ABSTRACT
<p><b>OBJECTIVE</b>To compare the features of patients with pulmonary hypertension due to left heart disease classified according to transpulmonary gradient (TGP) or diastolic pressure difference (DPD).</p><p><b>METHODS</b>Thirty-three patients with pulmonary hypertension due to left heart disease diagnosed by right heart catheterization were enrolled. Patients were divided into two groups according to TPG: 17 patients with TPG ≤ 12 mmHg (1 mmHg = 0.133 kPa) and 16 patients with TPG > 12 mmHg; or divided into two groups according to DPD: 23 patients with DPD < 7 mmHg and 10 patients with DPD ≥ 7 mmHg. McNemar's method was used to test the agreement of the two classification methods.</p><p><b>RESULTS</b>Below are the patients features according to the classification by TPG: central venous pressure ((9.0 ± 2.5) vs. (12.7 ± 5.4) mmHg), mean right atria pressure ((9.1 ± 2.4) vs. (12.8 ± 5.2) mmHg), right heart systolic pressure ((45.5 ± 9.8) vs. (66.8 ± 15.4) mmHg), right heart mean pressure ((22.6 ± 5.2) vs. (33.1 ± 7.5) mmHg), pulmonary systolic pressure ((44.2 ± 10.3) vs. (64.8 ± 14.2) mmHg), pulmonary diastolic pressure ((24.2 ± 4.5) vs. (33.1 ± 8.3) mmHg), pulmonary mean pressure ((32.3 ± 5.7) vs. (45.8 ± 8.6) mmHg), cardiac index ((2.6 ± 1.0) vs. (1.9 ± 0.9) L · min(-1) · m(-2)), right heart EF ((31.2 ± 12.6)% vs. (22.6 ± 7.1) %) and pulmonary vascular resistance ((2.3 ± 0.8) vs. (6.3 ± 2.6) Wood) were significantly different between the two groups (all P < 0.05). According to the classification of DPD, only right heart diastolic pressure ((7.4 ± 3.7) vs. (11.5 ± 5.7) mmHg), pulmonary diastolic pressure ((25.9 ± 6.4) vs. (34.7 ± 8.0) mmHg) and pulmonary vascular resistance ((3.3 ± 2.0) vs. (6.2 ± 3.4) Wood) were significantly different between the two groups (all P < 0.05). These was a weak agreement (κ = 0.386 6, 95% CI: 0.092 2-0.681 0) between the two classification methods.</p><p><b>CONCLUSION</b>TPG classification is superior to DPD classification for pulmonary hypertension patients due to left heart disease on identifying the hemodynamic differences.</p>