Objective: To evaluate segmental right ventricular (RV) dysfunction in pulmonary hypertension (PH) using cardiac magnetic resonance (CMR).
Design: Cross-sectional analysis in a retrospective cohort of consecutive adult patients.
Setting: Mount Sinai Hospital in New York.
Patients: 192 patients with known or suspected PH undergoing right heart catheterisation and CMR. PH was defined as mean pulmonary artery pressure ≥ 25 mm Hg. Abnormal RV ejection fraction (RVEF) was defined as <50%. Patients were classified into: group 1 (no PH, normal RVEF; n = 40), group 2 (PH, normal RVEF; n = 41) or group 3 (PH, abnormal RVEF; n=111).
Interventions: CMR and right heart catheterisation within a 2-week interval. Main outcome measures On cine CMR images, the stack of RV short-axis views was divided into two equal halves. Basal and apical RVEF were calculated using Simpson's method, and a ratio of basal-to-apical RVEF (RVEF(ratio)) was derived.
Results: Basal RVEF did not differ between groups 1 and 2 (63 ± 8% vs 64 ± 8%; p = 1); however, patients in group 2 had significantly lower apical RVEF (46 ± 13% vs 58 ± 10%; p<0.01) and higher RVEF(ratio) (median 1.4 vs 1.1; p<0.01). Both apical and basal RVEF were reduced in group 3 compared with groups 1 and 2 (p<0.01), and the RVEF(ratio) increased with increasing PH severity (p<0.01 for trend). An apical RVEF <50% was more sensitive than global RV dysfunction for the detection of PH.
Conclusions: Apical dysfunction appears to occur before global RVEF decreases in chronic PH, potentially constituting an early and sensitive marker of RV dysfunction in this setting.