.64)), or CHA2DS2VASc (0.61 (0.60-0.62)). An ensemble model in a cohort subset combining the TTE model with an electrocardiogram (ECGs) deep learning model performed better than using the ECG model alone (AUC 0.81 vs. 0.79, p = 0.01). Deep learning using TTEs can predict patients with active or occult AF and could be used for opportunistic AF screening that could lead to earlier treatment.

Deep Learning-Derived Myocardial Strain.

BACKGROUND: Echocardiographic strain measurements require extensive operator experience and have significant intervendor variability. Creating an automated, open-source, vendor-agnostic method to retrospectively measure global longitudinal strain (GLS) from standard echocardiography B-mode images would greatly improve post hoc research applications and may streamline patient analyses. OBJECTIVES: This study was seeking to develop an automated deep learning strain (DLS) analysis pipeline and validate its performance across multiple applications and populations. METHODS: Interobserver/-vendor variation of traditional GLS, and simulated effects of variation in contour on speckle-tracking measurements were assessed. The DLS pipeline was designed to take semantic segmentation results from EchoNet-Dynamic and derive longitudinal strain by calculating change in the length of the left ventricular endocardial contour. DLS was evaluated for agreement with GLS on a large external dataset and applied across a range of conditions that result in cardiac hypertrophy. RESULTS: In patients scanned by 2 sonographers using 2 vendors, GLS had an intraclass correlation of 0.29 (95% CI: -0.01 to 0.53, P = 0.03) between vendor measurements and 0.63 (95% CI: 0.48-0.74, P < 0.001) between sonographers. With minor changes in initial input contour, step-wise pixel shifts resulted in a mean absolute error of 3.48% and proportional strain difference of 13.52% by a 6-pixel shift. In external validation, DLS maintained moderate agreement with 2-dimensional GLS (intraclass correlation coefficient [ICC]: 0.56, P = 0.002) with a bias of -3.31% (limits of agreement: -11.65% to 5.02%). The DLS method showed differences (P < 0.0001) between populations with cardiac hypertrophy and had moderate agreement in a patient population of advanced cardiac amyloidosis: ICC was 0.64 (95% CI: 0.53-0.72), P < 0.001, with a bias of 0.57%, limits of agreement of -4.87% to 6.01% vs 2-dimensional GLS. CONCLUSIONS: The open-source DLS provides lower variation than human measurements and similar quantitative results. The method is rapid, consistent, vendor-agnostic, publicly released, and applicable across a wide range of imaging qualities.

Prognostic Value of Left Ventricular Global Longitudinal Strain in Transcatheter Edge-to-Edge Repair for Chronic Primary Mitral Regurgitation.

AIMS: Left ventricular global longitudinal strain (LVGLS) is a known outcome predictor in transcatheter edge-to-edge repair (TEER) for functional mitral regurgitation (MR). We aimed to assess its prognostic yield in the setting of TEER for chronic primary MR. METHODS AND RESULTS: We conducted a single-center, retrospective analysis of 323 consecutive patients undergoing isolated, first-time procedures. Stratified by baseline LVGLS quartiles (≤-19%, -18.9-(-16)%, -15.9-(-12)%, > -12%), the cohort was evaluated for the primary composite outcome of all-cause mortality or heart failure hospitalizations, as well as secondary endpoints consisting of mitral reinterventions and the persistence of significant residual MR and/or functional disability - all along the first year after intervention. Subjects with worse (i.e., less negative) LVGLS exhibited higher comorbidity, more advanced HF, and elevated procedural risk. Post-TEER, those belonging to the worst LVGLS quartile group sustained increased mortality (16.9 vs 6.3%, Log-Rank p = 0.005, HR 1.75, 95% CI 1.08-4.74, p = 0.041) and, when affected by LV dysfunction/dilatation, more primary outcome events (21.1 vs 11.5%, Log-Rank p = 0.037, HR 1.68, 95% CI 1.02-5.46, p = 0.047). No association was demonstrated with other endpoints. Upon exploratory analysis, 1-month postprocedural LVGLS directly correlated with and was worse than its baseline counterpart by 1.6%, and a more impaired 1-month value - but not the presence/extent of deterioration - conferred heightened risk for the primary outcome. CONCLUSION: TEER for chronic primary MR is feasible, safe, and efficacious irrespective of baseline LVGLS. Yet, worse baseline LVGLS forecasts a less favorable postprocedural course, presumably reflecting a higher-risk patient profile.

