Abstract Aims Randomized trials comparing percutaneous left atrial appendage occlusion (LAAO) with oral anticoagulation (OAC) for stroke prevention in patients with atrial fibrillation have yielded conflicting results across device generations and anticoagulant eras. This Bayesian meta-analysis of randomized trials aimed to compare LAAO vs. OAC for stroke or systemic embolism (SSE) and non-procedural clinically relevant bleeding (CRB). Methods and results We conducted a systematic search across five databases (PubMed, Embase, Scopus, Web of Science, and Cochrane CENTRAL) to identify randomized trials of LAAO vs. OAC. Primary outcomes of stroke or systemic embolism, non-procedural CRB and clinical benefit composite were estimated using a Bayesian hierarchical random effects model and findings confirmed across robust sensitivity and subgroup analyses. Posterior probabilities for superiority, non-inferiority and equivalence were estimated using clinically meaningful margins. Six randomized trials including 7004 participants in the intention-to-treat groups, were analysed. LAAO was not associated with lower SSE vs. OAC (pooled RR, 1.11; 95% CrI, 0.80–1.49), with a 74.6% posterior probability of favouring OAC. The posterior probability of crossing non-inferiority was P(HR < 1.4) of 89%. In contrast, LAAO reduced non-procedural CRB (pooled RR, 0.59; 95% CrI, 0.45–0.78). The net clinical benefit composite, pooling contemporary trials, demonstrated a pooled RR of 0.90 (95% CrI 0.51–1.50), with P(RR < 1) of 76%, with substantial heterogeneity for this outcome. Conclusion This Bayesian meta-analysis found no clear evidence supporting clinically meaningful non-inferiority of LAAO over OAC for stroke prevention. Despite reduced non-procedural bleeding, LAAO did not demonstrate a similar reduction in major bleeding.
Abstract 4359985: Uncovering True Severity: The Role of Dobutamine Stress Echocardiogram in Paradoxical Low Gradient Aortic Stenosis
Background: In patients with paradoxical low-gradient severe aortic stenosis (AS) based on aortic valve area (AVA) at rest (<1cm2) and normal left ventricular ejection fraction (LVEF >50%), the role of dobutamine stress echocardiography (DSE) is unclear. While current guidelines recommend assessing aortic valve calcium score in this context, DSE may still offer clinical value. Methods: We conducted a retrospective study on patients with paradoxical low gradient AS (LVEF >50% AVA <1cm 2 , MG < 40 mmHg) at rest who underwent DSE after Institutional Review Board approval. Data was extracted using an internal database. Patients > 18 yrs old with LVEF >50%, mean gradient (MG) < 40 mmHg, and valve area < 1 cm 2 at rest were included. Kruskal-Wallis test was used to identify which resting variables were associated with severe AS (MG >40 mm Hg and Valve area <1 cm 2 ) with DSE. Results: A total of 42 patients were included in the study and variables were reported as means (±SD). The mean age of patients was 78 years (±10) and 60% were female. The mean resting LVEF was 60% (±5%), MG at rest was 28 mmHg (±7) while it was 40 mmHg (±14) with DSE, and mean aortic valve area at rest was 0.9 cm 2 (±0.09) while it was 1.1 cm 2 (±0.23) with DSE. Of the 42 patients, 11 (26%) were found to have severe AS during DSE, defined by a MG >40 mmHg and AVA <1.0 cm 2 . Baseline AVA and MG at rest were significantly associated with severe AS on DSE (p=0.008 and p=0.024, respectively), while age, stroke volume index, and baseline LVEF were not. Univariate regression analysis showed that the area under the curve (AUC) for predicting severe AS was 0.73 for resting MG and 0.77 for resting AVA. A resting AVA cutoff of 0.78 cm 2 provided optimal sensitivity (0.63) and specificity (0.90). For resting MG, a cutoff of 29 mmHg gave a sensitivity of 0.91 and specificity of 0.68 for identifying patients with severe AS. Conclusion: Our study indicated that DSE remains useful in identifying severe AS in substantial number of patients (26%) who exhibit paradoxical low gradient severe AS. Additionally, AVA at rest and baseline mean gradient were statistically the reliable parameters to determine those who may benefit significantly from undergoing DSE. This is one of the first studies to our knowledge in the literature suggesting that DSE may still be useful in identifying severe AS patients despite “paradoxical low gradient severe AS” at rest. Further research is warranted to validate our findings.
