A “Catastrophic” Complication of an Implantable Cardioverter Defibrillator

Introduction 

The superior vena cava (SVC) is the major vein responsible for draining blood from the head, neck, upper extremities, and upper thorax. A partial or complete obstruction of the SVC results in a variety of symptoms collectively called superior vena cava syndrome (SVCS). Traditionally, it was thought to be caused primarily by infections, tumors, or fibrosing mediastinitis. More recently, the incidence of SVCS due to thrombosis has risen, largely because of increased use of intravascular devices such as central vein catheters and intracardiac devices.¹

Case Report

A 71-year-old male has been on chronic anticoagulation with warfarin since being diagnosed with antiphospholipid syndrome in his 40s. Past medical history also includes coronary artery disease, ischemic cardiomyopathy, and transient ischemic attacks (TIA). In addition, nine years ago he received an implantable cardioverter defibrillator (ICD) for malignant ventricular tachycardias, with a revision done about three years ago. 

He presented to the hospital with severe rectal bleeding, along with dizziness and lightheadedness. He was hemodynamically stable, but the INR was supratherapeutic at 3.5. Subsequently, warfarin was withheld and two units of fresh frozen plasma were transfused to reverse the anticoagulation in view of acute bleeding. He underwent a colonoscopy that showed internal hemorrhoids, and was scheduled for hemorrhoidal surgery.

The patient’s hospital stay was then complicated by an episode of dizziness as well as numbness and flushing of his face. There was a concern regarding ongoing TIAs secondary to hypercoagulable state. At this time, he also developed acute renal failure with creatinine rising from a baseline of a 1.2 mg/dl to 2.16 mg/dl, along with progressive thrombocytopenia with platelet count dropping from 142,000 to 53,000 cells/microliter. Considering three-system involvement in the acute setting, there was suspicion for catastrophic antiphospholipid syndrome (CAPS). Antiphospholipid antibody titers were checked, which showed elevated beta-microglobulin IgM titers at greater than 150 and cardiolipin IgM at 144 (normal being less than 20 and 12, respectively), confirming CAPS. The patient was started on IV steroids, intravenous immunoglobulin, and plasmapheresis. The renal function improved with creatinine, dropping to 1.9 mg/dl, and platelet count increased to 152,000 cells/microliter. There wasn’t much improvement in the facial and upper extremity swelling, and CT of the brain did not reveal any acute abnormality. Bilateral upper extremity ultrasound was negative for deep venous thrombosis. SVC venogram was eventually done, which showed near-complete obstruction of the left SVC near the cavoatrial junction (Figure 1). There were numerous venous collaterals draining retrograde through the azygos vein into the inferior vena cava, suggesting acute with superimposed chronic obstruction near the existing ICD leads in the SVC secondary to antiphospholipid syndrome. Treatment was promptly started with fondaparinux bridging with warfarin. Angioplasty (Figure 2) was initially done to relieve the stenosis with subsequent explantation of the entire ICD system, and he has been following up routinely.

Discussion

SVCS, which was first described in 1757 by William Hunter, is due to different degrees of obstructions or stenosis of the central venous system. In the pre-antibiotic era, syphilitic thoracic aortic aneurysms, fibrosing mediastinitis, and other complications of untreated infection were frequent causes of SVCS. In the post-antibiotic era, malignancy became the most common cause, accounting for over 80 percent of cases.²

Venous obstruction of various degrees occurs frequently after ICD lead insertion. In a study by Lickfett et al,³ 105 ICD recipients were tested with contrast venography, which showed severe stenosis (6%) and complete occlusion (9%) of the central venous system in patients. However, overt SVCS remains a rare complication of ICD placement. In another study by Alter et al,⁴ it was found that a symptomatic brachial, subclavian, or jugular vein thrombosis occurred in only 3 (0.7%) of 440 patients after ICD therapy. In fact, patients with thrombosis of the central venous system become symptomatic only in 1-3% of cases as a result of extensive collateral circulation. 

The presence of cardiac leads can cause disruption of the endothelial lining, which can activate fibroblasts and cause fibrous tissue formation. This can eventually lead to chronic stenosis. In addition, presence of a foreign body (i.e., the cardiac leads), can cause inflammation and venostasis, increasing the risk of a thrombus formation. Infection following insertion is also another factor in the development of SVCS, occurring in approximately 0.5-2.0% of cases. 

In this case, we describe the association of SVCS with an intracardiac device and antiphospholipid antibodies. Recurrent vascular injury from the leads produced release of tissue factor, which promoted thrombosis and chronic stenosis. Transient reversal of anticoagulation promoted the generation of antiphospholipid antibodies, which triggered CAPS.^5,6 This procoagulant state then caused the formation of an acute thrombus in an already stenosed vein, leading to SVC occlusion. 

Presentation

SVCS may occur as early as two days or as late as 206 months after the device insertion,⁷ but there has also been a case documented in which SVCS developed hours after the procedure.⁸ The development of collateral circulation delays the onset of symptoms, as blood is diverted around the obstruction. The most common of the signs and symptoms are facial or neck swelling, arm swelling, dyspnea, cough, and dilated chest veins.⁹ Patients may also report chest pain, dysphagia, hoarseness, headache, confusion, dizziness, and syncope. Orthopnea is commonly noted, since a supine position will increase the amount of blood flow to the upper torso. 

Worrisome signs include stridor, as this is usually indicative of laryngeal edema, as well as confusion and obtundation, since these may indicate cerebral edema. If untreated, tracheal obstruction and/or brain herniation will result in death.

