Background: Patients who are diagnosed with heart failure (HF) are almost universally characterized by left ventricular ejection fraction (LVEF) at the time of diagnosis, where the most common dichotomy is preserved LVEF (HFpEF, LVEF > 50%) or reduced LVEF (HFrEF, LVEF < 40%). The concept of recovered LVEF (< 40% to > =50%) is considered by some to indicate a separate category of HF. We sought to study the natural history of a patient’s LVEF using natural language processing among a large cohort of patients.
Methods: We identified 457,457 patients in the VA Health Care System between 2005 and 2016 with a first outpatient diagnosis of heart failure with an LVEF between 6 months before or one year after the heart failure diagnosis and a second LVEF after the diagnosis. We used all LVEF data from 2005-2016 obtained from previously validated natural language processing of echo reports. LVEF at baseline was grouped into deciles (1-29, 30-39, 40-49, 50-59, 60-69 and >=70%).
Results: The 457,457 patients had 8,857,436 echos over a mean 4 +/- 3 years of follow-up (median 11 echos per patient). At the time of diagnosis the mean age was 69 +/- 11 years, 97.6% male, 19% were African-American, 45% had a diagnosis of diabetes, and 61% had a diagnosis of ischemic heart disease. During follow-up among those with an initial LVEF < 40%, between 21% and 31% recovered their LVEF to over 50% at some point during follow-up (Table). A similar frequency was noted for those dropping to an LVEF < 40% if the initial LVEF was high. When the last LVEF was used to define change, then a recovered LVEF (>50%) was less common (9% if initial LVEF was < 20%, 8% if the initial LVEF was 20-29%, 13% if the initial LVEF was 30-39%). The final LVEF was < 40% in 30% of patients with an initial LVEF of 40-49%, 15% if the initial LVEF was 50-59%, 9% if the initial LVEF was 60-69%, and 6% if the initial LVEF was >=70%.
Conclusion: In this multiyear study of a national cohort, LVEF varied substantially over time, with a recovered LVEF (<40% to >=50%) noted at some point in 20-30% depending on initial LVEF. However, when the last LVEF is used, recovery occurred in only 8-13%. Thus, approximately half of patients with a recovered LVEF at some point will revert to depressed LVEF.