Prognostic value of dipyridamole-thallium myocardial scintigraphy in patients with Kawasaki disease

The Long-term Cardiac and Noncardiac Prognosis of Kawasaki Disease: A Systematic Review

CONTEXT

It is uncertain if children with Kawasaki Disease (KD) are at risk for non-cardiac diseases and if children with KD but without coronary artery aneurysms (CAA) are at risk for long-term cardiac complications.

OBJECTIVE

To determine the long-term mortality and prognosis of children after KD.

DATA SOURCES

Medline, Embase, and the Cochrane Central Register.

STUDY SELECTION

Controlled trials and observational studies were included if they included children with KD and reported mortality, major adverse cardiovascular events (MACE), chronic cardiac or other disease over an average follow-up of ≥1 year.

DATA EXTRACTION

Data extracted included sample size, age at diagnosis, the proportion with coronary artery aneurysms (CAA), follow-up duration, and outcome(s).

RESULTS

Seventy-four studies were included. Thirty-six studies reported mortality, 55 reported a cardiac outcome, and 12 reported a noncardiac outcome. Survival ranged from 92% to 99% at 10 years, 85% to 99% at 20 years, and 88% to 94% at 30 years. MACE-free survival, mostly studied in those with CAA, varied from 66% to 91% at 10 years, 29% to 74% at 20 years, and 36% to 96% at 30 years. Seven of 10 studies reported an increased risk in early atherosclerosis. All 6 included studies demonstrated an increased risk in allergic diseases.

LIMITATIONS

Our study may have missed associated chronic comorbidities because short-term studies were excluded. The majority of outcomes were evaluated in East-Asian patients, which may limit generalizability. Studies frequently excluded patients without CAA and did not compare outcomes to a comparison group.

CONCLUSIONS

Studies demonstrate >90% survival up to 30 years follow-up. MACE is observed in children with CAA, but is not well studied in those without CAA.

Assessment of coronary ischaemia by myocardial perfusion dipyridamole stress technetium-99 m tetrofosmin, single-photon emission computed tomography, and coronary angiography in children with Kawasaki disease: pre- and post-coronary bypass grafting

BACKGROUND

Coronary artery lesions in Kawasaki disease invasively assessed by coronary angiography. Evaluation of myocardial perfusion by single-photon emission computed tomography may identify the haemodynamic significance of coronary lesions.

OBJECTIVE

To evaluate diagnostic accuracy of dipyridamole stress technetium-99 m tetrofosmin, single-photon emission computed tomography as a possible alternative to invasive coronary angiography for detection and follow-up of myocardial ischaemia in patients with Kawasaki disease, and pre- and post-coronary bypass grafting.

PATIENTS AND METHODS

Coronary angiography and single-photon emission computed tomography were performed on 21 patients who were classified into three groups - group I (stenosis), group II (giant aneurysms), and group III (small aneurysms). Of the 21 patients, 16 (groups I and II) patients with myocardial perfusion defects, who underwent coronary bypass grafting, were followed up with single-photon emission computed tomography.

RESULT

In group I, all patients had significant coronary stenosis and 100% of them had perfusion defects in the anterior and septal walls. In group II, all patients had giant aneurysms and 83% of them had inferior and inferolateral perfusion defects. In group III, all patients had small aneurysms and 100% of them had normal perfusion. Pre-coronary bypass grafting myocardial ischaemic defects disappeared in all patients after surgery. Sensitivity, specificity, and accuracy of single-photon emission computed tomography were 94, 100, and 95%, respectively.

CONCLUSION

Technetium-99 m tetrofosmin single-photon emission computed tomography can be applied as an accurate non-invasive diagnostic technique for detecting myocardial perfusion defects with coronary artery lesions, and to show improved or even normalised perfusion of the myocardium in patients after surgical revascularisation.

Assessment of radiation dose in nuclear cardiovascular imaging using realistic computational models

PURPOSE

Nuclear cardiology plays an important role in clinical assessment and has enormous impact on the management of a variety of cardiovascular diseases. Pediatric patients at different age groups are exposed to a spectrum of radiation dose levels and associated cancer risks different from those of adults in diagnostic nuclear medicine procedures. Therefore, comprehensive radiation dosimetry evaluations for commonly used myocardial perfusion imaging (MPI) and viability radiotracers in target population (children and adults) at different age groups are highly desired.

