The relation of echocardiography and carotid ultrasound to the results of stress myocardial SPECT in asymptomatic patients with Type-2 diabetes mellitus
Abstract
Aim: The aim of our study was to evaluate the relation of myocardial stress SPECT results to diabetes control, presence of micro-/macroalbuminuria, and echocardiographic results-particularly in relation to the presence of left ventricular hypertrophy and its diastolic function and in relation to carotid ultrasound findings (IMT, intima/media thickness of the common carotid artery, its distensibility and the presence of carotid artery atheroma). Patients and methods: We examined 126 patients with Type-2 diabetes mellitus with two more risk factors according to the guidelines of the American Associations of Cardiology and Diabetes.
All our patients underwent a clinical examination including risk factor evaluation, diabetes control, transthoracic echocardiography, and carotid ultrasound. Results: Out of the 126 Type-2 diabetics, abnormal SPECT was found in 33 (26%).
Fasting blood sugar (9.3 +- 1.4 mmol/l in patients with abnormal SPECT vs. 9.7 +- 1.9 mmol/l in the other diabetics, NS) and HbA1c (7.5 +- 1.3% vs. 7.5 +- 1.3%, NS) were not significantly different in patients with abnormal SPECT from the other diabetics without this finding. Micro-/macroalbuminuria was seen significantly more often in patients with abnormal SPECT (60% of patients with abnormal SPECT and 29% in other diabetics; p = 0.01).
Left ventricular ejection fraction (LV EF) was normal almost in all patients. Left ventricular hypertrophy was noted in 54% of diabetics with abnormal SPECT and in 56% of the rest of our patients (NS).
Left ventricular diastolic dysfunction was diagnosed in 27 (82%) of diabetics with abnormal SPECT compared with 51 (54%) among the rest of diabetic patients (p = 0.006). Univariate analysis of carotid artery data showed that, in the group with abnormal SPECT, IMT was significantly thicker (0.71 +- 0.07 mm to 0.66 +- 0.09 mm; p = 0.03), distensibility was significantly smaller (0.296 +- 0.07 to 0.325 +- 0.06, p = 0.045) and, most importantly, the number of patients with atheromas was significantly higher (72% of patients with abnormal SPECT vs. 21.5% in the other diabetic patients; p = 0.0001).
In multivariate analysis, a significant correlation to abnormal SPECT was found in the number of patients with atheromas and distensibility, but not with IMT. Conclusion: Diastolic dysfunction, as assessed by echocardiography, and decreased distensibility in carotid ultrasound are significantly related to abnormal myocardial SPECT.
However, the most significant correlation to abnormal myocardial SPECT was found in the presence of carotid artery atheromas.