C-reactive protein evaluation in community-acquired pneumonia with comorbid chronic heart failure as criterion of antibiotic prescription

Abstract

Aim. To prove that diagnostic algorithm based on additional measurement of serum C-reactive protein (CRP) for administration of systemic antibacterial therapy (ABT) to patients with suspected community-acquired pneumonia (CAP) and concomitant chronic heart failure (CHF) does not influence outcomes of disease. Materials and methods. This open, single-center, randomized, prospective, non-inferiority study included 160 adult patients with documented functional class II–IV CHF who had been admitted with a preliminary diagnosis of non-severe CAP. Patients were randomized at 1:1 to two groups; group 1 – with additional measurement of CRP (n=80) and group 2 – with the use of routine diagnostic methods (n=80). In group 1, systemic ABT was administered only when serum CRP was >28.5 mg/l (threshold level of the biomarker calculated at the previous stage of the study); group 2 received a standard treatment. Non-inferiority test result for both algorithms was evaluated by the number of patients with clinical success on days 12–14 (primary endpoint). Non-inferiority margin was δ=–13.5%. In addition secondary endpoints (early clinical response on days 3–5; early in-hospital adverse events (development of complications; admission to intensive care unit (ICU); death), death, recurrent CAP or CHF worsening with readmission at 28 day; mortality at 90 and 180 days) were estimated. Standard statistical tools were used for all intergroup comparisons. Results: 76 patients of each group reached the primary endpoint. Systemic ABT was administered to 51 (67.1%) patients in group 1 and 76 (100%) patients in group 2 (p<0.05). Both groups were comparable (p>0.05) regarding all endpoints: clinical success, 70 (92.1%) vs. 69 (90.8%), Δ=1.3% (one-sided 97.5% CI: – 8.25% for non-inferiority margin δ=–13.5%); early clinical response, 66 (86.8%) vs. 68 (89.5%); admission to ICU, 1 (1.3%) vs. 1 (1.3%); development of complications, 20 (26.3%) vs. 22 (28.9%); readmission, 5 (6.6%) vs. 6 (7.9%); in-hospital mortality, 2 (2.6%) vs. 1 (1.3%), mortality at 28 day, 3 (3.9%) vs. 2 (2.6%), at 90 day, 5 (6.6%) vs. 4 (5.3%), at 180 day, 8 (10.5%) vs. 9 (11.8%) cases, respectively. Conclusion: additional measurement of serum CRP in patients with CHF and suspected non-severe CAP was able to reduce rate of systemic ABT administration without outcomes and prognosis worsening.