Suboptimal medical therapy in patients with systolic heart failure is associated with less improvement by cardiac resynchronization therapy

Background Proven medical therapy is under-prescribed in heart failure (HF) for various reasons. Cardiac resynchronization therapy (CRT) is of proven value in selected patients with HF; however, the degree of benefit in those without the optimal therapy is not clear. Methods This is a retrospective study comparing the effect of CRT in 30 patients without optimal combination therapy (group 1; 10 (33%) without ACEi or equivalent and 25 (83%) without beta-blockers) to an age, sex, ejection fraction (EF) and New York Heart Association (NYHA) class matched control but with the combination (group 2; n = 30) at baseline. All patients were in NYHA class III or IV with EF ≤ 35% and QRS interval ≥ 120 ms. Echocardiographic examination and N-terminal pro-brain natriuretic peptide (NT pro-BNP) levels before and 3 months after CRT were compared between the two groups. The composite endpoints of HF hospitalization or death during follow-up were compared by Kaplan–Meier analysis. Results There were significantly less improvement in EF (+ 4.0 ± 2.5% vs + 10.1 ± 3.2%; p < 0.05) and degree of reverse remodeling in group 1 after 3 months. Patients in group 1 had significantly higher level of NT pro-BNP levels at 3 months (2221 ± 2001 pg/mL vs 1038 ± 905 pg/mL; p < 0.001) and higher rates of HF hospitalization or death (53.3% vs 23.3%; Log rank χ2 5.52; p = 0.019). Conclusion Patients receiving CRT but without optimal medical therapy were associated with less echocardiographic and clinical improvement. Optimal medical therapy, if tolerated, before CRT is necessary.