Long-term outcomes and impact of diagnostic coding of patients with heart failure identified in primary care: insights from the OSCAR-HF cohort

Background and aims Misclassification of heart failure (HF) in primary care electronic health records (EHRs) may affect care quality and outcomes. The OSCAR-HF (Optimising Standards of Care of Heart Failure in general practice) study implemented audit and feedback to improve HF identification in Belgian general practices. We assessed long-term outcomes in the OSCAR-HF cohort and examined differences by preaudit HF registration status.Methods and results We followed 538 patients identified with HF after an EHR audit in eight primary care practices (2017, median follow-up 7.4 years). Overall survival at 1, 2 and 5 years was 93.2%, 84.3% and 62.4%. During follow-up, 1083 hospital admissions occurred; 11.3% were HF-related and 64.3% were non-cardiovascular. We compared patients with a preaudit registered HF diagnosis (n=177) versus those without (n=361). Preaudit registered patients had more HF admissions during follow-up (23% of patients vs 13%, p=0.002), yet lower all-cause mortality in multivariable analysis (adjusted HR 0.62; 95% CI 0.40 to 0.95). Nearly half of the HF with reduced ejection fraction (HFrEF) population had no preaudit HF registration (49%, n=54/110). Unregistered patients more often had HF with preserved ejection fraction (HFpEF) (61% of patients vs 49%, p<0.001).Conclusion In this primary care HF cohort, HF admissions were infrequent and most hospitalisations were non-cardiovascular. Patients with a registered preaudit HF diagnosis had more HF admissions but lower mortality. The high proportion of unregistered HFrEF and the increased range of therapeutic options for the HFpEF spectrum underscore the need for comprehensive case-finding and accurate coding across the HF spectrum in primary care.