METHODS

Using Monte Carlo calculations and biological effects of ionizing radiation VII model, we calculate the S-values for a number of radionuclides (Tl-201, Tc-99m, I-123, C-11, N-13, O-15, F-18, and Rb-82) and estimate the absorbed dose and effective dose for 12 MPI radiotracers in computational models including the newborn, 1-, 5-, 10-, 15-yr-old, and adult male and female computational phantoms.

RESULTS

For most organs, (201)Tl produces the highest absorbed dose whereas (82)Rb and (15)O-water produce the lowest absorbed dose. For the newborn baby and adult patient, the effective dose of (82)Rb is 48% and 77% lower than that of (99m)Tc-tetrofosmin (rest), respectively.

CONCLUSIONS

(82)Rb results in lower effective dose in adults compared to (99m)Tc-labeled tracers. However, this advantage is less apparent in children. The produced dosimetric databases for various radiotracers used in cardiovascular imaging, using new generation of computational models, can be used for risk-benefit assessment of a spectrum of patient population in clinical nuclear cardiology practice.

Right ventricle myocardial perfusion scintigraphy: feasibility and expected values in children

Stress myocardial perfusion scintigraphy imaging (SMPSI) has important applications for evaluating coronary disease and ventricular function. Studies consistently focus on the left ventricle (LV), with no normal right ventricle (RV) data available. This study sought to evaluate the feasibility of RV perfusion with technetium (Tc-99m) sestamibi using a low radiotracer dose for children free of coronary artery (CA) anomalies and to determine its normal pattern. Patients with a history of Kawasaki disease who showed no coronary complications on selective angiography or no LV perfusion defects on SMPSI were studied at rest and during an exercise challenge. The RV uptake counts were compared with those for different segments of the LV, and multiple ratios of the uptakes between RV and LV segments were calculated. The study subjects were 23 children (age, 11.1 ± 3.3 years) imaged with 0.12 ± 0.03 mCi/kg at rest and 0.31 ± 0.06 mCi/kg during stress. The RV to LV uptake proportion was approximately 6%. Exercise-related uptake increased threefold in both the RV and the LV. The findings showed RV myocardial scintigraphy to be feasible with reproducible ratios. Potential clinical applications include acquired and congenital CA anomalies such as Kawasaki disease, right CA ostium stenosis after a switch operation, and anomalous origin of the right CA.

Role of myocardial perfusion single photon emission computed tomography in pediatric cardiology practice

Diagnostic and prognostic power of myocardial perfusion imaging in patients with coronary artery disease has been demonstrated with planar imaging which was further improvised with addition of gated SPECT and newer Technetium labeled myocardial perfusion tracers like SestaMIBI, Tetrofosmin. Myocardial perfusion abnormalities at rest and after stress are considered to be the best predictors of cardiac event-free survival in adults with ischemic heart disease. This article highlights various myocardial perfusion imaging (MPI) radiopharmaceuticals, exercise procedures, pharmacological stress protocols, indications for MPI and myocardial perfusion patterns in children with some of the common congenital and acquired heart diseases.

Catheter-based management for the congenital coronary arteriovenous fistula indicated by the stress 99mTc-MIBI SPECT

A 10-year-old boy, who had suffered Kawasaki disease 7 years ago, presented chest pain, pale face, and cold sweating in the stress (99m)technetium-methoxyisobutylisonitrile ((99m)Tc-MIBI) single-photon emission computed tomography (SPECT), which showed reversible perfusion abnormality indicative of myocardial ischemia involving the right coronary artery. Angiography identified congenital coronary arteriovenous fistula (CAVF) from the right coronary artery to the main pulmonary artery, to which the patient's symptoms and signs of myocardial ischemia, by means of coronary steal phenomenon that entails reversible perfusion abnormality in the stress (99m)Tc-MIBI SPECT, could be ascribed. The penny shall finally be dropped without sudden cardiac event after coaxial transarterial coil occlusion on this boy with the congenital CAVF that is indicated significantly by the stress (99m)Tc-MIBI SPECT.

