Clinical, electrical, and functional changes following CRT-P implantation: short-term results in patients with non-ischaemic cardiomyopathy

Abstract

Aim . Assessment of the correlation between cardiac remodeling, functional status and electrical remodeling after cardiac resynchronisation therapy (CRT) in patients with non-ischaemic cardiomyopathy. Material and methods . A single center, prospective, observational study included 50 patients with non-ischaemic cardiomyopathy who were candidate for CRT implantation. All patients prior to CRT and then 3 months after implantation had standard 12-lead surface ECGs to assess QRSd for assessment electrical response, for assessment of left ventricular ejection fraction (LVEF) and volumes (left ventricular end diastolic and systolic volume, LVEDV and LVESV), mitral regurgitation (degree of mitral regurgitation), pulmonary artery systolic pressure (for diagnosis of pulmonary hypertension), NYHA class and 6 minute walk test (6MWT) to assess patient’s functional capacity. Results . 50 patients with CRT were included (35 males and 15 females, mean age 54.88±7.48 years). All patients were in sinus rhythm with QRS duration (QRSd) ≥120 ms, EF<35% and left bundle branch block. After 3 months; there was significant improvement in QRSd in 82% of the cases (145.3±16.3 ms vs 133.3±17.2 ms, p<0.001). NYHA class improved at least one class in 78% and 6 min walk test improved in 80% (168.5 [131.0; 181.0] m vs 280.0 [237.0; 297.0] m, p<0.001). LVEF increased significantly in 74% of study cases (28.6±2.7 vs 34.5±3.1, p value 0.001) also there were statistically significant improvement in LVEDV (267.0±45.7 to 221.8±41.9 ml, p=0.002) and LVESV (137.43±47.19 to 105.03±42.7 ml, p=0.003). There was statistically significant correlation between QRSd and NYHA class (r=0.392, p=0.005), QRSd and 6MWT (r=0.323, p=0.022) and QRSd with LVEF (r=0.672 with p<0.001). Only seven patients showed improvement in the 3 parameters: LVESV, QRS duration and 6 min walk test. Conclusion . The CRT-pacemaker implantation was associated with significant improvement in QRSd, NYHA class, 6MWT and LV volumes in the short-term period. QRSd improvement was significantly correlated with functional status and LV EF.