Reverse of left ventricular volumetric and structural remodeling in heart failure patients treated with cardiac resynchronization therapy.

Patients with heart failure and mechanical dyssynchrony suffer a progressive increase in left ventricular (LV) mass and asymmetrical regional hypertrophy with eventual poor prognosis. The present study sought to investigate whether cardiac resynchronization therapy (CRT) could reverse these abnormalities. The study included 66 consecutive heart failure patients who received CRT. All patients underwent serial evaluation before, 3 months after, and 12 months after CRT. At 12 months after CRT, 50 patients (76%) were echocardiographic volumetric responders, defined as a >15% reduction in LV end-systolic volume. LV end-systolic volume was decreased from 214 +/- 97 ml to 179 +/- 88 ml at 3 months and was further decreased to 158 +/- 86 ml at 12 months after CRT (all p <0.01). LV ejection fraction was improved from 18% +/- 4% to 28% +/- 7% (p <0.001) at 3 months without further change at 12 months after CRT. LV mass was reduced from 242 +/- 52 g to 222 +/- 45 g at 3 months and was further reduced to 206 +/- 50 g at 12 months after CRT (all p <0.01). Improvement of LV geometry was seen as improvements of the end-diastolic (1.64 +/- 0.14 vs 1.77 +/- 0.17, p <0.001) and the end-systolic (1.63 +/- 0.14 vs 1.99 +/- 0.22, p <0.001) sphericity indexes, respectively, at 3 months, without further significant changes at 12 months after CRT. Volumetric responders had a reduction in LV mass from 240 +/- 50 to 210 +/- 38 at 3 months, and LV mass was further reduced to 186 +/- 37 g at 12 months after CRT (all p <0.01). In contrast, nonresponders had a progressive increase in LV mass from 248 +/- 59 g to 258 +/- 54 g at 3 months, and LV mass was further increased to 269 +/- 60 g at 12 months after CRT (all p <0.05). Likewise, only in volumetric responders, regression of the asymmetric hypertrophy of the lateral wall was noted. In conclusion, CRT results in not only volumetric improvement but also in true reverse LV structural remodeling, evidenced by progressive reduction in LV mass and restoration of regional wall symmetry.