Elevated left ventricular filling pressures can be estimated with accuracy by a new mathematical model.

BACKGROUND

Although the clinical assessment of jugular venous pressure (JVP) provides accurate estimate of right atrial pressure (RAP), there is no reliable non-invasive method for assessing pulmonary capillary wedge pressure (PCWP). Our objective was to evaluate the sensitivity and specificity for detecting elevated left ventricular filling pressures using a model for PCWP estimation, based on the clinical assessment of RAP and association between RAP and PCWP, which is unique for each patient, identified in a recent right heart catheterization (RHC).

METHODS

The study included 377 patients (age, 54.3 ± 13 years) with heart failure with reduced ejection fraction (left ventricular ejection fraction of 30.5 ± 10.8%) who underwent 2 RHCs within 1 year. In Group A (189 randomly selected patients), hemodynamic variables with significant correlation with the current wedge pressure (PCWP(2)) were identified and an equation estimating PCWP(2) based on these variables was formed. The validity of the equation was evaluated in the remaining 188 patients (Group B). The equation was also evaluated, prospectively in 39 new patients where RAP was estimated clinically, by physicians blinded to the results of the RHC.

RESULTS

PCWP(2) in Group A correlated with RAP(1), systolic pulmonary artery pressure (SPAP(1)), and PCWP(1) of the first RHC and with RAP(2) and SPAP(2) of the second. The equation is PCWP(2) = [3RAP(2) + (PCWP(1) - RAP(1)) + 4]/2. In Group B, the sensitivity and specificity of estimated PCWP(2) for diagnosis of elevated LV filling pressures (invasive values >18 mm Hg) was significant, reflected by an area under the curve (AUC) of 0.954 (p < 0.001). In the prospective sub-group, where JVP was entered in the formula as an estimate of RAP(2), correlation between estimated and measured PCWP(2) was r = 0.803 (p < 0.001).

CONCLUSIONS

The current PCWP of a patient with heart failure can be estimated accurately by a simple equation based on measurements of a previous RHC and the current value of clinically assessed JVP.