Reclassification of Diastolic Function by the 2025 American Society of Echocardiography Diastolic Function Guidelines and Risk of Mortality

Background: Whether the 2025 American Society of Echocardiography (ASE) diastolic dysfunction (DD) algorithm (DD25) improves mortality prognostication compared to the 2016 algorithm (DD16) in real-world practice is uncertain. Methods: We applied the DD25 algorithm to adult transthoracic echocardiography reports across a large academic multisite echocardiography laboratory from 2018 2024, linked to state mortality data, and determined reclassification of DD and mortality risk. Results: Of 12,948 included (age 62.8 ± 18.1, 51.4% women, 55.8% outpatient), 10,205 (78.8%) had diastology quantified by the 2016 and 2025 guidelines. Of these, 2,601 (25.5%) were reclassified by DD25 with increases in DD grade in 1,428 (54.9%) and decreases in 1,173 (45.1%). Among those reclassified, 2,391 (91.9%) had a single grade change in DD severity. A larger proportion of female patients (52% vs 48.7%) were classified as having DD by DD25 versus DD16. The rate of indeterminate DD was lower by DD25 (1,358 [10.4%]) vs DD16 (1,983 [15.3%]). The DD25 algorithm improved discrimination of mortality risk compared to DD16 (difference in areas under the curve = 0.02; 95% CI, 0.001-0.04; P = .03), although the magnitude of the associated risk across the follow-up period was similar after multivariable adjustment (P value for comparison of adjusted hazard ratios = .67). Conclusions: In a large academic health system, one-quarter of patients had reclassification of diastolic function by the 2025 ASE diastology guidelines. As compared to the 2016 algorithm, the 2025 algorithm resulted in a larger proportion with DD, less indeterminate diastolic function, and improved discrimination of mortality.