Long-term left ventricular reverse remodelling with cardiac resynchronization therapy: results from the CARE-HF trial

The aim of the present study was to assess the long-term effects of cardiac resynchronization therapy (CRT) on the reverse remodelling of the left ventricle (LV). The effects of CRT compared with controls on LV dimensions and function were assessed at 3, 9, and 18 months and at the end of study (average 29 months) in 735 (90%) patients with adequate echocardiographic examinations, randomized in the CARE-HF trial. Echocardiographic recordings were submitted to a core laboratory to ensure consistent quantitative analysis. LV volume decreased and ejection fraction increased substantially in the CRT group by 3 months and improved further at each assessment when compared with the control group. Effects were less marked in patients with ischaemic heart disease and those with right ventricular dysfunction, but not in patients with a restrictive LV filling pattern. The extent of reverse remodelling at 18 months showed a modest relationship with baseline interventricular mechanical delay (IVMD). CRT induces sustained LV reverse remodelling with the most marked effects occurring within the first 3-9 months. The extent of remodelling in response to CRT is related to the aetiology of heart failure and, to a lesser extent, to the IVMD.