Background:
Pulmonary hypertension (PH) is classified as pre-capillary, isolated post-capillary (IpcPH), combined pre- and post-capillary (CpcPH), or exercise PH. On the one hand, IpcPH associated with left heart disease may lead to pulmonary vascular remodelling and eventually to CpcPH. On the other hand, pre-capillary PH may be diagnosed in the presence of cardiovascular comorbidities such as left heart disease. Left/right atrial (LA/RA) functional impairment is a frequent finding in cardio-pulmonary disease reflecting both intrinsic atrial impairment and congestion. Consequently, we sought to investigate this across the PH spectrum.
Methods:
Patients referred to both right heart catheterisation (RHC) and cardiovascular magnetic resonance (CMR) imaging were enrolled in this monocentric registry. Patients were classified by RHC according to current guideline recommendations. CMR assessment included left ventricular (LV) volumes as well as LA/RA deformation for reservoir (Es), passive conduit (Ee) and active booster pump (Ea) functional assessment.
Results:
The study population consisted of n=63 patients (n=19 without PH, n=20 pre-capillary PH, n=12 CpcPH, n=5 IpcPH and n=7 exercise PH). Normal haemodyamics showed similar atrial function compared to pre-capillary (Es LA 32.2% vs. 32.5%, p=0.923; RA 27.6% vs. 18.3%, p=0.184) and exercise-induced PH despite a statistical trend for impaired LA Es (32.5% vs 23.2%, p=0.094) in the latter. Patients with CpcPH had impaired LA but not RA function compared to pre-capillary PH (Es LA 16.1% vs. 32.5%, p=0.009; RA 18.1% vs. 18.3%, p=0.863). IpcPH patients had the numerically lowest LA Es (12.8%) which did not achieve statistical significance compared to CpC patients (p=0.328). Impaired LA contractility (Ea) best identified patients with left cardiac involvement (pulmonary artery wedge pressure ≥15mmHg; 16.7% vs 4.7%, AUC 0.82) outperforming LV ejection fraction (LVEF, AUC 0.68, p=0.021).
Conclusions:
Left atrial functional impairment is a sign of left heart involvement in PH patients and emerges superior to LVEF. This may imply LA deformation imaging as an innovative method to detect left cardiac disease in PH.
