NICE vs BTS: Management of Pulmonary Hypertension (2025)
This guide provides a factual comparison for UK clinicians between the National Institute for Health and Care Excellence (NICE) guideline NG232 and the British Thoracic Society (BTS) guideline on the management of pulmonary hypertension (PH). While both aim to standardise and improve care, their approaches, particularly in classification and treatment pathways, differ significantly. Understanding these differences is crucial for navigating service provision and clinical decision-making within the NHS.
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Diagnosis and Assessment
NICE (NG232)
The NICE guideline adopts a pragmatic, symptom-focused approach to initiate assessment. It emphasises identifying patients earlier in the diagnostic pathway within non-specialist settings.
- Referral Triggers: Recommends considering a diagnosis of PH in people with unexplained dyspnoea, syncope, or angina, particularly if they have a relevant risk factor (e.g., connective tissue disease, portal hypertension, family history).
- Initial Tests: Stresses the importance of ECG and NT-proBNP as initial investigations to gauge the likelihood of PH before proceeding to echocardiography.
- Echocardiography: Provides clear, probability-based criteria for referral to a specialist PH centre following an echocardiogram (e.g., high probability, intermediate probability with high clinical suspicion, or tricuspid regurgitant velocity >3.4 m/s).
- Classification: Uses a simplified, practical classification primarily distinguishing between Group 1 PAH (including associated forms like CTD-PAH and CHD-PAH) and non-Group 1 PH (e.g., due to left heart or lung disease). This simplification aims to aid non-specialists.
BTS Guideline
The BTS guideline provides a more detailed, comprehensive framework rooted in the established international (WHO/ESC) classification system.
- Classification: Adheres strictly to the five-group WHO/ESC classification (Group 1: PAH, Group 2: Left heart disease, Group 3: Lung disease/hypoxia, Group 4: CTEPH, Group 5: Unclear/multifactorial). This is familiar to PH specialists and aligns with European practice.
- Assessment: Focuses on a detailed diagnostic work-up within the specialist setting, including comprehensive right heart catheterisation (RHC) protocols and vasoreactivity testing for selected IPAH patients.
- Risk Stratification: Places a strong emphasis on multi-parameter risk stratification (using tools like the ESC/ERS risk table) at diagnosis and follow-up to guide treatment intensity and prognostication.
Key Difference: Diagnostic Philosophy
NICE is geared towards case-finding in primary and secondary care, using a simplified binary (Group 1 vs non-Group 1) approach. BTS is designed for specialist centre practice, employing the full five-group classification to guide nuanced management. The BTS's detailed risk stratification is a cornerstone of its treatment philosophy, which is less prominent in the NICE guideline.
Pharmacological Treatment
This area contains the most significant practical differences between the guidelines.
NICE (NG232)
NICE structures treatment around a treatment escalation pathway with distinct lines of therapy, heavily influenced by health economic assessment.
- First-line: Recommends monotherapy with a PDE-5 inhibitor (e.g., sildenafil, tadalafil) for most cases of Group 1 PAH (WHO-FC II-III).
- Second-line: If monotherapy is insufficient (based on clinical assessment), recommends escalating to combination therapy by adding an endothelin receptor antagonist (ERA).
- Ambrisentan: Specifically recommended as the preferred ERA when moving to combination therapy due to its cost-effectiveness.
- Initial Combination Therapy: Does not routinely recommend initial dual oral combination therapy, reserving it for patients with a high-risk profile at presentation.
- Riociguat and Selexipag: Riociguat is positioned as an option after PDE-5 inhibitor monotherapy or for inoperable CTEPH. Selexipag is a later-line option.
BTS Guideline
The BTS guideline advocates for a more aggressive, risk-driven treatment strategy, closely aligned with European Society of Cardiology (ESC/ERS) guidelines.
- Risk Stratification: Treatment choices are primarily determined by the patient's risk category (low, intermediate, high) at diagnosis.
- Initial Combination Therapy: Strongly recommends initial dual oral combination therapy (ERA + PDE-5 inhibitor) for the majority of patients presenting in WHO-FC III to rapidly reduce morbidity and mortality, reflecting the evidence from pivotal clinical trials.
- Triple Therapy: Supports the early use of triple therapy (including parenteral prostacyclin analogues) for high-risk patients.
- Agent Selection: Provides a broader range of options for combination therapy without stipulating a preferred ERA, allowing for greater clinician and patient choice based on individual factors.
Key Difference: Treatment Strategy
The fundamental difference is the initial therapeutic approach. NICE advocates a sequential monotherapy -> combination pathway, largely for economic reasons. BTS advocates initial combination therapy for most symptomatic patients, based on a stronger emphasis on long-term outcome data. This creates a significant practical challenge for specialists who must reconcile BTS/ESC clinical evidence with NICE's funding-directed pathway.
