Transient Ischemic Dilation Ratio in Regadenoson, Single Isotope Gated Single-photon Emission Computed Tomography Myocardial Perfusion Imaging.

Single isotope 99mTc single-photon emission computed tomography-myocardial perfusion imaging (SPECT-MPI) is the most commonly used protocol for nuclear stress testing. Transient ischemic dilation of the left ventricle (TID) has been considered a specific marker of severe coronary artery disease (CAD). Recent publications have questioned the clinical utility of TID, specifically with regadenoson as a stressor and 4DM-SPECT software for TID analysis. These findings have not been demonstrated using other imaging packages. The goal of our study was to establish the TID threshold in the identification of Multi-vessel CAD using Quantitative Perfusion SPECT (QPS) software. Included in this study are 190 patients that had undergone regadenoson-stress, same day, single-isotope 99mTc MPI and had a coronary angiography within a designated 3-month period. QPS (Cedars-Sinai, LA, CA) automated image analysis software was used to calculate TID ratios which were compared across different CAD categories. Coronary angiograms were reviewed to identify both obstructive and nonobstructive CAD. The mean TID for patients with nonobstructive CAD (n = 91) was 1.02 ± 0.11, and the threshold for TID was 1.24. A receiver operating characteristic curve showed that TID had a poor discriminatory capacity to identify MVD (area under the curve 0.58) with a sensitivity of 3% and a specificity of 97%. In our study with regadenoson MPI in a predominantly African-American population, TID was found to be a poor predictor of MVD using QPS software. The reason is unclear but possibly related to the significant decline in the prevalence of severe CAD in the area where our study took place.

Natural history of severe aortic stenosis: Diastolic wall strain as a novel prognostic marker.

BACKGROUND AND AIM: Diastolic wall strain (DWS) has been proposed as a simple noninvasive measure of left ventricular (LV) stiffness. This study investigated DWS as a possible predictor of mortality in severe aortic stenosis (AS). METHODS: 138 patients with severe AS (indexed aortic valve area [AVA]<0.6 cm2 /m2 ) and normal ejection fraction (>55%) were included. 52 patients (38%) had aortic valve interventions or poor image quality (n=5) and were excluded leaving 86 in the study group (84±8 years, 70% female, 69% African American). DWS was defined as (LVPWs-LVPWd)/LVPWs where LVPWs=left ventricular posterior wall thickness in systole and LVPWd=left ventricular wall thickness in diastole. RESULTS: Follow-up extended 2.0±1.9 years (median 1.6 years). Mean DWS for the group was 0.21±0.11 (normal=0.4±0.07). In patients who died, DWS was significantly lower than in survivors (0.18±0.09 vs 0.24±0.11, P=.02). By contrast, traditional measures of diastolic dysfunction did not predict death. Regression analysis showed DWS predicted death even after adjusting for age, sex, race, indexed AVA, symptoms (angina, shortness of breath, dizziness, syncope), and clinical factors (creatinine, smoking, diabetes, hypertension, hyperlipidemia) (HR 2.5 [95% CI 1.02-5.90], P<.05). The best cutoff value for DWS of 0.25 had a sensitivity of 42% and specificity of 83% for predicting death. CONCLUSIONS: DWS is an independent predictor of all-cause mortality in patients with severe AS, even after accounting for traditional clinical and echocardiographic parameters.

Relation Between Epicardial Adipose and Aortic Valve and Mitral Annular Calcium Determined by Computed Tomography in Subjects Aged ≥65 Years.

Epicardial adipose tissue (EAT) has been linked to coronary artery calcium deposits and atherosclerotic disease. Mitral annular (MAC) and aortic valve calcium (AVC) have also been associated with atherosclerosis. This study examined the possible relation between EAT thickness and valvular calcium deposits. We included 294 patients aged ≥65 years who had noncontrast computed tomography scans of the chest. Mean age was 76 ± 7 years; 47% were men. Using reconstructed images, EAT thickness was measured at various locations. MAC and AVC were quantified by Agatston technique. The sum of AVC and MAC was reported as the grand total score (GTS). Subjects were divided into 2 groups based on the value of GTS; GTS = 0, no cardiac calcification and GTS ≥1, cardiac calcification group. Epicardial fat (left and right atrioventricular grooves and superior interventricular groove) was significantly greater in the cardiac calcification group compared with the no cardiac calcification (all values, p <0.05). After adjusting for clinical variables including BMI, EAT at the superior interventricular groove remained significantly associated with total calcium. Left atrioventricular groove EAT demonstrated a trend toward an association with total calcium, but this did not reach statistical significance. In conclusion, epicardial fat is associated with calcium deposits of the mitral annulus and aortic valve.

Effect of Mitral Annular Calcium on Left Ventricular Diastolic Parameters.

Assessment of left ventricular (LV) diastolic function by Doppler flow imaging and tissue Doppler is an integral part of the echocardiographic examination. Mitral annular calcium (MAC) is frequently encountered on echocardiography. The aim of this study was to assess the impact of MAC, quantitatively measured by computed tomography scan, on echocardiographic LV diastolic parameters. We included 155 patients aged ≥65 years. Computed tomography reconstructions of the mitral annulus were created, and calcium identified and quantified by Agatston technique. Calcium locations were assigned using an overlaid template depicting the annular segments in relation to surrounding anatomic structures. Echocardiographic assessment of diastolic function was performed in standard fashion. Mean age was 77 years; 49% were men; and 43% were black. Patients with MAC had lower septal e' (p = 0.003), lateral e' (p = 0.04), and average e' (p = 0.01) compared with those without MAC. They also had a higher E-wave velocity (p = 0.01) and E/e' ratio (p <0.001). When evaluated by severity of MAC, and after adjustment for multiple clinical factors, there was a graded (inverse) relation between MAC severity and septal e' (p = 0.01), lateral e' (p = 0.01), and average e' (p = 0.01). In conclusion, LV diastolic parameters, as measured by Doppler echocardiography, are altered in the presence of MAC. This could be due to direct effects of MAC on annular function or might reflect truly reduced diastolic function. Interpretation of diastolic parameters in patients with MAC should be performed with caution.

Distribution of Mitral Annular and Aortic Valve Calcium as Assessed by Unenhanced Multidetector Computed Tomography.

Aging is associated with calcium deposits in various cardiovascular structures, but patterns of calcium deposition, if any, are unknown. In search of such patterns, we performed quantitative assessment of mitral annular calcium (MAC) and aortic valve calcium (AVC) in a broad clinical sample. Templates were created from gated computed tomography (CT) scans depicting the aortic valve cusps and mitral annular segments in relation to surrounding structures. These were then applied to CT reconstructions from ungated, clinically indicated CT scans of 318 subjects, aged ≥65 years. Calcium location was assigned using the templates and quantified by the Agatston method. Mean age was 76 ± 7.3 years; 48% were men and 58% were white. Whites had higher prevalence (p = 0.03) and density of AVC than blacks (p = 0.02), and a trend toward increased MAC (p = 0.06). Prevalence of AVC was similar between men and women, but AVC scores were higher in men (p = 0.008); this difference was entirely accounted for by whites. Within the aortic valve, the left cusp was more frequently calcified than the others. MAC was most common in the posterior mitral annulus, especially its middle (P2) segment. For the anterior mitral annulus, the medial (A3) segment calcified most often. In conclusion, AVC is more common in whites than blacks, and more intense in men, but only in whites. Furthermore, calcium deposits in the mitral annulus and aortic valve favor certain locations.