Reliability of reporting left ventricular systolic function by echocardiography: A systematic review of 3 methods

An accurate assessment of left ventricular (LV) systolic function is of central importance to the diagnosis and management of heart failure. Echocardiography is currently the technique most widely used for this purpose. A systematic review was performed of the evidence for the accuracy of 3 echocardiographic methods—Simpson's rule, wall motion index (WMI), and subjective visual assessment—compared with radionuclide or contrast ventriculography for the assessment of LV ejection fraction (LVEF). Twenty-five studies were identified in which data on agreement between echocardiography and reference methods were obtainable. A further 18 studies provided correlation data alone. For Simpson's rule, Bland-Altman limits of agreement (95% CI) ranged from LVEF ±7% to ±25% (median ±18%); for WMI ±13% to ±20% (median ±16%); and for subjective visual assessment ±16% to ±24% (median ±19%). Subject echogenicity, the nature of underlying disease, and the use of additional imaging technology, including secondary harmonic imaging and contrast agents, is likely to influence the accuracy of different methods. No method appears to systematically under- or overestimate LVEF to any major extent. These findings have important implications for the investigation of heart failure and for the practice and reporting of echocardiography.