INTRODUCTION

Blunt cardiac injuries (BCIs) have a wide clinical spectrum, ranging from asymptomatic myocardial contusion to cardiac rupture and death. BCIs have been reported to occur in 20% to 76% of all patients with blunt thoracic trauma, whereas blunt cardiac rupture has been reported to occur in 0.16% to 2% of affected patients [1-6]. BCIs rarely require surgical intervention, but can be rapidly fatal. Therefore, a severe BCI may require prompt evaluation and surgical treatment [7]. In addition, it may be necessary to evaluate the prognosis to determine the surgical method before surgery [8]. Thus, the aim of this study was to identify potential factors associated with in-hospital mortality after surgery in patients with BCI and to review our experiences of the surgical management of BCI.

METHODS

The study was approved by the Institutional Review Board (IRB) of the Gachon University Gil Medical Center (IRB No. GDIRB2020-392), which waived the requirement for informed consent because of the retrospective nature of the study.

Study design and patient

We conducted a retrospective study in a single center from January 2014 to August 2020. We included patients ≥18 years of age who underwent emergency cardiac surgery for BCI. We excluded patients who were dead on arrival. Patients were divided into survivors and non-survivors. These groups were compared with respect to clinical and laboratory variables.

Clinical and laboratory variables

Baseline characteristics included age, sex, mechanism(s) of injury, Injury Severity Score (ISS), Abbreviated Injury Scale (AIS), Glasgow Coma Scale, the American Association for the Surgery of Trauma-Organ Injury Scale (AAST-OIS) grade, the number of units of preoperative packed red blood cells (PRBCs) transfused, preoperative cardiac arrest, presence of preoperative cardiac tamponade, abnormal electrocardiogram (ECG) findings, the presence of sternum fracture, preoperative vasopressor use, diagnostic methods, and the time to surgery. Hemodynamic and laboratory results were measured immediately after arrival at the emergency department and compared between survivors and non-survivors. Intraoperative parameters, such as injury site, operation time, skin incision, intraoperative fluid replacement, type of operation, and any concomitant operations were compared between the two groups. Clinical outcomes, such as length of hospital stay (LOHS), length of intensive care unit stay (LOICUS), duration of mechanical ventilation (MV), and postoperative complications were collected and analyzed.

Statistical analysis

Categorical variables are expressed as numbers (%) and were evaluated using the Fisher exact test. Continuous variables are expressed as medians and interquartile ranges, and were compared between the groups using the Mann-Whitney U test. Statistical significance was accepted for two-sided p-values of <0.05. Statistical analysis was performed using SPSS version 23.0 (IBM Corp., Armonk, NY, USA)

RESULTS

The overall mortality rate after surgery was 26.6%. Non-survivors showed a significantly higher ISS (p=0.001) and AIS in the chest region (p=0.001) than survivors. AAST-OIS grade V was significantly more frequent in non-survivors than in survivors (p=0.031). Non-survivors had a significantly higher median number of units of preoperative PRBC transfusions (p=0.019) and were significantly more likely to have preoperative cardiac arrest (p=0.001) than survivors (Table 1). There was no significant difference between the two groups with respect to preoperative troponin I (p=0.392) and creatine kinase-myocardial band levels (p=0.851). However, initial pH (p=0.010), lactate (p=0.026), and base excess (BE; p=0.026) levels showed significant differences between the two groups (Table 2).

The left ventricle was the most common site of injury in non-survivors and the pericardium was the most common site of injury in survivors; however, this difference did not reach statistical significance (p=0.053). Median sternotomy was performed all survivors, but in non-survivors, left anterolateral thoracotomy and clamshell thoracotomy were performed, as well as median sternotomy (p=0.016) (Table 3). Postoperative complications, such as severe coagulopathy (n=2) or heart failure (n=1), were significant more frequent in non-survivors than in survivors (p=0.009) (Table 4).

