Abstract 17765: Stress Myocardial Blood Flow is Abnormal During Acute Takotsubo Syndrome

Abstract

Introduction: Coronary microvascular dysfunction (CMD) is a proposed mechanism for takotsubo syndrome (TS). Therefore, we performed cardiac magnetic resonance imaging (CMR) with quantitative stress/rest perfusion and T2 mapping during acute TS and at 6-month post recovery. AIM: Quantitate stress/rest myocardial blood flow (MBF) in acute/recovery TS and compare basal with apical MBF. Methods: TS diagnosed by internationally accepted criteria. Each patient underwent acute and 6-month recovery CMR with automated in-line quantification of global/regional MBF, cine imaging, T2-mapping, and late gadolinium enhancement (LGE) imaging. Normal rest and stress MBF are 0.8-1.0 and > 2.0 ml/min/g, normal myocardial perfusion reserve (MPR) is > 2.4. Results: Acute and recovery studies were performed on 7 patients, all women, average age 63 + 8.5 years. CMR was performed within 72 hours of TS diagnosis. Initial versus (vs) follow-up EF: 40.3% vs 67.1%, left ventricular (LV) mass: 108.7 grams vs 86.3 grams. Acute studies demonstrated hypokinesis in the mid-apical segments with corresponding myocardial edema, LGE was absent in all patients. Myocardial edema and wall motion abnormality normalized at recovery. During acute TS, rest and stress MBF were 1.14 and 2.58 ml/min/g (base) vs 0.96 and 1.73 ml/min/g (apex). While at recovery, rest-stress MBF were 1.14 and 3.12 ml/min/g at base versus 1.09 and 2.76 ml/min/g at apex (Figure). MPR improved from acute to recovery: 2.14 vs 2.74 (global), 2.25 vs 2.84 (base), and 1.85 vs 2.64 (apex); p = 0.126; 0.035; 0.012 respectively (Figure). Conclusion points: Resting MBF is normal during acute TS in both basal and apical LV segments despite typical apical ballooning consistent with stunned myocardium. MPR is more abnormal in apical than base segments during acute TS, returning to normal at recovery. Myocardial edema might contribute to apical CMD during acute TS.