BMPR2 variants in pulmonary arterial hypertension. Are they really worrisome?

Background

Pulmonary arterial hypertension (PAH) is a rare and severe disease. The discovery of the gene encoding Bone Morphogenetic Protein Receptor Type 2 (BMPR2) in 2000 was the first evidence of an association between genetics and PAH. BMPR2 mutation carriers are younger and have higher haemodynamic severity, determining higher risk than sporadic cases. In the last few years, novel genetic variants have been identified. The risk of mortality of the currently known mutations is scarce.

Purpose

To describe the role of gene variants regarding long-term survival in a cohort of PAH patients.

Methods

We included patients diagnosed with PAH between January 2011-December 2020, following the ESC/ERC Guidelines recommendations. At least one genetic study was available in included individuals. Pulmonary venooclusive disease, PAH associated with congenital heart disease, or connective tissue disorders were excluded. Three groups were compared: no mutation, BMPR2 carriers and other genetic variants. Comparison of qualitative and quantitative variables was done by Chi-square test and ANOVA test, respectively. Crude and adjusted Log-rank test was performed for the evaluation of mortality.

Results

361 were finally included. The most frequent gene variant was BMPR2. Among the eight other gene variants, there were 2 cases of KCKN3, 2 of ACVRL1, and 1 case of KCNA5, TBX4, CPS1, and GDF2.

BMPR2 and the rest of mutation carriers were younger at diagnosis and had worse haemodynamic parameters than non-carriers. Nevertheless, these patients tended to perform higher distances in the 6-minute walk test. Interestingly, BMPR2 patients had higher DLCO values at diagnosis (table).

After 104.1±77.2 months of follow-up, there was a tendency for BMPR2 carriers toward lower crude free survival of mortality or lung transplantation. Nevertheless, this survival benefit disappears when adjusted by age (Table, figure).

Conclusions

The diagnostic yields of genetic analysis for pathogenic or likely pathogenic variants in idiopathic PAH are approximately 11%. BMPR2 is the most frequent causal gene. These patients are associated with marked haemodynamic impairment. Nevertheless, its younger age probably determines the better long-term results regarding mortality or lung transplantation observed when comparing these results with sporadic patients or those carrying other mutations.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Rio Hortega grant. Instituto de Salud Carlos III (ISCIII), Ministry of Science and Innovation, Spanish Government.

Pulmonary hypertension and congenital heart disease: medical treatment and risk factors for survival

Background

Pulmonary arterial hypertension (PAH) is a common comorbidity in congenital heart disease (CHD) and significantly affects prognosis. There are four large clinical groups of CHD-related PAH: Eisenmenger syndrome, PAH associated with non-restrictive shunt, PAH associated with restrictive shunt and postoperative PAH. Our purpose was to study the clinical and prognostic differences among them.

Methods

The REHAP is a Spanish multicentre voluntary registry of patients over 14 years of age, which includes patients with CHD and PAH, starting in 2007. 664 patients were analyzed: Baseline characteristics, functional class, right catheterization data, treatment and survival were compared.

Results

664 patients were analyzed: characteristics are detailed in the table. Patients with Eisenmenger were more frequently treated with oral monotherapy as a first line therapy and received less frequently prostanoids during the follow-up. Patients with Eisenmenger had significantly better prognosis, with the best long-term survival of the 4 groups. In a cox regression model, postoperative PAH has a 1.7 hazard ratio (HR) (reference group: Eisenmenger) after adjustment for age (HR 1.02 p 0,001), functional class (HR NYHA III-IV 2.3 p<0,001), sex (p 0.8) and pulmonary vascular resistance (p 0.7).

Conclusion

The clinical classification of PAH associated with CHD defines both the baseline characteristics and the prognosis of patients. Outcome relates closely to functional class and type of PAH–CHD. Eisenmenger group, which has the most severe hemodynamics, is the one with the best prognosis despite a less aggressive treatment.

Funding Acknowledgement

Type of funding source: Private grant(s) and/or Sponsorship. Main funding source(s): Ferrer, Janssen

P4672Current outcome of chronic thromboembolic pulmonary hypertension in Spain

Background

Chronic thromboembolic pulmonary hypertension (CTEPH) treatment has evolved over the last decade. Increasing evidence regarding new therapeutic developments has shown clinical benefit among these patients in different scenarios. However, there is scarce information about the long-term impact of these achievements in a real-life population on a national scale. We aimed to analyze the impact of current CTEPH therapies on survival in Spain.

Methods

We prospectively collected epidemiological, clinical and prognostic data from CTEPH patients consecutively included in the Spanish REHAP registry from January 1, 2007, to December 31, 2017. All-cause mortality data were gathered during this period.

Results

Eight hundred thirteen patients were included. The mean age was 61 (15) years and 58.1% were women. Out of the 813 patients, 537 (66%) were referred to an expert PH-center. Overall, 245 (30.1%) patients were selected for surgery and 52 (6.4%) for percutaneous treatment and 452 (60.5%) received medical treatment exclusively with specific PH drugs. Survival rates of patients who underwent an invasive procedure (pulmonary thrombendarterectomy or balloon pulmonary angioplasty) were remarkably high.

Figure 1. Cumulative survival from date

Conclusions

Patients who underwent pulmonary thrombendarterectomy or balloon pulmonary angioplasty associated a better outcome.

Acknowledgement/Funding

We gratefully acknowledge all investigators of the REHAP Registry. We express our gratitude to Actelion, Ferrer, GlaxoSmithKline (GSK) and Merck Sharp