Abstract 4364600: Non-Severe Aortic Stenosis with Reduced LVEF: Role of Dobutamine Stress Echo
Background: Patients with low gradient non-severe aortic stenosis (AS) at rest, in the context of reduced left ventricular ejection fraction (LVEF) (less than 50%), occasionally undergo dobutamine stress echocardiogram (DSE). However, limited data is available in the literature regarding the utility of DSE in this context. Methods: We conducted a retrospective study on patients with non-severe AS and LVEF less than 50% at rest who underwent DSE after Institutional Review Board approval. Retrospective data was extracted including rest and DSE parameters using an internal database. Only patients greater than 18 years old, who had an LVEF less than 50%, mean gradient (MG) less than 40 mmHg, and valve area greater than or equal to 1 cm 2 at rest were included in the study. Univariate and multivariate regression methods were used to identify which resting variables were associated with severe AS (MG greater than 40 mm Hg and valve area less than 1 cm 2 ) with DSE. Results: A total of 124 patients were included in the study. The mean age of patients was 78 years (±9) and 84% were male. The mean resting LVEF was 34% (±8%) while it was 40% (±12%) with DSE, mean stroke volume index at rest was 39 mL/m2 (±9) while it was 45 mL/m2 (±10) with DSE, MG at rest was 20 mmHg (±7) while it was 31 mmHg (±10) with DSE, and mean aortic valve area at rest was 1.27 cm 2 (±0.27) while it was 1.24 cm 2 (±0.29) with DSE. Of the 124 patients with non-severe AS at rest, 13 (10.5%) patients had severe AS with DSE. MG at rest was associated with severe AS (OR 1.3; 95% Cl: 1.1 - 1.5; p < 0.001) in a multivariate logistic regression model after adjusting for age, sex, LVEF at rest, SV index at rest. Resting aortic valve mean gradient also showed the highest AUC in relation to likelihood of having severe AS (0.87) (figure 1). Conclusion: Our study indicated that DSE remains useful in identifying severe AS in certain patients (up to 10%) who exhibit non-severe AS at rest in the setting of reduced LVEF. Additionally, MG at rest is the most reliable parameter to determine those who may benefit from undergoing DSE. This is one of the first studies to our knowledge in the literature suggesting that DSE may still be useful in identifying severe AS patients despite non-severe AS (i.e., valve area greater than or equal to 1 cm 2 ) at rest with reduced LVEF. Further research is warranted to validate our findings.
Abstract 4134589: Evaluating risk factors of embolism in patients with cardiac myxoma: A systematic review and meta-analysis
Background: Risk stratification for embolism in cardiac myxomas remains poorly explored. Goals: By this meta-analysis we studied the risk factors assicated with embolism among patients with cardiac myxoma. Methods: A comprehensive search was conducted across PubMed, Embase, Cochrane Library, and Google Scholar from their inception until January 2024. Statistical analyses were performed using Cochrane's RevMan 5.4 software. For each risk factor, the pooled odds ratio or mean difference was calculated along with the corresponding 95% confidence interval. Results: We included 18 studies in our analysis with a total population of 2601 out of which 525 patients (20.1%) had at least one episode of embolism. The pooled analyses showed that hypertension (p = 0.001), New York Heart Association I/II (p = 0.03), irregular tumor surface (p <0.00001), hyperlipidemia (p < 0.0001), coronary artery disease (p=0.01), high mean platelet volume (p=0.02), high tumor mobility (p<0.00001), were significantly associated with increased incidence of embolism. Female gender (p = 0.03) was the only risk factor associated with reduced risk. Other factors like smoking, atrial fibrillation, tumor size, age, body mass index (BMI), diabetes, left ventricular ejection fraction (LVEF), left atrial diameter (LAD) were not significantly associated with embolism (p > 0.05). Conclusion: Our study is the first to report significant pooled outcomes for gender, hyperlipidemia, coronary artery disease, mean platelet volume, and tumor mobility in the population discussed. Hypertension, New York Heart Association I/II, irregular tumor surface, hyperlipidemia, coronary artery disease, mean platelet volume and tumor mobility were significantly associated with high risk while female gender was associated with low risk of embolism. Patients with high-risk factors might benefit from early evaluation and definitive treatment (surgery).