M LVEF X MORTY

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• Although left ventricular ejection fraction (LVEF) is commonly reported, the relationship between its clinical measurement and survival is unclear. This retrospective study used data from 403,977 echocardiograms from 203,135 patients and mortality data from US electronic health records to assess this relationship. Data from 45,531 echocardiograms and 35,976 patients in a New Zealand dataset were used for validation. Over a median follow-up of 4.0 years, 23% of the patients in the US dataset died. There was a U-shaped relationship between LVEF and mortality risk, with the lowest risk for patients with an LVEF between 60% and 65% and higher risk for LVEF of 35% to 45% (HR, 1.73) and for LVEF 70% or greater (HR, 1.71). A similar pattern was present in the validation dataset, in subgroup analyses, and in analyses with additional adjustments.

• These results show a relationship between LVEF and survival and identify a potential risk to supra-normal LVEF, which needs to be examined further in future studies.