BACKGROUND : Tuberculous pericarditis is considered to be a paucibacillary process; the large pericardial fluid
accumulation is attributed to an inflammatory response to tuberculoproteins.Mortality rates are high. Weinvestigated
the role of clinical andmicrobial factors predictive of tuberculous pericarditismortality using the artificial
intelligence algorithm termed classification and regression tree (CART) analysis.
METHODS : Patientswere prospectively enrolled and followed in the Investigation of theManagement of Pericarditis
(IMPI) registry. Clinical and laboratory data of 70 patients with confirmed tuberculous pericarditis, including
time-to-positive (TTP) cultures frompericardial fluid, were extracted and analyzed formortality outcomes using
CART. TTP was translated to log10 colony forming units (CFUs) per mL, and compared to that obtained from
sputum in some of our patients.
FINDINGS : Seventy patients with proven tuberculous pericarditis were enrolled. The median patient age was 35
(range: 20–71) years. The median, follow up was for 11.97 (range: 0·03–74.73) months. The median TTP for
pericardial fluid cultures was 22 (range: 4–58) days or 3.91(range: 0·5–8·96) log10CFU/mL, which overlapped
with the range of 3.24–7.42 log10CFU/mL encountered in sputum, amulti-bacillary disease. The overall mortality
rate was 1.43 per 100 person-months. CART identified follow-up duration of 5·23 months on directly observed
therapy, a CD4+ count of ≤199.5/mL, and TTP ≤ 14 days (bacillary load ≥ 5.53 log10 CFU/mL) as predictive of
mortality. TTP interacted with follow-up duration in a non-linear fashion.
Interpretation: Patients with culture confirmed tuberculous pericarditis have a high bacillary burden, and this
bacterial burden drivesmortality. Thus proven tuberculosis pericarditis is not a paucibacillary disease.Moreover,
the severe immunosuppression suggests limited inflammation. There is a need for the design of a highly
bactericidal regimen for this condition.