Effects of pericardiocentesis on renal function and cardiac hemodynamics.

BACKGROUND: Previous case studies have reported reversal of acute renal failure after pericardiocentesis in pericardial effusion. This study examines the effects of pericardiocentesis on preprocedural low cardiac output and acute renal dysfunction in patients with pericardial effusion. METHODS: This is a retrospective study of 95 patients undergoing pericardiocentesis between 2015 and 2020. Pre- and post-procedure transthoracic echocardiograms (TTE) were reviewed for evidence of cardiac tamponade, resolution of pericardial effusion, and for estimation of right atrial (RA) pressure and cardiac output. Laboratory values were compared at presentation and post-procedure. Patients on active renal replacement therapy were excluded. RESULTS: Ninety-five patients were included for analysis (mean age 62.2 ± 17.8 years, 58% male). There was a significant increase in glomerular filtration rate pre- and post-procedure. Fifty-six patients (58.9%) had an improvement in glomerular filtration rate after pericardiocentesis (termed "responders"), and these patients had a lower pre-procedure glomerular filtration rate than "non-responders." There was a significant improvement in estimated cardiac output and right atrial pressure for patients in both groups. Patients who had an improvement in renal function had significantly lower pre-procedural diastolic blood pressure and mean arterial pressure. CONCLUSIONS: Pericardial drainage may improve effusion-mediated acute renal dysfunction by reducing right atrial pressure and thus systemic venous congestion, and by increasing forward stroke volume and perfusion pressure.

Mitral Transcatheter Edge-to-Edge Repair in Nonagenarians.

BACKGROUND: There are scarce data regarding mitral transcatheter edge-to-edge repair (TEER) in individuals aged 90 years and above. We aimed to evaluate patient characteristics, procedural aspects, and outcomes in this rapidly growing group. METHODS: We retrospectively studied a single-centre database of 967 isolated, first-time interventions, 103 (10.7%) of which were performed in nonagenarians. Outcomes included all-cause mortality, heart failure (HF) hospitalizations, and the persistence of significant mitral regurgitation (MR) or New York Heart Association functional class III/IV during the first postprocedural year. Analyses were repeated on a 204-patient, propensity score-matched subcohort, controlling for MitraScore elements, sex, race, MR etiology, functional status, atrial fibrillation/flutter, and procedural urgency. RESULTS: Compared with subjects below 90 years of age, nonagenarians were more likely to be white women of higher socioeconomic status; had a higher interventional risk, driven mainly by age and chronic kidney disease; presented more often with primary MR (71.8 vs 39.1%, P < 0.001); and exhibited less advanced biochemical/echocardiographic indices of cardiac remodelling. Further, their procedures were more commonly nonurgent and used fewer devices. A similarly high (> 97%) technical success rate was achieved in the 2 study groups. Likewise, no intergroup differences were observed in the rates or cumulative incidences of any of the explored endpoints, and neither of the outcomes' risks was associated with age 90 and above. Comparable outcomes were also noted in the propensity score-matched subgroups. CONCLUSIONS: In our experience, mitral TEER was equally feasible, safe, and efficacious in patients below and above 90 years of age.

Implications of Mitral Annular Calcification on Outcomes Following Mitral Transcatheter Edge-to-Edge Repair.

