TY - JOUR T1 - Inline perfusion mapping provides insights into the disease mechanism in hypertrophic cardiomyopathy JF - Heart JO - Heart SP - 824 LP - 829 DO - 10.1136/heartjnl-2019-315848 VL - 106 IS - 11 AU - Claudia Camaioni AU - Kristopher D Knott AU - Joao B Augusto AU - Andreas Seraphim AU - Stefania Rosmini AU - Fabrizio Ricci AU - Redha Boubertakh AU - Hui Xue AU - Rebecca Hughes AU - Gaby Captur AU - Luis Rocha Lopes AU - Louise Anne Elizabeth Brown AU - Charlotte Manisty AU - Steffen Erhard Petersen AU - Sven Plein AU - Peter Kellman AU - Saidi A Mohiddin AU - James C Moon Y1 - 2020/06/01 UR - http://heart.bmj.com/content/106/11/824.abstract N2 - Objective In patients with hypertrophic cardiomyopathy (HCM), the role of small vessel disease and myocardial perfusion remains incompletely understood and data on absolute myocardial blood flow (MBF, mL/g/min) are scarce. We measured MBF using cardiovascular magnetic resonance fully quantitative perfusion mapping to determine the relationship between perfusion, hypertrophy and late gadolinium enhancement (LGE) in HCM.Methods 101 patients with HCM with unobstructed epicardial coronary arteries and 30 controls (with matched cardiovascular risk factors) underwent pixel-wise perfusion mapping during adenosine stress and rest. Stress, rest MBF and the myocardial perfusion reserve (MPR, ratio of stress to rest) were calculated globally and segmentally and then associated with segmental wall thickness and LGE.Results In HCM, 79% had a perfusion defect on clinical read. Stress MBF and MPR were reduced compared with controls (mean±SD 1.63±0.60 vs 2.30±0.64 mL/g/min, p<0.0001 and 2.21±0.87 vs 2.90±0.90, p=0.0003, respectively). Globally, stress MBF fell with increasing indexed left ventricle mass (R2 for the model 0.186, p=0.036) and segmentally with increasing wall thickness and LGE (both p<0.0001). In 21% of patients with HCM, MBF was lower during stress than rest (MPR <1) in at least one myocardial segment, a phenomenon which was predominantly subendocardial. Apparently normal HCM segments (normal wall thickness, no LGE) had reduced stress MBF and MPR compared with controls (mean±SD 1.88±0.81 mL/g/min vs 2.32±0.78 mL/g/min, p<0.0001).Conclusions Microvascular dysfunction is common in HCM and associated with hypertrophy and LGE. Perfusion can fall during vasodilator stress and is abnormal even in apparently normal myocardium suggesting it may be an early disease marker. ER -