Haemodynamic validation of the three-step HFA-PEFF algorithm to diagnose heart failure with preserved ejection fraction

The HFA-PEFF algorithm (Heart Failure Association-Pre-test assessment, Echocardiography and natriuretic peptide score, Functional testing in cases of uncertainty, Final aetiology) is a three-step algorithm to diagnose heart failure with preserved ejection fraction (HFpEF). It provides a three-level likelihood of HFpEF: low (score < 2), intermediate (score 2-4), or high (score > 4). HFpEF may be confirmed in individuals with a score > 4 (rule-in approach). The second step of the algorithm is based on echocardiographic features and natriuretic peptide levels. The third step implements diastolic stress echocardiography (DSE) for controversial diagnostic cases. We sought to validate the three-step HFA-PEFF algorithm against a haemodynamic diagnosis of HFpEF based on rest and exercise right heart catheterization (RHC).

Seventy-three individuals with exertional dyspnoea underwent a full diagnostic work-up following the HFA-PEFF algorithm, including DSE and rest/exercise RHC. The association between the HFA-PEFF score and a haemodynamic diagnosis of HFpEF, as well as the diagnostic performance of the HFA-PEFF algorithm vs. RHC, was assessed. The diagnostic performance of left atrial (LA) strain < 24.5% and LA strain/E/E' < 3% was also assessed. The probability of HFpEF was low/intermediate/high in 8%/52%/40% of individuals at the second step of the HFA-PEFF algorithm and 8%/49%/43% at the third step. After RHC, 89% of patients were diagnosed as HFpEF and 11% as non-cardiac dyspnoea. The HFA-PEFF score resulted associated with the invasive haemodynamic diagnosis of HFpEF (P < 0.001). Sensitivity and specificity of the HFA-PEFF score for the invasive haemodynamic diagnosis of HFpEF were 45% and 100% for the second step of the algorithm and 46% and 88% for the third step of the algorithm. Neither age, sex, body mass index, obesity, chronic obstructive pulmonary disease, or paroxysmal atrial fibrillation influenced the performance of the HFA-PEFF algorithm, as these characteristics were similarly distributed over the true positive, true negative, false positive, and false negative cases. Sensitivity of the second step of the HFA-PEFF score was non-significantly improved to 60% (P = 0.08) by lowering the rule-in threshold to >3. LA strain alone had a sensitivity and specificity of 39% and 14% for haemodynamic HFpEF, increasing to 55% and 22% when corrected for E/E'.

As compared with rest/exercise RHC, the HFA-PEFF score lacks sensitivity: Half of the patients were wrongly classified as non-cardiac dyspnoea after non-invasive tests, with a minimal impact of DSE in modifying HFpEF likelihood.