Treatment of Strep Throat in a Patient with Hypertension, Bradycardia, and Scheduled CABG
Treat the strep throat with penicillin V 800 mg four times daily for 5 days, continue all antihypertensive medications except beta-blockers (which should be held given the bradycardia), and proceed with CABG surgery once the acute infection is adequately treated and the patient is clinically stable.
Antibiotic Selection and Dosing
Penicillin V remains the first-line treatment for Group A streptococcal pharyngitis, as azithromycin should not be relied upon as first-line therapy due to increasing resistance patterns and the fact that some strains are resistant to macrolides 1.
The optimal regimen is penicillin V 800 mg four times daily for 5 days, which has been shown to provide earlier recovery compared to the traditional 10-day regimen, with patients reporting symptom relief approximately 1 day earlier and no difference in side effects 2.
If penicillin allergy is documented, azithromycin can be used as an alternative, but susceptibility testing should be performed when possible, and this agent is often effective in eradication of susceptible Streptococcus pyogenes strains from the nasopharynx 1.
Critical Cardiac Medication Management
Beta-Blocker Considerations
In this specific case, beta-blockers should be held or used with extreme caution due to the documented bradycardia, as beta-blockers are typically reinstituted as soon as possible after CABG in patients without contraindications 3.
Bradycardia is a known complication after CABG surgery, and prophylactic beta-blockade, while generally beneficial for preventing atrial fibrillation (which occurs in up to 40% of post-CABG patients), must be balanced against the risk of symptomatic bradycardia 4.
Other Antihypertensive Medications
Continue ACE inhibitors or ARBs until the day of surgery, as these should only be discontinued perioperatively and reinstituted once the patient is stable postoperatively 3.
All antihypertensive medications should generally be continued until the day of surgery in hemodynamically stable patients, as hypertension occurs in up to 80% of patients scheduled for CABG, and maintaining blood pressure control is essential 5.
Aggressive blood pressure lowering should be avoided to prevent hemodynamic collapse, and treatment should be started with the lowest possible dosage 5.
Antibiotic-Cardiac Interaction Concerns
QT Prolongation Risk
If azithromycin is used instead of penicillin, extreme caution is warranted due to the risk of QT prolongation and torsades de pointes, particularly in patients with bradycardia, which is an ongoing proarrhythmic condition 1.
Providers must consider that azithromycin can cause prolonged cardiac repolarization and QT interval prolongation, which can be fatal in at-risk groups including patients with bradyarrhythmias 1.
This is another compelling reason to use penicillin V as first-line therapy in this patient rather than a macrolide antibiotic.
Timing of CABG Surgery
The surgery should be delayed until the acute streptococcal infection is adequately treated and the patient is clinically stable, typically after 24-48 hours of appropriate antibiotic therapy when the patient is no longer febrile and symptoms are improving.
Aspirin should be continued until the day of CABG and restarted within 6 hours postoperatively if not contraindicated by bleeding concerns 6.
If the patient is on clopidogrel or other P2Y12 inhibitors, these should be discontinued at least 5 days before elective CABG to allow for dissipation of antiplatelet effects 6.
Perioperative Anticoagulation Management
If the patient is on unfractionated heparin (UFH), this should be continued until surgery, as UFH is the preferred anticoagulant for patients proceeding to CABG and can be stopped when needed during the procedure 6.
Other anticoagulants such as enoxaparin should be discontinued 12-24 hours before CABG, fondaparinux 24 hours before, and bivalirudin 3 hours before, with transition to UFH per institutional practice 6.
Common Pitfalls to Avoid
Do not use azithromycin as first-line therapy when penicillin is available and the patient has no documented penicillin allergy, as resistance patterns are increasing and cardiac risks are higher 1.
Do not continue beta-blockers in the setting of symptomatic bradycardia, even though they are generally beneficial in CABG patients for preventing atrial fibrillation 4.
Do not delay antibiotic treatment while waiting for surgery, as untreated streptococcal pharyngitis can lead to suppurative complications and, rarely, rheumatic fever 1.
Do not abruptly discontinue all antihypertensive medications preoperatively, as this can lead to rebound hypertension, which occurs in more than one-third of CABG patients and is associated with increased systemic vascular resistance 7.