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 ʹsr) 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 ʹsr. Methods We conducted a systematic review and meta-analysis of all studies involving E / e ʹsr. Of 598 identified studies, 16 met our inclusion criteria. Studies involving E / e ʹsr 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 ʹsr 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 ʹsr 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 ʹsr 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 ʹsr correlates well with invasive measures of LV filling pressure. In addition, E / e ʹsr provides significant prognostic information across various patient populations. Further studies are needed to test if E / e ʹsr has an advantage to E / e ʹ.