Heart failure ejection fraction class conversions: impact of biomarkers, co‐morbidities, and pharmacotherapy

AIMS: Temporal conversions among ejection fraction (EF) classes can occur across the heart failure (HF) spectrum reflecting amended structural and functional outcomes unaccounted for by current taxonomy. This retrospective study aims to investigate the differences in serum laboratory values, guideline‐directed medical therapy (GDMT), and co‐morbidity burden across EF conversion groups. METHODS AND RESULTS: Heart failure patients at least 18‐year‐old who obtained at least two echocardiograms between January 2018 and January 2020 were identified using ICD‐10 codes. Analysis of variance, chi‐square tests, and analysis of means for proportions were used as appropriate to identify associations with class conversion groups. A total of 874 patients who underwent 1748 echocardiograms on unique visits were categorized according to initial EF as HF with preserved EF (HFpEF) (n = 531, 61%), HF with mildly reduced or midrange EF (HFmrEF) (n = 132, 15%), or HF with reduced EF (HFrEF) (n = 211, 24%). In accordance with follow‐up EF, class conversions were categorized into HF with improved EF (HFiEF) (n = 143, 16%), HF with worsened EF (HFwEF) (n = 171, 20%), or HF with stable EF (HFsEF) (n = 560, 64%). The average age was 75 ± 13 years old; 54% were male, 85% were Caucasian, 11% were African American, and 4% other. The mean time between EF assessments was 208.6 ± 170.2 days. Serum sodium levels were greater in HFwEF (139 ± 3 mmol/L) when compared with HFsEF (138 ± 4 mmol/L) (P = 0.05). Pro‐BNP levels were higher in HFiEF (12 150 ± 19 554 pg/mL) versus HFsEF (6671 ± 10 525 pg/mL) (P = 0.007). Angiotensin receptor‐neprilysin inhibitors (ARNI) were more frequently ordered on index visit in HFiEF (P = 0.03), but no other significant differences in GDMT were identified. Despite similar Elixhauser Co‐morbidity Measure (ECM) scores, ECM categorical analysis revealed that HFwEF was more likely to have an established diagnosis of depression (P = 0.03) and a spectrum of psychiatric illnesses (P = 0.03) on preliminary visit. HFsEF was less likely to have an established diagnosis of blood loss anaemia (P = 0.04). Metastatic cancer was more likely to have been diagnosed in HFiEF and less likely in HFsEF (P = 0.002). CONCLUSIONS: Despite similar ECM scores, EF class conversion groups demonstrated salient differences in average serum sodium and pro‐BNP levels. Inpatient ARNI orders, psychiatric, hematologic, and oncologic co‐morbidity patterns were also significantly different. Findings demonstrate blood‐based biomarker patterns and targetable co‐morbid conditions which may play a role in future EF class conversion. Dedicated studies evaluating measurements related to GDMT dose‐titration, quality of life, and functionality are the next steps in this field of HF.