Baqal, Omar J

Background Connective tissue disorders (CTDs) such as Marfan syndrome, Loeys-Dietz syndrome, and Ehlers-Danlos syndromes are traditionally defined by vascular fragility and aortic complications. Increasing evidence, however, demonstrates that CTDs also predispose to atrial and ventricular arrhythmias, often independent of overt cardiomyopathy or severe valvular disease. Content This review integrates emerging data on the arrhythmogenic substrates of CTDs. Four mechanistic bridges are emphasized: (1) diffuse myocardial fibrosis driven by dysregulated TGF-β signaling, (2) structural valve and annular abnormalities, particularly mitral valve prolapse and mitral annular disjunction, (3) altered mechanotransduction linking extracellular matrix instability to cytoskeletal and nuclear signaling pathways, and (4) downstream ion-channel and gap-junction remodeling as secondary amplifiers. We outline the genetic architecture underlying these processes, focusing on established CTD-implicated genes in the TGF-β/SMAD pathway, valve and annulus regulators, cytoskeletal and myocyte-coupling proteins, and extracellular matrix components, while incorporating emerging CTD modifiers that expand the spectrum of arrhythmia susceptibility. Summary Recognition of CTDs as both vascular and electrical disorders reframes clinical management. Imaging markers such as mitral annular disjunction and diffuse fibrosis, together with targeted ambulatory rhythm monitoring and consideration of genetic context, may improve recognition of higher-risk phenotypes. Therapeutic strategies must balance arrhythmia control with procedural risk in fragile connective tissue substrates. Conclusions By unifying genetic, mechanistic, and clinical insights, this review provides an integrated framework for understanding arrhythmias in CTDs. It underscores the need for prospective registries and genotype-phenotype studies to refine surveillance and prevention strategies.

ABSTRACT Patients requiring permanent pacing after tricuspid valve intervention present challenges due to the need to cross tricuspid valve prostheses. We report three cases of successful dual coronary sinus (CS) lead implantation for biventricular pacing following a range of tricuspid interventions—surgical tricuspid annuloplasty, transcatheter edge‐to‐edge repair, and transcatheter tricuspid valve replacement. The approach avoided tricuspid valve traversal, was technically feasible and resulted in satisfactory pacing performance without procedural complications. Dual CS lead configurations were individualized based on CS anatomy and pacing characteristics. The degree of QRS narrowing achieved varied according to lead location and ventricular activation patterns, highlighting the importance of individualized lead placement strategies and device programming. Dual CS lead pacing may represent a viable alternative for biventricular pacing in selected patients with prior tricuspid valve interventions. Larger studies are needed to evaluate long‐term outcomes and define the optimal role of this approach among available pacing strategies in this patient population.

Abstract: Cardiovascular disease (CVD) remains the leading cause of death worldwide. While advances in treatment have improved outcomes, the greatest gains in public health will come from primary prevention. Risk stratification is the foundation of CVD prevention. Traditional tools, such as pooled cohort equations (PCEs) and SCORE2, do not capture non-traditional risk factors and individual variability, driving efforts to refine existing approaches. We critically discuss emerging risk determinants for primary CVD prevention. Coronary artery calcium scoring can reclassify CVD risk but has limitations related to cost, access, and unvalidated improvements in clinical endpoints. Biomarkers such as apolipoprotein B and lipoprotein(a) may identify residual risk beyond LDL-C, particularly in patients with lipid discordance, but remain underused due to uncertain thresholds and the lack of prospective triallevel outcome data. Trials of colchicine in primary prevention have yielded mixed results, making the role of targeting inflammation unclear in CVD prevention. Polygenic risk scores can stratify genetic risk but face challenges in sensitivity, specificity, and generalizability. Multiomics approaches, while offering the promise of deeper phenotyping, lack established clinical applications and consensus on when their use is appropriate. Artificial intelligence may allow better prediction across cohorts but requires broader validation. Clonal hematopoiesis of indeterminate potential, a marker of inflammation and age-related CVD risk, lacks evidence supporting routine screening or intervention in younger, asymptomatic individuals. The proliferation of new risk stratification tools poses a key challenge: determining when additional data meaningfully alter clinical decisions. Until robust outcome-based evidence emerges, risk enhancers should guide, but not dictate, therapy in selected patients.

