Daily Cardiology Research Analysis
A randomized trial shows conduction system pacing outperforms right ventricular septal pacing in atrioventricular block, reducing pacing-induced cardiomyopathy and CRT upgrades. A meta-analysis confirms late gadolinium enhancement on CMR is highly sensitive for non-sustained VT and associates with sudden cardiac death in hypertrophic cardiomyopathy. Nationwide analyses reveal increasing traditional and nontraditional risk factors among young adults with AMI, especially in women and non-White gro
Summary
A randomized trial shows conduction system pacing outperforms right ventricular septal pacing in atrioventricular block, reducing pacing-induced cardiomyopathy and CRT upgrades. A meta-analysis confirms late gadolinium enhancement on CMR is highly sensitive for non-sustained VT and associates with sudden cardiac death in hypertrophic cardiomyopathy. Nationwide analyses reveal increasing traditional and nontraditional risk factors among young adults with AMI, especially in women and non-White groups.
Research Themes
- Conduction system pacing vs right ventricular pacing in AV block
- CMR late gadolinium enhancement for arrhythmic risk stratification in HCM
- Epidemiologic trends of AMI risk factors in young adults
Selected Articles
1. Clinical Outcomes of Conduction System Pacing vs Right Ventricular Septal Pacing in Atrioventricular Block: The CSPACE Randomized Controlled Trial.
In 202 AV block patients randomized to conduction system pacing or RV septal pacing, CSP significantly reduced the composite of PICM, CRT upgrade, HF hospitalization, and all-cause mortality over ~25 months. The benefit was driven by lower PICM incidence and the virtual elimination of CRT upgrades.
Impact: This is randomized evidence demonstrating superior clinical outcomes with CSP, directly informing pacing strategy to prevent PICM. It supports upfront CSP in AV block, likely influencing device-therapy guidelines.
Clinical Implications: For AV block patients without CRT indication, CSP should be considered as the default pacing strategy to minimize PICM and downstream need for CRT upgrade. Centers should build expertise to achieve high CSP success rates.
Key Findings
- CSP achieved lower composite adverse outcomes than RV septal pacing (HR 0.35; 95% CI 0.19-0.64).
- PICM incidence was substantially reduced with CSP (HR 0.31; 95% CI 0.15-0.67).
- No CRT upgrades occurred in the CSP arm vs measurable events with RV pacing.
- CSP procedural success was 88.1% (89/101).
Methodological Strengths
- Prospective randomized controlled design with clinically relevant composite endpoints
- Adequate follow-up (~25 months) and time-to-event analysis with hazard ratios
Limitations
- Single-trial, modest sample size may limit power for mortality alone
- CSP success was 88%, highlighting potential learning-curve and generalizability issues; blinding not feasible
Future Directions: Multicenter pragmatic RCTs with larger samples to evaluate mortality and HF hospitalization separately, operator learning curves, cost-effectiveness, and long-term lead performance of CSP.
BACKGROUND: Patients with atrioventricular (AV) block receiving right ventricular (RV) pacing are at risk of pacing-induced cardiomyopathy (PICM), need for upgrade to biventricular cardiac resynchronization therapy (CRT), heart failure hospitalization (HFH), and mortality. Conduction system pacing (CSP) is a promising pacing strategy to mitigate these adverse outcomes. OBJECTIVES: The aim of this study was to compare the clinical outcomes between RV septal pacing (RVsP) and CSP. METHODS: A randomized controlled trial (RCT) was performed in 202 consecutive patients with pacing indication for AV block without CRT indication, with a 1:1 randomization allocation ratio between RVsP and CSP. The primary outcome was a composite endpoint of PICM, upgrade to biventricular CRT, HFH, and all-cause mortality. This trial was registered with the Australian New Zealand Clinical Trials Registry. RESULTS: CSP was successful in 89 of 101 patients (88.1%). After a mean follow-up period of 25.2 ± 11.8 months, CSP was associated with lower composite endpoint (7.17 vs 20.69 events per 100 person-years; HR: 0.35; 95% CI: 0.19-0.64; P < 0.001) primarily driven by lower PICM (CSP 4.58 vs RVsP 14.69 events per 100-person-years; HR: 0.31; 95% CI: 0.15-0.67; P = 0.002) and need for CRT upgrade (0 vs 1.92 events per 100-person-years; HR: 1.65e CONCLUSIONS: This RCT demonstrates the superiority of CSP over RVsP in achieving improved clinical outcomes and supports the indication of CSP as an upfront pacing technique for patients with AV block. (CSPACE: A Randomised Controlled Trial Comparing Right Ventricular Pacing with Conduction System Pacing; ACTRN12619001613190).