Abnormalities in myocardial perfusion after surgical correction of pulmonary atresia with intact ventricular septum

We describe the results of myocardial perfusion scintigraphy performed 4 to 15 years after surgery in 12 patients with pulmonary atresia and intact ventricular septum. We used single photon emission computed tomography after injection of technetium Tc-99m tetrofosmin at submaximal exercise test. The patients, 7 girls and 5 boys, with a mean age of 11 years, and a range from 6 to 19 years, had either undergone biventricular repair, in 5 cases, or univentricular palliation in the remaining 7. This second group included 4 patients with ventriculo-coronary arterial communications. Of the children, 3 with biventricular repair and 6 with univentricular palliation had perfusion defects. Children with biventricular repair had perfusion defects in the ventricular septum, while those having univentricular palliation also had defects located to the left ventricular free wall. All children with ventriculo-coronary arterial communications had perfusion defects both in the ventricular septum and in the left ventricular free wall.

An exercise tissue Doppler and strain rate imaging study of diastolic myocardial dysfunction after Kawasaki syndrome in childhood

OBJECTIVE

Myocardial dysfunction due to coronary arterial lesions is an important complication after Kawasaki syndrome in childhood. Tissue Doppler echocardiography, and strain rate imaging, have shown their value in detecting regional myocardial dysfunction in coronary arterial disease. We aimed to examine the diagnostic value of these methods in patients with coronary arterial lesions after Kawasaki syndrome.

METHODS

We assessed regional myocardial function in 17 asymptomatic patients with coronary arterial lesions. Follow-up coronary angiographies were available in all cases. Tissue Doppler echocardiography, and strain rate imaging, were performed at rest and during bicycle exercise. Examination included peak systolic and diastolic velocities, peak systolic strain and strain rate. We enrolled 17 age- and gender-matched persons to serve as a control group.

RESULTS

Segmental left ventricular longitudinal function did not significantly differ between the groups with respect to peak systolic velocity, strain, and strain rate. Diastolic abnormalities were identified in segments supplied by coronary arteries with stenotic lesions. Peak diastolic velocity decreased significantly during exercise in those areas, from 77 plus or minus 34 to 59 plus or minus 56 millimetres per second, p smaller than 0.05. Under exercise, a peak diastolic velocity value under 90 millimetres per second enabled us to identify coronary arterial stenosis with a sensitivity of 75 percent and specificity of 64 percent.

CONCLUSIONS

After Kawasaki syndrome, diastolic impairment develops in segments supplied by stenotic coronary arteries before systolic dysfunction is detectable. Exercise tissue Doppler echocardiography has the potential to detect these subtle abnormalities, and help monitor progression of the disease.

Kawasaki disease: diagnosis, management and cardiac sequelae

Kawasaki disease (KD) is an acute self-limiting systemic vasculitis of unknown etiology and the most common cause of acquired coronary disease in children aged 6 months to 5 years. The inflammatory process results in coronary arteritis, aneurysmal lesions, arterial thrombotic occlusion or even sudden death. The diagnostic tests are unknown but treatment with immunoglobulin and aspirin is effective at reducing cardiac complications from 25 to 4.7% in the UK. Myocardial, endocardial or pericardial inflammation may occur acutely or many years later and abnormalities of myocardial blood flow may require ongoing medication, interventional catheterization or even cardiac surgery. There are several new drugs that may have important roles to play in managing KD in children and young adults.

Calcified occlusion of the right coronary artery in Kawasaki disease: evidence of myocardial ischaemia using cardiac technetium-99m-tetrofosmin perfusion single-photon emission computed tomography

We report the case of a 14-year-old boy who developed Kawasaki disease at 5 months of age. The patient developed severe aneurysmal disease of both the left and right coronary arteries. He eventually developed total calcified occlusion of the right coronary artery despite long-term treatment with aspirin. Catheterisation showed no antegrade flow into the right coronary artery, with retrograde flow from the left coronary system into the right coronary. At the most recent follow-up he was asymptomatic, with normal exercise tolerance and a negative exercise stress test. Single-photon emission computed tomography (SPECT) myocardial perfusion imaging was carried out during stress and at rest using intravenous persantine (dipyridamole) and technetium-99m tetrofosmin. During stress, there were prominent left ventricular apical and anteroseptal defects, which normalised at rest. SPECT during stress and at rest may detect subclinical ischaemia and influence further management options in such patients.

