Clinical Outcomes and Prognosis
Bradley Chambers, MBChB BSc MRCP
Cardiology Registrar
University of Leeds, England, United Kingdom
Jonathan Farley, BSc, MB
Cardiology
University of Leeds, United Kingdom
David A. Broadbent, PhD
Clinician scientist
Leeds Institute of Cardiovascular and Metabolic Medicine, England, United Kingdom
Wasim Javed, MBChB, MRes
Cardiology Clinical Research Fellow/ Registrar
Leeds Institute of Cardiovascular and Metabolic Medicine, United Kingdom
Melanie Spurr
Cardiac MRI Research nurse
Leeds General Infirmary, United Kingdom
Pankaj Garg, PhD
Associate Professor of Cardiovascular Medicine
University of East Anglia, United Kingdom
Nicholas Jex, MD
PhD Fellow
Leeds Institute of Cardiovascular and Metabolic Medicine, England, United Kingdom
Sharmaine Thirunavukarasu, MbCHB
Cardiology
University of Leeds
WILMSLOW, England, United Kingdom
Amrit Chowdhary, MD
Cardiology
University of Leeds
WAKEFIELD, England, United Kingdom
Noor Sharrack, MBChB, MRCP, DTM&H
Clinical Research Fellow
University of Leeds, England, United Kingdom
Miroslawa Gorecka
Cardiology
University of Leeds, United Kingdom
Eylem Levelt, PhD
Associate Professor and Honorary Consultant
University of Leeds
Leeds, England, United Kingdom
Erica Dall'Armellina, DPhil
Associate Professor
University of Leeds
John P. Greenwood, PhD
Professor
University of Leeds
Leeds, England, United Kingdom
Sven Plein, MD, PhD
Professor
University of Leeds
Leeds, England, United Kingdom
Peter P. Swoboda, PhD
Consultant Cardiologist & Senior Lecturer
University of Leeds
Leeds, England, United Kingdom
Ratio of right/left ventricular blood pool T2 times can be measured from balanced steady-state free precession (bSSFP) T2 maps. This ratio is dependent on oxygen saturation of mixed venous blood/arterial blood in the heart. T2 blood pool ratio is yet to be established as a reliable marker in humans however T2 oxygen measurement has been validated invasively in pig models (1).
We aimed to establish if whether cardiac T2 ratio in patients being investigated for heart failure is associated with major adverse cardiovascular events (MACE).
Methods: Patients newly diagnosed with heart failure underwent stress perfusion CMR including bSSFP T2 maps planned in the short-axis. Patients were followed up for MACE defined as heart failure hospitalisation, myocardial infarction, ventricular tachycardia/fibrillation, stroke and cardiovascular death. Manual segmentation excluding trabeculation of both left and right ventricular blood pool from T2 maps was performed. The optimal cut-off of T2 ratio was identified as < 52% by receiver operator curve (ROC) analysis. Univariate and stepwise multivariate Cox regression were performed to identify which clinical factors has significant association with MACE.
Results: CMR and follow up data from 355 patients was included (mean age 63±12, 237 male (67%), mean LVEF 40±13, table 1). On Cox regression analysis, the association between T2 ratio and MACE was stronger in the basal slice (HR 3.4, 95% CI 1.8-6.4, P< 0.001) than the mid ventricular slice (HR 2.1, 95% CI 1.1-4.0, P=0.024) and the basal slice was therefore used for all subsequent analyses. In addition, LVEF and ischaemic LGE were associated with MACE, table 2. Basal T2 ratio < 52% was also associated with heart failure hospitalisation (HR 2.93, 95% CI 1.31-6.53, P=0.009). Basal T2 ratio < 52% was still associated with MACE after adjusting for LVEF and ischaemic LGE (HR 2.88, 95% 1.43-5.81, P=0.003).
Conclusion: Ratio of T2 times from RV/LV blood pool was associated with both MACE and heart failure hospitalisation in patients being investigated for heart failure. This remained significant even after adjustment for conventional risk factors including LVEF and ischaemic LGE. Further work is needed to validate T2 ratio as a novel prognostic marker in heart failure in external cohorts.