Management of Group 2 Pulmonary Hypertension
The primary management approach for Group 2 pulmonary hypertension must focus on optimizing treatment of the underlying left heart disease before considering any specific measures to address pulmonary hypertension. 1, 2
Understanding Group 2 PH
Group 2 PH is defined as pulmonary hypertension due to left heart disease (PH-LHD), which is the most common form of PH in developed countries 3. It develops in response to:
- Passive backward transmission of filling pressures 1
- Left ventricular diastolic dysfunction 1
- Exercise-induced mitral regurgitation 1
- Loss of left atrial compliance 1
In some patients, these mechanical components may trigger additional pulmonary vasoconstriction, decreased nitric oxide availability, increased endothelin expression, and vascular remodeling 1.
Diagnostic Considerations
Suspect PH-LHD when patients present with:
- Age >65 years 1
- Structural left heart abnormalities on echocardiography 1
- Left atrial enlargement >4.2 cm 1
- Bowing of interatrial septum to the right 1
- Left ventricular dysfunction or hypertrophy 1
- Doppler indices of increased filling pressures 1
- Features of metabolic syndrome 1
- History of heart disease or persistent atrial fibrillation 1
Treatment Algorithm
Step 1: Optimize Management of Underlying Left Heart Disease
- For valvular heart disease: Repair when indicated 1
- For heart failure with reduced ejection fraction: Aggressive therapy with neurohormonal antagonists (ACE inhibitors, beta-blockers, spironolactone) 1, 2
- For heart failure with preserved ejection fraction: No strong evidence-based recommendations exist, but volume management is critical 1, 2
Step 2: Optimize Volume Status
- Careful diuresis to reduce pulmonary congestion 1
- May require invasive monitoring in severe heart failure 1
- Consider left ventricular assist device in appropriate candidates, which has been shown to lower pulmonary pressures through LV unloading 1
Step 3: Address Cardiovascular Risk Factors and Comorbidities
- Control risk factors for cardiovascular disease 1, 2
- Manage features of metabolic syndrome 1, 2
- Identify and treat concomitant disorders that can worsen PH:
Step 4: Consider Non-Specific Vasodilators
- Some patients may benefit from nitrates and hydralazine, although evidence is limited 1
Important Cautions
- PAH-specific therapies (prostanoids, endothelin receptor antagonists, PDE-5 inhibitors) are NOT recommended for Group 2 PH 1, 2, 3
- Multiple studies have shown disappointing results with PAH-specific therapies in Group 2 PH 4
- A multicentre, placebo-controlled trial with riociguat showed no effect on mean pulmonary artery pressure in patients with PH due to systolic heart failure 1
- These medications may worsen outcomes in patients with Group 2 PH 5
- Risk of severe drug-induced pulmonary edema with vasodilators, particularly intravenous epoprostenol 1
Special Considerations
- Patients with severe PH disproportionate to their underlying left heart disease should be referred to a PH expert center 2
- For patients being considered for heart transplantation with fixed or out-of-proportion PH, specialized management is required to reduce pulmonary vascular resistance prior to transplantation 5
- Distinguishing between Group 2 PH and Group 1 PAH is critical as treatment strategies differ completely 4
Monitoring and Follow-up
- Regular assessment of functional capacity (6-minute walk test) 6
- Echocardiographic monitoring of right ventricular function 1
- BNP/NT-proBNP plasma levels to assess disease progression 1
- Right heart catheterization may be necessary to reassess hemodynamics in patients with worsening symptoms despite optimal treatment of left heart disease 1
By focusing on optimizing the treatment of the underlying left heart condition and addressing modifiable risk factors, the management of Group 2 PH aims to improve symptoms, exercise capacity, and ultimately patient outcomes.