A new study in Circulation-Cardiovascular Imaging has identified the Cardiac Contractility Index (CCI) as a more reliable predictor of mortality in heart failure (HF) than the traditionally used left ventricular ejection fraction (LVEF). Unlike LVEF, which is limited by its sensitivity to changes in blood pressure, CCI offers a relatively afterload-independent way to assess cardiac function.

Researchers examined individuals newly diagnosed with heart failure based on reduced or preserved ejection fraction. They found that mortality increased consistently across lower CCI tertiles (P<0.001). In patients with heart failure and preserved ejection fraction (HFpEF), a below-median CCI was linked to an all-cause mortality rate nearly double that of those with above-median CCI (17.3 vs. 8.8 events per 100 patient-years). These patients exhibited mortality risks comparable to those with heart failure and reduced ejection fraction (HFrEF), despite having normal LVEF.

CCI showed a curvilinear relationship with mortality, revealing higher death rates with declining CCI values. In contrast, LVEF did not show a clear association with mortality across the 20%–55% range.

In individuals with normal LVEF and no known heart failure, those with below-median CCI had a 33% higher risk of developing HF later on (adjusted hazard ratio 1.33; 95% CI: 1.01–1.75; P=0.043). These individuals also showed signs of subclinical myocardial dysfunction, including reduced global radial and circumferential strain.