A Simple Derived Prediction Score for the Identification of an Elevated Pulmonary Artery Wedge Pressure Using Precatheterization Clinical Data in Patients Referred to a Pulmonary Hypertension Center.

Background: One of the foremost diagnostic challenges in clinical pulmonary hypertension is discriminating between pulmonary arterial hypertension (group 1) and heart failure with preserved ejection fraction (group 2.2). Group 2.2 is defined as a normal left ventricular ejection fraction (> 50%) and a pulmonary arterial wedge pressure (PAWP) > 15 mm Hg. We aimed to determine whether patient history, demographics, and noninvasive measures could predict PAWP before to right heart catheterization.

Methods: Data were prospectively collected on 350 consecutive patients at a single tertiary care medical center; of these patients, 151 met criteria for entry into our study (88 in group 1 and 63 in group 2.2). Data included historical features, demographics, and results of a transthoracic echocardiogram. A multivariate regression model was developed to predict PAWP > 15 mm Hg.

Results: Univariate predictors of PAWP > 15 mm Hg included older age, higher BMI and weight, systemic systolic BP and pulse pressure, more features of the metabolic syndrome, presence of hypertension and left atrial enlargement, absence of right ventricular enlargement, and lower glomerular filtration rate and 6-min walk distance. The optimal model for predicting PAWP > 15 mm Hg was composed of age (> 68 years), BMI (> 30 kg/m(2)), absence of right ventricular enlargement, and presence of left atrial enlargement (area under the curve, 0.779).

Conclusions: Clinical characteristics obtained before diagnostic right heart catheterization accurately predict the probability of elevation of PAWP > 15 mm Hg in patients with preserved ejection fraction. These combined clinical characteristics can be used a priori to predict the likelihood of group 2.2 pulmonary hypertension.