The Cornerstone of Prevention: Benzathine Penicillin G
The primary focus in the pharmacological management of rheumatic heart disease (RHD) is preventing the recurrence of acute rheumatic fever (ARF). Recurrent ARF episodes lead to cumulative damage to the heart valves, worsening RHD. Therefore, the drug of choice is not for treating established valve damage, but for preventing its progression. Intramuscular benzathine penicillin G (BPG) is the universally recommended and most effective treatment for this purpose, known as secondary prophylaxis. Administered as a deep intramuscular injection, BPG maintains low, but effective, serum penicillin concentrations over several weeks, providing prolonged protection against group A streptococcal (GAS) infections.
Clinical trials and extensive experience have repeatedly shown that regular, long-term BPG injections are significantly more effective at preventing ARF recurrence than oral penicillin, primarily due to better patient adherence with the injectable regimen. The typical dosing schedule involves injections every three to four weeks, with frequency potentially increased in high-risk populations.
Alternatives for Penicillin-Allergic Patients
While penicillin is the gold standard, some individuals have a documented allergy. For these patients, alternative medications are necessary for secondary prophylaxis. For non-severe penicillin hypersensitivity, a cephalosporin like cefalexin might be used for acute infection, followed by a macrolide such as erythromycin for prophylaxis. In cases of immediate or severe penicillin hypersensitivity, an allergist should be consulted, and alternative macrolides or sulfadiazines may be used. Macrolide resistance in some areas highlights why penicillin should be used whenever possible.
Managing Established Rheumatic Heart Disease
For patients with established RHD and permanent heart valve damage, pharmacological management shifts from prevention to treating the symptoms and complications of heart failure and arrhythmias. Secondary prophylaxis with BPG continues to prevent further damage, but other medications are needed to manage the cardiac consequences.
- Heart Failure: Medications are used to manage fluid overload and improve cardiac function. These often include diuretics like furosemide and spironolactone to reduce fluid retention, and ACE inhibitors (e.g., captopril, enalapril) to improve blood flow and heart output.
- Arrhythmias: Atrial fibrillation is a common complication. Blood-thinning medications (anticoagulants) such as warfarin are crucial to reduce the risk of stroke from blood clots.
- Inflammation: In cases of active, severe carditis (inflammation of the heart), corticosteroids (e.g., prednisone) may be prescribed in addition to antibiotics to rapidly reduce inflammation, though evidence on long-term outcomes is mixed.
Surgical Intervention for Severe Cases
When medication is no longer sufficient to manage symptoms or heart valve function, surgical intervention becomes necessary. The goal is to repair or replace the damaged heart valves.
- Valve Repair: In suitable cases, particularly for mitral stenosis, a balloon valvuloplasty can widen the narrowed valve without surgery. Surgeons may also perform open-heart surgery to repair the valve.
- Valve Replacement: For severely damaged valves, replacement with either an artificial mechanical valve or a biological tissue valve may be required. Patients with mechanical valves will need lifelong anticoagulant therapy.
The Duration of Prophylaxis
For individuals with a history of ARF, the duration of secondary prophylaxis is determined by the patient's age and the severity of their RHD. Standard guidelines, such as those adapted from the Australian guidelines, provide a framework for duration.
| Category | Duration of Prophylaxis | Key Considerations |
|---|---|---|
| ARF without carditis | 5 years or until age 21 (whichever is longer) | Requires adherence monitoring to ensure effectiveness. |
| ARF with mild carditis | 10 years or until age 21 (whichever is longer) | Longer duration reflects increased risk of future damage. |
| Established RHD | 10 years or until age 40 (whichever is longer) | Extends significantly due to permanent cardiac damage. |
| Post-valve surgery | Lifelong | Necessary to prevent recurrent attacks from damaging the new valve. |
Conclusion
There is no single "drug of choice" for established rheumatic heart disease, as the damage is permanent and requires management of its cardiovascular complications. However, for preventing the progression of RHD, the drug of choice for secondary prophylaxis is undoubtedly benzathine penicillin G. This long-term antibiotic regimen is the most effective strategy for preventing recurrent strep infections and subsequent ARF episodes, which cause cumulative heart damage. For managing the consequences of RHD, a broader pharmacological approach involving diuretics, ACE inhibitors, and anticoagulants may be necessary, often complementing potential surgical interventions for severe valve damage. Adherence to long-term prophylaxis is the most impactful step a patient can take to protect their heart health.
For more detailed guidance on prevention and diagnosis, see the WHO guideline on the prevention and diagnosis of rheumatic fever and rheumatic heart disease.