Exercise myocardial perfusion stress testing in children with Kawasaki disease

AIM

Kawasaki disease is the commonest cause of acquired coronary artery disease in children. Although echocardiography and treadmill stress testing have been the traditional methods of assessing coronary artery abnormalities and detecting myocardial ischaemia, respectively, these are inadequate for assessing perfusion and performance. We studied the safety and utility of exercise myocardial perfusion stress testing in children with previous Kawasaki disease.

METHODS

Eleven subjects (median age 12 years; seven male and four female adolescents) with a history of childhood Kawasaki disease underwent 99mTechnetium-Tetrofosmin myocardial perfusion scan using a modified protocol. All had New York Heart Association effort tolerance class 1 and were asymptomatic at time of testing. Eight of 11 subjects had been treated with intravenous immunoglobulin during the acute phase. Six of 11 subjects had transient coronary artery dilatation. One subject with persistently dilated coronary arteries suffered an acute myocardial infarction 6 months after onset of Kawasaki disease but recovered well. Results were compared with clinical and echocardiographic findings.

RESULTS

All subjects were able to complete the exercise test. There were no side effects associated with radioisotope injection. Ten of 11 patients, including the one who suffered a myocardial infarction had normal tests. The single subject with an abnormal scan showed a minimal (2%) fixed defect in the left ventricular wall.

CONCLUSION

Exercise myocardial perfusion stress is a safe and useful method for the assessment of myocardial perfusion in co-operative children with a history of Kawasaki disease and is a useful addition to conventional methods for coronary risk stratification in such patients.

Regression of cardiac enzyme and ventriculocoronary communication in an infant with pulmonary atresia and intact ventricular septum after radiofrequency valvulotomy and valvuloplasty

I report on a 3-month-old infant with pulmonary atresia-intact ventricular septum and ventriculocoronary communication (VCC) who underwent percutaneous radiofrequency valvulotomy and valvuloplasty (RFVV). The patient's cardiac troponin-I, creatine kinase (CK), and myocardial fraction of (CK-MB) were elevated before RFVV and were gradually regressed to normal levels 12 days after RFVV. The VCC disappeared after RFVV. The transvalvular pressure gradients across the pulmonary valve were less than 30 mmHg in the follow-up echocardiography at 4-12 months of age. Oxygen saturation was approximately 90% in room air. Dipyridamole-thallium myocardial scintigraphy showed positive reperfusion over the apex and interventricular septum.

Impaired cardiac sympathetic nerve function in patients with Kawasaki disease: comparison with myocardial perfusion

Kawasaki disease (KD) is a leading cause of CAD in children. The impairment of cardiac sympathetic nerve function (CSNF) in the adult patients with coronary artery disease (CAD) could often be seen. However, little is known concerning the impairment of CSNF in KD patients. We investigated CSNF and its relationship with myocardial perfusion in KD patients. Eleven children with KD and 4 controls were studied with 123I-metaiodobenzylguanidine (MIBG) and stressed 201Tl single photon emission computed tomography. By the findings on coronary artery angiography (CAG), the patients were divided into 2 groups: A, without stenosis; B, with significant stenosis and/or old myocardial infarction. CSNF was evaluated from the uptake of 123I-MIBG. While myocardial perfusion was evaluated from 201Tl uptake. The numbers of patients in the groups A and B were 7 and 4. Perfusion defect was found in 0, and 2 patients in group A (0%), and B (50%). 123I-MIBG defects were found in 1 and 4 patients in the group A (14%) and B (100%). There were excellent concordances between the finding of 201Tl and 123I-MIBG in group A. While in group B, the coronary territories with 123I-MIBG defects were significantly more than those with perfusion defects (p < 0.05). In KD patients, the impairment of CSNF might be subsequent to coronary artery stenosis and was more severe than the injury of myocardial perfusion.

