Influence of study discontinuation during the run-in period on the estimated efficacy of sacubitril/valsartan in the PARAGON-HF trial

Aims: The 4822 patients randomized in the PARAGON-HF trial were a subset of 5746 initially eligible patients who entered sequential run-in periods. We identified patient factors associated with study discontinuation during the run-in period and estimated the implications of these discontinuations for the overall study result.

Methods and results: We utilized multivariable logistic regression models to identify patient factors associated with study discontinuation during the run-in period. The efficacy of sacubitril/valsartan in a broader cohort approximating the full run-in population was estimated by weighting randomized patients according to the inverse probability of run-in completion. A total of 924 (16.1%) subjects failed to complete the run-in period. In multivariable models, non-completion was associated with region other than Central Europe, lower systolic blood pressure, lower serum sodium, lower haemoglobin, lower estimated glomerular filtration rate, higher N-terminal pro-B-type natriuretic peptide, higher New York Heart Association functional class, prior heart failure (HF) hospitalization, and lack of prior use of renin-angiotensin system inhibitors or beta-blocker. In repeat analysis of the effect of randomized treatment in PARAGON-HF giving greater weight to participants resembling those who failed to complete the run-in period, the incidence of HF hospitalizations and cardiovascular death was higher, and sacubitril/valsartan treatment reduced the composite of total HF hospitalizations and cardiovascular death compared with valsartan (rate ratio 0.86; 95% confidence interval 0.74-1.00).

Conclusion: Patients with more advanced HF were at higher risk for non-completion of the run-in period in PARAGON-HF. Re-analysis of study outcomes accounting for the effect of run-in non-completion did not alter the estimated treatment effects of sacubitril/valsartan vs. valsartan.