Myocardial perfusion scintigraphy [Gated-SPECT] and coronary disease risk factors in Behcet's disease with metabolic syndrome

ABSTRACT

Behcet's disease [BD] is a multi-system vasculitis that can have a wide range of effects on the cardiovascular system. To determine the existence of myocardial perfusion defects caused by coronary microvascular dysfunction in asymptomatic BD patients with and with out metabolic syndrome and to evaluate coronary arterial distribution and left ventricular systolic function by gated single-photon emission computed tomography [G-SPECT]. The study population consisted of 20 [17 men and 3 women] patients with BD and 20 healthy controls of age and sex match. Technetium-99m methoxyisobutylisonitrile [Tc-99m MIBI] gated SPECT studies were performed using a 1-day rest-stress protocol. Stress and rest left ventricular ejection fraction [LVEF] were calculated. Using gated SPECT images myocardial perfusion scores [summed stress score [SSS], summed rest score [SRS] and summed difference score [SDS]] were determined. Echocardiography was performed for comparison. Carotid intima-media thickness [1MT] was recorded to detect the macrovascular involvement in BD and to detect if there is any possible correlation with the microvascular myocardial affection. Abnormal myocardial perfusion scintigraphy [MRS] was detected in 15 patients [2 with infarction, 13 with perfusion defects], 5 patients had normal perfusion pattern. Scmiquantitative scores [SSS, SRS and SDS] were significantly higher in the BD patients compared to control [p 0.000]. There was a statistically significant difference between BD patients and control regarding the carotid artery IMT by ultrasonography being increased in the patients. On the other hand, the G-SPECT and echocardiographic LVEF was significantly lower in the BD patients [p 0.001 and p 0.002 respectively]. On comparing the results of the BD patients with and without metabolic syndrome, the studied parameters for coronary risk factors as blood pressure, cholesterol, triglycerides and fasting blood sugar they were significantly higher in the metabolic syndrome group. On the other hand, the HDE was significantly lower in the metabolic syndrome group. Both the disease activity [BDCAF] and the myocardial perfusion gated SPECT [SSS] were significantly higher in those BD patients with metabolic syndrome [p 0.03]. On the contrary, the differences in results of the carotid artery IMT and the echocardiographic LVEF% in BD patients with and without metabolic syndrome did not reach significance. There was a tendency to increased disease duration in BD patients with more severe myocardial perfusion defect. The difference was only significant between patients with perfusion defect and those with old myocardial infarction involving the antero-septal wall [p 0.04]. There was a statistically significant difference among the three myocardial perfusion scan subgroups as regards the level of triglycerides, systolic and diastolic blood pressure [p 0.29, 0.38, 0.13 respectively]. The CRP level was higher in the infarct patients followed by the defective perfusion. A significant difference was only found when comparing the level of those with history of infarction [severe ischemia] with those with normal myocardial perfusion scan [p 0.047]. On comparing the carotid artery IMT, echocardiographic LVEF%, and myocardial perfusion G-SPECT parameters, they were all significantly different among BD patients with infarction, defective and normal myocardial perfusion. A significant positive correlation was present between the SRS and the disease duration [p 0.04]. CRP significantly correlated with both the SSS and SDS [p 0.04 and 0.00 respectively]. Furthermore, the SSS and SRS significantly correlated with the blood pressure, triglycerides and cholesterol levels. The BDCAF significantly correlated with the SSS and SDS [p 0.009 and 0.007 respectively]. Carotid artery IMT significantly correlated only with SRS [0.02]. However, the echocardiographic LVEF% significantly correlated with all the myocardial perfusion gated SPECT parameters. Myocardial perfusion and function are disturbed owing to influenced coronary microvascularity in BD with silent myocardial ischemia [SMI]. Gated SPECT is a non-invasive more reliable method compared to echocardiography that simultaneously evaluates the existence, extent and severity of myocardial ischemia or infarction in cardio-Behcet. Myocardial perfusion defects increase with increased disease activity and carotid artery IMT. Metabolic syndrome risk factors account for an augmented perfusion defect and should be considered a high risk group in BD patients