BACKGROUND: Limited data exist regarding the impact of mitral annular calcification (MAC) on outcomes of transcatheter edge-to-edge repair for mitral regurgitation (MR). METHODS: We retrospectively analyzed 968 individuals (median age, 79 [interquartile range, 70-86] years; 60.0% males; 51.8% with functional MR) who underwent an isolated, first-time intervention. Stratified by MAC extent per baseline transthoracic echocardiogram, the cohort was assessed for residual MR, functional status, all-cause mortality, heart failure hospitalizations, and mitral reinterventions post-procedure. RESULTS: Patients with above-mild MAC (n=101; 10.4%) were older and more likely to be female, exhibited a greater burden of comorbidities, and presented more often with severe, primary MR. Procedural aspects and technical success rate were unaffected by MAC magnitude, as was the significant improvement from baseline in MR severity and functional status along the first postprocedural year. However, the persistence of above-moderate MR or functional classes III and IV at 1 year and the cumulative incidence of reinterventions at 2 years were overall more pronounced within the above-mild MAC group (significant MR or functional impairment, 44.7% versus 29.9%, P=0.060; reinterventions, 11.9% versus 6.2%, P=0.033; log-rank P=0.035). No link was demonstrated between MAC degree and the cumulative incidence or risk of mortality and mortality or heart failure hospitalizations. Differences in outcomes frequencies were mostly confined to the primary MR subgroup, in which patients with above-mild MAC also experienced earlier, more frequent 2-year heart failure hospitalizations (20.8% versus 9.6%; P=0.016; log-rank P=0.020). CONCLUSIONS: Mitral transcatheter edge-to-edge repair in patients with and without above-mild MAC is equally feasible and safe; however, its postprocedural course is less favorable among those with primary MR.

Outcome of BMI2+: Motivational Interviewing to Reduce BMI Through Primary Care AAP PROS Practices.

BACKGROUND: Pediatric obesity rates in the United States remain at an all-time high. Pediatric primary care clinicians and registered dietitians can help treat childhood obesity, and motivational interviewing (MI) has shown promising effects in prior trials. METHODS: We randomized 18 pediatric primary care practices to receive the Brief Motivational Interviewing to Reduce BMI or BMI2+ intervention or continue with usual care (UC). Practices were recruited through the American Academy of Pediatrics Pediatric Research in Office Settings network. The intervention comprised 4 components1: in-person and telehealth MI counseling by pediatric clinicians; 4 recommended sessions,2 6 telephone MI counseling sessions from a registered dietitian,3 text message reminders and tailored motivational messages, and4 parent educational materials. The main outcome was the change in the percentage of the 95th percentile of BMI. The study was conducted 2017 through 2021. RESULTS: There was a significant treatment x time interaction (b = 0.017, 95% confidence interval: [0.0066-0.027]) for the main outcome, favoring the UC group, with youth in the intervention arm showing a greater relative increase in their percent of the 95th percentile. CONCLUSIONS: There was no overall benefit of the intervention and, contrary to expectations, youth in the intervention arm gained more weight, based on percent of the distance from the 95th percentile than matched youth from UC practices. The absolute excess weight gain among intervention relative to UC youth was small, approximately 0.5 BMI units and 1 kg over 2 years. We offer several potential explanations for these unexpected findings.

Echocardiographic Characteristics of Left and Right Ventricular Longitudinal Function in Patients With a History of Cardiac Surgery.

Previous studies have indicated a reduction in right ventricular (RV) longitudinal motion after cardiac surgery. However, the long-term effect of cardiac surgery on longitudinal motion and the involvement of left ventricular (LV) motion remains unclear. Therefore, this study aimed to comprehensively investigate the longitudinal function of the right ventricle and left ventricle in patients who underwent cardiac surgery. The study included patients who underwent comprehensive transthoracic echocardiography with 3-dimensional RV data sets. By propensity score matching of the clinical and echocardiographic variables, including LV and RV ejection fraction, the echocardiographic parameters were compared between patients with and without a history of cardiac surgery (the surgery and nonsurgery groups, respectively). In this study, the surgery group had significantly lower LV global longitudinal strain values than the nonsurgery group, despite having similar LV ejection fraction. The tricuspid annular plane systolic excursion (TAPSE), tricuspid annular velocity, and RV free wall longitudinal strain were also significantly smaller in the surgery group, whereas the RV ejection fraction was comparable between the 2 groups. In addition, a subgroup analysis based on the time from previous surgery to transthoracic echocardiography (≤1 and >1 year) revealed that TAPSE was reduced in both postoperative phases. In conclusion, LV and RV longitudinal parameters were reduced after cardiac surgery, despite preserved LV and RV global functions. Moreover, TAPSE was reduced even after a long time after cardiac surgery. These findings emphasize the need for careful interpretation of biventricular longitudinal motion in patients with a history of cardiac surgery.

