Introduction: Antibiotics used to treat post 32 -stroke infections have differing antimicrobial and anti-inflammatory effects. Our aim was to investigate whether antibiotic class was associated with outcome after post-stroke infection.
Methods: We analysed pooled individual participant data from the Virtual International Stroke Trials Archive (VISTA)-Acute. Patients with ischaemic stroke and with an infection treated with systemic antibiotic therapy during the first two weeks after stroke onset were eligible. Antibiotics were grouped into eight classes, according to antimicrobial mechanism and prevalence. The primary analysis investigated whether antibiotic class for any infection, or for pneumonia, was independently associated with a shift in 90 day modified Rankin Scale (mRS) using ordinal logistic regression.
Results: 2708 patients were eligible (median age [IQR]=74 [65 to 80] y; 51% female; median [IQR] NIHSS score=15 [11 to 19]). Pneumonia occurred in 35%. Treatment with macrolides (5% of any infections; 9% of pneumonias) was independently associated with more favourable mRS distribution for any infection (OR (95% CI)=0.59 (0.42 to 0.83), p=0.004) and for pneumonia (OR (95% CI)=0.46 (0.29 to 0.73), p=0.001). Unfavourable mRS distribution was independently associated with treatment of any infection either with carbapenems, cephalosporins or monobactams (OR (95% CI)=1.62 (1.33 to 1.97), p<0.001), penicillin plus β-lactamase inhibitors (OR (95% CI)=1.26 (1.03 to 1.54), p=0.025) or with aminoglycosides (OR (95% CI)=1.73 (1.22 to 2.46), p=0.002).
Conclusion: This retrospective study has several limitations including effect modification and confounding by indication. Macrolides may have favourable immune-modulatory effects in stroke-associated infections. Prospective evaluation of the impact of antibiotic class on treatment of post-stroke infections is warranted.