Infections after trauma are associated with subsequent cardiac injury

Elevated Levels of Plasma Mitochondrial DNA Are Associated with Clinical Outcome in Intra-Abdominal Infections Caused by Severe Trauma

BACKGROUND

The purpose of our study was to determine prospectively relationships between plasma mitochondrial deoxyribonucleic acid (mtDNA) concentration and clinical outcome in patients with intra-abdominal infections (IAIs) induced by severe abdominal trauma.

PATIENTS AND METHODS

The DNA was isolated from serum samples taken from patients with IAIs at hospital days zero, one, and two. Plasma mtDNA concentration was assessed by real-time polymerase chain reaction (PCR). The study population's clinical and laboratory data were analyzed.

RESULTS

The mtDNA damage-associated molecular patterns were expressed as a PCR threshold cycle number using four selected sequences. The patients with IAIs had significant higher plasma mtDNA than healthy control subjects. Patients with IAIs with sepsis apparently had elevated mtDNA levels compared with non-septic patients with IAIs (30.9 ± 2.0 vs. 28.7 ± 2.4; 33.3 ± 2.6 vs. 28.9 ± 2.4; 32.9 ± 1.6 vs. 31.2 ± 2.2; 33.1 ± 3.6 vs. 28.1 ± 2.2, respectively). Patients with IAIs in whom multiple organ dysfunction syndrome (MODS) developed also had increased mtDNA concentration compared with those who did not (31.0 ± 1.8 vs. 27.9 ± 1.8; 32.9 ± 2.4 vs. 27.8 ± 1.7; 32.9 ± 1.5 vs. 29.8 ± 1.7; 32.0 ± 3.8 vs. 27.1 ± 2.1, respectively). Baseline mtDNA concentration had high effectiveness in predicting death for patients with IAIs who had severe trauma using receiver operating characteristic analysis. Furthermore, serum mtDNA levels on admission correlated with the lactate concentration, but no significant correlations were found between mtDNA levels and levels of white blood cells, C-reactive protein, and procalcitonin.

CONCLUSIONS

Plasma mtDNA was associated with the occurrence of sepsis, MODS, and death in patients with IAIs caused by severe abdominal trauma.

Postoperative Infections are Associated with Increased Risk of Cardiac Events in Vascular Patients

BACKGROUND

Despite advances in perioperative care, the rate of cardiac events in vascular patients remains high. We have previously shown that infections in trauma patients are associated with higher rates of subsequent cardiac complications, likely due to the additive effect of a second hit of an infection following the trauma. The aim of this study was to investigate whether there is an association between postoperative infections and subsequent cardiac events in vascular patients.

METHODS

A 5-year retrospective review of demographics, comorbidities, operative interventions, infectious, and cardiac events in all vascular patients who underwent an operative intervention at a single tertiary referral center was performed. In patients with clinical suspicion of myocardial injury, myocardial damage was defined as troponin >0.15 ng/mL and myocardial infarction (MI) as troponin >1 ng/mL. Pneumonia was diagnosed using bronchoalveolar lavage (BAL) and considered positive if BAL fluid culture contained >10,000 colony-forming units (cfu). Urinary tract infection (UTI) was diagnosed if the urine culture contained >100,000 cfu. All other infections were diagnosed by culture data. Regression analysis was performed to assess risk of cardiac events as a function of infections adjusting for age, gender, and comorbidities.

RESULTS

We analyzed 1,835 vascular operative interventions with the mean age of the cohort 65.5 years (65.9% male). The overall infection rate was 13.2%, with UTI being the most common (60.3%). The overall rate of myocardial damage was 8.1% and the rate of MI 3.8%. Rates of both myocardial damage (15.5 vs. 7.7%; P = 0.0015) and MI (7.1 vs. 3.4%; P = 0.018) were significantly higher in patients with infections, compared to those without infections. Adjusting for age, gender, medical comorbidities, open versus endovascular cases as well as statin and steroid use, patients with UTI were more likely to subsequently develop either myocardial damage (odds ratio [OR] = 3.57 [95% confidence interval = 1.51-8.45]) or MI (OR = 4.20 [1.23-14.3]). A similar association was noted between any infections and either myocardial damage (OR = 2.97 [1.32-6.65]) or MI (OR = 4.31 [1.44-12.94]).

CONCLUSIONS

We herein describe an association between postoperative infections, most commonly UTI, and subsequent cardiac events. Efforts should be made to minimize the risk of developing infections to ensure cardioprotection in vascular patients during perioperative period.