Non-invasive intraventricular pressure differences estimated with cardiac MRI in subjects without heart failure and with heart failure with reduced and preserved ejection fraction

Objective Non-invasive assessment of left ventricular (LV) diastolic and systolic function is important to better understand physiological abnormalities in heart failure (HF). The spatiotemporal pattern of LV blood flow velocities during systole and diastole can be used to estimate intraventricular pressure differences (IVPDs). We aimed to demonstrate the feasibility of an MRI-based method to calculate systolic and diastolic IVPDs in subjects without heart failure (No-HF), and with HF with reduced ejection fraction (HFrEF) and HF with preserved ejection fraction (HFpEF). Methods We studied 159 subjects without HF, 47 subjects with HFrEF and 32 subjects with HFpEF. Diastolic and systolic intraventricular flow was measured using two-dimensional in-plane phase-contrast MRI. The Euler equation was solved to compute IVPDs in diastole (mitral base to apex) and systole (apex to LV outflow tract). Results Subjects with HFpEF demonstrated a higher magnitude of the early diastolic reversal of IVPDs (-1.30 mm Hg) compared with the No-HF group (-0.78 mm Hg) and the HFrEF group (-0.75 mm Hg; analysis of variance p=0.01). These differences persisted after adjustment for clinical variables, Doppler-echocardiographic parameters of diastolic filling and measures of LV structure (No-HF=-0.72; HFrEF=-0.87; HFpEF=-1.52 mm Hg; p=0.006). No significant differences in systolic IVPDs were found in adjusted models. IVPD parameters demonstrated only weak correlations with standard Doppler-echocardiographic parameters. Conclusions Our findings suggest distinct patterns of systolic and diastolic IVPDs in HFpEF and HFrEF, implying differences in the nature of diastolic dysfunction between the HF subtypes

Association of arginine vasopressin with low atrial natriuretic peptide levels, left ventricular remodelling, and outcomes in adults with and without heart failure

AIMS: The arginine vasopressin (AVP) pathway has been extensively studied in heart failure (HF) with reduced ejection fraction (HFrEF), but less is known about AVP in HF with preserved EF (HFpEF). Furthermore, the association between AVP and atrial natriuretic peptide (ANP, a well-known inhibitor of AVP secretion) in HF is unknown. METHODS AND RESULTS: We studied subjects with HFpEF (n = 28) and HFrEF (n = 25) and without HF (n = 71). Left ventricular (LV) mass and left atrial (LA) volumes were measured with cardiac magnetic resonance imaging. Arginine vasopressin and ANP were measured with enzyme-linked immunosorbent assay. Arginine vasopressin levels were significantly greater in HFpEF [0.96 pg/mL; 95% confidence interval (CI) = 0.83-1.1 pg/mL] compared with subjects without HF (0.69 pg/mL; 95% CI = 0.6-0.77 pg/mL; P = 0.0002). Heart failure with preserved ejection fraction (but not HFrEF) was a significant predictor of higher AVP after adjustment for potential confounders. Arginine vasopressin levels were independently associated with a greater LA volume and also paradoxically, with lower ANP levels. Key independent correlates of higher AVP were the presence of HFpEF (standardized beta = 0.32; 95% CI = 0.09-0.56; P = 0.0073) and the ANP/LA volume ratio (standardized beta = -0.23; 95% CI = -0.42 to -0.04; P = 0.0196). Arginine vasopressin levels were independently associated with LV mass (beta = 0.26; 95% CI = 0.09-0.43; P = 0.003) and with an increased risk of death or HF admissions during follow-up (hazard ratio = 1.61; 95% CI = 1.13-2.29; P = 0.008). CONCLUSIONS: Arginine vasopressin is increased in HFpEF and is associated with LV hypertrophy and poor outcomes. Higher AVP is associated with the combination of LA enlargement and paradoxically low ANP levels. These findings may indicate that a relative deficiency of ANP (an inhibitor of AVP secretion) in the setting of chronically increased LA pressure may contribute to AVP excess