Can left ventricular end-diastolic volumes be estimated with prospective ECG-gated CT coronary angiography?

Background With the goal of minimizing patient radiation exposure, many centres have adopted prospective ECG-gated computed tomographic coronary angiography. Since image acquisition occurs only during ventricular diastasis, the ability to measure left ventricular (LV) ejection fraction (EF) and LV volumes has been lost. Given that LV volumes have prognostic value, the ability to estimate LV end diastolic volume (EDV) may be clinically desirable. Objective We sought to predict LV EDV using CT coronary angiography (CTA) images obtained during ventricular diastasis. Methods Consecutive patients who underwent retrospective ECG-gated CTA were enrolled. Images were reconstructed at the 75% phase and at end-diastole. LV and left atrial (LA) volumes were measured. Results A total of 153 consecutive patients were analyzed (mean age=56.7±11.2 years; men=56.2%). The mean LV EDV and EF were 144.4±40.2mL and 63.4±9.9%, respectively. There appeared to be a very strong linear relationship between the 75% phase LV volume and LV EDV with an R 2 of 0.993. Using LV and LA volumes at the 75% phase, a prediction model of LV EDV was developed (LV EDV=(1.021×75% phase LV volume)+(0.259×75% phase LA volume), adjusted R 2 =0.995). Conclusion LV EDV can be estimated using CTA data obtained during ventricular diastasis. Further studies are needed to demonstrate that such estimates of LV EDV have incremental prognostic value over coronary artery disease severity assessment with prospective ECG-gated CTA.