2. Prognostic value of late gadolinium enhancement on cardiac magnetic resonance imaging for non-sustained ventricular tachycardia and sudden cardiac death in hypertrophic cardiomyopathy: a meta-analysis.
Across 20 studies, CMR LGE exhibited high sensitivity (~91%) but limited specificity (~37%) for predicting NSVT in HCM, with greater LGE burden in patients with NSVT. Presence of LGE was significantly associated with SCD (OR 3.64), supporting its role in risk stratification alongside other clinical and imaging markers.
Impact: Synthesizes heterogeneous evidence to quantify LGE’s prognostic utility in HCM, reinforcing its incorporation in arrhythmic risk assessment while acknowledging specificity limitations.
Clinical Implications: CMR LGE should inform SCD risk stratification in HCM, especially when combined with NSVT surveillance and other markers; however, clinicians should avoid over-reliance given modest specificity.
Key Findings
- Pooled sensitivity 91.33% and specificity 37.45% for predicting NSVT using LGE.
- Greater LGE extent in patients with NSVT (WMD 5.95%).
- Presence of LGE significantly associated with SCD (OR 3.64).
Methodological Strengths
- Systematic meta-analysis using random-effects models across 20 studies
- Comprehensive evaluation of diagnostic metrics and effect sizes (sensitivity, specificity, OR, WMD)
Limitations
- Heterogeneity across studies in LGE quantification and NSVT ascertainment
- Predominantly observational data; potential publication bias; limited specificity
Future Directions: Prospective, standardized CMR protocols to quantify LGE and integrate with diffuse fibrosis markers and ECG/ambulatory rhythm data for improved SCD risk models.
OBJECTIVE: Non-sustained ventricular tachycardia (NSVT) is an independent predictor of sudden cardiac death (SCD) in hypertrophic cardiomyopathy (HCM). This meta-analysis evaluates the prognostic value of late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR) for predicting NSVT and its association with SCD in HCM. MATERIALS AND METHODS: We screened electronic databases for studies evaluating the prognostic value of LGE in predicting NSVT and SCD in HCM patients. A random-effects model estimated pooled sensitivity, specificity, accuracy, predictive values, and likelihood ratios for NSVT prediction. Association between LGE extent and NSVT incidence was analyzed using weighted mean differences (WMDs), while pooled odds ratios (ORs) with 95% CIs were calculated to assess LGE's association with SCD. RESULTS: Among 20 studies, LGE showed a pooled sensitivity, specificity, and accuracy of 91.33% (95% CI: 88.81-93.86), 37.45% (95% CI: 31.60-43.31), and 52.86% (95% CI: 45.73-59.98), respectively, for NSVT prediction. Positive and negative likelihood ratios and predictive values were, 1.40 and 0.23, and 36.35% and 92.03%, respectively. Patients with NSVT had a significantly greater LGE extent than those without (WMD: 5.95%, 95% CI: 3.08-8.81, p < 0.0001). NSVT prevalence was 28.73% (95% CI: 20.91-36.54). Additionally, LGE presence and SCD were significantly associated (OR 3.64, 95% CI: 2.36-5.61, p < 0.00001). CONCLUSION: LGE on CMR shows high sensitivity but limited specificity and accuracy for NSVT prediction. Moreover, LGE presence was significantly associated with SCD, and NSVT patients had greater LGE extent. Nonetheless, variability in predictive values and likelihood ratios underscores the need to combine LGE with other imaging biomarkers. KEY POINTS: Question Can LGE on CMR predict NSVT and SCD in HCM patients? Findings LGE demonstrated high sensitivity but limited specificity for NSVT prediction. Moreover, LGE presence was significantly associated with SCD, and NSVT patients had greater LGE extent. Clinical relevance LGE on CMR is a valuable marker for NSVT prediction and SCD in HCM patients, but it is not widely integrated into clinical practice. Our study highlights the need to integrate LGE with other imaging biomarkers for improved risk stratification.
