A case of early ischemic stroke after LVAD implantation successfully treated with mechanical thrombus extraction

• Zorinas A.
• Janušauskas V.
• Gaižauskas E.
• Gaižauskienė K.
• Urbonas K.
• Samalavičius R.S.
• Ručinskas K.

Abstract

Background. Left ventricular assist devices (LVAD) are increasingly used for patients with advanced heart failure (HF) improving life expectancy and quality of life. However, even with the latest generation fully magnetically levitated centrifugal-flow pumps, cerebral thromboembolic events remain one of the major challenges to keep patients free of impairment. While late post-op LVAD patients can be treated with thrombolytic agents, it is contraindicated in the early period after LVAD implantation. We report a case of an acute ischemic stroke several hours after LVAD implantation, successfully treated with mechanical thrombus extraction.

Aim of this clinical report is to attract attention of the surgeons and intensive therapy physicians on ischemic cerebrovascular complication at the early postoperative course after LVAD implantation. In addition, to present timely effective treatment modality resulting in no long-term neurologic disability.

Keywords:heart failure, left ventricular assist device, ischemic stroke

A 32 years old socially and physically active female with no previously known comorbidities has presented to tertiary hospital with shortness of breath at rest, progressive weakness and dry cough.

On admission, she was conscious and alert, pale with cool clammy peripheries. Her respiratory rate was 26 breaths per minute. Electrocardiogram revealed sinus rhythm with rate of 100 beats per minute. According to the patient, she had no diuresis for the past 12 hours. A patient underwent urgent transthoracic echocardiogram. It revealed severely impaired and enlarged left ventricle. Patient was admitted to hospital, a diagnosis of dilated cardiomyopathy resulting severe heart failure (NYHA class IV) was made.

She received an optimal medical treatment with loop and potassium sparing diuretics, angiotensinconverting-enzyme inhibitor and р-Receptor blockers. Despite that management her clinical symptoms deteriorated rapidly and the patient was transferred to intensive therapy unit were intravenous p1-agonist (Dobutamine) was initiated. A given treatment has not improved patient's clinical status and she was sliding into INTERMACS class II [1]. It allowed clinicians to put the patient on the heart transplant-awaiting list.

Patients clinical symptoms continued to deteriorate rapidly and fully magnetically levitated centrifugal-flow pump was implanted (HeartMate 3, Abbott). The operation was performed in the routine manner, through median sternotomy, on beating heart and completed without any incident or complications. After procedure the patient transferred to the intensive care unit with mild inotrope doses.

After 4 hours sedation was discontinued and weakness of the left upper and lower limbs was noticed. Computed tomography (CT) perfusion and CT scan angiography were performed, revealing right middle cerebral artery (M1) thrombosis (ASPECTS 10) and wide penumbra with no ischemic core zone (fig. 1 and 2).

Fig. 1. Computed tomography of cerebral perfusion showing wide penumbra with no ischemic core zone on the right cerebral hemisphere

Fig. 2. Computed tomography scan angiography revealing occlusion of the right middle cerebral artery (M1) (arrow) and no blood flow to distal arteries (circle)

Mechanical thrombus extraction was performed in the catheterization laboratory by the interventional radiologist using 6x25 mm stent retriever restoring blood flow to the right middle cerebral artery (Thrombolysis in Cerebral Infarction [TICI] score = 3) (fig. 3 and 4).

Fig. 3. Thrombosis in the right middle cerebral artery (M1)

Fig. 4. Completely restored blood flow to the right middle cerebral artery (TICI score 3) with Trevo XP Stentriever 6×25 mm

Patient limb strength fully recovered within two days with no residual symptoms. Further down the clinical course of the patient was relatively uneventful and she was discharged to rehabilitation facility on the 20^th postoperative day. 21 months after LVAD implantation the patient is well, she returned to her normal social and physical activities. She continues to attend scheduled outpatient visits; no other cerebrovascular episodes occurred or were documented.

Discussion

Cerebral thromboembolic complications in LVAD patients, despite reduced incidents of stroke with the newest generation devices, remain a difficult challenge, keeping patients with no disability. Even with the latest fully magnetically levitated technology ischemic stroke incidence may reach 6.5% [2]. Regarding long-term, LVAD patients in time have a risk of developing ischemic stroke, as a result of atrial fibrillation, pump thrombosis, systemic infection, inadequate antithrombotic treatment [3]. Although these risk factors increase chances of ischemic cerebrovascular events in the long-term after LVAD implantation, in the first days after the procedure theoretically they are less likely to take place. In our case, the patient had none of the risk factors mentioned above, LVAD implantation performed without any procedural complications, exact onset of the stroke symptoms was unknown, and it leaves only to speculate on the cerebral thrombosis etiology.

The treatment options for ischemic stroke include intravenous thrombolytic therapy with intravenous recombinant tissue plasminogen activator (rtPA), intra-arterial thrombolysis in patients major stroke onset less than 6 hours' due to occlusions of the MCA and who is not otherwise candidates for intravenous rtPA, and mechanical thrombus extraction [4, 5].

In our case thrombolysis was contraindicated since the operation was executed on the same day, which could lead to major bleeding. Regardless of the unexplained etiology and unclear thromboembolic event time, to avoid unfavorable neurological sequel immediate treatment had to be performed. Mechanical thrombus removal was the most suitable choice for immediate restoration of the blood flow to an occluded cerebral artery decreasing chances of irreversible changes in brain tissue.

Conclusion

Despite the progress of LVAD's in reducing the risk of stroke, cerebral thromboembolic events remain an undesirable possibility and often are disabling and/ or life threatening. Early stroke incident after LVAD implantation eliminates the method of thrombolytic therapy, as could lead to major bleeding. Urgent mechanical thrombus extraction is encouraged, having favorable results in symptoms-free recovery.

References

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2.    Colombo P.C., Mehra M.R., Goldstein D.J., et al. Comprehensive Analysis of Stroke in the Long-Term Cohort of the MOMENTUM 3 Study: A Randomized Controlled Trial of the HeartMate 3 Versus the HeartMate II Cardiac Pump. Circulation. 2019; 139 (2): 155-68. DOI: https:// doi.org/10.1161/CIRCULATIONAHA.118.037231

3.    Cho S.M., Hassett C., Rice C.J., Starling R., Kat-zan I., Uchino K. What Causes LVAD-Associated Ischemic Stroke? Surgery, Pump Thrombosis, Antithrombotics, and Infection. ASAIO J. 2019; 65 (8): 775-80. DOI: https://doi.org/10.1097/MAT.0000000000000901

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5.    Powers W.J., Rabinstein A.A., Ackerson T., et al. 2018 Guidelines for the Early Management of Patients With Acute Ischemic Stroke: A Guideline for Healthcare Professionals From the American Heart Association/ American Stroke Association. Stroke. Published online 2018. DOI: https://doi.org/10.1161/STR.0000000000000158