Cardiac markers may identify which patients with community-acquired pneumonia (CAP) are at high risk for early or long-term cardiovascular (CV) events, a new study has found.
Researchers in Spain performed a prospective multicenter study of patients hospitalized with CAP to determine the usefulness of cardiac and inflammatory biomarkers in assessing early or long-term risk for a cardiac event. Early was defined as within 30 days, while long-term was defined as within one year. Cardiac events were defined as acute coronary syndrome (acute myocardial infarction or unstable angina), new or worsening heart failure, de novo or recurrent arrhythmia that required hospital admission or ED care, or cerebrovascular accident (stroke or transient ischemic attack). Biomarkers, including cardiovascular proadrenomedullin (proADM), pro B-type natriuretic peptide (proBNP), proendothelin-1, troponin T, inflammatory interleukin 6 (IL-6), C-reactive protein (CRP), and procalcitonin (PCT), were measured on day 1, on day 4 or 5, and at 30 days. Patients were followed for one year. The study results were published Aug. 2 by CHEST.
A total of 730 patients with CAP were included in the study, with a median age of 70 years. Of these, 95 had an early event and 67 had an event in the long term. Patients who had CV events had significantly higher initial levels of proADM, proendothelin-1, troponin T, proBNP, and IL-6. Biomarker levels at day 1 and day 30 appeared to independently predict CV events, adjusted for age, previous cardiac disease, a PaO2/FiO2 below 250, and sepsis. Odds ratios for early events were 2.25 (95% CI, 1.34 to 3.79) for proendothelin-1, 2.53 (95% CI, 1.53 to 4.20) for proADM, 2.67 (95% CI, 1.59 to 4.49) for proBNP, and 2.70 (95% CI, 1.62 to 4.49) for troponin T. Odds ratios for long-term events were 3.13 (95% CI, 1.41 to 7.80) for proendothelin-1, 2.29 (95% CI, 1.01 to 5.19) for proADM, and 2.34 (95% CI, 1.01 to 5.56) for proBNP. When IL-6 levels at day 30 were added to proendothlin-1 or proADM, the odds ratios associated with each increased to 3.53 and 2.80, respectively.
The researchers noted that individual biomarkers might be more useful for predicting different CV events, that cause of death at one year was not known in most patients, and that no control group was included. However, they concluded that cardiac biomarkers at day 1 and day 30 after admission for CAP are useful for predicting early and long-term cardiovascular events, respectively, even in patients who had no previous cardiac disease. They noted that patients may continue to have high levels of these biomarkers at day 30, when they may be referred to primary care without any recommendations for additional care, and said that a change in practice may be needed to reduce CV complications in CAP.
“ProADM, proBNP, proendothelin-1, and IL-6 levels may help in the individual assessment of risk, and therefore they may guide the design of personalized cardiovascular rehabilitation programs and treatment optimization in patients both with and without known prior cardiac disorders,” the authors wrote. They said that cardiac biomarkers may help researchers select high-risk patients for future interventional studies and that prevention strategies to reduce CV risk in patients who have had CAP are required.