Adenosine stress CT can identify stress-induced myocardial perfusion defects with diagnostic accuracy comparable to SPECT, with similar radiation dose and with the advantage of providing information on coronary stenosis.

Several large, recent studies have demonstrated the impact of coronary CTA on prognosis, although the follow-up time has been relatively short.1,2 Only 1 study has evaluated the longer term follow-up of cardiovascular events among patients referred for coronary CTA.3 Because patients referred forBackground-The contribution of plaque extent to predict cardiovascular events among patients with nonobstructive and obstructive coronary artery disease (CAD) is not well defined. Our objective was to evaluate the prognostic value of plaque extent detected by coronary computed tomography angiography. Methods and Results-All consecutive patients without prior CAD referred for coronary computed tomography angiography to evaluate for CAD were included. Examination findings were classified as normal, nonobstructive (<50% stenosis), or obstructive (≥50%). Based on the number of segments with disease, extent of CAD was classified as nonextensive (≤4 segments) or extensive (>4 segments). The cohort included 3242 patients followed for the primary outcome of cardiovascular death or myocardial infarction for a median of 3.6 (2.1-5.0) years. In a multivariable analysis, the presence of extensive nonobstructive CAD (hazard ratio, 3.1; 95% confidence interval, 1.5-6.4), nonextensive obstructive (hazard ratio, 3.0; 95% confidence interval, 1.3-6.9), and extensive obstructive CAD (hazard ratio, 3.9; 95% confidence interval, 2.2-7.2) were associated with an increased rate of events, whereas nonextensive, nonobstructive CAD was not. The addition of plaque extent to a model that included clinical probability as well as the presence and severity of CAD improved risk prediction. Conclusions-Among patients with nonobstructive CAD, those with extensive plaque experienced a higher rate of cardiovascular death or myocardial infarction, comparable with those who have nonextensive disease. Even among patients with obstructive CAD, greater extent of nonobstructive plaque was associated with higher event rate. Our findings suggest that regardless of whether obstructive or nonobstructive disease is present, the extent of plaque detected by coronary computed tomography angiography enhances risk assessment. (Circ Cardiovasc Imaging. 2014;7:282-291.)

OBJECTIVES This study sought to determine whether the extent of late gadolinium enhancement (LGE) can provide additive prognostic information in patients with a nonischemic dilated cardiomyopathy (NIDC) with an indication for implantable cardioverter-defibrillator (ICD) therapy for the primary prevention of sudden cardiac death (SCD). BACKGROUND Data suggest that the presence of LGE is a strong discriminator of events in patients with NIDC. Limited data exist on the role of LGE quantification. METHODS The extent of LGE and clinical follow-up were assessed in 162 patients with NIDC prior to ICD insertion for primary prevention of SCD. LGE extent was quantified using both the standard deviation–based (2-SD) method and the full-width half-maximum (FWHM) method. RESULTS We studied 162 patients with NIDC (65% male; mean age: 55 years; left ventricular ejection fraction [LVEF]: 26 ± 8%) and followed up for major adverse cardiac events (MACE), including cardiovascular death and appropriate ICD therapy, for a mean of 29 ± 18 months. Annual MACE rates were substantially higher in patients with LGE (24%) than in those without LGE (2%). By univariate association, the presence and the extent of LGE demonstrated the strongest associations with MACE (LGE presence, hazard ratio [HR]: 14.5 [95% confidence interval (CI): 6.1 to 32.6; p < 0.001]; LGE extent, HR: 1.15 per 1% increase in volume of LGE [95% CI: 1.12 to 1.18; p < 0.0001]). Multivariate analyses showed that LGE extent was the strongest predictor in the best overall model for MACE, and a 7-fold hazard was observed per 10% LGE extent after adjustments for patient age, sex, and LVEF (adjusted HR: 7.61; p < 0.0001). LGE quantitation by 2-SD and FWHM both demonstrated robust prognostic association, with the highest MACE rate observed in patients with LGE involving >6.1% of LV myocardium. CONCLUSIONS LGE extent may provide further risk stratification in patients with NIDC with a current indication for ICD implantation for the primary prevention of SCD. Strategic guidance on ICD therapy by cardiac magnetic resonance in patients with NIDC warrants further study.

