Reduced stroke volume by resting 2-dimensional echocardiography negatively affects survival in patients with abnormal ejection fraction

Abstract Background Abnormal (<50%) ejection fraction (EF) is a cornerstone of risk stratification and therapy, but also an imperfect proxy of left ventricular (LV) cardiac pump function, better assessed with stroke volume (SV). Aim To assess the value of SV in stratifying risk of patients with abnormal EF. Methods In a prospective, observational, multicenter study, we recruited 746 patients (age 66± 11 years, 536 males, 72%, 359 with previous myocardial infarction, 48%) with chronic coronary syndromes (CCS) and EF <50% referred for resting transthoracic echocardiography with technically successful 2-dimensional volumetric echocardiography in 17 accredited laboratories. We quantitatively assessed LV end-diastolic volume (EDV) and end-systolic volume (ESV) by Simpson’s biplane method. EF (EDV-ESV/EDV) and SV (EDV-ESV) were calculated from LV volumes. The outcome end-point was all-cause death. Results EF was 39±9%, SV 48±20 ml. There were 100 all-cause deaths during a median follow-up of 796 days (interquartile range 420-1286 days). Receiver-operating curve analysis identified SV≤31.4 ml/b as the best cut-off for predicting mortality. At multivariable analysis, after adjustment for age and prior myocardial infarction, EF <40% and SV ≤31.4 ml/b were significantly associated with decreased survival (HR 2.09, 95%, confidence intervals 1.09-4.01, p=0.024). The annual mortality was lowest (3.19%) in the group with mildly reduced (40-49%) EF and normal (>31.4 ml) SV, and highest (8.30%) in patients with both reduced EF and abnormal SV: see figure. Conclusion Patients with CCS and abnormal EF are a prognostically heterogeneous group, and the mortality rate is almost 3-times worse in patients with reduced EF and abnormal SV compared to patients with mildly reduced EF and normal SV. A simple resting volumetric two-dimensional echocardiography can offer an efficient risk stratification, beyond EF, with no extra imaging or analysis time.Figure