Abstract Introduction Despite its prevalence, risk stratification for tachycardia-induced cardiomyopathy remains poorly understood. A deep learning model developed at Mayo Clinic uses standard 12-lead electrocardiograms (ECGs) to predict reduced LVEF (≤35%) in the general population with high accuracy (AUC 0.93) Purpose We investigated the performance of AI-ECG in predicting systolic dysfunction among patients with atrial fibrillation and rapid ventricular response, and compared it with NT-proBNP. Methods We conducted a retrospective study (IRB approval #25-000904) of adult patients (age ≥ 18 years) evaluated across our Clinic enterprise with atrial fibrillation and rapid ventricular response (heart rate >100 bpm), including AF occurring in-hospital and AF at presentation, between January 2017 and May 2025. We excluded patients with a known history of heart failure with reduced EF (<50%). We also collected data on NT-proBNP levels when available within one week of the ECG and echocardiogram. Results A total of 11,801 patients were included, with a mean age of 73.2 +- 12.6 years, 48.6% female and 94.8% White. A combination of AI ECG low EF probability cutoff of 75% had specificity of 96% and 98% NPV in ruling out LVEF < 35%. A combination of AI ECG low EF probability cutoff of 17% and LVEF <35% provided the best balance of sensitivity and specificity, 66% and 78%, respectively with an accuracy of 78%. NT-proBNP data was available on 5,279 patients (48%). Mean NT-proBNP level was 4090 pg/mL. Based on ROC curve analysis, AI ECG was superior to NT-proBNP in predicting LVEF <35% (AUC 0.72 vs 0.59), with accuracy of 77% versus 47% at Youden’s cutpoints of AI-ECG probability of 17% and NT-proBNP level of 1767 pg/mL, respectively Conclusions Our study demonstrates the utility of AI-ECG in predicting reduced LVEF among patients with AF RVR. AI-ECG demonstrated excellent specificity and NPV in ruling out reduced LVEF, serving as a powerful clinical screening tool to assist with the pharmacologic choice of rate control and could change the timing of further echocardiographic evaluation. Our study offers novel insights paving the way for future investigations to help fine-tune and further delineate the role of AI ECG in risk stratifying patients with suspected tachycardia-induced cardiomyopathy, guiding therapeutic and diagnostic clinical decisions

Complete revascularization improves outcomes in patients with ST-segment elevation myocardial infarction (STEMI) and multivessel coronary artery disease (MVD); however, the optimal timing of noninfarct-related artery intervention during the index procedure, immediate revascularization (IR) versus a staged approach (SR), remains uncertain. We conducted a systematic review and meta-analysis of randomized controlled trials comparing SR and IR in patients with STEMI and MVD. The primary outcome was major adverse cardiovascular events. Secondary outcomes included all-cause and cardiovascular mortality, recurrent myocardial infarction, unplanned ischemia-driven revascularization, stent thrombosis, stroke, major bleeding, acute kidney injury, and heart failure hospitalization. Random-effects models with Hartung–Knapp adjustment were used. Trial sequential analysis assessed evidence conclusiveness, and the certainty of evidence was evaluated using the Grading of Recommendations Assessment, Development, and Evaluation. Eight randomized trials, including 5077 patients (2556 SR; 2521 IR), were analyzed. No significant differences were observed between SR and IR for major adverse cardiovascular events [odds ratios (ORs), 1.07; 95% confidence intervals (CI), 0.76–1.49], recurrent myocardial infarction (OR, 1.30; 95% CI, 0.80–2.14), cardiovascular mortality (OR, 0.76; 95% CI, 0.51–1.13), or all-cause mortality (OR, 0.75; 95% CI, 0.54–1.06). Rates of stent thrombosis, stroke, unplanned ischemia-driven revascularization, major bleeding, acute kidney injury, and heart failure hospitalization were also comparable. Trial sequential analysis indicated insufficient information size to draw definitive conclusions, and the certainty of evidence ranged from very low to low. In patients with STEMI and MVD, staged and immediate complete revascularization provide comparable ischemic, safety, and mortality outcomes. Current evidence supports clinical equipoise, and revascularization timing should be individualized pending results from adequately powered trials.

Summary Frailty is independently associated with significantly higher 1‐year mortality and MACCE following MTEER. Frail patients also demonstrated increased risks of HF exacerbation, major bleeding, and readmission. Incorporating frailty assessment into pre‐procedural evaluation may improve risk stratification and guide personalized management strategies.

