From the Guidelines
Elevated Pulmonary Artery Systolic Pressure (PASP) with mild Tricuspid Regurgitation (TR) is a significant finding that requires further evaluation, as it may indicate underlying cardiopulmonary disease and is associated with increased morbidity and mortality if left untreated. This finding should not be dismissed, even with only mild TR, as it may signal the presence of pulmonary hypertension or other conditions that can lead to right ventricular dysfunction and failure over time. According to the most recent and highest quality study 1, patients with a PASP > 30 mm Hg are at risk for increased morbidity and mortality, which may potentially relate to underlying multimorbidity, the elevated pressure within the pulmonary circulation itself, and its consequent effects on the heart.
Key Considerations
- Elevated PASP is associated with 25-40% 5-year mortality and is frequently associated with cardiopulmonary and metabolic co-morbidities 1
- Current pulmonary hypertension (PH) guidelines outline assessment and referral approaches to identify Group 1 and Group 4 PH, which are relatively rare diseases, but management of the large number of patients with elevated ePASP associated with cardiopulmonary and metabolic co-morbidities is not well addressed 1
- A comprehensive workup is recommended, including complete echocardiography, pulmonary function tests, and possibly right heart catheterization for definitive diagnosis
- Common causes of elevated PASP include left heart disease, lung diseases like COPD, sleep apnea, pulmonary embolism, or connective tissue disorders
Management
- Treatment depends on the underlying cause but may include diuretics like furosemide 20-40mg daily for volume overload, oxygen therapy for hypoxemia, or specific pulmonary vasodilators such as sildenafil 20mg three times daily or tadalafil 40mg daily for pulmonary arterial hypertension
- Regular follow-up echocardiograms every 6-12 months are important to monitor progression
- A multidisciplinary approach to evaluate and manage these patients is ideal, as it allows for the identification and management of treatable and/or modifiable factors such as manifest volume overload, systemic hypertension, hypoxia, diabetes, obesity, and obstructive sleep apnea 1
From the Research
Significance of Elevated Pulmonary Artery Systolic Pressure (PASP) with Mild Tricuspid Regurgitation (TR)
- Elevated PASP is a common cause of functional tricuspid regurgitation (TR), but other factors also play a role in determining TR severity 2
- The frequency of moderate or severe TR is progressively greater in patients with higher PASP, however, TR can be only mild in a substantial proportion of patients with high PASP 2
- In patients with PASP ≥ 70 mm Hg, right atrial size, tricuspid annular diameter, and tricuspid valve tethering area are greater in patients with greater degrees of TR 2
Determinants of TR Severity
- PASP is a strong determinant of TR severity, but demographic characteristics, mechanical factors, remodeling of the right heart cavities, and other factors are also predictive of TR severity 2
- RV dilatation and the tricuspid regurgitant gradient are independently related to the degree of TR in patients with pre-capillary pulmonary hypertension 3
- The accuracy of ultrasound measurements of pulmonary arterial systolic pressure (US-PASP) is more trustworthy when the tricuspid regurgitant spectrum quality grade (TR-SQG) is III or IV, especially in patients with mild TR 4
Clinical Implications
- Elevated PASP is associated with recurrent hospital admissions, prolonged hospitalizations, and increased mortality, and deserves further clinical evaluation 5
- The estimation of systolic pulmonary artery pressure (sPAP) by transthoracic echocardiography (TTE) can be challenging in patients with severe TR, and may be altered by high right atrial pressure (RAP) 6
- The presence of a 'V-wave cut-off' sign on continuous-wave Doppler is an independent predictor of sPAP misestimation by TTE in patients with severe TR 6