Comparison of prognostic value among echocardiographic surrogates of right ventricular-pulmonary arterial coupling: A three-dimensional echocardiographic study.

OBJECTIVES: Right ventricular (RV)-pulmonary arterial (PA) coupling is important in various cardiac diseases. Recently, several echocardiographic surrogates for RV-PA coupling have been proposed and reported to be useful in predicting outcomes. However, it remains unclear which surrogate is the most clinically relevant. This study aimed to comprehensively compare the prognostic value of different echocardiographic RV-PA coupling surrogates. METHODS: We retrospectively reviewed 242 patients with various cardiac conditions who underwent comprehensive transthoracic echocardiography with three-dimensional RV data. In addition to conventional parameters including tricuspid annular plane systolic excursion (TAPSE), fractional area change (FAC), and PA systolic pressure (PASP), we analyzed RV free wall and global longitudinal strain (FWLS and GLS). We also obtained RV ejection fraction (RVEF), stroke volume (SV), and end-systolic volume (ESV) using three-dimensional RV analysis. RV-PA coupling surrogates were calculated as TAPSE/PASP, FAC/PASP, FWLS/PASP, GLS/PASP, RVEF/PASP, and SV/ESV. The study endpoint was a composite outcome of all-cause death or cardiovascular hospitalization within 1 year. RESULTS: In multivariable analysis, all the RV-PA coupling surrogates were independent predictors of the outcome. Among the surrogates, the model with TAPSE/PASP showed the lowest prognostic value in model fit and discrimination ability, whereas the model with RVEF/PASP exhibited the highest prognostic value. The partial likelihood ratio test indicated that the model with RVEF/PASP was significantly better than the model with TAPSE/PASP (p < .024). CONCLUSION: All the RV-PA coupling surrogates were independent predictors of the outcome. Notably, RVEF/PASP had the highest prognostic value among the surrogates.

Implications of Mitral Annular Disjunction in Patients Undergoing Transcatheter Edge-to-Edge Repair for Degenerative Mitral Regurgitation.

BACKGROUND: Little is known about mitral transcatheter edge-to-edge repair (TEER) in patients with mitral annular disjunction (MAD). OBJECTIVES: The authors sought to explore TEER for degenerative mitral regurgitation (MR) according to MAD status. METHODS: We retrospectively analyzed 271 consecutive patients (median age 82 [Q1-Q3: 75-88] years, 60.9% men) undergoing an isolated, first-ever TEER for whom there were viewable preprocedural echocardiograms. Stratified by MAD status at baseline, the cohort was evaluated for all-cause mortality, heart failure hospitalizations, and mitral reinterventions-the composite of which constituted the primary outcome-as well as functional capacity and residual MR, all along the first postprocedural year. RESULTS: Individuals with (n = 62, 22.9%) vs without MAD had more extensive prolapse and larger valve dimensions. Although the former's procedures were longer, utilizing more devices per case, technical success rate and residual MR were comparable. MAD presence was associated with higher mortality risk (HR: 2.64; 95% CI: 1.82-5.52; P = 0.014), and increased MAD length-with lower odds of functional class ≤II (OR: 0.65; 95% CI: 0.47-0.88; P = 0.006). Among 47 MAD patients with retrievable 1-month data, MAD regressed in 91.5% and by an overall 50% (Q1-Q3: 22%-100%) compared with baseline (P < 0.001). A greater MAD shortening conferred attenuated risk for the primary outcome. CONCLUSIONS: In our experience, TEER for degenerative MR accompanied by MAD was feasible and safe; however, its postprocedural course was somewhat less favorable. MAD shortening following TEER was observed in most patients and proved prognostically beneficial.

Preprocedural transthoracic echocardiography for predicting outcomes of transcatheter edge-to-edge repair for chronic primary mitral regurgitation.

