A Simple Echocardiographic Prediction Rule for Hemodynamics in Pulmonary Hypertension

Background— Pulmonary hypertension (PH) has diverse causes with heterogeneous physiology compelling distinct management. Differentiating patients with primarily elevated pulmonary vascular resistance (PVR) from those with PH predominantly because of elevated left-sided filling pressure is critical. Methods and Results— We reviewed hemodynamics, echocardiography, and clinical data for 108 patients seen at a referral PH clinic with transthoracic echocardiogram and right heart catheterization within 1 year. We derived a simple echocardiographic prediction rule to allow hemodynamic differentiation of PH attributed to pulmonary vascular disease (PH PVD , defined as pulmonary artery wedge pressure PAWP≤15 mm Hg and PVR>3 WU). Age averaged 61.3±14.8 years, μPAWP and PVR were 16.4±7.1 mm Hg and 6.3±4.0 WU, respectively, and 52 (48.1%) patients fulfilled PH PVD hemodynamic criteria. The derived prediction rule ranged from –2 to +2 with higher scores suggesting higher probability of PH PVD : +1 point for left atrial anterior–posterior dimension 10; –1 for left atrial anterior-posterior dimension >4.2 cm. PVR increased stepwise with score (for –2, 0, and +2, μPVR were 2.5, 4.5, and 8.1 WU, respectively), whereas the inverse was true for pulmonary artery wedge pressure (corresponding μPAWP were 21.5, 16.5, and 10.4 mm Hg). Among subjects with complete data, the score had an area under the curve (AUC) of 0.921 for PH PVD . A score ≥0 had 100% sensitivity and 69.3% positive predictive value for PH PVD , with 62.3% specificity. No patients with a negative score had PH PVD . Patients with a negative score and acceleration time >100 ms had normal PVR (μPVR=1.8 WU, range=0.7–3.2 WU). Conclusions— We present a simple echocardiographic prediction rule that accurately defines PH hemodynamics, facilitates improved screening and focused clinical investigation for PH diagnosis and management.