Aims: In this study, we investigated the relationship between longitudinal morphology reconstructed from pre-intervention intravascular ultrasound (IVUS) images and thrombolysis in myocardial infarction (TIMI) flow grade at initial angiograms in the acute phase of acute coronary syndrome (ACS).
Methods and results: Our patient population comprised 72 ACS patients in whom we obtained successful reconstructed longitudinal images. On the basis of the site of the maximum aperture of rupture in the longitudinally reconstructed IVUS images, patients were divided into three groups: plaques with rupture in the proximal shoulder (proximal type; n = 28), mid-portion (mid-type; n = 18), and distal shoulder (distal type; n = 26) of the plaque. There were no differences in terms of coronary risk factors or the angiographic findings. The proximal-type group more frequently showed TIMI 0 on initial angiogram (proximal type, 86%; mid-type, 50%; and distal type, 31%; P = 0.002). A multivariable logistic regression model revealed that the presence of a proximal-type rupture correlated with the presentation of ST-elevation myocardial infarction (P = 0.019; odds ratio, 8.12; 95% CI, 1.404-49.996).
Conclusions: Longitudinal morphological features in a ruptured plaque may affect the formation of obstructive thrombus in ACS. Our results suggest that longitudinal morphology may be an important determinant of coronary artery occlusion.