Association between reverse electrical remodeling and cardiac fibrosis markers in patients with cardiac resynchronization therapy.

OBJECTIVE: Cardiac resynchronization therapy (CRT) induces structural and electrical reverse remodeling of the failing heart. However, the association between native QRS narrowing and cardiac fibrosis markers has not been investigated in patients with an implanted CRT device. METHODS: A total of 41 symptomatic patients diagnosed with systolic heart failure who underwent CRT implantation were included in this study. Electrocardiogram findings and cardiac fibrosis marker levels [galectin-3, growth-differentiation factor-15 (GDF-15) and procollagen III N-terminal propeptide (P3TD)] were collected before and 12 months after initiation of biventricular pacing. Reverse electrical remodeling was defined as a decrease in 12-month intrinsic QRS (iQRS) duration by ≥20 milliseconds after CRT implantation. RESULTS: The median QRS duration decreased from 155 milliseconds (interquartile range [IQR]: 142-178 milliseconds) before CRT to 142 milliseconds (IQR: 130-161 milliseconds) (p=0.001) after 12 months of CRT. According to the predefined criteria, electrical remodeling was detected in 16 (39.0%) patients. The median galectin-3, GDF-15, and P3TD levels were significantly decreased after CRT implantation in patients with electrical remodeling [27.65 ng/mL (IQR: 24.4-35.2 ng/mL) vs 23.00 ng/mL (IQR: 16.0-36.7 ng/mL), p=0.017; 3104 pg/mL (IQR: 2923-4825 pg/mL) vs 2276 pg/mL (IQR: 1294-3209 pg/mL), p=0.002; 0.43 ng/mL (IQR: 0.23-0.64) vs 0.15 ng/mL (IQR: 0.04-0.29 ng/mL), p=0.034, respectively]. The galectin-3, GDF-15, and P3TD levels were not significantly changed in patients without electrical remodeling [26.80 ng/mL (IQR: 23.9-31.5 ng/mL) vs 28.80 ng/mL (IQR: 23.0-34.8 ng/mL), p=0.211; 4221 pg/mL (IQR: 2709-4995 pg/mL) vs 3035 pg/mL (IQR: 2038-4872 pg/mL), p=0.143; and 0.34 ng/mL (IQR: 0.11-0.68 ng/mL) vs 0.21 ng/mL (IQR: 0.09-0.37 ng/mL), p=0.112, respectively]. CONCLUSION: The results from the small sample used in this study indicated that electrical reverse remodeling after CRT was associated with a decrease in cardiac fibrosis.

Evaluating the Efficacy and Safety of Internal Cardioversion with Implantable Cardioverter Defibrillator Device for Atrial Fibrillation in Systolic Heart Failure Patients.

BACKGROUND: Atrial fibrillation (AF) commonly observed in patients with heart failure and cardioversion was often needed to restore the sinus rhythm. Previously, there is no study evaluating usefulness of internal cardioversion with implantable cardioverter defibrillator (ICD) device. In this study, we aimed to compare the efficacy and long-term effects of internal cardioversion with ICD devices compared to conventional external cardioversion in patients with AF and heart failure. METHODS: Seventy patients with AF and heart failure who underwent electrical cardioversion were enrolled in the study. Forty patients (mean age 65.36 ± 10.37, 35 male) were assigned to undergo internal cardioversion with approximately 35 J shocks delivered through the ICD electrode. Standard external cardioversion was performed for the remaining patients (30 patients; mean age 66.20 ± 11.89; 24 male) that were similar with regard to baseline, and electrocardiographic characteristics. RESULTS: Sinus rhythm was restored in 32 of 40 patients (80.0%) assigned to internal cardioversion compared with 25 of 30 patients (83.3%) assigned to external cardioversion (P = 0.725). We did not witness any serious complication during the procedure and hospitalization. On the follow-up, there was no statistically significant difference in recurrence of AF and incidence of major cardiovascular events between the internal and external cardioversion groups. CONCLUSIONS: Internal cardioversion with ICD device is an effective and safe method to restore sinus rhythm in heart failure patients with AF.