LAUSR

Introduction: Post-capillary pulmonary hypertension (PH) is diagnosed with rest hemodynamics and requires management of left heart disease. However, in subclinical PH and mixed PH (mixed pre- and post-capillary), it is imperative to identify a predominant post-capillary phenotype with exercise (aka. Pulmonary venous hypertension). Hypothesis: In suspected subclinical and mixed PH, greater left atrial volume index (LAVI; >35) and E/E’ (>8) on echocardiogram can reliably predict a predominant post-capillary PH with exercise, assessed with invasive cardiopulmonary exercise testing (iCPET). Methods: We reviewed clinical, echocardiographic and iCPET data for 37 patients undergoing exercise right heart catheterization and then analyzed the data with receiver operator curve (ROC) and area under the curve (AUC) analysis to estimate the different echo parameters to identify post-capillary PH. Results: Within the cohort, mean age (± SD) was 63.6±11.3 years, and 19 subjects were female (51%). On ROC analysis, LAVI and E/E’ had high predictive ability to identify a pulmonary venous hypertension response with exercise (AUC=0.860, p=0.003 for LAVI, and AUC=0.788, p=0.014) with optimal cut-offs identified as: LAVI >35 and E/E’ >8. These variables also notably had a significant association with PCWP/CO>2. To understand the hemodynamics associated with these differentiable echo features, we divided the overall cohort (n=37) into 2 groups: group 1 ( Abnormal-LA group ) =LAVI>35 and/or E/E’ >8, group 2 ( Normal-LA group )=LAVI≤ 34 and E/E’≤8. The LAVI in group 1 vs group 2 was: 44.3±15.2 vs 23.1±4.4 (p<0.001) and E/E’ was: 15.8±9.9 vs 7.7±1.95 (p<0.01). Results are summarized in Table 1. Conclusions: Among individuals with suspected PH, LAVI>35 and E/E’ >8 are reliable non-invasive markers to identify post-capillary PH. In a patient with a new diagnosis of PH based on screening echocardiogram, LAVI≤ 34 and E/E’≤8 may identify a patient who is likely to benefit from PH drugs.