Abstract
Aims
The definition of pulmonary hypertension (PH) requires the documentation of mean pulmonary arterial pressure (PAPm) ≥20 mmHg at rest, assessed by right cardiac catheterization. This condition can characterize multiple clinical conditions with different pathophysiological and haemodynamic aspects. Specifically, in pulmonary arterial hypertension (IAP) (Group 1), the increase in PAP is due to an intrinsic pathology of the pulmonary microcirculation; Group 2 includes the forms of IP associated with a pathology of the left heart; Group 3 includes all pathologies of the pulmonary parenchyma and/or hypoxic conditions that lead to a secondary impairment of the small circulation; Group 4 identifies patients with chronic thromboembolic pulmonary heart (CPCTE); finally, Group 5 includes rare clinical conditions in which IP is linked to direct involvement or ab extrinsic compression of the pulmonary vessels.
Methods and results
To examine the number of deaths and the differences between the various subgroups, we analyzed the follow-up of approximately 76 patients (64.30 ± 13.20 years, 37% male) enrolled in the Pulmonary Hypertension Clinic of the San Giovanni AOU Dio and Ruggi d’Aragona of Salerno from 2014 to 2020 excluding patients with IP under definition and those ‘screened’ who did not show pulmonary hypertension at rest. At each visit, the patients were subjected to anamnestic data collection, physical examination, measurement of blood pressure, heart rate, arterial saturation, transthoracic cardiac echo color Doppler at rest, attribution of the functional class NYHA, evaluation of functional capacity by performing the test of the 6-min walk test (6MWT) and possible programming of right cardiac catheterization. From the data analysis it was found that 26 patients (34.21%, 55.81 ± 13.90 years, 27% males) were affected by IP group 1; 15 patients (19.48%, 74.12 ± 6.26 years, 20% male) were affected by IP group 2; 14 patients (18.18%, 63.34 ± 11.52 years, 71% male) were affected by IP group 3; 12 patients (15.58%, 67.22 ± 11.53 years, 33% male) were affected by IP group 4; 2 patients (2.60%, 71.57 ± 12.48 years, 0% male) were affected by IP group 5; 7 patients (9.09%, 70.07 ± 8.27 years, 57% male) were affected by group 2–3 mixed IP. Analysing the number of deaths, of the 76 patients, 17 deaths were recorded in total (22.37%). All patients in group 1 had been treated with specific therapy and survival was 88% at 3 years. Of the three deaths (12%) in this group, one patient had idiopathic PAH non-responder to pulmonary vasoreactivity test, one patient belonged to the IAP subgroup associated with congenital heart shunt but with concomitant lung disease, and the third patient belonged to the IAP subgroup associated with connective tissue disease (specifically Takayasu’s arteritis). From the analysis of the idiopathic IAP subgroup it emerged that the patients were all women, with an average age of 50.81 ± 3.98 years, and that the deceased patient was distinguished at the first visit from the other patients for: a history of arterial hypertension, dysthyroidism, and obesity; worst NYHA class (III vs. II), elevated heart rate (102 vs. 70.00 ± 7.07 b.p.m.) and blood pressure (SBP: 150.00 vs. 127.50 ± 10.61; DBP 90.00 vs. 75.00 ± 7.07 mmHg) at rest at the clinic visit. Transthoracic echocardiography revealed elevated PAPs values (100.00 vs. 42.50 ± 20.51 mmHg), low TAPSE values (20.00 vs. 26.50 ± 3.54 mm), reduced pulmonary acceleration time (ACT 60 ms), enlargement of the right atrium (area 22 cm2), worst exercise tolerance parameters (6MWT 300 m and 86% final SO2 vs. 427.50 ± 74.25 m and 96.50 ± 0.71% final SO2).
Conclusions
The percentage of deaths in the different groups appears very heterogeneous, especially if we consider the six deaths (42.86%) in group 3 and three deaths (42.86%) in patients with mixed IP groups 2 and 3. In these two groups, age and advanced NYHA class were the most representative prognostic factors. On the other hand, analysing patients belonging to the idiopathic IAP subgroup, a worse prognosis is entrusted to the negativity of the vasoreactivity test, to the presence of cardiovascular comorbidities (arterial hypertension and dysthyroidism in our case), to worse echocardiographic values (PAPs, TAPSE, ACT, atrial area right) and reduced functional capacity at the 6MWT. However, early treatment and innovative drugs together with a careful strategy have been allowed.
Reducing TRPC1 Expression through Liposome-Mediated siRNA Delivery Markedly Attenuates Hypoxia-Induced Pulmonary Arterial Hypertension in a Murine Model
