Impaired renal function is associated with echocardiographic nonresponse and poor prognosis after cardiac resynchronization therapy.

OBJECTIVES: Aims of this study were to investigate the effect of renal function on left ventricular (LV) reverse remodeling and long-term outcome after cardiac resynchronization therapy (CRT), and to explore the relation between LV reverse remodeling and changes in renal function at 6-month follow-up.

BACKGROUND: Renal insufficiency is highly prevalent in heart failure patients, including patients eligible for CRT, and is associated with poor prognosis.

METHODS: The study comprised 490 patients undergoing CRT. Response to CRT was defined as a decrease in LV end-systolic volume ≥15% at 6-month follow-up. Primary end point during long-term follow-up was all-cause mortality.

RESULTS: At baseline, mean estimated glomerular filtration rate (eGFR) was 70 ± 28 ml/min/1.73 m². At 6-month follow-up, 263 patients (54%) demonstrated response to CRT. Responders had an eGFR of 74 ± 26 ml/min/1.73 m² versus 64 ± 28 ml/min/1.73 m² in nonresponders (p < 0.001). During long-term follow-up, patients with an eGFR <60 ml/min/1.73 m² had higher mortality than patients with an eGFR of 60 to 90 ml/min/1.73 m² or an eGFR >90 ml/min/1.73 m² (p < 0.001). Finally, responders to CRT had preservation of renal function (ΔeGFR -0.6), whereas nonresponders had a slight worsening in renal function (ΔeGFR -4.7, p < 0.05).

CONCLUSIONS: Impaired renal function in CRT candidates is associated with nonresponse during 6-month follow-up. Additionally, patients with impaired renal function have worse long-term survival after CRT. Response to CRT results in preservation of renal function.