Detection of left ventricular hypertrophy by Tc-99 tetrofosmin gated-SPECT.

Introduction. Left ventricular hypertrophy (LVH) is a strong cardiovascular risk factor and an independent major cardiac risk factor for sudden cardiac death, myocardial infarction and stroke. The objective of this study was to determine the specificity, sensitivity, positive predictive value (PPV) Negative Predictive Value (NPV) and accuracy of a Tc-99 gated-SPECT method for detecting LVH. Methods: Patients referred for evaluation of known or suspected CAD, who underwent myocardial perfusion SPECT imaging with Tc-99 Tetrofosmin and who had also an echocardiogram performed within the previous 2 months were prospectively enrolled in the study. The group consisted of 52 patients, 25 men and 27 women, the mean age was 64.5 ± 12 yrs. Results: When the echocardiographic LVH was defined as a mean wall thickness VSTd + PWTd/2 ≥ 11mm, the SPECT method had aspecificity and sensitivity of 91% and 33% respectively, a PPV of 94%, a NPV of 48% and an accuracy of 58%. When the LVH was defined as a thickness to radius ratio (h/r) >0.45, the SPECT Method showed a specificity of 95%, sensitivity of 37% and a PPV of 97% and NPV of 54% with an accuracy of 62% . In Men, when the LVH criteria was a LV Mass >111 g/m2, the specificity and sensitivity for the SPECT method criteria was 100% and 20% respectively with a PPV, NPV and Accuracy of 100%, 45% and 48%. In Women, when LVH was defined as a LV Mass >106 g/m2, the SPECT method had a specificity of 91% and sensitivity of 44%, a PPV of 94%, and NPV and Accuracy of 42% and 63%. If the criteria was a LV Mass >125 g/m2, SPECT showed a specificity and sensitivity of 86% and 30% respectively and a PPV of 85% and a NPV of 64% with an Accuracy of 62 %

Myocardial perfusion in patients with ST depression during the recovery phase of treadmill stress tests

Objectives: To determine the incidence and characteristics of myocardial perfusion abnormalities in patients with ST depression in recovery only, using Tc-99m gated-SPECT. Background: The significance of ST depression in recovery only after exercise treadmill testing (ETT) remains controversial. Such finding has been classified as a false positive, false negative and inconclusive sign of CAD. Methods: Fifty patients who underwent ETT and Tc-99m gated-SPECT and demonstrated ST depression only in recovery were analyzed. The group consisted of 28 men and 22 females, mean age of 61 ± 9 years. Perfusion abnormalities, reverse redistribution, heart/lung ratio, changes in LV cavity size and global function were assessed. Results: The mean peak heart rate (PHR) was 139 ± 18 bpm (88% ± 14 of the predicted maximal heart rate). Sixty % of the patients had evidence of CAD in form of either fixed or reversible perfusion abnormalities. Fixed only perfusion abnormalities were found in 3 patients (6%), seven (14%) had fixed and reversible perfusion defects and 20 (40%) showed ischemia only. Ischemia was observed in the anterior wall in 10 patients, inferior wall in 12, lateral wall in 5, apex in 8 and septum in 1 patient. Mean extent of the perfusion abnormalities were 3.7 segments (out of 20) ± 2. Conclusions: Evidence of CAD was found in 60% of the patients with ST depression in recovery only. The most common finding was ischemia in 54% of the patients, and the anterior and inferior walls were most frequently involved. The mean extent of myocardial involvement was moderate, which implies prognostic significance

Reproducibility of 3D free-breathing magnetic resonance coronary vessel wall imaging