Abstract Background Emerging evidence suggests that premature ventricular contractions (PVCs) may influence atrial electrophysiology and remodeling, potentially leading to higher rates of atrial fibrillation (AF) recurrence. However, existing data is limited to small-scale studies. Therefore, we conducted a retrospective study to evaluate the potential association between PVCs and AF ablation outcomes, which may suggest the need for more aggressive management of ventricular ectopy in this population. Objective This study aims to assess the 5-year outcomes of catheter ablation for AF in patients with and without a diagnosis of PVCs. Methods Using the TriNetX Analytics Research Network, we included patients aged ≥ 18 years who underwent AF catheter between January 1, 2014, and January 1, 2020. Patients were further categorized into two groups based on the presence of a diagnosis of PVCs. Propensity score matching (PSM) was performed using patient demographics, left ventricular ejection fraction (LVEF), cardiac comorbidities, and medications. Study outcomes included all-cause mortality & hospitalization, acute heart failure (HF), and rhythm control interventions during a 5-year follow-up. Results A total of 15,987 patients with PVCs and 40,605 patients without PVCs were identified. After PSM, 15,152 patients from each group were included for further analysis. Compared to control group, patients with PVCs had significantly higher odds of all-cause mortality (odds ratio [OR], 1.138; 95% confidence interval [CI], 1.034–1.253), all-cause hospitalization (OR, 1.300; 95% CI, 1.243–1.360), acute heart failure (HF) (OR, 1.223; 95% CI, 1.162–1.287), and cardiogenic shock (OR, 2.059; 95% CI, 1.751–2.420) following catheter ablation for AF at 5-year follow-up. Additionally, higher odds of AF requiring cardioversion (OR, 1.135; 95% CI, 1.074–1.199) or repeated ablation (OR, 1.164; 95% CI, 1.085–1.249) were observed in the PVCs group. Conclusion Premature ventricular contractions were associated with poorer clinical outcomes and a higher odds of requiring additional rhythm control intervention following catheter ablation for AF. These findings suggest that PVCs may be a marker for worse outcomes after AF ablation.

Background: Transthyretin (TTR) cardiac amyloidosis is a progressive cardiomyopathy with high mortality; however, the role of implantable cardioverter-defibrillators (ICDs) in this population remains unclear. Methods: This retrospective cohort study included patients with confirmed TTR cardiac amyloidosis, with or without ICDs, from January 1, 2001, to December 31, 2024, across all three Mayo Clinic sites (Arizona, Florida, and Minnesota). Diagnosis was confirmed by endomyocardial biopsy or abnormal technetium pyrophosphate (PYP) scintigraphy. A 1:4 propensity score-matched cohort of non-ischemic cardiomyopathy (NICM) patients with ICDs served as a control group. The primary outcome was all-cause mortality, comparing transthyretin cardiac amyloidosis (TTR-CA) patients by ICD status and against matched NICM patients. Secondary analyses evaluated predictors of mortality, including the use of tafamidis and the indication for ICD (primary vs. secondary prevention). Kaplan–Meier and Cox regression analyses were used to assess predictors of survival and mortality. Results: A total of 463 patients with confirmed TTR cardiac amyloidosis were included. The median follow-up duration was 7.4 years (interquartile range (IQR): 5.3–9.2 years) for the non-ICD group and 6.8 years (IQR: 4.5–9.0 years) for the ICD group. The median age was 74.5 years (IQR: 68.0–80.0 years), and 92.9% of patients were male. Among them, 206 (44.5%) received ICDs and 257 (55.5%) did not. ICD recipients were younger (71.0 vs. 77.0 years; p = 0.001) and had higher rates of hypertension (62.6% vs. 45.6%; p = 0.001), chronic kidney disease (CKD) (62.6% vs. 44.4%; p = 0.001), and diabetes (30.1% vs. 21.8%; p = 0.043). Median left ventricular ejection fraction was lower in the ICD groups (43% vs. 54%; p = 0.007), and N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels were higher in the ICD group (2259.0 pg/mL vs. 1503.0 pg/mL; p = 0.007). Among ICD recipients, 157 (76.2%) received the device for primary prevention, while 48 (23.3%) received the ICD for secondary prevention. Appropriate shocks were delivered in 22 patients (10.6%), primarily for ventricular tachycardia (n = 18) and ventricular fibrillation (n = 4). Inappropriate shocks occurred in six patients (3.0%), and 12 patients (5.8%) experienced device-related complications. Over 10 years of follow-up, ICD implantation did not confer a survival benefit for patients with TTR-CA compared to those without an ICD (p = 0.74). In contrast, a 1:4 propensity-matched NICM cohort with ICDs, which had a median follow-up of 7.1 years (IQR: 4.6–8.8 years), showed significantly improved survival than TTR-CA patients with ICDs (p = 0.034). Among the TTR-CA patients with ICDs, neither the use of tafamidis (p = 0.10) nor the ICD indication (primary vs. secondary prevention; p = 0.85) influenced mortality. In the Cox regression analysis, predictors of mortality in TTR-CA patients included older age (hazard ratio (HR) 1.048; p = 0.001), CKD (HR 1.637; p = 0.029), troponin T >50 ng/L (HR 1.594; p = 0.031), NT-proBNP >3000 pg/mL (HR 1.514; p = 0.050), and ejection fraction <40% (HR 1.935; p = 0.003). ICD implantation was not associated with improved survival (HR 0.932; p = 0.763). Conclusions: In conclusion, our data suggest that ICD therapy may not provide a significant overall survival benefit in older TTR-CA patients with impaired pump function; thus, prospective studies are warranted before any changes to clinical practice are considered. Key predictors of mortality included reduced ejection fraction and elevated cardiac biomarkers. Additional prospective studies are needed to clarify the role of ICDs in treatment strategies for patients with TTR-CA.

