Accuracy of Electrocardiographic-Gated Versus Nongated Volumetric Intravascular Ultrasound Measurements of Coronary Arterial Narrowing

Intravascular ultrasound (IVUS) allows precise measurements of plaque plus media (P+M) volume and neointimal hyperplasia after coronary artery stenting. Conventional IVUS volumetric analysis is performed mostly without electrocardiographically gated acquisition, and the IVUS images are selected at 1-mm intervals, whereas the electrocardiographically gated approach consists of images in end-diastole. The accuracy in the luminal, P+M, and external elastic membrane (EEM) volumes between 2 pullbacks with the electrocardiographically gated and nongated approaches has not previously been compared. In 15 patients, 19 segments were studied with electrocardiographically gated and nongated IVUS systems. Two identical pullbacks were performed with each system using the same IVUS catheter. Volumes of the lumen, EEM, and P+M obtained using the electrocardiographically gated pullback technique did not differ significantly from the corresponding volumes obtained using the nongated pullback technique (lumen: 109.7 ± 47.7 vs 109.2 ± 45.0 mm3, p = NS; EEM: 242.6 ± 109.2 vs 235.0 ± 108.1 mm3, p = NS; P+M: 134.8 ± 67.7 vs 129.8 ± 69.1 mm3, p = NS). No significant differences were seen in changes between 2 electrocardiographically gated and 2 nongated pullbacks (lumen: 0.37 ± 1.76 vs −0.23 ± 2.32 mm3, p = NS; EEM: 0.25 ± 3.22 vs −0.94 ± 4.27 mm3, p = NS; P+M: −0.18 ± 3.42 vs −0.74 ± 3.88 mm3, p = NS). In conclusion, in moderate atherosclerotic or stented coronary arteries, electrocardiographically gated IVUS acquisition is not superior in accuracy to conventional nongated IVUS acquisition.