Myocardial Injury in Critically Ill Patients with Community-acquired Pneumonia. A Cohort Study.

Rationale: Myocardial 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.

Objectives

Our aim was to determine the incidence of troponin release in patients with CAP and identify risk factors that may point to underlying etiologic mechanisms.

Methods

We 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 we used mixed-effects regression to model the daily rise and fall of troponin levels over time.

Results

Of 200 eligible patients, 179 were included, yielding 792 observation days. A total of 152 (85%) patients developed raised troponin levels greater than 26 ng/L. Baseline factors independently associated with troponin release included coronary artery disease (176% increase; 95% confidence interval [CI], 11-589), smoking (248% increase; 95% CI, 33-809), and higher Acute Physiology and Chronic Health Evaluation IV score (2% increase; 95% CI, 0.8-3.3), whereas Staphylococcus aureus as a causative pathogen was protective (70% reduction; 95% CI, 18-89). Time-dependent risk factors independently associated with daily increase in troponin concentrations included reduced platelet count (2.3% increase; 95% CI, 0.6-4), tachycardia (1.5% increase; 95% CI, 0.1-2.9), hypotension (6.2% increase; 95% CI, 2.1-10.6), dobutamine use (44% increase; 95% CI, 12-85), prothrombin time (8.2% increase; 95% CI, 0.2-16.9), white cell count (1.7% increase; 95% CI, 0-3.5), and fever (22.7% increase; 95% CI, 0.1-49.6).

Conclusions

Cardiac injury develops in a majority of patients with severe CAP. Myocardial oxygen supply-demand mismatch and activated inflammation/coagulation are associated with this injury. Clinical trial registered with www.clinicaltrials.gov (NCT01905033).