Follow-Up Strategy for Pulmonary Stenosis
All patients with pulmonary stenosis require lifelong follow-up with an adult congenital heart disease (ACHD) cardiologist, with frequency determined by physiological stage and severity, ranging from every 2-3 years for mild disease to every 3-6 months for severe disease. 1
Follow-Up Intervals Based on Physiological Stage
The 2018 AHA/ACC guidelines provide specific surveillance schedules stratified by disease severity 1:
Stage A (Mild Disease)
- ACHD cardiologist visit: Every 24-36 months 1
- ECG: Every 24-36 months 1
- Transthoracic echocardiography (TTE): Every 24-36 months 1
- Cardiac MRI or CT: Every 36-60 months 1
- Exercise testing: Every 36 months 1
Stage B (Moderate Disease)
- ACHD cardiologist visit: Every 24 months 1
- ECG: Every 24 months 1
- TTE: Every 24 months 1
- Cardiac MRI or CT: Every 36-60 months 1
- Exercise testing: Every 24 months 1
Stage C (Severe Disease)
- ACHD cardiologist visit: Every 6-12 months 1
- ECG: Every 12 months 1
- TTE: Every 12 months 1
- Cardiac MRI or CT: Every 24-36 months 1
- Exercise testing: Every 24 months 1
Stage D (Very Severe/Complicated Disease)
- ACHD cardiologist visit: Every 3-6 months 1
- ECG: Every 12 months 1
- TTE: Every 12 months 1
- Cardiac MRI or CT: Every 24-36 months 1
- Exercise testing: Every 12 months 1
Critical Monitoring Parameters
Echocardiographic Assessment
Monitor for the following specific parameters at each visit 1, 2:
- Peak gradient across pulmonary valve: Mild <36 mmHg, moderate 36-64 mmHg, severe >64 mmHg 1, 2
- Peak velocity: Mild <3 m/s, moderate 3-4 m/s, severe >4 m/s 1, 2
- Right ventricular (RV) systolic pressure estimated by tricuspid regurgitation velocity 1, 2
- RV size and function: Progressive dilation or dysfunction warrants intervention 1, 3
- Pulmonary regurgitation severity: Particularly important after intervention 1, 3
- Valve morphology: Assess for thickening, dysplasia, doming, or restricted mobility 2
Clinical Surveillance
At each visit, specifically evaluate for 1:
- Symptoms: Dyspnea, chest pain, exercise intolerance, syncope, or presyncope 1, 2
- Cyanosis: Indicates right-to-left shunting through patent foramen ovale from elevated right atrial pressure 1, 4
- Functional capacity decline: Measured objectively with cardiopulmonary exercise testing (CPET) 1, 3
- Arrhythmias: Atrial or ventricular arrhythmias signal deterioration 1, 5
Post-Intervention Follow-Up
After Balloon Valvuloplasty
Patients require ongoing surveillance for specific complications 1, 4:
- Residual stenosis: Occurs in 85% of patients requiring re-intervention after balloon valvuloplasty 6
- Pulmonary regurgitation: Almost all patients develop mild PR after balloon valvuloplasty 6
- Re-intervention rates: 9.4% require cardiac re-intervention, with freedom from re-intervention of 95.1% at 5 years, 87.5% at 10 years, and 84.4% at 20 years 6
- Repeat balloon valvuloplasty: Up to 30% may require repeat procedure 7
After Surgical Valvotomy
Long-term surveillance is critical as outcomes are worse than historically believed 1, 6, 5:
- Pulmonary regurgitation: The primary long-term complication, occurring in 81% of patients requiring re-intervention 6
- RV dilation and dysfunction: Develops after 3-4 decades in many patients 1, 5
- Tricuspid regurgitation: Secondary TR develops in 40% of patients 5
- Re-intervention rates: 20.3% require cardiac re-intervention, with freedom from re-intervention declining to 70.9% at 30 years and 55.7% at 40 years 6, 5
- Pulmonary valve replacement: Most commonly needed >20 years after initial surgery 6, 5
Indications for Pulmonary Valve Replacement During Follow-Up
For patients with residual pulmonary regurgitation after treatment 1, 3:
Class I Recommendation (Definitive Indication)
- Symptomatic patients with moderate or greater PR and RV dilation or dysfunction require pulmonary valve replacement 1, 3
- Symptoms include: Dyspnea, chest pain, exercise intolerance referable to PR 1, 3
Class I Recommendation (Serial Follow-Up)
- Asymptomatic patients with residual PR and dilated RV require serial follow-up with clinical evaluation, CPET, echocardiography, and advanced imaging 1, 3
Class IIb Recommendation (May Be Reasonable)
- Asymptomatic patients with moderate or greater PR and progressive RV dilation and/or dysfunction may benefit from pulmonary valve replacement 1, 3
Critical Pitfalls to Avoid
Diagnostic Accuracy
If moderate or greater PR is present but RV size is normal, the PR severity estimation is likely inaccurate, or restrictive RV physiology exists requiring further investigation 1, 3. This discrepancy warrants advanced imaging with cardiac MRI 1.
Timing of Intervention
Pulmonary valve replacement should occur before severe RV enlargement and more than mild RV dysfunction develop 1. Waiting too long results in irreversible RV dysfunction 1, 5.
False Reassurance After Treatment
Both surgical and balloon interventions require lifelong follow-up despite initial success 1, 6, 5. The notion that patients are "cured" after intervention is incorrect and dangerous 5.
Peripheral Pulmonary Stenosis
For branch and peripheral PS, TTE alone is inadequate for imaging peripheral pulmonary arteries 1. Cardiac MRI or CT is superior for visualizing these lesions and quantifying relative pulmonary blood flow 1.
Arrhythmia Risk
Pulmonary valve replacement alone does not consistently reduce risk of ventricular tachycardia or sudden cardiac death 3. Additional interventions such as VT surgery and/or ICD implantation may be needed 3.
Advanced Imaging Considerations
Routine TTE may be unnecessary in years when cardiac MRI is performed unless clinical indications warrant otherwise 1. However, cardiac MRI is recommended for baseline assessment with periodic follow-up, with frequency determined by anatomic and physiological findings 1. CT may be used if MRI is not feasible, particularly for evaluating post-stent therapy for peripheral PS, though radiation exposure must be considered 1.