More on myocardial contusion--with additional insight on myocardial concussion

Association between hypotension and myocardial injury in patients with severe trauma

PURPOSE

During resuscitation of patients with severe trauma, guidelines recommend permissive hypotension prior to surgical bleeding control. However, hypotension may be associated with reduced organ perfusion and multiple organ dysfunction, e.g. myocardial injury. The association between hypotension and myocardial injury in trauma patients is underexplored. We hypothesized that hypotension is associated with myocardial injury in this population.

MATERIALS AND METHODS

This retrospective study included patients ≥ 18 years suffering from severe trauma [defined as Injury Severity Score (ISS) ≥ 16] that were treated in the emergency department resuscitation room between 2016 and 2019. Primary endpoint was the incidence of myocardial injury defined as high-sensitive troponin T > 14 ng/l. Main exposure was the duration of arterial hypotension during resuscitation period defined as mean arterial pressure < 65 mmHg.

RESULTS

Out of 368 patients screened, 343 were analyzed (73% male, age: 55 ± 21, ISS: 28 ± 12). Myocardial injury was detected in 143 (42%) patients. Overall in-hospital mortality was 26%. Multivariate binary logistic regression with forced entry of nine predefined covariables revealed an odds ratio of 1.29 [95% confidence interval 1.16-1.44]; p = 0.012) for the association between the duration of hypotension and myocardial injury.

CONCLUSION

The duration of hypotension during resuscitation period is independently associated with the incidence of myocardial injury in patients with severe trauma.

Classification of Myocardial Contusion and Blunt Cardiac Trauma

Myocardial injury caused by blunt chest trauma has been recognized with increased frequency over the past 2 decades. Increased awareness by physicians and the increased use of various clinical and laboratory diagnostic modalities have contributed to this recognition. Injuries range from inconsequential to catastrophic and can affect any or all areas of the heart: pericardium, myocardium, coronary arteries and veins, chordae, papillary muscles, valves, and great vessels. In addition to the medical importance of the diagnosis, substantial forensic implications have been known to arise. It is important to assess and classify properly the extent of the trauma and its prognostication as to the possibility of residual sequelae. A proposed classification is presented that has both medical and legal application. The uses of stages 0 (suspect), I (mild), II (moderate), III (severe), and IV (catastrophic) are illustrated in detail.

Troponin increases in the critically injured patient: mechanical trauma or physiologic stress?

BACKGROUND

Serum troponin (Tn) is a sensitive and specific marker of myocardial injury. Tn increase after injury is usually attributed to mechanical chest trauma, but this relationship remains unproven. We sought to examine the etiologic factors and prognostic significance of increased Tn levels in a widely screened trauma population.

METHODS

We reviewed all trauma intensive care unit (ICU) admissions over a 5-year period with serial Tn I (TnI) measurements as part of a screening protocol. TnI was categorized as normal (0-1.2 microg/L), intermediate (1.3-5 microg/L), or high (>5 microg/L), and mortality rates were compared between groups. Multivariate regression analysis was used to identify independent predictors of TnI increase and mortality.

RESULTS

There were 1,081 patients identified. An increased TnI was found in 29% of patients. Mortality significantly increased from 16% in the normal group to 33 and 44% in the intermediate and high TnI groups, respectively. Independent predictors of an increased TnI were admission base excess (p = 0.04), Injury Severity Score (ISS) (p < 0.001), and Acute Physiology and Chronic Health Evaluation score (p < 0.001). Chest Abbreviated Injury Scale score and the presence or absence of severe chest injury did not independently predict TnI increase (p = 0.5 and 0.83). Any increase of TnI (>1.2 microg/L) was a strong independent predictor of mortality (odds ratio, 2.1; 95% confidence interval, 1.4-3.1) after controlling for age, sex, mechanism, base excess, Glasgow Coma Scale score, and ISS. Beta-blocker use was associated with a 50% reduction in mortality among patients with an increased Tn (38 versus 16%; p < 0.01).

CONCLUSIONS

Increased serum TnI after trauma is related to the degree of overall injury and physiologic stress and not mechanical chest trauma. Intermediate and high TnI increases are associated with increased mortality, which may be improved by selective use of beta-blockade.