Background
The 2022 ERS/ESC guidelines recommend that low and intermediate risk patients with pulmonary arterial hypertension (PAH) are initiated on dual oral therapy with a PDE5i (phosphodiesterase-5 inhibitor) and an ERA (endothelin receptor antagonist), whilst monotherapy is recommended in those with comorbidities. This study aimed to assess whether the presence of cardiopulmonary comorbidities influenced response to treatment.
Methods
Patients diagnosed with idiopathic, hereditary or drug-induced (I/H/D) PAH between 2016 and 2022 and initiated on dual oral therapy from the Scottish Pulmonary Vascular Unit (SPVU) were included. Data were collected at diagnosis and first follow up, and the response to treatment for those with and without cardiopulmonary comorbidities assessed.
Results
59 patients with full datasets were included. 40 (68%) had comorbidities; for those who continued therapy improvements were seen in NT-proBNP, 6-minute walk distance (6MWD) and COMPERA 2.0 risk strata (table 1).
| Pure I/H/D-PAH (n=19) | Comorbid I/H/D- PAH (n=40) | |
| Age, years | 54 | 67 |
| MPAP, mmHg | 52 | 45 |
| PVR, WU | 13 | 11 |
| Cardiac Index, L/min/m2 | 1.86 | 1.97 |
| Median NT-proBNP (pg/ml) | 1119 | 2819 |
| 6MWD (m) | 258 | 230 |
| Proportion stopped ERA | 2(11) | 6 (15) |
| - Due to oedema | 1 (5) | 5 (13) |
| Remained on ERA (n) | 17 | 34 |
| Improvement in COMPERA 2.0 Risk Strata | 9 (53) | 17 (50) |
| ?6MWD (n=15, 30) | +46 (p=0.088) | +64 (p<0.001) |
| ?NT-proBNP | -62.8% (p<0.001) | -36% (p<0.001) |
Table 1 - Data presented as mean or n (%) unless otherwise stated.
Conclusion
Dual oral therapy still has a significant benefit on risk strata in a comorbid PAH population. Further stratification of the comorbid group with inclusion of connective tissue disease-PAH is planned.