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Arrhythmic prognosis according to left ventricular systolic dysfunction severity in cardiac sarcoidosis
B Michelle Kim1, Daniel Sykora2, Andrew N Rosenbaum2
1Mayo Clinic Alix School of Medicine, Mayo Clinic, Rochester, Minnesota.
Insights
Cardiac sarcoidosis patients with reduced ejection fraction (LVEF) and implantable cardioverter-defibrillators (ICDs) face high ventricular arrhythmia risk. Secondary prevention ICDs are linked to the highest risk in these patients.
Area of Science:
- Cardiology
- Electrophysiology
- Sarcoidosis Research
Background:
- Current guidelines offer varied recommendations for implantable cardioverter-defibrillator (ICD) use in cardiac sarcoidosis (CS) patients with left ventricular ejection fraction (LVEF) <50%.
- This highlights a need for clearer risk stratification in this patient population.
Purpose of the Study:
- To investigate the risk of ventricular arrhythmias in CS patients who received an ICD.
- To compare this risk based on different degrees of left ventricular systolic dysfunction (LVEF ≤35% vs. 36%-49%) and ICD indication (primary vs. secondary prevention).
Main Methods:
- The study analyzed 61 CS patients with an ICD and LVEF <50% at initial evaluation.
- Primary outcome was survival free of sustained ventricular tachycardia (VT)/ventricular fibrillation (VF) post-ICD implantation.
- Comparative analysis was performed for LVEF groups and primary vs. secondary prevention indications.
Main Results:
- No significant difference in VT/VF risk was found between LVEF ≤35% and 36%-49% groups in univariable analysis.
- Secondary prevention ICD indication was the sole significant predictor of incident sustained VT/VF in multivariable analysis (HR 2.86, P=.015).
- Patients receiving ICDs for secondary prevention had a higher VT/VF event burden (0.47 events/patient-year) compared to primary prevention (0.11 events/patient-year).
Conclusions:
- Cardiac sarcoidosis patients with LVEF 36%-49% exhibit a similar high arrhythmic risk as those with LVEF ≤35%.
- Patients receiving ICDs for secondary prevention demonstrate the highest overall risk for ventricular arrhythmias.
- These findings suggest a need to reconsider current guidelines for ICD implantation in CS patients with varying LVEF.
Background:
Current guidelines present varying classes of recommendations for implantable cardioverter-defibrillator (ICD) utilization in patients with cardiac sarcoidosis (CS) and left ventricular ejection fraction (LVEF) <50%.
Objective:
The purpose of this study was to investigate the ventricular arrhythmia risk in CS patients with ICDs and varying degrees of left ventricular systolic dysfunction.
Methods:
The study included CS patients with an ICD and LVEF <50% at index evaluation. The primary outcome was survival free of sustained ventricular tachycardia (VT)/ventricular fibrillation (VF) after ICD implantation and was assessed comparatively for LVEF ≤35% vs 36%-49% and for primary vs secondary prevention ICD indication.
Results:
The study included 61 patients (median age 57 years; 61% male) with LVEF 36%-49% (n = 23) or LVEF ≤35% (n = 38). An ICD was implanted for secondary prevention in 24% and 44% of the LVEF ≤35% and 36%-49% groups, respectively (P = .11). The primary outcome did not differ between the 2 groups in univariable analysis (LVEF ≤35% vs 36%-49%: hazard ratio [HR] 0.85; 95% confidence interval [CI] 0.39-1.82; P = .67). In multivariable analysis, secondary prevention ICD indication was the only significant predictor of incident sustained VT/VF (HR 2.86; 95% CI 1.23-6.67; P = .015). Mean sustained VT/VF event burden was higher in the secondary compared with the primary prevention ICD patients (0.47 vs 0.11 events per patient-year; P = .005) but did not differ significantly between LVEF ≤35% and 36%-49% patients.
Conclusion:
CS patients with ICD indications and LVEF 36%-49% carry similarly high arrhythmic risk as those with LVEF ≤35%. Patients with secondary prevention ICDs have the highest overall risk.
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