Thallium-201 stress scintigraphy in Takayasu arteritis

Novel Therapies in Takayasu Arteritis

Takayasu Arteritis (TAK) is a large-vessel vasculitis that preferentially involves the aorta and its primary branches. Cardiac involvement is frequent in TAK and is a major determinant of the patient's outcome. Glucocorticoids (GC) are the mainstay of therapy for TAK, with high doses of GC effective to induce remission. However, relapses are common and lead to repeated and prolonged GC treatments with high risk of related adverse events. Potential GC toxicity is a major concern, especially because patients with TAK are young and need to be treated for several years, often for the whole life. Conventional immunosuppressive drugs are used in patients with severe manifestations but present some limitations. New therapeutic approaches are needed for patients with refractory disease or contraindications to conventional therapies. Fortunately, major progress has been made in understanding TAK pathogenesis, leading to the development of targeted biotherapies. In particular, IL-6 and TNF-α pathways seems to be the most promising therapeutic targets, with emerging data on Tocilizumab and TNF inhibitors. On the other hand, new insights on JAK-Inhibitors, Rituximab, Ustekinumab and Abatacept have been explored in recent studies. This review summarizes the emerging therapies used in TAK, focusing on the most recent studies on biologics and analyzing their efficacy and safety.

Association between Takayasu arteritis and ischemic heart disease: a cohort study

Purpose of the study:

Takayasu arteritis (TA) is an idiopathic large vessel vasculitis, which involves the aorta and its major branches. Our aim was to examine the association between TA and the development of ischemic heart disease (IHD) and its impact on survival.

Study design:

Using data from Clalit Health Services (CHS), the largest Health Maintenance Organization (HMO) in Israel, the proportion of IHD was compared between patients diagnosed with TA and age- and gender-matched controls. Chi-square and t-tests were used for univariate analysis, and a logistic regression model was employed for multivariate analysis. Survival analysis was performed using Kaplan-Meier plots and cox regression.

Results:

The study included 155 TA patients and 755 age- and gender-frequency matched controls. The proportion of IHD in TA patients was increased in comparison with controls (32.3% and 8.9%, p<0.001). In multivariate analysis, IHD was associated with TA (OR=6.576, 95% CI: 4.09–10.64) and male gender (OR=2.29, 95% CI: 1.43–4.26). Survival analysis over 15 years of follow-up showed a higher proportion of all-causes mortality in the TA group. In a multivariate analysis, TA (HR=2.58, 95%CI: 1.64–4.06) and IHD (HR=1.64, 95%CI: 1.05–2.55) were found to be associated with reduced survival.

Conclusions:

TA patients present an increased proportion of IHD, and a reduced 15-years survival rate compared to controls.

Myocardial Perfusion Imaging in Takayasu Arteritis

Objective.

Myocardial perfusion defects using scintigraphy have been frequently observed in patients with Takayasu arteritis (TA) without coronary stenosis. The aim of our study was to evaluate coronary microcirculation in TA using thallium-201 (201Tl) myocardial scintigraphy and dipyridamole (DPM) as vasodilator agent.

Methods.

Twenty-five consecutive patients with TA were prospectively recruited. They were asymptomatic for cardiac issues and examined using 201Tl myocardial scintigraphy at rest and after coronary artery vasodilation with intravenous DPM. Factors associated with improvement in myocardial perfusion after DPM were identified in patients with TA.

Results.

Among 25 patients with TA, 21 (84%) had 201Tl myocardial perfusion defects and 4 (16%) had normal resting myocardial perfusion. Using a 17-segments model for quantitative image analysis, DPM significantly improved resting 201Tl myocardial perfusion in 14 patients (61%) versus 9 patients without improvement (39%). We were able to examine coronary artery stenoses in 11 patients, including 10 patients with thallium perfusion defects, and significant coronary artery stenoses were present in only 2 patients (18.2%). No significant difference was found in traditional cardiovascular risk factors between TA patients with or without improvement of myocardial perfusion after DPM. The absence of improvement in myocardial perfusion after DPM tended to be closely associated with specific features and prognostic factors of TA, such as aortic regurgitation at diagnosis, renovascular hypertension, longer duration of TA disease, and male sex.

Conclusion.

We found the significantly high prevalence of myocardial perfusion defects mostly improved after vasodilation with DPM, which may indicate the major role of microcirculatory dysfunction in myocardial ischemia in TA.

