To compare the diagnostic ability of multiple CMR-derived indices for the detection of PH as determined by right heart catheterization (RHC).
A total of 185 patients with known or suspected chronic PH who underwent cardiac CMR and RHC in ¡Ü 15 days were included. PH was defined as a mean pulmonary artery (PA) pressure ¡Ý 25 mm Hg. Right ventricular (RV) volumes, RV ejection fraction (RVEF), PA areas, and PA average blood flow velocity were quantified with CMR. A novel index ¦Á was defined as the ratio between minimal PA area and RVEF.
According to the RHC, PH was present in 152 patients. All CMR-derived parameters correlated with the degree of mean PA pressure, with ¦Á having the highest correlation coefficient (r = 0.61, p < 0.001). Correlations were also highest for ¦Á in the patients with pulmonary arterial hypertension (PAH; r = 0.55, p < 0.001) and non-PAH subgroup (r = 0.61, p < 0.001). Diagnostic accuracy for the detection of PH, based on receiver operating curve analysis, was best for ¦Á (area under the curve = 0.95). A cutoff value of 7.2 demonstrated a sensitivity of 90 % and a specificity of 88 % .
An easily-obtainable and novel CMR index ¦Á that combines geometrical and functional information of the PA and the RV allows for the noninvasive diagnosis of PH with high accuracy, above other common CMR-derived parameters.