E-point septal separation (EPSS) for diagnosing reduced left ventricular ejection fraction (LVEF): a systematic review and meta-analysis

The estimation of LVEF with the standard quantitative methods is a difficult and time-consuming process, which requires experience and relies on the ability of the physician. An alternative method for a rapid assessment of LVEF could be EPSS, which measures the distance between the anterior mitral valve leaflet and septum in early diastole, demonstrated on a parasternal long axis view with M-Mode.

To determine how accurate EPSS is for diagnosing reduced LVEF in adult patients.

We used the Cochrane methods for diagnostic test accuracy (DTA) reviews. We searched Pubmed, Ovid, CENTRAL, OATD, ClinicalTrials.gov and WHO-ICTRP up to 21 June 2024.

We included studies that assess the accuracy of EPSS against an acceptable reference standard (Biplan Simpson’s method, angiographically determined, or visually determined ejection fraction) in adult patients.The articles were screened and data from the articles was extracted using the Metagear package in R Studio. We extracted data into a 2 x 2 table (true positives, true negatives, false positives, and false negatives). We used GetData Graph Digitizer to extract numbers from the histograms in studies where direct data wasn't available. We synthesized and summarized the data into a forest plot and a summary receiver operating characteristic (SROC) plot. We used a bivariate meta-analysis model to synthesize the meta-analysis in RevMan.

We identified 757 titles and abstracts and after removal of duplicates, we assessed 730 unique studies. After exclusion, 14 studies were deemed eligible for inclusion in the meta-analysis (914 patients). EPSS with a threshold of > 7 mm showed a summary sensitivity of 84% (95% CI 81% to 88%) and a summary specificity of 88% (95% CI 77% to 85%). If we take the median prevalence of reduced LVEF in the included studies (48%) and apply it to a cohort of 1000 patients, 480 patients will have a reduced LVEF. Of these, 403 (84%) would be correctly diagnosed and 77 (16%) would be misdiagnosed and not receive appropriate treatment. 520 of the 1000 patients will have a normal LVEF. Of these, 421 (81%) would be correctly deemed to have a normal LVEF, and 99 (19%) would be falsely diagnosed with reduced LVEF and undergo inappropriate treatment.

The findings of this review provide evidence to suggest that EPSS is an accurate diagnostic tool compared to reference standards and it could be used to provide a quick initial assessment of the LVEF as a precursor to the standard quantitative methods.

Summary of findings