INTRODUCTION AND OBJECTIVES: Limited data exist on the prognostic usefulness of transthoracic echocardiography preceding MitraClip for chronic primary mitral regurgitation (MR). We evaluated the predictive ability of transthoracic echocardiography in this setting. METHODS: A total of 410 patients (median age, 83 years, 60.7% males) were included in the study. The primary outcome was the 1-year composite of all-cause mortality or heart failure hospitalization. Secondary endpoints encompassed individual elements of the primary outcome, the persistence of significant functional impairment or above-moderate MR at 1 year, and above-mild MR at 1-month. RESULTS: Left ventricular end-systolic diameter index of ≥ 2.1cm/m2, corresponding to the cohort's 4th quartile (HR, 2.44; 95%CI, 1.09-4.68; P=.022). Concurrently, higher left atrial volume index (LAVi) and a mid-diastolic medial-lateral mitral annular diameter (MAD) equal to or above the cohort's median of 32.2mm were linked to a higher probability of death and heart failure hospitalization, respectively. LAVi of ≥ 60mL/m2, above-mild mitral annular calcification, and above-moderate tricuspid regurgitation conferred higher odds of functional class III-IV or above-moderate MR persistence. All variables except LAVi and MAD, as well as indexed mid-diastolic medial-lateral MAD of ≥ 20.2mm/m2 and mitral effective regurgitant orifice area of ≥ 0.40 cm2, were associated with greater-than-mild MR at 1 month. CONCLUSIONS: Preprocedural increased indexed left heart dimensions, mainly left ventricular end-systolic diameter index, MAD, mitral annular calcification, mitral effective regurgitant orifice area, and tricuspid regurgitation mark a less favorable course post-MitraClip for chronic primary MR.

Decoding the role of angiopoietin-like protein 4/8 complex-mediated plasmin generation in the regulation of LPL activity.

After feeding, adipose tissue lipoprotein lipase (LPL) activity should be maximized, therefore the potent LPL-inhibitory activity of angiopoietin-like protein 4 (ANGPTL4) must be blocked by ANGPTL8 through formation of ANGPTL4/8 complexes. ANGPTL4/8 tightly binds and protects LPL but also partially inhibits its activity. Recently, we demonstrated ANGPTL4/8 also binds tissue plasminogen activator (tPA) and plasminogen to generate plasmin that cleaves ANGPTL4/8 to restore LPL activity. Although fully active LPL in the fat postprandially is desirable, ANGPTL4/8 removal could subject LPL to profound inhibition by ANGPTL3/8 (the most potent circulating LPL inhibitor), inhibition by other LPL inhibitors like ANGPTL4, ANGPTL3, and ApoC3 or interfere with ApoC2-mediated LPL activation. To understand better these potential paradoxes, we examined LPL inhibition by ANGPTL3/8, ANGPTL4, ANGPTL3, and ApoC3 and LPL stimulation by ApoC2 in the presence of ANGPTL4/8 + tPA + plasminogen. Remarkably, ANGPTL3/8-mediated LPL inhibition was almost completely blocked, with the mechanism being cleavage of fibrinogen-like domain-containing ANGPTL3 present in the ANGPTL3/8 complex. The LPL-inhibitory effects of ANGPTL4, ANGPTL3, and ApoC3 were also largely reduced in the presence of ANGPTL4/8 + tPA + plasminogen. In contrast, the ability of ApoC2 to stimulate LPL activity was unaffected by ANGPTL4/8-mediated plasmin generation. Together, these results explain how plasmin generated by increased postprandial ANGPTL4/8 levels in adipose tissue enables maximal LPL activity by preventing ANGPTL3/8, ANGPTL4, ANGPTL3, and ApoC3 from inhibiting LPL, while permitting ApoC2-mediated LPL activation to occur.

Impact of eccentric jet on outcomes in patients with atrial functional mitral regurgitation: An echocardiographic study.