Background: Cardiac amyloidosis (CA) patients with reduced left ventricular ejection fraction (EF) are at increased risk for mortality. The benefit of cardiac resynchronization therapy (CRT) in terms of mortality reduction has not been established in this population. Aim: To evaluate the survival benefit of CRT, either CRT-D or CRT-P, in a large cohort of patients with cardiac amyloidosis and reduced EF. Methods: We retrospectively analyzed patients with confirmed CA and reduced EF (<40%) between 2009 and 2023 across Mayo Clinic sites. Patients were stratified into three groups: no device, CRT with pacemaker function (CRT-P), and CRT with defibrillator function (CRT-D). CRT devices were indicated for low ejection fraction less than 40% and patients who had chronic heart failure with a wide QRS. Kaplan-Meier survival estimates were generated, and log-rank tests were used for comparison. A secondary analysis was conducted combining CRT-P and CRT-D versus no device (EF <40%), and a tertiary analysis compared CRT-P versus CRT-D. Results: Among 184 patients [36 AL (20%), 148 ATTR (80%)], 38 (19%) had no cardiac device and EF <40%, 20 (11%) received CRT-P, and 116 (63%) received CRT-D. The median follow-up was 3.4 years (1.7, 5.0). The probability of survival was significantly higher in the CRT group compared to the no device-EF<40 group (Log Rank p=0.013; figure B). Among patients receiving CRT, there was no significant difference in all-cause mortality between those receiving CRT-P and those receiving CRT-D (Log Rank p=0.5; figure C). Conclusion: In patients with cardiac amyloidosis and reduced EF, CRT is associated with significantly improved survival compared to no device. No mortality difference was observed between CRT-P and CRT-D. Prospective studies are warranted.

Background: Sudden cardiac death (SCD) is a leading cause of mortality in the U.S., with emerging evidence pointing to racial disparities and the impact of social vulnerability. Yet, geographic patterns integrating race and county-level vulnerability remain underexplored. Objective: To identify U.S. counties where socially vulnerable communities, stratified by race/ethnicity, experience disproportionate burdens of SCD-related mortality. Methods: We analyzed county-level data (1999-2020), integrating age-adjusted mortality rates (AAMR) for SCD with the 2020 CDC Social Vulnerability Index (SVI). Counties were categorized into SVI quartiles (Q1: Low to Q4: High Social Vulnerability). Analyses were stratified by race/ethnicity: Black or African American, Hispanic/Latino, White, American Indian/Alaska Native (AI/AN), and Asian/Pacific Islander (API). We used RStudio (v2023.06.1) for data cleaning, ANOVA testing, and descriptive analysis. “Unreliable” mortality values were handled as missing or set to zero, with only valid AAMR > 0 included. Hotspot counties were identified by selecting the top decile of AAMR SCD within Q4 SVI counties. Results: Significant disparities emerged across SVI quartiles for Black (p = 0.0003), Hispanic (p < 0.0001), and White (p < 0.0001) groups. Mean AAMR more than doubled from low to high SVI counties in Black communities (17.0 to 39.4 per 100,000). White and Hispanic groups showed smaller but consistent increases. API (p = 0.60) or AI/AN (p = 0.63) groups showed no significant trends. Madison Parish, LA appeared in the top-10 highest-burden counties across all groups. Black populations faced extreme rates in some SVI counties (e.g., Madison Parish, LA: 351.4 per 100,000), while API groups had low AAMR even in vulnerable areas. Data misclassification limited interpretation in the Hispanic group. Conclusions: Black, Hispanic, and White populations showed significant differences in SCD mortality tied to social vulnerability. Black populations in the most vulnerable areas experienced more than twice the rate of mortality compared to those in less vulnerable areas, suggesting a strong correlation between social vulnerability and SCD mortality in Black communities. API and AI/AN groups showed no significant associations, likely due to small sample sizes. Madison Parish, LA reflects the compounded impact of structural disadvantage. Findings support targeted interventions in socially and racially vulnerable counties to reduce preventable cardiac deaths.