Daily Cardiology Research Analysis
A randomized trial shows left bundle branch area pacing is non-inferior to biventricular pacing for cardiac resynchronization, potentially reshaping device strategy. A prospective, protocolized investigation identifies pulmonary and cardiac causes as dominant etiologies of in-hospital cardiac arrest and exposes low agreement with presumed causes. Stress CMR robustly predicts major adverse events in diabetics and non-diabetics alike, supporting broader risk stratification beyond symptoms.
Summary
A randomized trial shows left bundle branch area pacing is non-inferior to biventricular pacing for cardiac resynchronization, potentially reshaping device strategy. A prospective, protocolized investigation identifies pulmonary and cardiac causes as dominant etiologies of in-hospital cardiac arrest and exposes low agreement with presumed causes. Stress CMR robustly predicts major adverse events in diabetics and non-diabetics alike, supporting broader risk stratification beyond symptoms.
Research Themes
- Conduction system pacing versus biventricular pacing for CRT
- Protocolized etiologic workup after in-hospital cardiac arrest
- Stress CMR for long-term prognostication in diabetes
Selected Articles
1. Conduction system pacing vs. biventricular pacing for cardiac resynchronization: the CSP-SYNC randomized single centre study.
In a single-centre randomized trial of 62 CRT candidates, left bundle branch area pacing achieved non-inferior improvement in LVEF versus biventricular pacing (14.0% vs 8.5% at 6 months), with similar reductions in LVESV and improvements in functional status. Temporal remodeling and HF hospitalization rates were comparable across arms.
Impact: This randomized comparison directly informs device strategy, suggesting conduction system pacing can match conventional BiV pacing for CRT efficacy. It addresses a current practice shift with controlled evidence.
Clinical Implications: LBBAP may be considered an effective alternative to BiV for CRT in eligible patients, influencing lead selection and operator training while potentially simplifying venous anatomy constraints.
Key Findings
- Non-inferior LVEF improvement at 6 months with LBBAP vs BiV (14.0% vs 8.5%; non-inferiority P<0.001).
- Comparable decreases in LVESV and improvements in 6-minute walk test and NYHA class across groups.
- Similar trends in LV remodeling and heart failure hospitalizations between strategies through 12 months.
Methodological Strengths
- Randomized allocation with prespecified primary endpoint (LVEF change at 6 months).
- Multiple clinical and echocardiographic secondary endpoints including 12-month assessments.
Limitations
- Single-centre, small sample size (n=62) limits generalizability and power for safety endpoints.
- Non-inferiority design without blinding; trial registration and CONSORT adherence not specified.
Future Directions: Larger multicentre RCTs should confirm clinical outcomes, durability, and safety, and define patient subgroups most likely to benefit from LBBAP.
2. Why do patients develop in-hospital cardiac arrest? A prospective clinical observational study (WHY-IHCA).
In a prospective, protocolized IHCA workup including post-mortem imaging when no ROSC occurred, pulmonary (30%) and cardiac (29%) etiologies predominated. Hypoxia (21%) and myocardial ischemia (11%) were the most frequent subcategories, and agreement between presumed and expert-adjudicated causes was low.
Impact: Establishes a reproducible etiologic pathway for IHCA, demonstrating that protocolized imaging and testing improve cause attribution and challenge initial bedside assumptions.
Clinical Implications: Hospitals should consider standardized IHCA etiologic protocols, including early whole-body imaging and toxicology, and caution reliance on initial presumed causes to guide secondary prevention and quality review.
Key Findings
- Pulmonary (30%) and cardiac (29%) etiologies predominated among 150 IHCA cases.
- Hypoxia (21%) and myocardial ischemia (11%) were the leading subcategories.
- Low concordance between presumed and expert-adjudicated causes (kappa 0.16–0.42); expert panel unknown only 7% vs presumed unknown 26%.
Methodological Strengths
- Prospective, protocolized, and comprehensive etiologic investigation including post-mortem imaging.
- Expert panel adjudication with predefined main and subcategories.
Limitations
- Single-centre study limits generalizability; moderate sample size.
- No long-term outcomes beyond etiologic determination; potential adjudication subjectivity despite panel process.
Future Directions: Multicentre validation of protocolized IHCA workups and evaluation of their impact on secondary prevention, outcomes, and resource utilization.
3. The role of stress cardiovascular magnetic resonance in patients with Diabetes Mellitus.
In 2,718 propensity-matched patients followed a median 6.5 years, stress CMR markers—ischemia or LGE extent ≥3 segments—were strong, independent predictors of MACE (HR 7.14 and 5.03, both p<0.001) with similar prognostic value in diabetics and non-diabetics. Asymptomatic diabetics had event rates comparable to symptomatic patients.
Impact: Demonstrates robust, symptom-agnostic prognostic utility of stress CMR, supporting broader risk stratification in diabetes beyond symptom-based referral.
Clinical Implications: Stress CMR can guide intensity of preventive therapy in diabetics irrespective of symptoms; however, randomized trials are needed to assess whether CMR-guided strategies improve outcomes.
Key Findings
- Propensity-matched cohort of 1,359 diabetics and 1,359 non-diabetics; median follow-up 6.5 years with 14.2% MACE.
- Ischemia or LGE extent ≥3 segments independently predicted MACE (HR 7.14 and 5.03; both p<0.001).
- Prognostic value did not differ by diabetes status; asymptomatic diabetics had similar event rates to symptomatic patients.
Methodological Strengths
- Large, two-centre cohort with propensity-score matching and long follow-up.
- Hard clinical endpoints (CV death and non-fatal MI) with robust hazard estimates.
Limitations
- Observational design with potential residual confounding and referral bias.
- Only two centres; no randomized assessment of CMR-guided management.
Future Directions: Randomized trials to test CMR-guided prevention strategies in diabetics, including asymptomatic individuals, and cost-effectiveness analyses.