The role of cardiac magnetic resonance in patients with an angiographically diagnosed SCAD

Abstract Background/Introduction Spontaneous coronary artery dissection (SCAD) characterized by its non-atherosclerotic nature, poses challenges in diagnosis and management. While recent efforts shed light on SCAD's clinical aspects, the specific utility of CMR demands deeper investigation for enhanced diagnosis and patient care. Purpose This study aims to analyze the characteristics of patients with an angiographically diagnosed SCAD, evaluate qualitative and quantitative parameters of baseline CMR and investigate predictors of myocardial injury and the association between CMR parameters and clinical outcome (major adverse cardiac events, MACE). Methods The study is a prospective single-center analysis of 59 patients, presented acutely in our hospital, from March 2018 to November 2023, with an angiographically detected SCAD. CMR was performed after a median of 4 days (IQR 1.5-7) from the acute onset of symptoms. SCAD Types were angiographically categorized according to the Yip-Saw classification. Most patients (71%) were screened for fibromuscular dysplasia (FMD) with a brain MR and at least one contrast-enhanced abdominal vessels investigation (CT or MR). CMR imaging was performed on a clinical 1.5 T Scanner. T1-weighted, T2-weighted turbo-spin-echo (TSE) Black-Blood (BB) and Short-Tau-Inversion-Recovery (STIR) sequences in short-axis orientation were acquired. The scan protocol included standard cine and T1/T2-weighted TSE BB and Mapping sequences. Late gadolinium enhanced (LGE) images were acquired ≏10 min after the contrast injection and were visually assessed for the presence and extension of LGE areas. LGE quantification was assessed semiautomatically. Results 40 (68%) were females. 54(92%) complained of chest pain, in 55 (93%) high-sensitive Troponin T was eleveted (>14 ng/l) and 24 (41%) presented with the clinical picture of STEMI on admission. From an angiographic point of view, the majority (69.5%) were classified as SCAD Type 2 (a+b). Among patients who underwent a proper screening, 7 patients (16%) were diagnosed with FMD. Baseline CMR showed signs of active injury in 81% and LGE in 93% of the population; however, it was often moderate in size (median of LGE segments 3, IQR 2-5). Most patients had a preserved LVEF (55±10%). STEMI presentation is an independent predictor of LGE extension (p=0.02, OddsRatio(95% CI)=7(2-24)). ScadType1 (p=0.01, OR=10( 2-39)) and N°LGE transmural segments >3 (p=0.03, OR=5.4(1.2-25)) were found to be significant predictor of MACE. 6 of the 11 MACEs were SCAD recurrence/progression, and 4 out of these 11 had already shown signs of previous myocardial injury in the baseline CMR. Conclusion(s) This study emphasized the significance of CMR, which may provide further insights into extend of myocardial damage and may aid in patients’ risk stratification.