Myocardial perfusion imaging in pediatric cardiology

Myocardial perfusion imaging (MPI) is an important procedure in pediatric cardiology in terms of evaluating myocardial ischemia, infarction and damage associated with various congenital or acquired heart diseases, such as Kawasaki disease, anomalous origin of the left coronary artery from the pulmonary artery and complete transposition of the great arteries after arterial switch surgery. This type of imaging can detect myocardial damage in the morphological right ventricle when it functions as a systemic pumping chamber in patients with complex congenital heart diseases after intra-cardiac repair. Myocardial perfusion imaging can also evaluate myocardial damage associated with primary or secondary cardiomyopathy in children. The magnitude of increased right ventricular uptake on MPI is a useful noninvasive means of estimating right ventricular pressure overload due to congenital heart or pulmonary diseases. This article reviews myocardial perfusion tracers and pharmacological stress tests used to diagnose heart conditions in children, and the current clinical roles of MPI in pediatric cardiology.

Efficacy of iodine-123-15-(p-iodophenyl)-3-R, S-methylpentadecanoic acid single photon emission computed tomography imaging in detecting myocardial ischemia in children with Kawasaki disease

To evaluate its efficacy in detecting myocardial ischemia in children, iodine-123-labeled 15-(p-iodophenyl)-3-R, S-methylpentadecanoic acid (BMIPP) myocardial single photon emission computed tomography (SPECT) imaging was performed in 16 pediatric patients with Kawasaki disease (KD, 11 male, 5 female; mean age and range: 13 years 8 months and 8 years 11 months to 17 years 7 months). Five children with chest pain and no cardiac disease were studied as controls (2 male, 3 female; mean age and range: 13 years 4 months and 9 years 4 months to 17 years 11 months). Selective coronary angiography was also performed in the 16 patients to evaluate the location of coronary stenosis and coronary aneurysms. The SPECT images were expressed as polar maps (Bull's eye maps) and the 'defect' area was defined as where the uptake of BMIPP was less than the standardized BMIPP images of the 5 control children. In the 16 patients, 33 segments had coronary aneurysms and 10 (10/33: 30.3%) had significant coronary stenosis on selective coronary angiography. Nine of the 10 (90%) segments with significant coronary stenosis showed a defect on the BMIPP image whereas only 6 of the 23 (26.1%) segments without coronary stenosis showed a defect on BMIPP imaging. The sensitivity of BMIPP SPECT imaging for detection of coronary stenosis was 90% (9/10) and its specificity was 73.9% (17/23), whereas the sensitivity of (201)Tl SPECT imaging was 80% (8/10) and its specificity was 60% (14/23). There was no significant difference between the BMIPP and 201Tl SPECT images in either the sensitivity or specificity for the detection of coronary stenosis. In the present series, only one case had discordant BMIPP uptake (BMIPP uptake < (201)Tl uptake) in which there was a large coronary aneurysm and re-canalization after complete obstruction at segment 1 of the right coronary artery. This discordant BMIPP uptake reflects the possibility of ischemic but viable myocardium after re-canalization of a large aneurysm in KD. In conclusion, BMIPP SPECT imaging is useful for detecting the areas of ischemic myocardium caused by coronary artery stenosis in children with KD.

Adenosine and dipyridamole in nuclear imaging: pharmacoeconomic considerations

Adenosine and dipyridamole are coronary vasodilators used in nuclear imaging. The acquisition cost of adenosine is four to ten times higher than dipyridamole. Data suggest comparable sensitivity, although specificity may be lower with dipyridamole. While side effect profiles are similar, fewer patients who receive adenosine require medical intervention to manage their side effects. Only three pharmacoeconomic evaluations comparing adenosine and dipyridamole are available - the data are limited by the methodology and study design. Two studies found that total costs with adenosine were lower compared with dipyridamole. In contrast, the interim results of an evaluation conducted with generic dipyridamole found that total costs were higher with adenosine than with dipyridamole - the final results are awaited. In addition, evaluations of downstream costs are needed to clarify the economic implications of a lower specificity with dipyridamole.