DISCUSSION

BCIs may range from asymptomatic cardiac contusion with minor ECG abnormalities to fatal cardiac rupture [1-5]. While blunt cardiac rupture is rare, it may result in rapid hemodynamic deterioration [4,5]. Therefore, a rapid diagnostic tool is needed to detect BCI early. In addition, it is necessary to evaluate prognostic factors for BCI in the initial phase of trauma.

In our results, non-survivors had higher ISS, AIS in the chest region, and AAST-OIS grades, more preoperative PRBCs transfused, and a higher frequency of preoperative cardiac arrest. These factors reflect high-energy, severe injuries, and have been identified as poor prognostic factors in previous studies [2,8-10]. The overall mortality after surgery was 26.6%, which is similar to that of prior studies [1,11]. Cardiac tamponade was common in both groups before surgery. A previous study also reported a high incidence of cardiac tamponade after blunt cardiac rupture [12]. Cardiac tamponade secondary to BCI is extremely serious and requires rapid management.

Our data revealed that, unlike previous studies [13-16], ECG and cardiac enzymes had low diagnostic value and prognostic value in the early of BCI. Instead, pH, lactate, and BE emerged as potential prognostic factors associated with in-hospital mortality related to severe bleeding. In a previous study, increased lactate levels were identified as a strong predictor of in-hospital mortality [9]. Although we could not perform a multivariate analysis due to the small number of subjects, preoperative cardiac arrest, injury site, blood transfusion requirements, and the above blood measurements were important factors for predicting in-hospital mortality; further research is needed to validate these findings in the future.

Furthermore, non-survivors mainly had atrial and ventricular injuries, of which half were left ventricular. These results are consistent with other studies [1,8,12]. LOHS, LOICUS, MV duration, and complications were analyzed as clinical outcomes. Since most non-survivors died shortly after arrival at the emergency room, LOHS, LOICUS, and MV duration cannot be regarded as meaningful results. However, postoperative complications were significantly more common in non-survivors, and these complications were mainly severe coagulopathy and heart failure. These complications are similar to those reported in previous studies [5,7,12]. In survivors, median sternotomy was the primary approach, whereas in non-survivors, half of patients underwent left anterolateral thoracotomy or clamshell thoracotomy. This is because most of the survivors had pericardial injuries or localized injuries to the heart on preoperative imaging studies, whereas non-survivors had associated thoracic injuries or severe hemorrhage. If the patient was hemodynamically unstable or had cardiac arrest before surgery, surgeons showed a tendency to initially select resuscitative thoracotomy as a therapeutic option. This approach has also been recommended in recent guidelines [17,18].

This study has some limitations. First, this was a retrospective, single-center study. Second, the small sample size limits the ability to generalize the findings. Third, a multivariate analysis could not be performed to identify predictors of in-hospital mortality because of the small number of subjects. Thus, we are planning a multicenter study to overcome these limitations.

In conclusion, we found that initial pH, lactate, BE, ventricular injury, the amount of preoperative PRBC transfusions, and preoperative cardiac arrest may be predictors of in-hospital mortality. If patients with BCI before surgery have these factors, surgeons should consider expeditious salvage interventions, including cardiopulmonary bypass or damage control surgery.

ARTICLE INFORMATION

CONFLICTS OF INTEREST

No potential conflict of interest relevant to this article was reported.

INFORMED CONSENT

This type of study does not require informed consent.

