Contributions of cardiac dysfunction and volume status to central haemodynamics in chronic heart failure

Elevated cardiac filling pressures producing clinical congestion in heart failure (HF) patients may be secondary to intravascular volume expansion or abnormalities in cardiac diastolic properties. The objective of this study was to assess the extent to which measures of myocardial function and intravascular volume correlate with haemodynamic abnormalities in chronic HF.

Subjects underwent invasive haemodynamic assessment, measurement of total blood volume (TBV) using radiolabel indicator-dilution methodology, and echocardiography to evaluate cardiac structure and function. Patients were divided into those with hypervolaemia (defined as TBV > +8% above referenced normal volume) and normal volume ('euvolaemia') (TBV ≤ + 8%). Of 66 patients, 39 (59%) were hypervolaemic and 27 (41%) normal TBV. Central venous pressure (CVP, P = 0.01) and pulmonary capillary wedge pressure (PCWP, P < 0.001) were higher in hypervolaemic compared with euvolaemic patients; however, 15% of hypervolaemic patients displayed normal pressures. Of euvolaemic patients, 70% displayed elevated CVP and 63% elevated PCWP. PCWP was moderately correlated with TBV (r = 0.42), left ventricular diastolic function (e' velocity, r = -0.44), and left atrial strain (r = -0.47). In multivariable regression TBV, left ventricular e', and left atrial strain were independently associated with PCWP (all P < 0.05).

While hypervolaemic patients displayed elevations in filling pressures, a substantial proportion (15%) had normal pressures, and of all subjects with elevated filling pressures nearly one third had normal TBVs. Importantly, of patients with normal volumes, a majority (>60%) display elevated filling pressures. Combined analysis of volume, pressure, and cardiac function may be helpful to guide comprehensive assessments of HF status.