Aims Although the coronary artery vessel wall can be imaged non-invasively using magnetic resonance imaging (MRI), the in vivo reproducibility of wall thickness measures has not been previously investigated. Using a refined magnetization preparation scheme, we sought to assess the reproducibility of three-dimensional (3D) free-breathing black-blood coronary MRI in vivo. Methods and results MRI vessel wall scans parallel to the right coronary artery (RCA) were obtained in 18 healthy individuals (age range 25-43, six women), with no known history of coronary artery disease, using a 3D dual-inversion navigator-gated black-blood spiral imaging sequence. Vessel wall scans were repeated 1 month later in eight subjects. The visible vessel wall segment and the wall thickness were quantitatively assessed using a semi-automatic tool and the intra-observer, inter-observer, and inter-scan reproducibilities were determined. The average imaged length of the RCA vessel wall was 44.5±7 mm. The average wall thickness was 1.6±0.2 mm. There was a highly significant intra-observer (r=0.97), inter-observer (r=0.94), and inter-scan (r=0.90) correlation for wall thickness (all P<0.001). There was also a significant agreement for intra-observer, inter-observer, and inter-scan measurements on Bland-Altman analysis. The intra-class correlation coefficients for intra-observer (r=0.97), inter-observer (r=0.92), and inter-scan (r=0.86) analyses were also excellent. Conclusion The use of black-blood free-breathing 3D MRI in conjunction with semi-automated analysis software allows for reproducible measurements of right coronary arterial vessel-wall thickness. This technique may be well-suited for non-invasive longitudinal studies of coronary atherosclerosi

Exercise Echocardiography in Asymptomatic HCM Exercise Capacity, and Not LV Outflow Tract Gradient Predicts Long-Term Outcomes

ObjectivesThis study sought to assess long-term outcomes in asymptomatic or minimally symptomatic patients with hypertrophic cardiomyopathy (HCM) who underwent exercise echocardiography, without invasive therapies for relief of left ventricular outflow tract (LVOT) obstruction.BackgroundMany HCM patients present with LVOT obstruction, mitral regurgitation (MR), and diastolic dysfunction, often requiring invasive therapies for symptomatic relief. However, a significant proportion of truly asymptomatic patients can be closely monitored. In HCM patients, exercise echocardiography has been shown to be a useful assessment of functional capacity and risk stratification.MethodsWe included 426 HCM patients (44 ± 14 years; 78% men) undergoing exercise echocardiography, excluding hypertensive heart disease of elderly, ejection fraction <50% and invasive therapy (myectomy or alcohol ablation) during follow-up. Clinical, echocardiographic (LV thickness, LVOT gradient, and MR) and exercise variables (percent of age-sex predicted metabolic equivalents [METs] and heart rate recovery [HRR] at 1 min post-exercise) were recorded. A composite endpoint of death, appropriate internal defibrillator discharge, and admission for congestive heart failure was recorded.ResultsPatients were asymptomatic or minimally symptomatic on history, but 82% of patients achieved <100% of age-sex predicted METs, and 43% had ≥II+ post-stress MR. The mean LV septal thickness, post-exercise LVOT gradient, and HRR were 2.0 ± 0.5 cm, 62 ± 47 mm Hg, and 31 ± 14 beats/min, respectively. During a mean follow-up of 8.7 ± 3 years, there were 52 events (12%). Patients achieving >100% of age-sex predicted METs had 1% event rate versus 12% in those achieving <85%. On stepwise multivariate survival analysis, percent of age-sex predicted METs (hazard ratio [HR]: 0.76; 95% confidence interval [CI]: 0.64 to 0.90), abnormal HRR (HR: 0.89; 95% CI: 0.82 to 0.97), and atrial fibrillation (HR: 2.73; 95% CI: 1.30 to 5.74) (overall, p < 0.001) independently predicted outcomes.ConclusionsIn asymptomatic or minimally symptomatic HCM patients, exercise stress testing provides excellent risk stratification, with a low event rate in patients achieving >100% of predicted METs

Global left ventricular remodeling, extent of inferior wall infarct, and mitral valve geometry are important predictors of mitral regurgitation severity than total infarct size in advanced ischemic cardiomyopathy

Mitral regurgitation (MR) is common in patients with ischemic cardiomyopathy (ICM) and independently associated with worse mortality. We sought to determine the impact of adverse LV remodeling, total myocardial infarct (MI) size, location and extent of regional MI, and mitral valve geometry on the severity of mitral regurgitation