A device for determining whether a patient's physiology puts him or her at an increased risk of experiencing a Silent Clinical Event, comprising: a tissue - characterization system including an intravascular ultrasound - (IVUS) console electrically connectable to an intravascular ultrasound - (IVUS) catheter configured to acquire RF backscattered data of an artery of interest, in which the intravascular ultrasound-catheter is to be inserted, and a computing device comprising a database and a characterization application electrically connected to the database and adapted to receive IVUS data from the IVUS console or directly from a transducer attached to the end of the catheter; wherein the tissue - characterizing system is configured for ascertaining for one of more locations along the artery of interest the Plaque Burden of the artery, the Minimum Lumen Area of the artery and whether multiple Virtual Histology-Thin-cap Fibroatheromas (VH-TCFA) are present, a clinical outcome predictor device being operable on the computing device, or being operable separately and operatively connectable to the intravascular ultrasound - console, the computing device, the characterization application or database or any combination of these, wherein the clinical outcome predictor device is configured to determine whether there is a concurrence for the Plaque Burden, the Minimum Lumen Area, and multiple Virtual Histology-Thin-cap Fibroatheromas (VH-TCFA), and the Plaque Burden being between about 30% and about 70%, the Minimum Lumen Area being less than or equal to about 4 mm 2 and multiple Virtual Histology-Thin-cap Fibroatheromas (VH-TCFAs) being present; and, communicate whether such concurrence has occurred by indicating the patient's physiological condition has an increased risk of a Silent Clinical Event. a tissue - characterization system including an intravascular ultrasound - (IVUS) console electrically connectable to an intravascular ultrasound - (IVUS) catheter configured to acquire RF backscattered data of an artery of interest, in which the intravascular ultrasound-catheter is to be inserted, and a computing device comprising a database and a characterization application electrically connected to the database and adapted to receive IVUS data from the IVUS console or directly from a transducer attached to the end of the catheter; wherein the tissue - characterizing system is configured for ascertaining for one of more locations along the artery of interest the Plaque Burden of the artery, the Minimum Lumen Area of the artery and whether multiple Virtual Histology-Thin-cap Fibroatheromas (VH-TCFA) are present, a clinical outcome predictor device being operable on the computing device, or being operable separately and operatively connectable to the intravascular ultrasound - console, the computing device, the characterization application or database or any combination of these, wherein the clinical outcome predictor device is configured to determine whether there is a concurrence for the Plaque Burden, the Minimum Lumen Area, and multiple Virtual Histology-Thin-cap Fibroatheromas (VH-TCFA), and the Plaque Burden being between about 30% and about 70%, the Minimum Lumen Area being less than or equal to about 4 mm 2 and multiple Virtual Histology-Thin-cap Fibroatheromas (VH-TCFAs) being present; and, communicate whether such concurrence has occurred by indicating the patient's physiological condition has an increased risk of a Silent Clinical Event.