## 4 Discussion
\begin{table}
\begin{tabular}{l c c c c c c c} \hline \hline  & \multicolumn{3}{c}{**Poorly Perfused Group**} & \multicolumn{3}{c}{**Normally Perfused Group**} \\  & & **(\(n\) = 38)** & \multicolumn{3}{c}{**(\(n\) = 48)**} \\ \hline
**Variable** & **Baseline** & **After BPA** & \(p\) **Value** & **Baseline** & **After BPA** & \(p\) **Value** & \(p\) **Value** * \\ \hline Number of BPA session & & 4.1 \(\pm\) 2.2 & & & 4.4 \(\pm\) 1.6 & & 0.235 \\ NYHA FC (I/II/III/IV) (\%) & 0/17/73/10 & 34/58/8/0 & \textless{}0.001 & 2/23/71/4 & 42/56/2/0 & \textless{}0.001 & 0.395 \\ Hemodynamics after BPA & & & & & & & \\ Mean RAP (mmHg) & 4.4 \(\pm\) 3.7 & 3.7 \(\pm\) 3.5 & 0.033 & 5.2 \(\pm\) 3.3 & 3.8 \(\pm\) 2.4 & 0.030 & 0.712 \\ Systolic PAP (mmHg) & 68.5 \(\pm\) 16.9 & 34.5 \(\pm\) 7.7 & \textless{}0.001 & 57.0 \(\pm\) 19.3 & 32.3 \(\pm\) 6.5 & \textless{}0.001 & 0.090 \\ Diastolic PAP (mmHg) & 22.0 \(\pm\) 7.3 & 11.3 \(\pm\) 3.5 & \textless{}0.001 & 19.5 \(\pm\) 7.3 & 11.1 \(\pm\) 3.5 & \textless{}0.001 & 0.766 \\ Mean PAP (mmHg) & 37.5 \(\pm\) 10.5 & 19.6 \(\pm\) 5.0 & \textless{}0.001 & 32.5 \(\pm\) 11.1 & 19.2 \(\pm\) 3.3 & \textless{}0.001 & 0.220 \\ PAWP (mmHg) & 7.9 \(\pm\) 3.5 & 7.5 \(\pm\) 3.5 & 0.387 & 8.2 \(\pm\) 4.1 & 8.1 \(\pm\) 3.4 & 0.433 & 0.650 \\ Cardiac index (L/min/m\({}^{2}\)) & 1.95 \(\pm\) 0.85 & 2.48 \(\pm\) 0.64 & 0.013 & 2.32 \(\pm\) 0.74 & 2.29 \(\pm\) 0.71 & 0.398 & 0.419 \\ PVR (dynes-sec/cm\({}^{5}\)) & 611 \(\pm\) 467 & 270 \(\pm\) 118 & \textless{}0.001 & 422 \(\pm\) 280 & 220 \(\pm\) 88 & \textless{}0.001 & 0.133 \\ SvO\({}_{2}\) (\%) & 61.0 \(\pm\) 7.7 & 67.8 \(\pm\) 4.4 & \textless{}0.001 & 65.1 \(\pm\) 7.4 & 68.7 \(\pm\) 5.3 & 0.013 & 0.800 \\ Exercise capacity after BPA & & & & & & & \\
6 MWD (m) & 300 \(\pm\) 97 & 390 \(\pm\) 102 & \textless{}0.001 & 352 \(\pm\) 93 & 365 \(\pm\) 69 & 0.185 & 0.627 \\ Peak VO\({}_{2}\) in CTET & & & & & & & \\ (ml/min/kg) & 11.1 \(\pm\) 3.8 & 15.0 \(\pm\) 4.5 & \textless{}0.001 & 13.4 \(\pm\) 4.4 & 15.4 \(\pm\) 3.6 & 0.005 & 0.888 \\ VE/VCO\({}_{2}\) slope in CPET & 39.4 \(\pm\) 12.7 & 28.8 \(\pm\) 5.9 & \textless{}0.001 & 35.3 \(\pm\) 11.1 & 25.9 \(\pm\) 4.5 & \textless{}0.001 & 0.040 \\ Lung function test & & & & & & & \\ \%VC (\%) & 91.7 \(\pm\) 16.7 & 100.8 \(\pm\) & & & & & \\ FEV 1.0\% (\%) & 73.1 \(\pm\) 8.9 & 77.8 \(\pm\) 8.5 & 0.164 & 76.5 \(\pm\) 8.7 & 76.7 \(\pm\) 9.2 & 0.702 & 0.629 \\ \%DLCO/VA (\%) & 60.4 \(\pm\) 16.8 & 55.5 \(\pm\) 13.1 & 0.141 & 75.9 \(\pm\) 15.7 & 70.0 \(\pm\) 12.4 & 0.040 & 0.001 \\ Medication & & & & & & & \\ sGC stimulator (\(n\), \%) & 19 (50\%) & 18 (47\%) & 23 (48\%) & 21 (44\%) & 0.738 \\ \hline \hline \end{tabular} _List of abbreviations_: NYHA FC: New York Heart Association functional class; RAP; right atrial pressure; PAP: pulmonary artery pressure; PAWP: pulmonary artery wedge pressure pressure; PVR: pulmonary vascular resistance; SvO\({}_{2}\): mixed venous oxygen saturation; GMWD: 6 min walk distance; VO\({}_{2}\): oxygen consumption; CPET: cardiopulmonarymeyer exercise test; VE/VCO\({}_{2}\): ventilatory equivalent for carbon dioxide; VC: vital capacity; IFV: forced vital capacity; DLCO/VA: diffusing capacity for carbon monoxide divided by the alveolar volume; sGC: soluble galvanylate cyclase; Data are given as mean \(\pm\) standard deviation. * Comparison between poorly perfused group and normally perfused group after BPA.  
\end{table} 
Table 3: Hemodynamic results of CTEPH patients with BPA (\(n\) = 86) between the poorly and normally perfused groups. have already supported the diagnostic accuracy of DE-CT and concur with the usefulness of ventilation/perfusion scintigraphy and computed tomography pulmonary angiography in CTEPH [19; 20]. Lung vascular perfusion can be quantified by examining the lung PBV score, which is calculated as the sum of the iodine density scores of each lung segment. Additionally, PBV maps could calculate the iodine distribution in the lung parenchyma and be used as surrogate markers for the underlying vascular reserve [5]. [PERSON] et al.