Prolonged central circulation transit time in patients with HFpEF and HFrEF by magnetic resonance imaging

Aims: Prolonged central circulation transit time (TT) has long been associated with heart failure (HF) and left ventricular (LV) dysfunction. In this study, we assessed the central circulation TT using cardiovascular magnetic resonance imaging (CMR) in patients with HF of preserved ejection fraction (HFpEF) and of reduced EF (HFrEF) and investigated its relation to haemodynamics. Methods and results: Fifty eight prospectively recruited volunteers underwent CMR. TT was taken as the time between the peaks of time-intensity curves from first pass perfusion images and normalized to cardiac cycle length intervals. Left ventricular ejection fraction was 55 ± 3%, 57 ± 7%, and 28 ± 10% in control (N = 10), HFpEF (N = 20), and HFrEF (N = 28), respectively (P < 0.001). Global central TT from right atrium to ascending aorta was significantly prolonged in patients with HFrEF [17 ± 5 cardiac cycles (cc)] and HFpEF (12 ± 3 cc) when compared to the normal controls (8 ± 1 cc) (P < 0.001). Regional TT was also prolonged in HF patients between right atrium and pulmonary artery (PA), PA and left atrium (LA), and LA and ascending aorta (all P-value < 0.001) with the longest delay seen between PA and LA. Among 48 HF patients, 28 underwent same day cardiac catheterization. Multivariate regression analysis suggested while reduced left and right ventricular EF were the strongest correlates for HFrEF increased pulmonary capillary wedge (PCWP) and reduced PA oxygen saturation were the strongest correlates for HFpEF. Conclusions: Global and regional central TT can be assessed in the first pass perfusion imaging. Prolonged normalized global TT correlates with reduced EF in HFrEF and increased PCWP in HFpEF.