Contrast Enhanced Cardiac CT May Be Used to Accurately Measure the Coronary Calcium Score

Abstract

Introduction: Coronary artery calcium score (CACS) measurement is a well validated and commonly used prognostic tool that currently requires a second noncontrast scan in additional to contrast enhanced CT coronary angiography. We present the final results of a prospectively registered validation study of a new technique tomeasure the coronary calcium score froma single contrast-enhanced cardiac CT. Methods: Paired contrast enhanced and calcium score scans from 120 sequential patients were prospectively analysed. All scans were performed using a wide-volume 320-detector row CT scanner. Eleven contrast scans were excluded due to pre-specified exclusion criteria of complete coronary occlusion or excessive image noise. The volume of intramural coronary calcium above 320 regional myocardial dysfunction. Cardiac MRI (CMR) accurately evaluates LV morphology and can assess myocardial injury using late gadolinium enhancement (LGE). Although studies during the acute phase of ABS havedocumentedLGE, data is lacking regarding longterm sequelae. Methods: We retrospectively reviewed a cohort of ABS patients who had undergone convalescent CMR (>10 days since admission). Results: Thirty-two patients (mean age 64± 10 yrs) underwent convalescent CMR, and 94% were female. The average peak troponin I = 5.14± 6.39, and mean time to CMR=122± 206 days. LV volumetric analysis was normal with ejection fraction 63± 6%, EDV=127± 27mL andESV 48± 14mL. LGE was noted in four cases (12.5%), and all had a pattern which was non-coronary in distribution. In three cases the LGE was limited to the apical segments of which two notably involved all four apical segments with diffuse transmyocardial enhancement not typical of either ischaemic injury or myocarditis (figure). The apical location correlates to the acute wall motion abnormality – although convalescent wall motion was normal in all. One case had basal septal LGE, also with normal wall motion. Patients with LGE were similar to those without with respect to age, sex, peak troponin and LV volumes.