BACKGROUND: Previous studies have reported the mechanisms underlying atrial functional mitral regurgitation (A-FMR). Recently, A-FMR subtypes based on mitral regurgitation (MR) mechanisms were proposed: "central jet" due to insufficient leaflet remodeling and "eccentric jet" due to atriogenic tethering. However, their prognostic value remains unclear. Therefore, this study investigated the impact of A-FMR subtypes on clinical outcomes. METHODS: Outpatients with significant A-FMR between January 2013 and December 2016 were retrospectively reviewed. They were classified into two subtypes according to the MR jet's direction. All-cause mortality, heart failure hospitalization, and any mitral valve interventions were the primary composite endpoint. RESULTS: Among 101 patients with significant A-FMR, 32% had eccentric jet. The primary endpoint was observed in 56 patients during the follow-up period (median 0.7 years, range 0.1-4.2 years). Kaplan-Meier curves demonstrated that the composite endpoint was higher among patients with eccentric jet than those with central jet (log-rank p < 0.001). Eccentric jet (hazard ratio [HR] 2.46, 95% confidence interval [CI] 1.28-4.73; p = 0.007), age (HR 1.06, 95% CI 1.02-1.11; p = 0.002), symptoms (HR 6.22, 95% CI 2.18-17.8; p < 0.001), severe MR (HR 3.97, 95% CI 1.92-8.18; p < 0.001), and significant tricuspid regurgitation (TR; HR 2.00, 95% CI 1.01-3.97; p = 0.047) were independent predictors of the composite endpoint. CONCLUSIONS: Patients with eccentric jet had poorer outcomes than those with central jet. Eccentric jet, age, symptoms, severe MR, and significant TR were independently associated with poor outcomes.

The HLA class I immunopeptidomes of AAV capsid proteins.

Introduction: Cellular immune responses against AAV vector capsid represent an obstacle for successful gene therapy. Previous studies have used overlapping peptides spanning the entire capsid sequence to identify T cell epitopes recognized by AAV-specific CD8+ T cells. However, the repertoire of peptides naturally displayed by HLA class I molecules for CD8 T cell recognition is unknown. Methods: Using mRNA transfected monocyte-derived dendritic cells (MDDCs) and MHC-associated peptide proteomics (MAPPs), we identified the HLA class I immunopeptidomes of AAV2, AAV6 and AAV9 capsids. MDDCs were isolated from a panel of healthy donors that have diverse alleles across the US population. mRNA-transfected MDDCs were lysed, the peptide:HLA complexes immunoprecipitated, and peptides eluted and analyzed by mass spectrometry. Results: We identified 65 AAV capsid-derived peptides loaded on HLA class I molecules of mRNA transfected monocyte derived dendritic cells. The HLA class I peptides are distributed along the entire capsid and more than 60% are contained within HLA class II clusters. Most of the peptides are organized as single species, however we identified twelve clusters containing at least 2 peptides of different lengths. Only 9% of the identified peptides have been previously identified as T cell epitopes, demonstrating that the immunogenicity potential for the vast majority of the AAV HLA class I immunopeptidome remains uncharacterized. In contrast, 12 immunogenic epitopes identified before were not found to be naturally processed in our study. Remarkably, 11 naturally presented AAV peptides were highly conserved among the three serotypes analyzed suggesting the possibility of cross-reactive AAV-specific CD8 T cells. Discussion: This work is the first comprehensive study identifying the naturally displayed HLA class I peptides derived from the capsid of AAVs. The results from this study can be used to generate strategies to assess immunogenicity risk and cross-reactivity among serotypes during gene therapies.

Outcome of Patients With Both Moderate Aortic Stenosis and Moderate Mitral Stenosis.

Aims: This study aimed to investigate the symptoms and prognosis of patients with both moderate aortic stenosis (AS) and mitral stenosis (MS). Methods and Results: We studied 82 patients with moderate AS and MS diagnosed via transthoracic echocardiography. The patients had a mean age of 79 ± 13 years and 95% of patients had degenerative MS. Out of 82 patients, 34 (41%) had heart failure (HF) symptoms (New York Heart Association class ≥ Ⅱ) or a history of HF admission. Left ventricular ejection fraction, stroke volume index, atrial fibrillation, and right ventricular systolic pressure were independent determinants of HF symptoms. The median follow-up duration was 3.2 (interquartile range, 1.0-4.9) years and clinical events occurred in 48 (59%) patients, including death in 11 (13%) patients, aortic or mitral valve interventions in 22 (27%) patients, and HF hospitalization in 15 (18%) patients. The 5-year survival free of the combined endpoint of aortic or mitral valve interventions, HF hospitalization, or death was 19%. A multivariate predictor of clinical events was HF symptoms (hazard ratio [HR], 2.32; 95% confidence interval [CI], 1.30-4.14; p = 0.0045). Kaplan-Meier survival at 5 years was 61% without intervention and HF symptoms were not associated with mortality. Conclusions: Among patients with both moderate AS and MS, left ventricular ejection fraction, stroke volume index, atrial fibrillation, and right ventricular systolic pressure were strong determinants of HF symptoms. HF symptoms were independently predictive of clinical events.

