Prognostic value of systolic left ventricular ejection fraction using prospective ECG-triggered cardiac CT.

Background: Prospective ECG-triggered cardiac computed tomography (CT) imaging limits the ability to assess left ventricular (LV) ejection fraction (EF). We previously developed a new index derived from LV volume changes over 100 ​ms during systole (LVEF_100msec) as a surrogate of LV function in patients undergoing prospective ECG-triggered cardiac CT. We sought to evaluate the prognostic value of LVEF_100msec.

Methods: Patients undergoing prospective systolic ECG-triggered cardiac CT were enrolled between January 2015 and September 2022. Each CT was analyzed for LVEF_100msec. Area under the curve analysis and Cox proportional hazards models were used to define the best LVEF_100msec cut-off and to predict major adverse cardiovascular events (MACE), defined as a composite of all-cause death, cardiac death/arrest, non-fatal myocardial infarction, and stroke.

Results: The study enrolled 313 patients (median age ​= ​58 years, male ​= ​52.4 ​%). During a median follow-up of 924 (660-1365) days, 24 (7.7 ​%) patients had MACE. LVEF_100msec was significantly lower in the MACE group compared to the non-MACE group (4.8 ​% vs. 8.3 ​%, p ​= ​0.002). Optimal LVEF_100msec cut-off for predicting MACE was 6.3 ​%. MACE-free survival rate was significantly lower in patients with LVEF_100msec ≤6.3 ​% than those with >6.3 ​% (p ​< ​0.001). LVEF_100msec ≤6.3 ​% was an independent predictor of MACE, with an adjusted hazard ratio of 3.758 (95 ​% CI, 1.543-9.148; p ​= ​0.004). The prognostic value of LVEF_100msec was consistent across the various severities of coronary artery disease.

Conclusion: LVEF_100msec was an independent predictor of adverse events. The implementation of LVEF_100msec may improve the prognostic value of prospective ECG-triggered cardiac CT.