PURPOSE: The aim of this study was to assess the time of a contrast-free protocol for routine clinical heart failure assessment.
METHODS: Twelve heart failure patients (mean age 64±9 years; 36% female) and fourteen age-matched healthy volunteers (mean age 56±5 years; 64% female) underwent a CMR on a clinical 3T scanner (Skyra, Siemens, Erlangen, Germany). The short, contrast-free CMR protocol included standard cine sequences for ventricular function (short axis stack), T1 mapping (MOLLI, short axis view), T2 mapping (FLASH, short axis view), and OS-CMR (in basal and mid-ventricular short axis views). Strain values were obtained using the standard cine short-axis views and the 2- and 4-chamber long-axis images. The global myocardial oxygenation reserve (MORE) was obtained from OS-CMR images at baseline and during a long breath-hold that was preceded by a 60s period of hyperventilation. Time of scan was determined from the first and last sequences performed.
RESULTS: Compared with the control group, patients with HF had, on average, a higher global T1 (p<0.0001), higher global T2 (p=0.0009), larger end-diastolic volume (p=0.0005), larger end-systolic volume (p<0.0001), larger left-ventricular end-diastolic atrial volume (p=0.0016) and lower left-ventricular ejection fraction (p<0.0001), with a reduced global peak systolic circumferential strain (<0.0001), and global peak systolic longitudinal strain (p<0.0001). In patients, the breathing-induced MORE was also significantly lower than in healthy controls (0.3±3.3 vs 4.5±4.2, p=0.013). The study protocol was significantly shorter (p<0.0001) than the current clinical MRI protocol, 49.3±10.7 and 31.4±8.3 minutes, respectively.
CONCLUSION: A significantly shorter, contrast-free CMR protocol of 31- compared to the standard 49-minute protocol was able to determine that heart failure patients were characterized by functional, mapping, and strain CMR parameters as well as impaired coronary microvascular function, that could be detected by OS-CMR.