The proportion of patients hospitalized for heart failure (HF) with preserved left ventricular ejection fraction (LVEF) accounts for approximately half of HF patients, and this poorly known group of patients is quickly becoming the most prevalent form of HF. In this recent study, performed in collaboration with Novartis, we define the patient characteristics of HF across the LVEF range and highlight the importance of effective treatments that can reduce hospitalizations.
Heart failure (HF) is a global health problem, associated with frequent hospitalization periods, poor patient prognosis and high mortality rate. HF patients are typically characterized according to the measure of left ventricular ejection fraction (LVEF). LVEF is usually between 50% and 75% in healthy individuals. In general, a standard cut-off value of 40% is applied for abnormal LVEF, and patients with such low LVEF have reduced ejection fraction. However, a substantial proportion of HF patients may have normal, preserved ejection fraction. The proportion of patients hospitalized for preserved ejection fraction is rising, but the current understanding of the patient characteristics remain elusive. In this retrospective registry study, the aim was to increase the epidemiological understanding of HF patients across the LVEF range in Finland.
The study was conducted using the electronic health records of patients diagnosed with HF between 2005 and 2017 at the speciality care of the hospital district of Southwest Finland. This study included a large and robust cohort of HF patients across the full range of LVEF phenotype; patients with reduced ejection fraction (HFrEF), mid-range ejection fraction (HFmrEF), and preserved ejection fraction (HFpEF). Patients were followed for 12 years. Cardiovascular (CV) hospitalization and mortality, influence of pre-selected covariates on hospitalization and mortality were examined, as well as the progression of patients with preserved and mid-range ejection fraction to reduced ejection fraction.
As expected, hospitalization was frequent among all HF patients. HFrEF patients were rehospitalized for the first time slightly earlier than HFpEF and HFmrEF patients. However, the subsequent rehospitalization rates did not differ between the subgroups. Rehospitalization in HFmrEF and HFrEF patients was less likely in women and patients with better kidney function. Each additional hospitalization was associated with an increased risk of death. All-cause mortality was higher in patients with HFpEF. Notably, CV mortality was associated with increased NT-proBNP levels at index in all patient groups. All in all, 26% of HFmrEF patients and 10% of the HFpEF patients progressed to the more severe HFrEF phenotype.
This study showed the association of recurrent hospitalizations with increased mortality in HF patients and revealed differences between the HF phenotypes, providing data specific for HFpEF and HFmrEF patients from a large, robust real-world data source. NT-proBNP, independent of traditional LVEF measure, was identified as a strong predictor of mortality in consecutively hospitalized HFpEF and HFmrEF patients. The results suggest a role for monitoring NT-proBNP levels in the management of HFpEF patients. Utilizing the wealth of data in electronic health records enables comprehensive and efficient data mining with significant relevance for medical research and development of new treatments. Similar approach can be used in numerous distinct indications.
Recurrent hospitalizations are associated with increased mortality across the ejection fraction range in heart failure, Huusko J, Tuominen S, Studer R, Corda S, Proudfoot C, Lassenius MI ja Ukkonen H. ESC Heart Failure (2020)