From July 2012 until July 2019, we have registered data from 1012 patients who have the confirmed diagnosis as septal defects/shunts CHD. The clinical characteristics of the patients are shown in Table 1. The mean age of the patients at first diagnosis/enrollment was 34.7 years. The majority of patients were females, which accounted for 78.5% of all patients (as shown in Figure 2). Normal and underweight body mass categories were predominant. Mean peripheral oxygen saturation was 95.5%. The WHO functional class was predominantly class II (43.0% of patients), only the minority of patients had worse WHO functional class (10.0% class III and 1.1% class IV). The mean 6-minute walking distance was 356.5 meters.The increased probability of PH by TTE examination was predominant (77.1 %).The signs of Eisenmenger syndrome were encountered in 18.7% of patients. The laboratory results showed mean hemoglobin level was 13.8 g/dL, hematocrit 41.9% and median NTproBNP level 370.9 pg/mL. The main symptoms were dyspnea on effort (35.9%), easily fatigued (16.3%), chest pain/discomfort (10.8 %) and palpitations (9.3 %). As many as 9.4% of patients did not report any symptoms during first enrollment.The main symptoms of patients are depicted in Figure 3.
The majority of CHD type was secundum ASD (73.4%). Other CHD types were perimembranous VSD (9.0%), PDA(5.8%), doubly-committed subarterial (DCSA) VSD (3.6%), sinus venosus ASD (2.0%), primum ASD (1.3%), PFO (0.8%), AVSD (0.3%) and AP window (0.1%). The patients with multiple defects accounted for 0.9% of all patients. The majority of patients had undergone RA and RV dilatation, with mean RA diameter of 45.6 mm and RV diameter of 42.1 mm. The mean mPAP based on TTE examination was 36.1 mmHg. The mean tricuspid valve regurgitation gradient was 61.6 mmHg. The mean tricuspid annular plane systolic excursion was 24.3 mm.The mean left ventricle ejection fraction was 68.1%. Table 2 shows the results of TTE and TOE procedures.
The RHC had been performed in 614 subjects (60.7%). Among 1012 patients, 103 patients did not undergo RHC examination and 295 patients were on a waiting list to get RHC performed. The RHC was not performed in103 patients due to: (1) patients had already had closure of defects (24 patients), (2) patients died before scheduled for RHC (39 patients), (3) patients refused the RHC examination (n=10) and (4) patients did not respond to RHC schedule (30 patients). Patients who did not undergo RHC examination were mostly lost to follow-up from COHARD-PH registry and did not continue regular visits to our hospital. Patients who were on a waiting list wee managed based on clinical symptoms and probability of PH based on echocardiography signs. The RHC results confirmed that 411 patients (66.9%) had developed PAH.The hemodynamics data from RHC showed median mPAP was 34.0 mmHg, PVRi 3.3 Wood Unit.m2, PAWP 10.0 mmHg, and flow ratio 2.3. The vasoreactivity test was performed in 186 patients and indicated that 43 patients (23.1%) had vasoreactive response. As many as 363 patients (59.1%) had correctable criteria for defect closure. Table 3 shows the result of RHC procedure.
Table 4 shows the comparison of clinical and laboratory parameters between patients with CHD-related PAH and those without PAH. Patients with PAH had significantly older age at first diagnosis (36.4±12.9 vs. 32.2±12.0 years old, p<0.001), lower peripheral oxygen saturation (94.8±5.5 vs. 97.4±3.2 %, p <0.001), lower 6-minute walking distance (336.3±99.7 vs. 393.9±82.1 meters, p<0.001), worse WHO functional class (WHO III-IV: 14.2% vs. 5.0%, p<0.001), higher hemoglobin level (14.1±2.2 vs. 13.5±1.9 g/dL, p=0.006), higher hematocrit level (42.2±6.5 vs. 40.2±4.9 %, p<0.001) and higher NTproBNP level (median: 774.0 vs. 121.5 pg/mL, p<0.001). The proportion of ASD was predominant in patients with PAH (89.3 %), followed by PDA (5.1%) and VSD (4.1%). Among the patients with multiple defects, the majority had developed PAH (4 of 5 patients) and all subjects with AP window and AVSD had PAH. Multivariable analysis showed that only NTproBNP level independently predicts the PAH in patients with CHD (OR 1.002, 95%CI: 1.001-1.004, p=0.001), as shown in Table 5.
Table 6 shows the difference of characteristics among patients based on WHO functional class (total amount 602 patients). Worse WHO functional class (class III-IV) was marked by the least peripheral oxygen saturation, the least 6-minute walk distance and the highest NTproBNP level. Based on echocardiography examination, worse WHO functional class was associated with increased mPAP, higher TVRG, larger RA and RV diameters, lower TAPSE and lower LVEF. Based on RHC results, worse WHO functional class was related with higher mPAP and increased PVRi. The ASD patients were the majority among those with worse WHO functional class (95.5%).
The predominance of ASD patients in the COHARD-PH registry was in accord with previous reports. The development of PAH in ASD patients may be associated with defect size and shunt flow. We analysed the difference of minimal and maximal diameter of ASD defect based on echocardiography examination between ASD patients with PAH and those with no PAH. The ASD patients with PAH had larger minimal defect diameter as compared to those without PAH (2.3±0.8 vs. 1.9±1.5 cm, p<0.001) and larger maximal defect diameter (2.6±0.9 vs. 2.2±1.8 cm, p=0.001) (as shown in Figure 4). There was no significant difference in the Qp/Qs ratio based on echocardiography and RHC results between ASD patients with PAH and those without PAH (as shown in Figure 5).
There was an incremental increase of the proportion of PAH according to age range, with the highest proportion of PAH in the age group between 51 and 60 years old (Table 7).