PURPOSE: The purpose of this study was to investigate right atrial and ventricular strain parameters on cardiac magnetic resonance (CMR) in patients with precapillary pulmonary hypertension (PPH) and whether they can aid in the assessment of PPH prognosis.
MATERIALS AND METHODS: Adult patients with groups 1 and 4 PPH were invited to participate in the study. Age- and sex-matched healthy volunteers were also recruited as controls. At baseline, patients underwent clinical examination, N-terminal pro-B-type natriuretic peptide measurement and CMR with feature tracking post-processing (CMR-FT). Healthy controls underwent only CMR-FT. The study's primary endpoint was clinical failure, defined as death, hospitalization or demonstrable clinical deterioration during follow-up. Patients who were unable to perform 6-minute walking test due to musculoskeletal disorders were excluded from the study.
RESULTS: Thirty-six patients (8 men, 28 women; mean age, 50.6±13.8 [SD] years [range: 18.6-78.5years]) and 12 healthy control subjects (5 mean, 7 women; mean age, 40.6±13.5 [SD] years [range: 23.1-64.4years]) were recruited. Right ventricular global longitudinal strain (GLS) was significantly impaired in PPH patients (-20.2±5.3 [SD] % [range: -28.8 to -9.1%] vs. -28.4±3.1% [-33.7 to -22.7%] respectively, P<0.001). The right atrial GLS was significantly impaired in PPH compared to healthy controls (-19.9±4.5% [range: -28.6 to -3.6%] vs. -26.5±4.2% [range: -32.8 to -15.8%] respectively) (P<0.001). Clinical failure occurred in 19 (19/36, 53%) of patients. Right ventricular GLS predicted clinical failure most reliably among CMR parameters (-22.6±3.8 [SD] % [range: -27.6 to -12.7%] for patients without clinical failure vs. -18±5.6 [SD] % [range: -28.8 to -9.1%] for patients with clinical failure; hazard ratio [HR]=1.85; P=0.007; area under the AUC curve=0.75). Lower absolute right atrial GLS was significantly associated with clinical failure (-22.7±3.0 [SD] % [range: -28.6 to -17.7%] for patients without clinical failure vs. -16.9±5.8 [SD] % [range: -24.2 to -3.6%] for patients with clinical failure) (HR=1.53; P=0.035).
CONCLUSION: CMR feature tracking-derived myocardial strain parameters of both the right atrium and ventricle can assist clinicians in the prognosis of PPH.