Coronary CT angiography in Takayasu arteritis

OBJECTIVES

The aim of this study was to use coronary computed tomographic (CT) angiography to characterize coronary artery involvement in patients with known Takayasu arteritis who present with anginal chest pain or shortness of breath.

BACKGROUND

Takayasu arteritis is a primary vasculitis of the large vessels, which mainly affects the aorta and its branches but can also involve the coronary arteries. Coronary CT angiography allows visualization of the coronary vessels and can be used to detect both stenotic and nonstenotic coronary artery lesions.

METHODS

Eighteen consecutive patients with Takayasu arteritis and angina (typical or atypical) and/or dyspnea underwent contrast-enhanced 64-slice coronary CT angiography. The arterial injury was classified according to the Numano classification. Three patients had prior known coronary artery disease. Coronary arteries were evaluated concerning the presence of obstructive and nonobstructive lesions, and differences between the clinical presentations of patients with and without coronary artery involvement on CT angiography were analyzed.

RESULTS

Coronary artery involvement was found in 8 patients (44.4%), 3 of them with clinical activity. A total of 19 coronary lesions were present (13 in ostial locations, 5 in proximal coronary artery segments, and 1 in a mid segment). Eight lesions exceeded 50% diameter reduction (2 in ostial locations and 6 in proximal coronary artery segments). Median disease duration was significantly different between patients with coronary artery involvement (176 months; range 13 to 282 months) compared with those without (21 months; range 1 to 142 months) (p = 0.013).

CONCLUSIONS

Coronary CT angiography allows the assessment of coronary artery involvement in patients with Takayasu arteritis. These data confirm prior observations that most coronary lesions are in ostial or proximal coronary artery locations. Disease duration in patients with coronary artery involvement is longer than in patients without.

Long-term clinical and angiographic follow-up in patients with isolated ostial stenosis of the left coronary artery

BACKGROUND

Isolated ostial stenosis (IOS) of the left coronary artery is a rare disease of unknown etiology, and the long-term prognosis and angiographic characteristics of affected patients have not been fully studied.

METHODS AND RESULTS

The present study investigated 57 patients with stenosis of the left main trunk (LMT) who underwent coronary artery bypass grafting (CABG). They were categorized into 3 groups, based on the angiographic findings: Group I comprised 9 patients with IOS; Group II comprised 12 patients with left coronary ostial stenosis in the presence of distal vessel obstructions; Group III comprised 36 patients with stenosis of LMT excluding ostial stenosis and associated with distal vessel obstruction. The patients underwent serial angiography at 1, 5, and 10 years after CABG. Middle aged women with fewer coronary risk factors were more common in Group I compared with Groups II and III (P<0.01). The patency rate of the internal thoracic artery grafts was significantly higher in Groups II and III than in Group I (P<0.05). In Group I, the percentage stenosis of LMT lesions decreased significantly (P<0.05), but there was no difference in the other groups.

CONCLUSIONS

IOS had clinical characteristics and time course distinct from those of atherosclerotic LMT disease.

Tc-99m sestamibi/F-18 FDG myocardial SPECT in Takayasu arteritis with coronary artery involvement

Coronary arteries may be involved in some patients with Takayasu arteritis. Evaluation of myocardial involvement due to coronary lesions may provide important information in the clinical management of these patients. We report Tc-99m sestamibi and F-18 FDG myocardial single photon emission computed tomography in 3 cases of such patients.

Coronary reserve in Takayasu's arteritis: transesophageal echocardiographic analysis

BACKGROUND

The incidence of coronary arteries lesion in Takayasu's arteritis varies from 9% to 10% and is usually discovered at autopsy. Recent studies have demonstrated the value of echocardiography in noninvasive detection of significant coronary stenosis.

AIM

The aim of our study was to evaluate coronary reserve in 15 patients with Takayasu's arteritis using contrast transesophageal echocardiography (Optison).

METHODS

Transesophageal echocardiogram under basal conditions and in the hyperemic phase with dipyridamole challenge, myocardial perfusion studies and coronary angiography were performed on all patients. Seventy-three percent of them had histories of systemic hypertension, and the most frequent cardiovascular symptoms were shortness of breath (80%), headache (46%), angina (40%), and dizziness (33%).

