In this nationwide study of 10.9 million Czech residents, we developed and applied a nationwide claims-based staging framework aligned with the 2021 Universal Definition of HF, using routinely collected administrative healthcare data to approximate the HF continuum over a 10-year period. Four principal findings emerge. First, we demonstrate that nationwide administrative data can be used to classify all HF stages, enabling surveillance of the disease continuum beyond clinically overt HF. Second, the prevalence of both preclinical HF stages increased substantially over time, even after age standardization, indicating that the growing HF burden cannot be explained by population aging alone. Third, more than 95% of individuals who developed clinical HF had previously been classified as Stage A or B, highlighting a prolonged and potentially modifiable preclinical phase. Finally, despite recent improvements, substantial gaps remain in the implementation of guideline-directed medical therapy among patients with symptomatic HF.

Current epidemiological surveillance primarily focuses on symptomatic HF, whereas the preclinical stages remain poorly characterized at the population level. Most available data originate from prospective cohort studies,^{12, 25–27} which provide valuable mechanistic insights but are limited by selective recruitment, restricted age ranges, and relatively small sample sizes. Consequently, they are not ideally suited for monitoring nationwide trends or informing healthcare planning. By contrast, administrative healthcare databases encompass entire populations and are continuously updated, making them an attractive resource for population-level surveillance. Until now, however, the absence of a standardized administrative definition of HF stages has limited their application to the full HF continuum.

To address this gap, we operationalized the 2021 Universal Definition of HF within routinely collected administrative healthcare data. Because administrative datasets lack imaging and biomarker information required by the original definition, our framework incorporates pragmatic modifications based on diagnostic codes, prescription claims, and procedural records.

We also refined the definition of symptomatic HF to improve case ascertainment. Because HF is frequently undercoded in administrative databases, particularly among patients with preserved ejection fraction or those managed without hospitalization, we supplemented HF-specific diagnostic codes with a combination of broader cardiac disease codes and pharmacotherapy strongly suggestive of symptomatic HF (furosemide, spironolactone, eplerenone, or sacubitril-valsartan) within 90 days of the diagnostic code, as an indicator of Stage C disease. A prescription for sacubitril-valsartan alone was also sufficient to classify a patient as Stage C, given its near-exclusive indication for symptomatic HF.

These adaptations reflect the inherent limitations of administrative data, which do not capture echocardiographic findings or cardiac biomarkers required by the Universal Definition. Although this approach cannot achieve the diagnostic precision of comprehensive clinical phenotyping, it enables standardized HF staging at the population level using routinely available healthcare data. Future validation against echocardiographic registries and clinical datasets incorporating imaging and biomarker information will be essential to further establish the diagnostic performance of this administrative staging algorithm. The resulting framework demonstrated strong construct validity, with a progressive increase in both all-cause and cardiovascular mortality across successive HF stages, closely mirroring observations from community-based cohort studies.^{12, 15} Together, these findings support the use of this framework for nationwide surveillance of the HF continuum and for facilitating comparisons of HF burden across healthcare systems.

A particularly important finding is the substantial increase in the prevalence of Stage A and Stage B HF during the study period. Although population aging contributes to the increasing burden of HF, age-standardized prevalence also rose considerably, indicating that demographic changes alone do not explain these trends. While causal inferences cannot be drawn from administrative data, the increasing prevalence of obesity and cardiometabolic disease in Czechia is a plausible contributor.²⁸ Rising obesity rates not only increase the risk of HF directly but also promote hypertension, diabetes mellitus, chronic kidney disease, and atrial fibrillation, thereby accelerating progression along the HF continuum. These findings suggest that the future burden of symptomatic HF will depend increasingly on the effectiveness of primary prevention strategies targeting cardiometabolic risk factors.

Perhaps the most clinically relevant observation is that more than 95% of individuals with incident clinical HF had previously fulfilled administrative criteria for Stage A or Stage B. Although this proportion depends on the performance of the staging algorithm, it demonstrates that progression to overt HF is rarely abrupt and is typically preceded by years of identifiable cardiovascular risk or structural heart disease. This prolonged preclinical phase may represent the greatest opportunity for prevention. Our findings complement evidence from cohort studies suggesting that the majority of incident HF is attributable to a relatively small number of modifiable cardiovascular risk factors²⁹ and are consistent with recent recommendations advocating risk-based primary prevention of HF. Together, these observations support a shift in healthcare policy from reactive management of symptomatic HF toward earlier identification and intervention among individuals at increased risk, as outlined by the 2025 AHA Scientific Statement on risk-based primary prevention of HF.³⁰

Our analysis also provides a contemporary overview of HF pharmacotherapy at the national level. Uptake of sodium-glucose cotransporter-2 inhibitors increased substantially between 2023 and 2024, reflecting the rapid implementation of recent guideline recommendations. Nevertheless, use of angiotensin receptor–neprilysin inhibitors remained low, and a considerable proportion of patients with advanced HF continued to receive medications with limited or uncertain benefit. Because all major guideline-directed HF therapies are reimbursed within the Czech healthcare system, these findings suggest that barriers to implementation are more likely related to therapeutic inertia, clinician awareness, or healthcare organization than to treatment availability.

The prevalence of Stage A and Stage B observed in our study was lower than that reported in community cohorts incorporating systematic echocardiography and biomarker assessment.^{14, 31} This difference is expected because administrative databases cannot identify subclinical structural abnormalities, diastolic dysfunction, or elevated natriuretic peptide concentrations in asymptomatic individuals. Consequently, our estimates of preclinical HF should be regarded as conservative lower bounds. Conversely, the prevalence of symptomatic HF exceeded that reported in several Western European and North American populations,^{32, 33} suggesting that the burden of clinical HF in Czechia remains substantial and deserves continued public health attention.

Beyond the findings from Czechia, the proposed administrative staging framework may provide a standardized methodology for monitoring the HF continuum across healthcare systems. This framework could serve as a standardized methodology for international comparisons of HF epidemiology using routinely collected healthcare data, thereby facilitating benchmarking of disease burden, preventive strategies, and healthcare delivery.