Yuko Fumikura

Enhanced washout of 99mTc-tetrofosmin in hypertrophic cardiomyopathy: quantitative comparisons with regional 123I-BMIPP uptake and wall thickness determined by MRI

The diagnostic value of technetium-99m tetrofosmin (TF) washout in hypertrophic cardiomyopathy (HCM) was examined by investigating its relation to the metabolic abnormality depicted by iodine-123 β-methyl-p-iodophenylpentadecanoic acid (BMIPP) uptake and the left ventricular (LV) myocardial wall thickness as measured by magnetic resonance imaging (MRI). TF washout was evaluated in 31 patients with HCM and 23 normal control subjects using 30-min (early) and 3-h (delayed) TF single-photon emission tomography images. The LV myocardial wall was divided into 19 segments and the percentage TF washout, regional BMIPP uptake and LV wall thickness were measured in each segment. Mean TF washout in the patients with HCM was significantly faster than that in normal control subjects (23.7±5.7 vs 13.4±4.1, P<0.0001). In the patients with HCM, TF washout showed an excellent correlation with MRI wall thickness (r=0.82, P<0.0001) and a good inverse correlation with regional BMIPP uptake (r=−0.72, P<0.0001). In addition, a good linear correlation was observed between TF uptake and MRI wall thickness in the 19 regional segments. In conclusion, the degree of TF washout corresponds well with the severity of myocardial wall thickness and the degree of metabolic abnormality in patients with HCM. These results suggest that enhanced TF washout might provide additional clinical information regarding metabolic alterations in HCM.

Enhancement patterns detected by multidetector computed tomography are associated with microvascular obstruction and left ventricular remodelling in patients with acute myocardial infarction

AIMS This study evaluated the clinical value of myocardial contrast-delayed enhancement (DE) with multidetector computed tomography (MDCT) for detecting microvascular obstruction (MVO) and left ventricular (LV) remodelling revealed by DE magnetic resonance imaging after acute myocardial infarction (AMI). METHODS AND RESULTS In 92 patients with first AMI, MDCT without iodine reinjection was performed immediately following successful percutaneous coronary intervention (PCI). Delayed-enhancement magnetic resonance imaging performed in the acute and chronic phases was used to detect MVO and LV remodelling (any increase in LV end-systolic volume at 6 months after infarction compared with baseline). Patients were divided into two groups according to the presence (n = 33) or absence (n = 59) of heterogeneous enhancement (HE). Heterogeneous enhancement was defined as concomitant presence of hyper- and hypoenhancement within the infarcted myocardium on MDCT. Microvascular obstruction and LV remodelling were detected in 49 (53%) and 29 (32%) patients, respectively. In a multivariable analysis, HE and a relative CT density >2.20 were significant independent predictors for MVO [odds ratio (OR) 13.5; 95% confidence interval (CI), 2.15-84.9; P = 0.005 and OR 12.0; 95% CI, 2.94-49.2; P < 0.001, respectively). The presence of HE and relative CT density >2.20 showed a high positive predictive value of 93%, and the absence of these two findings yielded a high negative predictive value of 90% for the predictive value of MVO. Heterogeneous enhancement was significantly associated with LV remodelling (OR 6.75; 95% CI, 1.56-29.29; P = 0.011). CONCLUSION Heterogeneous enhancement detected by MDCT immediately after primary PCI may provide promising information for predicting MVO and LV remodelling in patients with AMI.

Diffuse and marked breast uptake of both123I-BMIPP and99mTc-TF by myocardial scintigraphy

Unexpected breast uptake was observed in a 32-year-old woman referred for evaluation of hypertrophic cardiomyopathy. Diffuse and marked bilateral breast uptake of123I-BMIPP and99mTc-TF was shown by both planar and SPECT imaging during the first study, and the uptake of both radionuclides had decreased significantly eleven months later. At the time of the first radionuclide examination, she was occasionally breast feeding her 2-year-old child and had small amounts of milk production. At the follow up examination, the frequency of breast feeding was significantly reduced and she produced only small amounts of milk. Therefore, the uptake of123I-BMIPP and99mTc-TF may have been caused by lactation.

Value of 3-Dimensional Speckle Tracking Echocardiography in the Prediction of Microvascular Obstruction and Left Ventricular Remodeling in Patients With ST-Elevation Myocardial Infarction

BACKGROUND In patients with myocardial infarction (MI), microvascular obstruction (MVO) determined by cardiac magnetic resonance imaging (CMR) is associated with left ventricular (LV) remodeling and worse prognosis.Methods and Results:In 71 patients with ST-segment elevation MI (STEMI) treated by primary percutaneous coronary intervention (PCI), speckle tracking echocardiography (STE) and CMR were performed early after PCI. All patients underwent CMR at 6 months after hospital discharge to assess the occurrence of LV remodeling. The values of 3-dimensional (3D)-circumferential strain (CS), area change ratio (ACR), and 2-dimensional (2D)-CS were significantly different for the transmural extent of infarct, whereas the values of 3D- and 2D- longitudinal strain (LS) were not significantly different. In transmural infarct segments, the values of 3D-CS and ACR were significantly lower in segments with MVO than in those without MVO. At 6-month follow-up, LV remodeling was observed in 22 patients. In multivariable logistic regression models, global 3D-CS and ACR were significant determinants of LV remodeling rather than the number of MVO segments. CONCLUSIONS Regional 3D-CS and ACR reflected the transmural extent of infarct and were significantly associated with the presence of MVO. In addition, global 3D-CS and ACR were preferable to the extent of MVO in the prediction of LV remodeling.