Mortality in patients with heart failure treated with cardiac resynchronisation therapy. A long-term multi-centre follow-up study

Background: Benefits of cardiac resynchronisation therapy (CRT) for survival in selected congestive heart failure (CHF) patients have been acknowledged by the 2005 ESC guidelines. Aim: To analyse mortality in CRT pacing only (CRT-P) patients during at least one-year follow-up. Methods: This was a prospective, multi-site, at least one-year observational study on mortality and mode of death in patients who received CRT-P due to commonly accepted indications. One-year follow-up data (or earlier death) were available for 105 patients (19 females, 86 males) aged 60.6 +/- 9.8 years (35-78). Baseline NYHA class was 3.2 +/- 0.4 (3-4). Coronary artery disease (CAD) was the underlying aetiology of CHF in 57 (54%) patients and 48 (46%) patients had CHF due to non-coronary factors. Results: Mean follow-up duration was 730 days (360-1780), median 625. There were 21 (20%) deaths: 5 (24%) sudden cardiac deaths (SCD), 13 (62%) deaths due to heart failure (HFD) and 3 (14%) other deaths. Thirteen (62%) patients died within the first year of observation. All SCID occurred in this period. Mean time to death was 303 +/- 277 days (19-960) to HFID -339 +/- 313 days (19-960) and to SCID -208 +/- 127 days (31-343). There were no significant differences between survivors and non-survivors with respect to left ventricular ejection fraction (LVEF) (25 +/- 10 vs. 20 +/- 8%), 6-minute walk test (6minWT) (276 +/- 166 vs. 285 +/- 163 m) and LV diastolic diameter (LVEDD) (71 +/- 9 vs. 78 +/- 10 mm) (all NS). The SCID and HFD patients had similar age (62.0 +/- 5.4 vs. 56.6 +/- 13.2 years), gender (80 vs. 83% males), NYHA class (3.1 +/- 0.2 vs. 3.5 +/- 0.3), LVEF (22 +/- 9 vs. 17 +/- 5%), LVEDD (86 +/- 10 vs. 79 +/- 9 mm), 6minWT (270 +/- 142 vs. 292 +/- 188 m) (NS). In 4 patients from the SCD group CHF was of non-coronary aetiology and only in 1 patient from the HFD group (p=0.003). The values of LVEF, LVEDD and NYHA class in HFD patients who died during the first year after implantation, compared with those who died later, were similar. Conclusions: Sudden cardiac death probability in the studied CRT-P population was the highest during the first year after implantation. Afterwards, the risk of HFD started to increase. Thus, in all patients eligible for CRT prophylactic defibrillation function should be considered.