The PARTHENON Registry: Acknowledging Value While Addressing the Gaps

We read with interest the report by McDonald et al. on the PARTHENON registry, a prospective observational study evaluating the long-term outcomes, safety, and tolerability of sacubitril valsartan in 996 Canadian patients with heart failure with reduced ejection fraction (HFrEF) over three years of follow-up (1). The registry provides clinically meaningful data in a healthcare system with known inter-provincial variability in access to specialist care and natriuretic peptide (NP) testing. While we commend the authors for the scope and duration of this effort, several methodological and interpretive concerns merit careful consideration.