Severe aortic regurgitation complicating Takayasu’s arteritis

Discussion

Takayasu’s arteritis often referred to as the “pulseless disease” is a chronic disease with variable severity and clinical manifestations, progression of which may cause damage to the arterial walls resulting in adverse outcomes such as rupture of the arteries.3 Such vascular complications in untreated patients with TA are the leading causes of morbidity and mortality.3 Initiating aggressive treatment for severe cases improves outcomes with a reportedly close to 90% 5-year survival rates.4 The diagnosis of TA is often made later when complications become evident posing a formidable challenge for early management and treatment of the disease. The difficulty for accurate TA diagnosis is compounded by the lack of specific diagnostic serologic tests; traditional biomarkers such as CRP and ESR levels are indicative of clinical inflammation but not all cases of active TA disease present with changes in ESR and CRP levels.5,6 Therefore, high index of suspicion is warranted in patients presenting with angina without any other identifiable risk factors or young adults diagnosed with hypertension and arterial bruits.

We have reported an uncommon case of a middle-aged female patient presenting with severe AR associated with aortic aneurysm as a secondary complication of TA. The carotid, subclavian, and vertebral arteries were all involved. The clinical diagnosis of TA in this patient was only established following the AR symptomatic presentation. The definitive diagnosis of TA was supported by the above findings together with the asymmetrical arm blood pressures, claudication symptoms, hypertension and the classical radiological changes. Over the past decade, the time frame from disease onset to clinical diagnosis has gradually diminished thanks to the advent in improved imaging modalities and medical treatment options. The classical characteristics of TA were not apparent in our patient at the time of diagnosis with AR and DCM. However, at later presentation the clinical features of TA were salient and it is plausible that a flare up was the reason for the worsening of her cardiac condition and the appearance of the diagnostic TA indications. Although the patient was diagnosed with TA at a relatively later stage, the condition; however, was amenable to immunosuppressive therapy and symptoms improved adequately to allow for the postponement of the surgical intervention. Despite improvement following surgery, valve detachment after anastomotic aneurysm may still occur due to the fragility of aortic wall or annular tissue because of TA.4 Previous studies5,7 found that immunosuppressive agents achieved remission in patients with TA anywhere from 46% to 84% success rate. Similarly, early medical intervention for TA management prior to surgery even with complication of severe forms of AR has been further demonstrated with implementation of effective treatment using newer biological agents.6 Surgical intervention with valve or root replacement in patients with active disease can be very challenging and carries high complications rate due to the fragility of the inflamed tissue, which may lead to valve detachment or anastomotic aneurysm formation. Surgical intervention is therefore best delayed for the vascular inflammation to be sufficiently treated with immunosuppressive therapy.

Aortic valve regurgitation has been reported as a complication of up to 25% of TA cases.8,9 However, AR associated with aneurysm of the ascending aorta is a relatively rare complication of TA with few cases published in more than 3 decades.6,9 The clinical presentation, treatment approaches and outcomes have been variable in these case reports with the differences primarily due to the changes in treatment modalities. It is now generally accepted to only consider surgical intervention after the medical therapy is instigated in order to reduce inflammation to manageable levels.5 McGraw et al9 also suggested a delay in the surgical intervention was deemed necessary as it complicated the need to manipulate the inflamed tissue leading to worsening of the outcome such as valve detachment or dilatation of the residual aorta. Previously, Matsuura et al8 reviewed the late outcome of surgical treatment for aortic valve regurgitation due to TA and its relation with inflammation over 24 years in 90 patients and found an overall survival rate of 76.1% after 15 years follow up. The authors findings further showed presence of active inflammation in 10 pathological specimens 4 of which showed detachment of the valve or graft confirming that active inflammation is a major risk factor for detachment.8

Previous studies have reported significantly increased survival rates following aortic valve replacement in patients with AR complication secondary to TA condition.4,10 Kaku et al4 review of cardiac operations over 30 years in 20 patients with AR associated with TA revealed a 5-year survival rate of 90.9% after surgery with no case of valve or composite graft detachment evident.4 In our findings, 2 patients required a repeat of aortic root replacement while 2 other patients developed late dilatation of the residual thoraco-abdominal aorta.4 Similarly, Li et al10 found satisfactory outcomes with no case of valve detachment in patients with TA and surgical treatment of AR.10 Despite the rare association of AR with TA, physicians should be alert to the possible diagnosis of TA given the high incidence of coronary artery diseases among these patients.

In conclusion, this case demonstrates a rare presentation of severe AR with aortic aneurysm secondary to TA in a middle-aged female patient of Arabian origin. High index of suspicion is necessary for early diagnosis of patients with TA to reduce or prevent further complications and adverse outcomes. The immunosuppressive therapy has proven as an effective perioperative measure in this case study and may benefit other patients with established cardiac complications by reducing or delaying the need for surgical intervention.