RESULTS

The transthoracic echocardiogram showed left ventricular systolic dysfunction in 6% and diastolic dysfunction in 53%. Aortic regurgitation was found in 67% of the patients, and 60% had mitral and/or tricuspid regurgitation. Coronary reserve was diminished in 3 patients with significant coronary lesions and in 2 patients with coronary dilation (33%). In the 3 patients with obstructive lesions and diminished coronary reserve, reversible perfusion defects were found with thallium-201 single-photon emission computed tomography. One patient with coronary dilation had normal perfusion, while the other demonstrated reversible and irreversible perfusion defects. One patient without coronary lesions and with normal coronary reserve had an irreversible fibrotic changes and the other reversible defects due to abnormal microcirculation.

CONCLUSIONS

Transesophageal echocardiography is a feasible and promising technique for assessing coronary reserve in patients with Takayasu's arteritis.

Isolated coronary ostial stenosis associated with coronary vasospasm

A 50-year-old woman was brought to the emergency room in a preshock condition. An emergency coronary angiogram revealed 90% ostial stenosis of the left coronary artery with delayed distal filling. After intracoronary nitrate, the degree of stenosis was reduced to 75%; no other coronary lesions were evident. The patient was found to have hyperthyroidism and she became euthyroid after a 2-month regimen of methimazole. A follow-up coronary angiogram showed that the left coronary artery had 50% ostial stenosis without delayed distal filling. At the same time, an aortogram showed complete occlusion of the right subclavian artery in its proximal site, a slight dilatation of the truncus brachiocephalic artery, and a diffuse wall irregularity of the abdominal aorta, suggestive of Takayasu's arteritis.

QT dispersion in patients with Takayasu arteritis

This study was designed to test the hypothesis that myocardial involvement exists in patients with Takayasu arteritis and is associated with increased QT dispersion, which is a marker of repolarization inhomogeneity. Twenty-one consecutive patients with Takayasu arteritis and no significant coronary artery disease were included. Twelve-lead electrocardiogram and exercise-induced thallium-201 myocardial scintigraphy were performed in all patients. Ten of 21 patients (48%) had abnormal findings on scintigraphy. Patients were divided into two groups by the presence (group P, n = 10) or absence (group N, n = 11) of exercise-induced thallium-201 myocardial scintigraphic perfusion abnormalities, including permanent defects in three, reversible defects in four, and slow washout in three. The QT dispersion at rest was significantly greater in group P than that in group N (54 +/- 12 vs 40 +/- 8 msec, p < 0.005). The QTc dispersion at rest was also significantly greater in group P than in group N (59 +/- 15 vs 43 +/- 11 msec, p < 0.01). In patients with Takayasu arteritis, myocardial involvement suggested by exercise-induced thallium-201 myocardial scintigraphic perfusion abnormalities is not rare, even when no significant coronary stenosis is present on angiography. Increased baseline QT dispersion was associated with scintigraphic abnormalities and may be a useful marker of myocardial involvement in patients with Takayasu arteritis.

Usefulness of beta blocker therapy in patients with Takayasu arteritis and moderate or severe aortic regurgitation

The objective of the present study was to evaluate the benefit of beta-blocker therapy for patients with Takayasu arteritis complicated by moderate or severe aortic regurgitation. Clinical and echocardiographic evaluation was performed in 20 Japanese women in a follow-up period of 7.0 +/- 2.0 years. The patients were divided into 2 groups: Group A (n=10) patients who did not receive beta-blockers, and Group B (n=10) patients treated with long-term (5.1 +/- 1.6 years) therapeutic doses of beta-blockers. Left ventricular wall thickness increased significantly in all Takayasu patients who did not receive beta-blockers. Consequently, a remarkable increment in left ventricular mass took place (232 +/- 59 to 361 +/- 79 g; p < 0.005). In the same group, progressive worsening of the symptoms, with no reduction in the percent fractional shortening, was observed in 2 patients, while reduction of this last index was present in 1 asymptomatic patient. On the other hand, among the patients who were treated with beta-blockers, left ventricular mass still increased in 6 cases, while it clearly decreased in the other 4 cases (290 +/- 171 to 284 +/- 61 g; NS). The increment in wall thickness or left ventricular mass observed among patients with beta-blocker therapy was clearly less than the one registered among those who had not received beta-blockers. Furthermore, no worsening of the symptoms and/or left ventricular performance was observed during the follow-up period for patients receiving beta-blockers. We conclude that beta-blocker therapy can slow and even reverse the progression of left ventricular hypertrophy in patients with Takayasu arteritis complicated by moderate or severe aortic regurgitation. The mechanism still needs to be elucidated. We believe an effective reduction in the excessive afterload imposed on the left ventricle to be most likely responsible, but cardiac beta-receptor up-regulation might also be involved. Deterioration of the clinical status and/or impairment of left ventricular function were not associated with beta-blocker therapy in our patients. Therefore, these agents can be used safely alone or in addition to standard anti-hypertensive therapy when attempting to reduce excessive afterload, in spite of the presence of severe aortic regurgitation.