Discordance between dipyridamole stress technetium-99m tetrofosmin single photon emission computed tomography and coronary angiography in patients with Kawasaki disease

Kawasaki disease (KD) is an acute vasculitis syndrome of unknown etiology that mainly affects the coronary arteries. The purpose of this study was to assess the agreement between dipyridamole stress technetium-99m tetrofosmin (Tc-TF) myocardial perfusion single photon emission computed tomography (SPECT) and coronary angiography in these patients. Twenty-nine children with KD were included in this study. All of the 29 children also received dipyridamole stress Tc-TF myocardial perfusion SPECT within 1 month of their coronary angiographic studies. The results showed that (1) 89.7% of children had negative coronary angiographic findings without significant coronary stenoses, and 10.3% of children had positive coronary angiographic findings with significant coronary stenosis; (2) 44.8% of children had negative Tc-TF myocardial perfusion SPECT findings without abnormal myocardial perfusion, and 55.2% of children had positive Tc-TF myocardial perfusion SPECT findings with abnormal myocardial perfusion; (3) 44.8% of children had both normal coronary angiographic and Tc-TF myocardial perfusion SPECT findings, and 10.3% of children had both abnormal coronary angiographic and Tc-TF myocardial perfusion SPECT findings; and (4) There was no significant agreement between coronary angiographic and Tc-TF myocardial perfusion SPECT findings. We concluded that poor agreement exists between coronary angiographic and Tc-TF myocardial perfusion SPECT findings with coronary stenoses and abnormal myocardial perfusion in children with KD.

Anaesthesia in a child with Hutchinson-Gildford progeria

Hutchinson-Gildford syndrome is an extremely rare condition characterized by the appearance of accelerated ageing. Reports of general anaesthesia in a child with progeria within the last 20 years in the English-spoken literature are very rare. We report a case of general anaesthesia in a 12-year-old boy with this condition. The child had a past history of failed intubation. Key points in the management of anaesthesia in progeria are discussed.

Dobutamine stress radionuclide ventriculography reveals silent myocardial dysfunction in Kawasaki disease

Dobutamine (DOB) stress radionuclide ventriculography (RVG) is proposed for evaluating left ventricular performance in patients with Kawasaki disease (KD). Dobutamine stress RVG, up to 15 microg x kg(-1) x min(-1), was performed in 40 patients with a history of KD, some of whom had a perfusion defect (PD group) on dipyridamole stress thallium-201 myocardial imaging, some of whom had no perfusion defects (NPD group), and some of whom had no coronary artery lesions (C group). No significant differences in either systolic or diastolic indices of the left ventricle at rest were observed between the 3 groups. Although hemodynamic responses were similar in all patients after DOB stress, early diastolic index of the first third filling fraction decreased only in the PD group and was significantly lower in this group compared with the C group (p<0.01). The asynchrony index increased significantly in those patients with coronary stenosis after DOB stress (p<0.05). No serious side-effects were observed during the study. Even late after onset, patients with myocardial ischemia as a result of KD still had impaired early diastolic filling and asynchronous relaxation of the left ventricle. As an alternative to exercise testing, DOB stress RVG is a safe and promising means for serially evaluating left ventricular performance in patients with KD.

Dipyridamole stress ultrasonic myocardial tissue characterization in patients with Kawasaki disease

Dipyridamole stress integrated backscatter (IBS) was used for evaluation of myocardial ischemia or damage in 31 children with coronary artery lesions caused by Kawasaki disease, in comparison with thallium-201 myocardial imaging. All patients underwent echocardiography at rest and after dipyridamole stress at the anterior interventricular septum, posterior wall (PW), and inferior wall (INF). At rest, no significant difference was seen in cyclic variation (CV) of IBS in the regions with normal or abnormal distribution on Tl-201 imaging. But in the regions showing abnormal distribution after stress, CV decreased significantly. A delayed study after stress showed the recovery of CV to the level at rest in all patients. Sensitivity of abnormal cyclic variation integrated backscatter was 75% in the PW and 91% in the INF, and specificity was 91% in the PW and 90% in the INF, compared with the results of thallium-201 imaging. Dipyridamole stress IBS can provide sensitive detection of myocardial ischemia or damage in Kawasaki disease.

Kawasaki-like syndromes associated with human immunodeficiency virus infection

Kawasaki disease is an acute febrile vasculitic syndrome of early childhood. It is very rarely seen in adults. Among the adult patients with Kawasaki disease who have been described, a disproportionate number are infected with human immunodeficiency virus (HIV). This suggests that the immunocompromised state may predispose individuals to this syndrome. We report our experience with 2 HIV-positive patients who presented with Kawasaki-like syndromes and review the published literature on HIV-positive patients with similar syndromes.