Takotsubo Cardiomyopathy in Traumatic Brain Injury

Background Takotsubo cardiomyopathy (TC) is a well-known complication after aneurysmal subarachnoid hemorrhage and has been rarely described in patients with traumatic brain injury (TBI). Methods Case report and review of literature. Results Here, we report a 73-year-old woman with mild traumatic brain injury (TBI) presenting in cardiogenic shock. Takotsubo cardiomyopathy (TC) was diagnosed by repeated echocardiography. Cardiovascular support by inotropic agents led to hemodynamic stabilization after initiation of levosimendan. Cardiac function fully recovered within 21 days. We performed an in-depth literature review and identified 16 reported patients with TBI and TC. Clinical course and characteristics are discussed in the context of our patient. Conclusion Takotsubo cardiomyopathy is under-recognized after TBI and may negatively impact outcome if left untreated. Electronic supplementary material The online version of this article (doi:10.1007/s12028-016-0334-y) contains supplementary material, which is available to authorized users.


Case Report
A previously healthy 73-year-old woman was admitted to the trauma ward of our tertiary hospital with mild TBI. On presentation, she was disoriented, had a Glasgow Coma Scale (GCS) score of 14, and suffered from retrograde amnesia. Neurological examination revealed bilateral gaze-evoked nystagmus, but no other focal neurological deficit and her vital signs were stable. Laboratory workup revealed 0.21 % blood alcohol concentration. Computed tomography (CT) scanning of the brain showed right parieto-occipital and left temporoparietal skull fractures with an acute subdural hematoma (ASDH) and traumatic SAH over the left hemisphere and a small left frontal hemorrhagic contusion (Fig. 1

, Panel
Electronic supplementary material The online version of this article (doi:10.1007/s12028-016-0334-y) contains supplementary material, which is available to authorized users. A). Six hours later, the patient deteriorated and repeat head-CT showed a significant progression of the left frontal hemorrhage with intraventricular extension and a midline shift of 11 mm (Fig. 1, Panel A). Hematoma evacuation and placement of an external ventricular drain were immediately performed, and the patient was transferred to the neurological intensive care unit.
Postoperatively the patient was on norepinephrine (0.073 mcg/kg/min), sufentanil (0.073 mcg/kg/min), and midazolam (6 mcg/kg/min). Within the next 24 h, norepinephrine had to be continuously increased to 0.29 mcg/kg/min to achieve a cerebral perfusion pressure (CPP) of >65 mmHg. In addition, dobutamine (6.038 mcg/kg/min), phenylephrine (0.725 mcg/kg/min), and hydrocortisone (1.933 mcg/kg/min, given to treat secondary adrenal insufficiency) were necessary to keep the patient hemodynamically stable. At this time, the electrocardiography showed sinus tachycardia at a rate of 130 beats per minute (bpm) with non-specific repolarization abnormalities with no correspondence to a distinct coronary artery territory. Laboratory myocardial biomarkers exceeded pathologic thresholds: Troponin T levels peaked at 0.54 ng/mL (normal range, <0.014 ng/mL) and NT-proBNP was 4690 ng/ L (normal range 0-303 ng/L). Creatinine kinase (CK) was within normal range. Bedside transthoracic echocardiography demonstrated severe left ventricular (LV) myocardial dysfunction (ejection fraction 35 %), marked hypokinesia of the apical and midventricular portions of the left ventricle suggestive of takotsubo cardiomyopathy (TC). Only mild mitral regurgitation was detected. Invasive coronary angiography was not performed because of typical findings on echocardiogram and the limited therapeutic possibility due to intracranial bleeding.
As dobutamine was not improving the severe myocardial dysfunction, levosimendan was added (initial dose 0.03 mcg/kg/min, gradually increased to 0.12 mcg/ kg/min) and maintained for 28 h. After initiation, no increased dosage of norepinephrine was needed. The heart rate decreased to less than 100 bpm, dobutamine and phenylephrine could be withdrawn, and norepinephrine was slowly decreased over the following days without significant drops in blood pressure. Repeated transthoracic echocardiography demonstrated improvement in LV myocardial function on day 8 (ejection fraction 40 %) ( Fig. 1, Panel B) and further recovery on day 21 ( Fig. 1, Panel C, ejection fraction 49.9 %, normal 54-74 %). Coronary angiography was not performed as coronary artery disease deemed unlikely due to recovery in cardiac function in repeated echocardiography suggestive for TC as underlying pathology. The patient was successfully weaned on day 11 and discharged for neurorehabilitation 21 days after trauma. At this time, she was fully awake with a GCS score of 15, mildly disabled with a grade 4 brachio-facial left-sided hemiparesis and dysphagia.