Special Situations
Pulmonary Hypertension in Pregnancy
- NICE: States that PH is associated with a high risk of maternal mortality. Advises that pregnancy should be avoided and, if it occurs, management must be within a specialist multidisciplinary team.
- BTS: Provides more detailed, specific advice. It strongly advises against pregnancy, outlines the need for specialist contraceptive counselling, and details the management of endothelin receptor antagonists (teratogenic) and the preferred use of PDE-5 inhibitors and inhaled prostacyclins if treatment is required during pregnancy.
Chronic Thromboembolic Pulmonary Hypertension (CTEPH)
- Both guidelines agree that pulmonary endarterectomy (PEA) surgery is the gold-standard, potentially curative treatment for eligible patients.
- NICE: Recommends riociguat for inoperable CTEPH or persistent/recurrent PH after PEA.
- BTS: Also covers the role of balloon pulmonary angioplasty (BPA) in detail, in addition to riociguat, for patients who are not surgical candidates.
Practical Clinical Flow and Takeaways
NICE-Driven Pathway (Common in NHS Commissioning)
- Suspicion in Primary/Secondary Care: Unexplained dyspnoea + risk factor -> ECG/NT-proBNP -> Echo.
- Referral: Echo suggests PH -> Refer to specialist PH centre.
- Diagnosis: RHC confirms Group 1 PAH.
- Treatment: Start PDE-5 inhibitor monotherapy. If inadequate response, add ambrisentan.
Takeaway: This pathway is often mandated by NHS commissioners. It is cost-effective but may not align with international standards for rapid disease control.
BTS/ESC-Aligned Pathway (Specialist Aspiration)
- Suspicion and Referral: As above.
- Diagnosis & Risk Stratification: RHC confirms PAH. Patient is stratified to low, intermediate, or high risk.
- Treatment: For WHO-FC III patients, start initial dual oral combination (ERA + PDE-5 inhibitor). For high-risk, consider triple therapy including prostacyclins.
Takeaway: This approach is favoured by specialists for its evidence-based efficacy but may require Individual Funding Requests (IFRs) for initial combination therapy outside of NICE recommendations.
Key Practical Takeaway for Clinicians
Be aware of the tension between the guidelines. In practice, the NICE pathway often dictates commissioned care. However, the BTS guideline provides the clinical rationale for deviating from this pathway via an IFR for high-risk or deteriorating patients, justifying initial combination therapy based on risk status.
Frequently Asked Questions (FAQs)
1. Which guideline should I follow in my NHS practice?
Local commissioning policies are typically based on NICE guidelines. Therefore, the NICE pathway is often the default. However, the BTS guideline represents specialist expert consensus and the international standard of care. For complex cases or where a patient is deteriorating on monotherapy, the BTS guideline provides the evidence base to seek funding for combination therapy via an IFR.
2. How do I get initial combination therapy for a patient if NICE recommends sequential therapy?
This requires an Individual Funding Request (IFR) to the local Integrated Care Board (ICB). The request should be supported by the patient's high-risk status (using BTS/ESC risk stratification tools), clinical evidence from the BTS/ESC guidelines, and justification of why monotherapy is deemed insufficient for this specific patient.
3. A patient has PH due to COPD (Group 3). Which guideline is most relevant?
For non-Group 1 PH, the primary focus is optimising treatment of the underlying condition (e.g., bronchodilators for COPD). Both guidelines caution against using PAH-specific therapies in Group 3 PH due to a lack of proven benefit and risk of worsening ventilation-perfusion mismatch. NICE's simplified classification may be particularly helpful here for non-specialists to avoid inappropriate prescribing.
4. What is the role of the specialist PH centre in both guidelines?
Both guidelines mandate that the diagnosis and management of PAH (Group 1) and CTEPH (Group 4) must be conducted within a designated specialist PH centre. This is non-negotiable. The centre is responsible for RHC, initiating and monitoring advanced therapies, and managing complex cases.
5. Are there differences in follow-up monitoring?
NICE recommends regular clinical review and specifies that echocardiography should be repeated if there is a change in clinical status. BTS provides a more structured follow-up schedule with regular, protocol-driven assessments (including 6-minute walk test, BNP, echocardiography) to formally re-assess risk scores and guide treatment decisions at every visit.
Source Links
- NICE Guideline NG232 (2022): Pulmonary hypertension: diagnosis and management
- British Thoracic Society Guideline (2021): BTS Guideline on Pulmonary Hypertension (Published in Thorax).
- ESC/ERS Guidelines (2022): 2022 ESC/ERS Guidelines for the diagnosis and treatment of pulmonary hypertension. (Important international reference that aligns closely with BTS).