Myocardial injury in critically ill patients with community-acquired pneumonia
BackgroundMyocardial injury, as reflected by elevated cardiac troponin levels in plasma, is common in patients with community-acquired pneumonia (CAP), but its temporal dynamics and etiology remain unknown. Our aim was to determine the incidence of troponin release in patients with CAP and identify risk factors which may point to underlying etiologic mechanisms.\n\nMethodsWe included consecutive patients admitted with severe CAP to two intensive care units in the Netherlands between 2011 and 2015. High-sensitivity cardiac troponin I was measured daily during the first week. We used multivariable linear regression to identify variables associated with troponin release on admission, and mixed-effects regression to model the daily rise and fall of troponin levels over time.\n\nResultsAmong 200 eligible patients, 179 were included, yielding 792 observation days. A total of 152 (85%) patients developed raised troponin levels >26 ng/L. Baseline factors independently associated with troponin release included coronary artery disease (160% increase, 95% CI 7-529), smoking (304% increase, 95% CI 59-924), and higher APACHE IV score (2% increase, 95% CI 0.7-3.3), whereas Staphylococcus aureus as a causative pathogen was protective (67% reduction, 95% CI 9-88). Time-dependent risk factors independently associated with daily increase in troponin concentrations included reduced platelet count (1.7% increase, 95% CI 0.1-3.4), tachycardia (1.6% increase, 95% CI 0.3-3), hypotension (5.1% increase, 95% CI 1-9.4) and dobutamine use (38.4% increase 95% CI 8.8-76).\n\nConclusionsCardiac injury develops in a majority of patients with severe CAP. Myocardial oxygen supply-demand mismatch and activated coagulation are potential causes of this injury.