Distinctively different predictors for long‐term outcomes between responders and nonresponders who underwent cardiac resynchronization therapy

BACKGROUND: It is common to develop heart failure (HF) events even in respondents to cardiac resynchronization therapy (CRT) during a long‐term observation period. We investigated the predictors for long‐term outcome in responders in comparison with nonresponders in patients diagnosed with HF along with implanted CRT. METHODS: We enrolled 133 consecutive patients (mean age, 70 ± 10 years; 72 males) implanted with CRT from April 2010 to July 2019. Accurate follow‐up information (mean follow‐up period, 983 ± 801 days) was obtained from 66 responders and 53 nonresponders. RESULTS: Kaplan‐Meier event‐free curves showed that major adverse cerebral and cardiovascular event (MACCE)‐free ratio was significantly lower as the stage of renal function progresses (log rank, 19.5; P < .0001). The baseline estimated glomerular filtration rate (e‐GFR) before CRT was not significantly different between nonresponders and responders. The e‐GFR after judgment of CRT response was lower in patients with MACCEs than those without. Cox proportional hazards regression analysis revealed that low baseline e‐GFR before CRT and after judgment of CRT response was closely related with MACCEs in responders, but not in nonresponders. The survival rate in responders without MACCEs assessed using Kaplan‐Meier analysis was significantly larger in the preserved e‐GFR (baseline value before CRT, >44 mL/min/1.73 m(2)) group than in the depressed group (log rank, 20.29; P < .0001). CONCLUSION: We demonstrate that the factors for MACCEs during long follow‐up periods were distinctively different between responders and nonresponders. Patients with depressed e‐GFRs are suggested to have poor prognosis even if they are responders to CRT.