Modifiers of the Association between E/e' Ratio and Survival among Patients with No Apparent Structural or Functional Cardiac Abnormality

BACKGROUND: The ratio between early mitral flow wave to early diastolic mitral annulus velocity (E/e' ratio) varies according to age and sex and is associated with mortality in heart failure. We sought to describe the association between E/e' and mortality in patients with no apparent structural or functional cardiac abnormality and explore possible modifiers of this association. METHODS: A retrospective study of 104,315 patients who underwent echocardiographic evaluation during 2009-2021 in the largest tertiary center in Israel. Patients with cancer, ventricular dysfunction, significant valvular or structural heart disease, or evidence of pulmonary hypertension were excluded. RESULTS: The final analysis included 32,836 patients with a median age of 56 (43-66) years, and 13,547 (41%) were female. The median E/e' was 8.3 (6.8-10.3), and 9,306 (28%) had an E/e' >10. During a median follow-up of 5.7 (3.3-8.5) years, 2,396 (7.3%) individuals died. E/e' >10 was associated with mortality (adjusted hazard ratio [HR] 1.16, 95% confidence interval [CI] 1.07-1.27, p<0.001). The mortality risk associated with E/e' >10 was significantly higher in those aged ≤70 (HR 1.26, 95% CI 1.12-1.42, p<0.001), males (HR 1.34, 95% CI 1.19-1.49, p<0.001), a normal left ventricular mass (HR 1.13, 95% CI 1.02-1.24, p = 0.017), and pulmonary artery pressure <30 mmHg (HR 1.18, 95% CI 1.06-1.30, p = 0.003). CONCLUSION: An elevated E/e' is associated with mortality, specifically in younger individuals, males, and those with a normal left ventricular mass and lower pulmonary artery pressure. This suggests that an elevated E/e' might be a marker of subclinical risk in these subgroups. Further studies are needed to identify whether an elevated E/e' is useful in shared decision-making regarding the management of cardiovascular risk factors.