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, noninferiority 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. Noninferiority 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.