Tl-201 myocardial SPECT in patients with systemic arterial diseases

We compared the results of Tl-201 myocardial SPECT of patients with arteriosclerosis obliterans (ASO), abdominal aortic aneurysm (AAA), and Takayasu arteritis (TA), so that coronary artery disease could be evaluated in them. Twenty-three patients (ASO, 9; AAA, 8; TA, 6) had Tl-201 myocardial SPECT with stress testing, and SPECT data was assessed qualitatively and quantitatively. Qualitative analysis showed that myocardial perfusion was decreased most in patients with ASO, followed by patients with AAA, and was minimally decreased in patients with TA. Quantitative analysis indicated that segmental uptake was significantly less in four segments in ASO compared with TA, less in two segments in AAA compared with TA, and less in two segments in ASO compared with AAA. Thus patients with ASO and AAA were found to have a marked abnormality in Tl-201 myocardial SPECT, indicating that this procedure should be performed in these patients. In patients with TA, however, because of minimal abnormality in myocardial perfusion, the role of SPECT is limited.

Four years follow-up study in patients with Takayasu arteritis and severe aortic regurgitation; assessment by echocardiography

We prospectively performed the follow-up study in 11 female patients with Takayasu arteritis and severe aortic regurgitation by echocardiography. A mean follow-up period was 4 years. The inflammatory state was controlled in all patients. Antihypertensive agents including beta-blocker were administered in nine patients. Heart failure did not progress in all patients except one. No candidate for cardiac surgery appeared during the follow-up period. Aortic root diameter, left atrial, left ventricular end-diastolic and end-systolic dimensions, wall thickness, left ventricular mass, and percent fractional shortening of the left ventricle showed no significant change in echocardiography. These data indicate that left ventricular disturbance might be slowly progressive in patients with Takayasu arteritis and severe aortic regurgitation. Systemic hypertension and the inflammatory state should be well controlled in managing the patients. beta-blocker might be useful in some patients with Takayasu arteritis and severe aortic regurgitation. Further follow-up is necessary for the decision of the cardiac surgical indication.

Concentric left ventricular hypertrophy in patients with Takayasu arteritis

Although aortic regurgitation (AR) in patients with Takayasu arteritis (TA) is believed to be caused by dilatation of the aortic ring or thickening of the aortic cusps, the pattern of left ventricular hypertrophy (LVH) in these patients has not been described. To clarify the geometry of the LV in patients with TA that had been documented both echocardiographically and hemodynamically, the authors evaluated 22 patients with TA and severe AR (group 1), 10 with TA and systemic hypertension (group 2), and 17 with isolated severe AR of other etiologies (group 3). M-mode echocardiography showed that LV dimensions were smaller in groups 1 and 2 than in group 3 and that wall thickness was greater in group 1 than in group 3. The concentric hypertrophic ratio (CHR = wall thickness/LV end-diastolic dimension+wall thickness) was larger than group 1 (p < 0.001) and group 2 (p < 0.01) than in group 3. CHR was similar in groups 1 and 2. Systolic blood pressure was significantly increased in group 2 and showed a tendency to increase in group 1 as compared with group 3. The results confirmed the presence of concentric LVH related to a pressure overload in patients with TA, even when TA was complicated by severe AR.

