Novel echocardiographic markers of elevated left ventricular filling pressure during diastolic stress testing

Aims Diastolic stress testing (DST) is recommended to confirm heart failure with preserved ejection fraction (HFpEF) in patients with exertional dyspnea, but algorithms lack sensitivity. We aimed to identify additional echocardiographic markers of elevated pulmonary arterial wedge pressure during exercise (exPAWP) in patients referred for DST. Methods and Results We analyzed 22 patients referred for exercise right heart catheterization with simultaneous echocardiography. We identified candidate parameters in patients with exPAWP [≥]25 mmHg. Elevated exPAWP was present in 14 patients, and was best identified by peak septal systolic annular velocity on color Doppler (exS', area under the receiver operating characteristic curve (AUC) 0.97, 95% confidence interval 0.92-1.0) and mean pulmonary artery pressure/cardiac output slope (mPAP/CO, AUC 0.88 [0.72-1.0]). We propose a three-step decision tree to identify patients with elevated exPAWP. Applying this decision tree to 376 patients in an independent non-invasive DST cohort showed that patients labeled as 'high probability of HFpEF' had reduced peak oxygen uptake (12.8 (10.5-15.9) mL/kg/min, p<.001 vs intermediate/low probability), high H2FPEF score (55 (44-75)%, p<.007 vs intermediate/low probability), and typical clinical characteristics. The amount of inconclusive DST decreased from 80% using current recommendations, to 29% using the decision tree. Conclusion In DST for suspected HFpEF, exS' was the most accurate echocardiographic parameter to identify elevated PAWP. We propose a decision tree including exS' and mPAP/CO for interpretation of DST. Application of this decision tree revealed typical HFpEF characteristics in patients labeled as high probability of HFpEF, and substantially reduced the amount of inconclusive results.