Outcome Prediction score for mitral transcatheter edge-to-edge repair in patients with concomitant significant tricuspid regurgitation.

BACKGROUND: Tricuspid regurgitation (TR) adversely affects prognosis following mitral transcatheter edge-to-edge repair (TEER). We aimed to derive a risk stratification tool for patients undergoing TEER for mitral regurgitation while exhibiting significant TR. METHODS: This is a single-center, retrospective analysis of 217 consecutive individuals referred to an isolated mitral TEER who had moderate-to-severe or greater TR at baseline. The primary outcome was the 1-year composite of all-cause mortality or heart failure hospitalizations. The cohort was randomly split in a 75%-to-25% ratio, creating train (n = 163) and test (n = 54) datasets. Model development, discrimination, and calibration were based on the train dataset. Internal validation was applied to the test dataset. RESULTS: Overall, 81 (37.3%) patients experienced the primary outcome. After multivariable analysis, a score for predicting the primary outcome was constructed that utilized a 0-to-3 scale, in which each point represented one of three baseline variables independently associated with this combined endpoint: serum B-natriuretic peptide (BNP) level >1,000 pg/mL, qualitative right ventricular (RV) dysfunction on transthoracic echocardiogram, and cardiac implantable electronic device (CIED). C-statistic of the model was 0.66 (95% CI, 0.57-0.75, p = 0.002) and 0.75 (95% CI, 0.61-0.89, p = 0.004) in the train and test datasets, respectively-representing comparable performance to current, more complex tools. Neither this BNP-RV-CIED (BRC) score nor other models were prognostically meaningful in 32 patients excluded from the main analysis who underwent a combined mitral-tricuspid TEER. CONCLUSION: The BRC score is a simple clinical prediction tool that may aid in the triage of isolated mitral TEER candidates with significant pre-existing TR.

Correlates and prognostic implications of LVEF reduction after transcatheter edge-to-edge repair for primary mitral regurgitation.

AIMS: To explore the characteristics and outcomes of patients undergoing transcatheter edge-to-edge repair (TEER) for primary mitral regurgitation (MR) according to the presence of left ventricular ejection fraction (LVEF) reduction post-procedure. METHODS AND RESULTS: We retrospectively analysed 317 individuals [median age 83 (interquartile range, 75-88) years, 197 (62.1%) males] treated with an isolated, first-time TEER that was concluded by a successful clip deployment. Stratified by LVEF change at 1-month compared with baseline, the cohort was evaluated for residual MR and heart failure (HF) indices up to 1-year, as well as all-cause mortality and HF hospitalizations at 2-years. Overall, 212 (66.9%) patients displayed LVEF reduction, which was mainly driven by lowered total stroke volume and diffuse hypocontractility. While post-procedural MR, transmitral mean pressure gradient, and functional status were comparable in the two study groups, patients with LVEF reduction exhibited a greater decline in filling pressures intra-procedurally; left ventricular mass index, pulmonary arterial systolic pressure, and serum natriuretic peptide level at 1-month; and walking limitation at 1-year. Also, by 2 years, they were less likely to die (13.3% vs. 5.7%, P = 0.019), be readmitted for HF (17.1% vs. 9.0%, P = 0.033), and experience either of the two (23.8% vs. 12.7%, P = 0.012). Lastly, LVEF reduction was the only 1-month echocardiographic parameter to independently confer an attenuated risk for the composite of deaths or HF hospitalizations (HR 0.28, 95% CI 0.10-0.78, P = 0.016). CONCLUSION: LVEF reduction at 1-month post-TEER for primary MR is associated with better clinical outcomes, possibly reflecting a more pronounced unloading effect of the procedure.