Purpose:First, to assess the feasibility of a protocol involving stressinduced perfusion evaluated at computed tomography (CT) combined with cardiac CT angiography in a single examination and second, to assess the incremental value of perfusion imaging over cardiac CT angio graphy in a dual-source technique for the detection of obstructive coronary artery disease (CAD) in a high-risk population. Materials and Methods:Institutional review board approval and informed patient consent were obtained before patient enrollment in the study. The study was HIPAA compliant. Thirty-fi ve patients at high risk for CAD were prospectively enrolled for evaluation of the feasibility of CT perfusion imaging. All patients underwent retrospectively electrocardiographically gated (helical) adenosine stress CT perfusion imaging followed by prospectively electrocardiographically gated (axial) rest myocardial CT perfusion imaging. Analysis was performed in three steps: (a) Coronary arterial stenoses were scored for severity and reader confi dence at cardiac CT angiography, (b) myocardial perfusion defects were identifi ed and scored for severity and reversibility at CT perfusion imaging, and (c) coronary stenosis severity was reclassifi ed according to perfusion fi ndings at combined cardiac CT angiography and CT perfusion imaging. The sensitivity, specifi city, negative predictive value (NPV), and positive predictive value (PPV) of cardiac CT angiography before and after CT perfusion analysis were calculated. Results:With use of a reference standard of greater than 50% stenosis at invasive angiography, all parameters of diagnostic accuracy increased after CT perfusion analysis: Sensitivity increased from 83% to 91%; specifi city, from 71% to 91%; PPV, from 66% to 86%; and NPV, from 87% to 93%. The area under the receiver operating characteristic curve increased signifi cantly, from 0.77 to 0.90 ( P , .005). Conclusion:A combination protocol involving adenosine perfusion CT imaging and cardiac CT angiography in a dual-source technique is feasible, and CT perfusion adds incremental value to cardiac CT angiography in the detection of signifi cant CAD.q RSNA, 2010

BACKGROUND Omega-3 fatty acids from fish oil have been associated with beneficial cardiovascular effects but their role in modifying cardiac structures and tissue characteristics in patients who have suffered an acute myocardial infarction (MI) while receiving current guideline-based therapy remains unknown. METHODS In a multicenter, double-blind, placebo-controlled trial, participants presenting with an acute MI were randomized 1:1 to 6-months of high-dose omega-3 fatty acids (n=178) or placebo (n=180). Cardiac magnetic resonance imaging was used to assess cardiac structure and tissue characteristics at baseline and following study therapy. The primary study endpoint was change in left ventricular systolic volume index (LVESVI). Secondary endpoints included change in non-infarct myocardial fibrosis, LVEF, and infarct size. RESULTS By intention-to-treat analysis, patients randomized to omega-3 fatty acids experienced a significant reduction of LVESVI (−5.8%, P=0.017), and non-infarct myocardial fibrosis (−5.6%, P=0.026) compared with placebo. Per-protocol analysis revealed that those subjects who achieved the highest quartile increase in RBC omega-3 index experienced a 13% reduction in LVESVI as compared with the lowest quartile. In addition, patients in the omega-3 fatty acid arm underwent significant reductions in serum biomarkers of systemic and vascular inflammation and myocardial fibrosis. There were no adverse events associated with high-dose omega-3 fatty acid therapy. CONCLUSIONS Treatment of acute MI patients with high-dose omega-3 fatty acids was associated with reduction of adverse LV remodeling, non-infarct myocardial fibrosis, and serum biomarkers of systemic inflammation beyond current guideline-based standard of care. CLINICAL TRIAL REGISTRATION URL: http://www.clinicaltrials.gov. Unique identifier: NCT00729430.

Thoracic aortic aneurysm (TAA) has been associated with mutations affecting members of the TGF-β signaling pathway, or components and regulators of the vascular smooth muscle cell (VSMC) actomyosin cytoskeleton. Although both clinical groups present similar phenotypes, the existence of potential common mechanisms of pathogenesis remain obscure. Here we show that mutations affecting TGF-β signaling and VSMC cytoskeleton both lead to the formation of a ternary complex comprising the histone deacetylase HDAC9, the chromatin-remodeling enzyme BRG1, and the long noncoding RNA MALAT1. The HDAC9–MALAT1–BRG1 complex binds chromatin and represses contractile protein gene expression in association with gain of histone H3-lysine 27 trimethylation modifications. Disruption of Malat1 or Hdac9 restores contractile protein expression, improves aortic mural architecture, and inhibits experimental aneurysm growth. Thus, we highlight a shared epigenetic pathway responsible for VSMC dysfunction in both forms of TAA, with potential therapeutic implication for other known HDAC9-associated vascular diseases.

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The prevalence of ACAOS on CTA was 1.7%, including 45% of cases discovered incidentally. CTA provided excellent characterization of ACAOS features associated with coronary revascularization, including the length and severity of proximal vessel narrowing.