REFERENCES

• 1. Schultz JM, Trunkey DD. Blunt cardiac injury. Crit Care Clin 2004;20:57–70. ArticlePubMed
• 2. Hanschen M, Kanz KG, Kirchhoff C, Khalil PN, Wierer M, van Griensven M, et al. Blunt cardiac injury in the severely injured - a retrospective multicentre study. PLoS One 2015;10:e0131362. ArticlePubMedPMC
• 3. Gao JM, Li H, Wei GB, Liu CP, Du DY, Kong LW, et al. Blunt cardiac injury: a single-center 15-year experience. Am Surg 2020;86:354–61. ArticlePubMed
• 4. Teixeira PG, Inaba K, Oncel D, DuBose J, Chan L, Rhee P, et al. Blunt cardiac rupture: a 5-year NTDB analysis. J Trauma 2009;67:788–91. ArticlePubMed
• 5. Nan YY, Lu MS, Liu KS, Huang YK, Tsai FC, Chu JJ, et al. Blunt traumatic cardiac rupture: therapeutic options and outcomes. Injury 2009;40:938–45. ArticlePubMed
• 6. El-Chami MF, Nicholson W, Helmy T. Blunt cardiac trauma. J Emerg Med 2008;35:127–33. ArticlePubMed
• 7. Malangoni MA, McHenry CR, Jacobs DG. Outcome of serious blunt cardiac injury. Surgery 1994;116:628–33. PubMed
• 8. Lancey RA, Monahan TS. Correlation of clinical characteristics and outcomes with injury scoring in blunt cardiac trauma. J Trauma 2003;54:509–15. ArticlePubMed
• 9. Joseph B, Jokar TO, Khalil M, Haider AA, Kulvatunyou N, Zangbar B, et al. Identifying the broken heart: predictors of mortality and morbidity in suspected blunt cardiac injury. Am J Surg 2016;211:982–8. ArticlePubMed
• 10. van Wijngaarden MH, Karmy-Jones R, Talwar MK, Simonetti V. Blunt cardiac injury: a 10 year institutional review. Injury 1997;28:51–5. ArticlePubMed
• 11. Tran HV, Charles M, Garrett RC, Kempe PW, Howard CA, Khorgami Z. Ten-year trends in traumatic cardiac injury and outcomes: a trauma registry analysis. Ann Thorac Surg 2020;110:844–8. ArticlePubMed
• 12. Yun JH, Byun JH, Kim SH, Moon SH, Park HO, Hwang SW, et al. Blunt traumatic cardiac rupture: single-institution experiences over 14 years. Korean J Thorac Cardiovasc Surg 2016;49:435–42. ArticlePubMedPMC
• 13. Velmahos GC, Karaiskakis M, Salim A, Toutouzas KG, Murray J, Asensio J, et al. Normal electrocardiography and serum troponin I levels preclude the presence of clinically significant blunt cardiac injury. J Trauma 2003;54:45–51. ArticlePubMed
• 14. Keskpaik T, Starkopf J, Kirsimägi Ü, Mihnovitš V, Lomp A, Raamat EM, et al. The role of elevated high-sensitivity cardiac troponin on outcomes following severe blunt chest trauma. Injury 2020;51:1177–82. ArticlePubMed
• 15. Kalbitz M, Pressmar J, Stecher J, Weber B, Weiss M, Schwarz S, et al. The role of troponin in blunt cardiac injury after multiple trauma in humans. World J Surg 2017;41:162–9. ArticlePubMed
• 16. Nagy KK, Krosner SM, Roberts RR, Joseph KT, Smith RF, Barrett J. Determining which patients require evaluation for blunt cardiac injury following blunt chest trauma. World J Surg 2001;25:108–11. ArticlePubMed
• 17. Working Group; Ad Hoc Subcommittee on Outcomes; American College of Surgeons. Committee on Trauma. Practice management guidelines for emergency department thoracotomy. Working Group, Ad Hoc Subcommittee on Outcomes, American College of Surgeons-Committee on Trauma. J Am Coll Surg 2001;193:303–9. PubMed
• 18. Seamon MJ, Haut ER, Van Arendonk K, Barbosa RR, Chiu WC, Dente CJ, et al. An evidence-based approach to patient selection for emergency department thoracotomy: a practice management guideline from the Eastern Association for the Surgery of Trauma. J Trauma Acute Care Surg 2015;79:159–73. PubMed

Figure & Data

References

Citations

Citations to this article as recorded by  

• Treatment results of cardiac tamponade due to thoracic trauma at Jeju Regional Trauma Center, Korea: a case series
  Jeong Woo Oh, Minjeong Chae
  Journal of Trauma and Injury.2023; 36(3): 180.     CrossRef