3. Trends in Risk Factor Prevalence and Incidence of Acute Myocardial Infarction in Young Adults.
In >4.4 million incident AMI hospitalizations (2011–2021), nearly one-quarter involved young adults; hypertension and tobacco were most prevalent, with higher rates of smoking and obesity than in older adults. Nontraditional risk factors—low income, family history, and psychiatric disorders—were more common in young adults, particularly women and non-White groups, and most risk factors increased over time.
Impact: Defines contemporary, granular risk profiles for young AMI across sex and race/ethnicity at national scale, highlighting rising nontraditional burdens and informing targeted prevention.
Clinical Implications: Primary prevention in young adults should prioritize tobacco cessation and obesity management, while addressing social determinants, family history, and psychiatric comorbidities—especially in women and non-White populations.
Key Findings
- Among 4,431,901 AMI hospitalizations, 22% were young adults (18–54 years).
- Hypertension (64.8%) and tobacco use (57.8%) were most prevalent in young adults; smoking and obesity exceeded older adults.
- Nontraditional RFs (low income, family history of ischemic heart disease, psychiatric disorders) were more common in young adults, with higher burdens in women and non-White groups.
- Most traditional and nontraditional RFs in young adults increased significantly over 2011–2021.
Methodological Strengths
- Very large, nationally representative dataset with decade-long trend analysis
- Stratified analyses by sex and race/ethnicity and inclusion of nontraditional risk factors
Limitations
- Administrative claims data subject to coding/measurement biases and lacks outpatient longitudinal detail
- Abstract truncation precludes full reporting of P-values; causality cannot be inferred
Future Directions: Linkage with outpatient and longitudinal cohorts to assess causality and interventions; targeted implementation studies for tobacco cessation, obesity, and psychosocial risk mitigation in young populations.
BACKGROUND: Contemporary trends in traditional and nontraditional risk factors (RFs) among young adults with acute myocardial infarction (AMI) are not well understood. OBJECTIVES: This study sought to determine differences and trends in the prevalence of traditional and nontraditional RFs among young and older adults hospitalized with incident AMI. METHODS: Incident AMI hospitalizations were analyzed from 2011 to 2021 from the National Inpatient Sample and stratified by age (young adults 18-54 years of age and older adults >54 years of age). Overall RF prevalence and trends in traditional (eg, hypertension) and nontraditional (eg, psychosocial factors) RFs were assessed. Subgroup analysis by sex and race/ethnicity was performed. RESULTS: Among 4,431,901 incident AMI hospitalizations, 974,521 (22%) were young adults. Hypertension (64.8%) and tobacco use (57.8%) were the most prevalent RFs in young adults overall. Among 5 traditional RFs, tobacco smoking and obesity were significantly higher in young adults compared to older adults. Among 12 nontraditional RFs, lowest income quartile, family history of ischemic heart disease, and psychiatric disorders were significantly higher in young adults. Within young adults, women and non-Whites had a higher prevalence of both traditional and nontraditional RFs. Across the study period, the prevalence of most traditional and nontraditional RFs in young adults increased significantly (P CONCLUSIONS: Young adults with AMI have a different and increasing burden of both traditional and nontraditional RFs compared to older adults. These findings could help guide strategies for primary prevention of AMI.