Optimization of heart failure medication after cardiac resynchronization therapy and the impact on long-term survival.

Aims: Treatment with evidence-based heart failure (HF) medication reduces morbidity and mortality, yet they remain underused and underdosed. Cardiac resynchronization therapy (CRT) improves haemodynamics, and might allow for optimization of HF medication. We analysed treatment with HF medication after CRT implantation, long-term adherence to this treatment, and its association with patient survival.

Methods And Results: This observational study included 826 consecutive patients who received a CRT device at a tertiary centre. Data were obtained from patient files and prescription data from the Danish National Prescription Registry. Doses are expressed as percentages of target doses. We used Cox proportional hazard model to compute adjusted hazard ratios (aHRs) for survival with 95% confidence intervals (CIs), adjusted for potential confounders. During the median (quartiles) follow-up of 4.4 (3.0-6.7) years, 324 patients died. Daily doses of beta-blocker (BB) (53 (27-90) vs. 43 (22-75)%; P < 0.001) and angiotensin-converting enzyme inhibitor (ACEi)/angiotensin receptor blocker (ARB) (78 (45-100) vs. 74 (44-97)%; P = 0.02) had increased after 6-month follow-up compared with pre-implantation doses. After 4 years, adherence was 95% to BB and 94% to ACEi/ARB. Treatments with low (≤50%) and high (>50%) doses were associated with prolonged survival for BB (low: aHR 0.65 (0.47-0.90); P = 0.009, and high: aHR 0.50 (0.35-0.70); P < 0.001) and for ACEi/ARB (low: aHR 0.68 (0.46-1.00); P = 0.05, and high: aHR 0.55 (0.38-0.80); P = 0.002).

Conclusion: After CRT implantation, optimization of HF treatment is possible, and long-term adherence to HF medication remains high. Higher doses of BB and ACEi/ARB were associated with prolonged survival.