Ventricular arrhythmias in Takayasu arteritis

We studied the prevalence, severity and clinical significance of ventricular arrhythmias in 78 female patients with Takayasu arteritis by 24-h ambulatory electrocardiography monitoring. Fifty (64%) of 78 patients had no or less than 30 beats/h premature ventricular contractions (Group A). The remaining 28 (36%) patients exhibited frequent or complex premature ventricular contractions (Group B). The frequency of HLA Bw52 which is closely associated with this morbid condition, echocardiographic and thallium-201 stress myocardial scintigraphic findings were then compared between these two groups. The frequency of positive HLA Bw52 was not significantly different between these two groups. Echocardiographically determined left ventricular mass (309 +/- 94 vs. 166 +/- 64 g; P < 0.01), frequency of complicated aortic regurgitation (77% vs. 24%; P < 0.01) and abnormal thallium-201 scintigraphic findings (76% vs. 38%; P < 0.05) were found higher in Group B as compared with those in Group A. These data indicate that frequent or complex ventricular arrhythmias in patients with Takayasu arteritis were associated with the presence of left ventricular hypertrophy, aortic regurgitation and decreased coronary reserve.

Aortic regurgitation in patients with Takayasu arteritis: Assessment by color Doppler echocardiography

To characterize aortic regurgitation in patients with Takayasu arteritis, we studied 48 females with arteritis (mean age 47 +/- 12 years) by means of color Doppler echocardiography. Aortic regurgitation was confirmed in 32 out of 48 patients (67%) by color-flow mapping. Twenty-four patients had mild or no aortic regurgitation (group A), 9 had moderate (group B), and 15 had severe (group C) aortic regurgitation. We compared the echocardiographic data obtained from patients with Takayasu arteritis with those of 14 normal controls and 9 patients with severe aortic regurgitation of valvular origins (group V). The aortic root diameter (AOD) in group B (23 +/- 4 mm/M2) and group C (22 +/- 3 mm/M2) revealed a statistically significant large value as compared with that in group A (18 +/- 2 mm/M2) and normal controls (17 +/- 3 mm/M2). However, the differences, between groups B and C and groups C and V, were not significant. The AOD was not obviously dilated in a considerable number of group C patients. Aortic valve involvement was seen in several group C patients and moderate concentric left ventricular hypertrophy was present in all group C patients. Group C patients therefore, have concentric left ventricular hypertrophy but may or may not have dilatation of the aortic root which can be detected on echocardiography. We conclude that aortic valve involvement may cause aortic regurgitation in some patients with Takayasu arteritis and that aortic regurgitation is more common than previously believed.

Hereditary factors of Takayasu arteritis

Takayasu arteritis is a chronic vasculitis characterized by a clinical pulseless condition and is predominant in young female patients. Its loci is found mainly in Asian countries, and its etiology is still unknown. Our experiences of cases of twin sisters with Takayasu arteritis led us to suppose that hereditary factors participate in the pathophysiology of this disease. Population and family-incidence studies employing HLA analysis in Japan have focused on an complotype Aw24-DW52-C4A2-C4BQ0-Dw12 which was in disequilibrium with Takayasu arteritis. Clinical features and clinical courses were found to be intimately related to this complotype. Recent studies on HLA typing in other countries have also suggested the important roles of hereditary factors in this morbid condition and international collaborative studies on these hereditary factors are now under way.

Left ventricular dysfunction and HLA Bw52 antigen in Takayasu arteritis

Heart disease is the main cause of death in patients with Takayasu arteritis. It has been reported that this disease is closely related to the presence of HLA Bw52 antigen. To assess the correlation between this antigen and left ventricular involvement, we studied 40 patients with Takayasu arteritis, 21 with and 19 without Bw52, using Tl-201 stress myocardial scintigraphy and echocardiography. Those with Bw52 had a significantly higher incidence of abnormal electrocardiographic findings (67% vs 26%; P < 0.05) and of aortic regurgitation (52% vs 11%; P < 0.05). The echocardiographically determined interventricular septal wall thickness plus left ventricular posterior wall thickness (25 +/- 8 vs 17 +/- 3 mm; P < 0.01) and the left ventricular mass (257 +/- 132 vs 142 +/- 51 g; P < 0.01) were significantly increased in the patients with Bw52. Scintigraphically determined perfusion abnormalities were significantly more frequent in those with Bw52 (76% vs 32%; P < 0.05). These observations indicate that patients with Takayasu arteritis and Bw52 antigen have a more severe left ventricular involvement than the patients without that antigen. The left ventricular impairment may account for the poor prognosis of Takayasu patients with Bw52.