Rheumatoid Arthritis and Pulmonary Hypertension: Established Association
Yes, there is a clear connection between rheumatoid arthritis (RA) and pulmonary hypertension (PH), though the relationship is less strong than with other connective tissue diseases like systemic sclerosis. Multiple guidelines recognize RA as an associated cause of pulmonary arterial hypertension (PAH), and the prevalence of PH in RA patients ranges from 21-31% depending on diagnostic criteria used 1, 2.
Prevalence and Clinical Significance
The evidence demonstrates a definite association between RA and elevated pulmonary artery pressures:
Echocardiographic studies show that 21-31% of RA patients have pulmonary hypertension (defined as pulmonary artery systolic pressure ≥30 mmHg), which is significantly higher than the 4.5% prevalence in age-matched controls 1, 2.
The 2015 ESC/ERS Guidelines explicitly list rheumatoid arthritis as a recognized cause of PAH within the connective tissue disease category, though it occurs less frequently than in systemic sclerosis, systemic lupus erythematosus, or mixed connective tissue disease 1.
The prevalence of confirmed RA in the French PH Registry was 0.35%, which is comparable to the general population prevalence of RA, suggesting that while PH can occur in RA, it may not represent a specific disease association requiring routine screening 3.
Pathophysiological Mechanisms
The connection between RA and PH is complex and involves multiple mechanisms:
Primary pulmonary vasculopathy can occur in RA patients, manifesting as true PAH with histological changes consistent with pulmonary arteriopathy 1.
Interstitial lung disease (ILD) is a common pulmonary manifestation of RA that can lead to PH through chronic hypoxia and parenchymal destruction 4.
Pulmonary vasculitis related to RA can directly damage pulmonary vessels and contribute to elevated pressures 4.
Chronic thromboembolic disease may occur more frequently in RA patients due to the prothrombotic state associated with chronic inflammation 4.
Left heart disease from RA-associated cardiac involvement can cause post-capillary PH, though this represents a different pathophysiological category 4.
Disease Duration Correlation
A critical finding is the strong correlation between RA disease duration and pulmonary artery pressure (r=0.68, p<0.0001), suggesting progressive subclinical involvement of the pulmonary vasculature over time 5. This indicates that PH in RA may represent a cumulative effect of chronic systemic inflammation rather than an acute complication.
Clinical Characteristics
When PH occurs in RA patients, specific patterns emerge:
The RA phenotype associated with PH is characterized by the presence of specific RA autoantibodies and joint erosions in 75% of cases 3.
All PH subsets may be identified in RA patients, including PAH (Group 1), PH due to lung disease (Group 3), and chronic thromboembolic PH (Group 4), making comprehensive evaluation essential 3.
RA patients demonstrate worse right ventricular function measured by TAPSE (23 vs 25 mm, p=0.033) and worse RV-pulmonary artery coupling (TAPSE/RVSP ratio 0.809 vs 0.933, p=0.009) compared to controls, even in the absence of overt PH 6.
Screening Considerations
The current evidence does NOT support routine echocardiographic screening for PH in all RA patients, as the prevalence of RA in PH registries is similar to the general population 3. However, targeted evaluation is warranted in specific circumstances:
Screen RA patients with unexplained dyspnea, reduced exercise tolerance, or signs of right heart dysfunction using transthoracic echocardiography 1, 2.
Consider PH evaluation in RA patients with long disease duration (>10 years), given the strong correlation between disease duration and pulmonary artery pressure 5.
Evaluate for multiple potential causes including ILD, vasculitis, chronic thromboembolic disease, and left heart disease, as all can contribute to PH in RA 4.
Right heart catheterization is required for definitive diagnosis when echocardiography suggests PH, as this distinguishes true PAH from other forms and guides treatment 1, 3.
Prognostic Implications
The outcomes of PH in RA patients are comparable to other patients in PH registries, and RA-specific therapies have not shown major impact on cardiopulmonary parameters 3. This suggests that PH in RA should be managed according to standard PH treatment algorithms rather than requiring RA-specific modifications.
Important Clinical Caveats
Do not assume all PH in RA patients is due to PAH—comprehensive evaluation must exclude lung disease, left heart disease, and chronic thromboembolic disease before diagnosing isolated PAH 4, 3.
Mild elevations in pulmonary artery pressure on echocardiography are common in RA (occurring in up to 31% of patients), but many of these patients do not have clinically significant PH requiring specific therapy 2.
The presence of reduced RV-PA coupling in RA patients with even mild echocardiographic PH suggests early hemodynamic compromise that may warrant closer monitoring 6.