Patients with Eisenmenger syndrome have a better prognosis than patients with idiopathic pulmonary arterial hypertension (iPAH) Preserved biventricular function has been suggested to be the primary reason, which might be attributed to a favorable adaptation of the heart to an increased right ventricular (RV) afterload. Therefore this study compared cardiac morphology in iPAH and Eisenmenger syndrome patients with increased RV afterload.
10 iPAH, 6 Eisenmenger patients and 7 healthy controls were studied. Right heart catheterization was performed in all patients to assess mean pulmonary artery pressure. Cardiac magnetic resonance imaging was performed in all individual and measured right and left ventricular ejection fractions, free wall and septal myocardial mass.
In iPAH mean pulmonary artery pressure was not different (63 ± 19 mmHg vs. 69 ± 12 mmHg) compared to Eisenmenger patients, and RV (21 ± 6 % vs. 35 ± 11%, p < 0.01) and LV (48 ± 10 % vs. 70 ± 11 %, p < 0.01) ejection fractions were depressed. Compared to controls all patients showed RV and septal hypertrophy. However, RV mass increase in iPAH was less than in Eisenmenger (54 ± 15 g/m2 vs. 75 ± 13 g/m2, p < 0.05), while septal mass was equally distributed (36 ± 7 g/m2 vs. 32 ± 4 g/m2) in both patient groups. LV mass was decreased in iPAH patients compared to controls (33 ±7 g/m2 vs. 42 ± 8 g/m2) and Eisenmenger (33 ±7 g/m2 vs. 44 ± 10 g/m2, p < 0.05).
These data show that to a similar increase in RV afterload iPAH patients had depressed RV and LV function compared to Eisenmenger. This might be due to a less favorable adaptation of the right and left ventricle in iPAH.
In patients with RV pressure overload RV adaptation and function remains the main focus. However, in iPAH LV remodeling, i.e. myocardial hypotrophy, and impaired function might have an additional value in the clinical management and prognosis.
Tji-Joong Gan, None.