• CT of Coronary Heart Disease: Part 2, Dual-Phase MDCT Evaluates Late Symptom Recurrence in ST-Segment Elevation Myocardial Infarction Patients After Revascularization

    AJR :198, March 2012

    Kuan-Rau Chiou Nan-Jing Peng Shih-Hung Hsiao Yi-Luan Huang Chin-Chang Cheng Huay-Ben Pan Ming-Ting Wu

    OBJECTIVE. The purpose of the study was to investigate dual-phase MDCT for assess­ing obstructive lesions and the extent and severity of the subtending myocardium at risk in patients presenting with chest pain syndromes 9 or more months after having undergone re­vascularization for the treatment of ST-segment elevation myocardial infarction (STEMI).

    MATERIALS AND METHODS. Dual-phase 64-MDCT was performed on 135 pa­tients with recurring chest symptoms 9 months or more after revascularization (mean ± SD, 23 ± 11 months after index invasive angiogram for treatment of STEMI). Obstructive lesions (≥ 50% stenosis) were detected by MDCT angiography and the extent of myocardium at risk was detected by delayed phase 3D myocardium maps. A myocardium at-risk score based on MDCT findings was defined as the extent of myocardium at risk governed by the coronary le­sion and weighted by lesion severity. Results were compared with stress-redistribution 201T1-SPECT and invasive angiography.

    RESULTS. In restenotic, new, progressive, and previously obstructive lesions that are not currently progressive, analysis of assessable segments (1966/2025, 97.1%) obtained true-posi­tive detection rates of 88.1%, 88.6%, 82.9%, and 100%, respectively; false-negative detection rates were 5.3%, 1.6%, 2.9%, and 8.8%. In 124 patients (91.9%) in whom all segments were as­sessable, the MDCT-based myocardium at-risk score correlated with the SPECT-based summed difference score (SDS) (r = 0.841, p < 0.001). For detecting SPECT-based SDS ≥ 1 and SDS > 3, areas under the receiver operating characteristic curve for the MDCT-based myocardium at-risk score were 0.874 (95% CI, 0.805-0.942) and 0.938 (95% CI, 0.895-0.981), with optimal cutoff values of 2.68 and 5.01, respectively.

    CONCLUSION. Dual-phase MDCT is useful in detecting different patterns of obstruc­tive lesions and the extent of myocardium at risk as an alternative for therapeutic planning in patients presenting with late symptoms after treatment for acute myocardial infarction.