Diagnostic Studies

The classic signs and symptoms of SVCS are diagnosed by clinical presentation alone, which can be confirmed by computed tomography (CT), magnetic resonance imaging (MRI), or contrast venography.¹⁰ A chest CT scan will provide visualization of the thoracic anatomy, extent of the occlusion, the existence of collateral circulation, and the presence and degree of thrombus formation. The downside of CT or MRI studies is that they require the patient to lie flat for the study; with the patient lying flat, dyspnea is usually a concern.

Contrast venography is probably the most informative of the tests, as it provides detailed information regarding the anatomy of the vessel in terms of patency, degree of obstruction, location of the obstruction, and adequacy of collateral vessels, if any. 

Management

Several treatments for SVCS have been proposed, which mostly address the underlying condition. Nevertheless, initial interventions should be directed toward supportive care. Oxygen support to minimize the hydrostatic pressure in the upper torso, head elevation, and diuretics to reduce the fluid overload, may improve symptoms in the short term. Steroids are frequently used to temporarily relieve inflammation, soft tissue edema, and respiratory distress. 

Recognition of life-threatening symptoms suggestive of airway compromise and/or cerebral edema is essential. Imaging for an intracranial cause of cerebral edema should be obtained as well. In both cases, the patient should be hospitalized, monitored closely, and treated urgently to relieve the SVCS.

In cases where the etiology is from a vascular device, strategies revolve around anticoagulation, thrombolysis, stent implantation and bypass surgery:

• Anticoagulation should be given for at least one year, especially in the presence of cardiac leads, as it reduces thrombus formation and maintains vessel patency. Sometimes anticoagulation is continued for the lifetime of the patient, especially if they have risk factors for repeat clot formation. 
• Catheter-directed thrombolysis is usually performed in the acute setting, when immediate resolution of the thrombus is required. Gray et al reported success rates of 88% for patients treated before the onset of symptoms and 25% for those treated five days after.¹¹ Catheter-directed thrombolysis tends to have a higher rate of complete clot resolution in comparison with systemic thrombolytics, and also reduces the risk of serious bleeding given the local action. An added advantage is that angioplasty or stenting can also be done at the same time if needed. 
• Endovascular intervention is done to reduce the stenosis. On occasion, stent placement is required because of the fibrous nature of the stenosis, for which simple angioplasty would only be temporizing. Anticoagulation is critical after stent placement. If possible, removal of the cardiac lead followed by stenting can also be done, but it is associated with more risks, such as SVC perforation and cardiac tamponade. Therefore, this strategy should be performed in tertiary or more experienced centers.
• Surgical intervention was, until recently, the mainstay of treatment for SVCS due to a benign etiology. Saphenous vein was the conduit of choice. Kalra et al evaluated the surgical and endovascular options and noted that surgery was more effective, but secondary endovascular interventions were needed to maintain graft patency.¹² Several studies concluded that a careful endovascular approach could yield the same results as that of surgical intervention, with the added advantage of being not invasive. 

Conclusion

Even though the majority of the cases of SVCS are from an underlying malignancy, with the increased usage of intracardiac devices, there should be a high suspicion for clinical diagnosis in such settings. Early and appropriate treatment with anticoagulation, angioplasty, and removal of the device being the mainstays of treatment can help prevent catastrophic outcomes. The underlying antiphospholipid syndrome probably caused aggravated thrombus formation in this patient, causing complete occlusion of the SVC. Prompt initiation of warfarin with angioplasty resulted in significant improvement of this patient’s condition.

Editor’s Note: This article underwent peer review by one or more members of EP Lab Digest^®’s editorial board.

Disclosures: The authors have no conflicts of interest to report regarding the content herein. 

References

1. Cheng S. Superior vena cava syndrome: a contemporary review of a historic disease. Cardiology Rev. 2009;17(1):16-23.
2. Shaheen K, Alraies M. Superior vena cava syndrome. Cleve Clin J Med. 2012;79(6):410-412.
3. Lickfett L, Bitzen A, Arepally A, et al. Incidence of venous obstruction following insertion of an implantable cardioverter defibrillator. A study of systematic contrast venography on patients presenting for their first elective ICD generator replacement. Europace. 2004;6(1):25-31.
4. Alter P, Waldhans S, Plachta E, Moosdorf R, Grimm W. Complications of implantable cardioverter defibrillator therapy in 440 consecutive patients. Pacing Clin Electrophysiol. 2004;28(9):926-932.
5. Arbabi EM, Carrim ZI, Doherty MD, Vize CJ. Catastrophic antiphospholipid syndrome. Clin Experiment Ophthalmol. 2013;41(6):609-611.
6. Townsend L, Cotton J, Altman D, et al. Catastrophic antiphospholipid syndrome. J Am Acad Dermatol. 2012;67(5):e214-e216. 
7. Gebreyes A, Pant H, Williams D, Kuehl S. Be aware of wires in the veins: a case of superior vena cava syndrome in a patient with permanent pacemaker. J Community Hosp Intern Med Perspect. 2012;2(3). doi: 10.3402/jchimp.v2i3.19159.
8. Rossi A, Baravelli M, Cattaneo P, et al. Acute superior vena cava syndrome after insertion of implantable cardioverter defibrillator. J Interv Card Electrophysiol. 2008;23(3):247-249.
9. Wan J, Bezjak A. Superior vena cava syndrome. Hematol Oncol Clin North Am. 2010;24(3):501-513.
10. Koetters KT. Superior vena cava syndrome. J Emerg Nurs. 2012;38(2):135-138.
11. Gray B, Olin J, Graor R, Young J, Bartholomew J, Ruschhaupt W. Safety and efficacy of thrombolytic therapy for superior vena cava syndrome. Chest. 1991;99:54-59.
12. Kalra M, Gloviczki P, Andrews JC, et al. Open surgical and endovascular treatment of superior vena cava syndrome caused by nonmalignant disease. J Vasc Surg. 2003;38:215-223