Risk stratification for cardiac complications in patients hospitalized for community-acquired pneumonia

To derive and validate a clinical rule that stratifies the risk of cardiac complications in patients hospitalized for community-acquired pneumonia (CAP) and compare its performance to the pneumonia severity index (PSI) score.

Corrales-Medina VF(1), Taljaard M(2), Fine MJ(3), Dwivedi G(4), Perry JJ(5), Musher DM(6), Chirinos JA(7).

OBJECTIVE: To derive and validate a clinical rule that stratifies the risk of cardiac complications in patients hospitalized for community-acquired pneumonia (CAP) and compare its performance to the pneumonia severity index (PSI) score.

PATIENTS AND METHODS: Two cohorts of patients hospitalized for CAP were selected for the study. We used regression techniques in the derivation cohort (1343 patients enrolled in the Pneumonia Patient Outcomes Research Team study between October 1991 and March 1994) to generate a prediction rule that we validated in the validation cohort (608 patients enrolled in the Dissemination of Guidelines for Length of Stay study between February 1998 and March 1999). Discrimination and reclassification analyses compared its performance against the PSI score.

RESULTS: A prediction model for cardiac complications in the derivation cohort included age, 3 preexisting conditions, 2 vital signs, and 7 common laboratory or radiographic parameters. Discrimination (C statistic, 0.81; 95% CI, 0.78-0.84) and calibration (Hosmer-Lemeshow goodness-of-fit test, χ(2)=13.0; P=.11) were good. We derived a point score system from this model that when applied to the validation cohort also had good discrimination (C statistic, 0.78; 95% CI, 0.74-0.83) and calibration (Hosmer-Lemeshow, χ(2)=9.0; P=.34). On the basis of this score, we defined 4 categories of incremental risk of cardiac complications. The incidence of cardiac complications across risk categories increased linearly (from lowest to highest) in both the derivation (3.0%, 17.8%, 35.2%, and 72.2%) and validation (5.0%, 8.2%, 28.3%, and 48.9%) cohorts (Cochran-Armitage linear trend test, P<.01). The new score outperformed the PSI score in predicting cardiac complications in the validation cohort (C statistic, 0.78 vs 0.74; P=.03; proportion of patients correctly reclassified by the new score, 44%).

CONCLUSION: We derived and validated a clinical rule that accurately stratifies the risk of cardiac complications in patients hospitalized for CAP.

Author information:

(1) Department of Medicine, University of Ottawa, Ottawa, Ontario, Canada; Ottawa Hospital Research Institute, Ottawa, Ontario, Canada. Electronic address: vcorrales@toh.on.ca.

(2) Department of Epidemiology and Community Medicine, University of Ottawa, Ottawa, Ontario, Canada; Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.

(3) Division of General Internal Medicine, Department of Medicine, University of Pittsburgh, and Center for Health Equity Research and Promotion, VA Pittsburgh Healthcare System, Pittsburgh, PA.

(4) Department of Medicine, University of Ottawa, Ottawa, Ontario, Canada; University of Ottawa Heart Institute, Ottawa, Ontario, Canada.

(5) Department of Emergency Medicine, University of Ottawa, Ottawa, Ontario, Canada Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.

(6) Department of Medicine and Department of Molecular Virology and Microbiology, Baylor College of Medicine, and Medical Care Line (Infectious Disease Section), Michael E. DeBakey VA Medical Center, Houston, TX.

(7) Division of Cardiology, University of Pennsylvania, and Philadelphia VA Medical Center, Philadelphia, PA.

PMID: 24388023 [PubMed – indexed for MEDLINE]

. Mayo Clin Proc. 2014 Jan;89(1):60-8. doi: 10.1016/j.mayocp.2013.09.015.