The clinical application of the ratio of transmitral early filling velocity to early diastolic strain rate: a systematic review and meta-analysis.

BACKGROUND: The ratio of transmitral early filling velocity to early diastolic strain rate (E/e'sr) has recently emerged as a novel and accurate non-invasive measure of left ventricular (LV) filling pressure. This systematic review and meta-analysis aimed to give an overview of the possible clinical implications of E/e'sr. METHODS: We conducted a systematic review and meta-analysis of all studies involving E/e'sr. Of 598 identified studies, 16 met our inclusion criteria. Studies involving E/e'sr either investigated its prognostic value (n = 9) or its correlation with invasively measured LV filling pressure (n = 7). RESULTS: The pooled meta-analysis showed a significant correlation between E/e'sr and pulmonary capillary wedge pressure (PCWP) measured invasively across the studies assessing this relationship (Cohen's d = 3.90 95% CI [2.38-6.39], p < 0.001) and between E/e'sr and left ventricle end-diastolic pressure (LVEDP) measured invasively across the studies assessing this relationship (Cohen's d = 5.30 95% CI [2.83-9.96], p < 0.001). The pooled analysis of the prognostic studies showed that E/e'sr was a significant predictor of adverse outcomes after multivariable adjustment across the different study populations in a random effects model (overall estimated HR: 1.58 95% CI [1.28-1.96], p < 0.001, per 1 m increase). CONCLUSION: E/e'sr correlates well with invasive measures of LV filling pressure. In addition, E/e'sr provides significant prognostic information across various patient populations. Further studies are needed to test if E/e'sr has an advantage to E/e'.