Routinely Reported Ejection Fraction and Mortality
What is the relationship between clinically assessed left ventricular ejection fraction (LVEF) and survival in a large, heterogeneous clinical cohort?
The investigators linked physician-reported LVEF on 403,977 echocardiograms from 203,135 patients to all-cause mortality using electronic health records (1998–2018) from the US regional healthcare system. Cox proportional hazards regression was used for analyses while adjusting for many patient characteristics including age, sex, and relevant comorbidities. A dataset including 45,531 echocardiograms and 35,976 patients from New Zealand was used to provide independent validation of analyses.
During follow-up of the US cohort, 46,258 (23%) patients who had undergone 108,578 (27%) echocardiograms died. Overall, adjusted hazard ratios (HRs) for mortality showed a u-shaped relationship for LVEF with a nadir of risk at an LVEF of 60–65%, an HR of 1.71 (95% confidence interval [CI] 1.64–1.77) when ≥70%, and an HR of 1.73 (95% CI, 1.66–1.80) at an LVEF of 35–40%. Similar relationships with a nadir at 60–65% were observed in the validation dataset as well as for each age group and both sexes. The results were similar after further adjustments for conditions associated with an elevated LVEF, including mitral regurgitation, increased wall thickness, and anemia and when restricted to patients reported to have heart failure at the time of the echocardiogram.
The authors concluded that deviation of LVEF from 60% to 65% is associated with poorer survival regardless of age, sex, or other relevant comorbidities such as heart failure.
This analysis exploring the relationship between mortality and echocardiographic LVEF reports that EF values of 60–65% were associated with the lowest mortality while both lower and higher LVEF had higher mortality. Furthermore, similar u-shaped relationships between mortality and LVEF were found among patients with heart failure, suggesting that it may be inappropriate to pool all patients with preserved LVEF into a single group. It is possible that in the future, a fourth LV phenotype, heart failure with supra-normal LVEF (HFsnEF), might one day be characterized. One should note that the present analysis was retrospective with all the inherent limitations, and prospective validation of adverse consequences of supra-normal LVEF is indicated. Too high an LVEF may be too much of a good thing with consequences.
Keywords: Anemia, Comorbidity, Echocardiography, Electronic Health Records, Heart Failure, Mitral Valve Insufficiency, Secondary Prevention, Risk, Stroke Volume, Survival, Ventricular Function, Left
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