Results
Overall we identified 13 published articles involving 16 TBI patients with TC [7][8][9][10][11][12][13][14][15][16][17][18][19] (Table 1). Among these, 13 were adults and 3 of pediatric age. All patients (except 1 uncharacterized) presented with impaired consciousness necessitating mechanical ventilation. The brain injury pattern was heterogeneous including various degrees of contusional hematoma, epidural hemorrhage (EDH), subdural hemorrhage (SDH), and traumatic SAH with 5 patients undergoing neurosurgical intervention. Six patients presented with polytrauma on admission. TC was diagnosed within 24 h in most patients (N = 10/16, 63 %); however, one patient developed TC 12 days after admission. In 4 patients, coronary angiography was performed and confirmed TC. Electrocardiography abnormalities were found in 9/16 patients (56 %) including ST segment and T wave changes, and 69 % (11/16) had elevated serum troponin levels. Treatment differed; however, most received inotropic support using dobutamine. In one patient, levosimendan at a dose of 0.1 mcg/kg/min was used for 24 h. In addition, various drugs were used to sustain adequate blood pressure including epinephrine, norepinephrine, and vasopressin. Five patients needed extracorporeal life support to treat severe refractory cardiovascular shock. Echocardiography revealed abnormal results in all patients (100 %) and was reversible in the majority of patients within 7 days except in 2 patients after 12 and 17 days, respectively.
In summary, (1) brain injury pattern in TBI patients presenting with TC is heterogeneous and therefore unspecific, (2) in the majority of patients inotropic support using dobutamine leads to improved cardiac function, (3) patients presenting in severe refractory cardiovascular shock may necessitate extracorporeal life support, and (4) with adequate management of TC long-term prognosis is more dependent on the severity of brain injury.

Discussion
Myocardial dysfunction in various degrees has been reported in patients with brain trauma [20][21][22] (Table 2), being more prevalent in severe TBI. TC represents a serious manifestation of myocardial dysfunction and is defined as an acute, transient, and reversible heart failure syndrome 3 days: EF 55-59 % in 2 survived patients due to regional wall abnormalities of the ventricular myocardium with associated new electrocardiography changes and elevation of myocardial biomarkers in the absence of culprit atherosclerotic coronary artery disease or cardiac condition causing the temporary ventricular dysfunction [23,24]. Since its' initial description in 1990, TC was almost exclusively reported in patients with severe SAH. Only a few reports were published in patients with severe TBI although pathophysiologic mechanisms of both entities may have similar effects on the neuro-cardiac axis. Perhaps, many of the earlier suggested criteria to define TC that excluded the presence of TBI had compounded the conundrum [25]. Underlying pathophysiologic mechanisms are still incompletely understood. Most investigations suggest an interconnected cascade of neuronal injury causing sympathetic overstimulation and direct catecholamine toxicity to the heart [26]. Supra-physiologic levels of epinephrine bind to myocardial B2-receptors causing myocardial protein Gs-to-Gi coupling switch, mediated cyclic adenosine monophosphate (cAMP) calcium overload in myocytes, and contraction-band necrosis reducing cardiac contractility [27,28].
Our patient had full recovery of cardiac function 21 days after trauma. Even though transient and reversible in nature, some reports suggest recovery even up to 12-week postinjury [23]. Hemodynamic support is critical in patients with severe TBI based on current treatment concepts that emphasize maintenance of an adequate CPP [29]. Improving cardiac function in patients with TC may be achieved by using dobutamine and other pharmacological, or nonpharmacologic treatment including extracorporeal life support. Our patient failed to improve by using dobutamine at a dose of 6.0 mcg/kg/min. After adding levosimendan, cardiac function and heart rate markedly improved.
Recently, the use of levosimendan has been reported in patients with aneurysmal SAH where dobutamine was deemed ineffective [30]. Levosimendan is a non-catecholamine inodilator used in the treatment of acute heart failure with higher improvement rate in cardiac function compared to dobutamine [31]. It increases the sensitivity of myofilaments to calcium, leading to increased myocardial contraction without increasing intracellular cAMP or calcium concentrations [31]. Through the opening of an ATPdependent potassium channel, vasodilatory effects in systemic, coronary, pulmonary, and venous blood vessels may be observed [31]. Unlike other vasopressors, it improves myocardial contractility without increasing myocardial oxygen consumption, and more importantly its action is independent of interactions with adrenergic receptors [31]. Nonetheless, its utilization in patients with TC remains scarce, bearing the rarity of the entity itself. In one of the largest case series, levosimendan was successfully used in 13 patients with TC [16].

Conclusions
We highlight the presentation of a patient suffering from TBI with takotsubo cardiomyopathy. Although transient in nature and commonly associated with a good overall prognosis, increasing evidence suggests it is a more serious acute cardiac disorder with a variety of complications [23,24]. Its hemodynamic effect may be deleterious in certain TBI patients if unrecognized. Levosimendan may be an effective therapeutic agent in severe cases.