Usefulness of cardiovascular magnetic resonance imaging of the superficial femoral artery for screening patients with diabetes mellitus for atherosclerosis.

Cardiovascular magnetic resonance (CMR) of the superficial femoral artery (SFA) allows direct and noninvasive visualization of atherosclerotic plaque burden. We examined atherosclerosis in 3 groups of patients without history or symptoms of peripheral arterial disease with varying expected burdens: those with diabetes mellitus (DM) and known coronary artery disease (CAD) (n = 24), those with DM and a high prevalence of CAD risk factors (n = 20), and controls of similar age without DM or CAD and few CAD risk factors (n = 15). We also assessed the diagnostic accuracy of this technique to differentiate among these 3 groups. T1-weighted spin-echocardiographic images were used to measure mean wall thickness (WT) and total wall volume indexed to total vessel volume. Diagnostic accuracy was assessed by area under receiver operating characteristics curve analysis. Patients with DM plus risk factors and DM plus CAD had higher mean WT (1.28 and 1.37 mm) and mean indexed wall volume (0.53 and 0.56) compared to controls (mean WT 1.16 mm and mean indexed wall volume 0.45; p <0.010 for all comparisons). Mean WT and indexed wall volume showed good diagnostic accuracy in discriminating controls from those with DM plus CAD (areas under curve 0.85 and 0.87, respectively, p <0.001), whereas only indexed wall volume discriminated DM plus risk factors from controls (area under curve 0.82, p <0.001). Neither could discriminate between DM plus risk factors and DM plus CAD. In conclusion, patients with DM plus risk factors and DM plus CAD had significantly greater atherosclerotic burden in the SFA on CMR imaging than controls of similar age, with good diagnostic accuracy in differentiating these groups. The high reproducibility and reliability of CMR of the SFA may facilitate improved assessment of atherosclerosis prevalence and progression/regression in studies of novel therapies.

The prevalence of extracardiac findings by multidetector computed tomography before atrial fibrillation ablation.

BACKGROUND AND OBJECTIVES: The study was designed to determine the prevalence of extracardiac findings discovered during multidetector computed tomography (CT) (MDCT) examinations before atrial fibrillation ablation. Multidetector CT has become a valuable tool in detailing left atrial anatomy before catheter ablation. The incidence of extracardiac findings has been reported for electron beam CT calcium scoring and coronary MDCT, but no data exist for the prevalence of extracardiac findings discovered before atrial fibrillation ablation with MDCT. METHODS AND RESULTS: Clinical reports from MDCT examinations before atrial fibrillation ablation and interpretations by 2 radiologists blinded to the clinical reports were reviewed for significant additional extracardiac findings and recommendations for follow-up. In 149 patients who underwent MDCT, the mean age was 55.9 +/- 11.0 years, 75% were men, and 47% had a history of smoking. Extracardiac findings were identified in 69% of patients with clinical, 90% of reader 1, and 97% of reader 2 interpretations (kappa = 0.086). Follow-up was recommended in 30% of clinical, 50% of reader 1, and 38% of reader 2 interpretations (kappa = 0.408). Pulmonary nodules were the most common additional finding and reason for suggested follow-up for all interpreters. CONCLUSIONS: The prevalence of extracardiac abnormalities detected by MDCT is considerable. Significant variability in their identification exists between interpreters, but there is good agreement about the need for further follow-up. It is important that those who interpret these examinations are adequately trained in the identification and interpretation of both cardiac and extracardiac findings.

Patterns of late gadolinium enhancement in chronic hemodialysis patients.

OBJECTIVES: The aim of this work was to characterize patterns of late gadolinium enhancement (LGE) by cardiovascular magnetic resonance imaging in a hemodialysis population at high risk for cardiovascular events. BACKGROUND: The prevalence and distribution of LGE and its relationship to left ventricular mass (LVM) and function in this population is unknown. METHODS: Chronic hemodialysis patients at high risk for cardiovascular events-age >50 years, diabetes, or known cardiovascular disease-were enrolled prior to concerns regarding nephrogenic systemic fibrosis. Cardiovascular magnetic resonance imaging was performed in 24 patients (age, 59 +/- 11 years; dialysis, 45 +/- 38 months) and included steady-state free precession cine imaging and late gadolinium-enhanced, phase-sensitive, inversion-recovery gradient echo images. Left ventricular mass, volumes, and function were calculated and indexed to body surface area. A 16-segment analysis was performed to calculate percentage of LGE, LV wall thickness, and percentage of wall thickening. RESULTS: Left ventricular ejection fraction was 48 +/- 15%, and the LV mass index was 100 +/- 52 g/m(2). Late gadolinium enhancement was observed in 79% (19 of 24) of patients in 3 distinct patterns: infarct-related (32%, 6 of 19), diffuse (37%, 7 of 19), and focal noninfarct (37%, 7 of 19). Late gadolinium enhancement constituted 15 +/- 18% of the LVM and correlated with LVM (r = 0.44, p = 0.03). A significant, inverse relationship existed between segmental LGE and the percentage of wall thickening (p > 0.0001). Excluding infarct-related segments, as end-diastolic wall thickness increased, so did LGE (p < 0.0001), and as LGE increased, the percentage of wall thickening decreased (p = 0.0012). After 23 +/- 3 months of follow-up, 1 patient had developed nephrogenic systemic fibrosis. Seven of the patients (29%) had developed a hard cardiovascular event, 5 of 19 (26%) with LGE and 2 of 5 (40%) without. CONCLUSIONS: Late gadolinium enhancement is prevalent in the hemodialysis population and its extent is related to LVM. Most cases of LGE are not infarct-related and are associated with hypertrophied, dysfunctional LV segments. Non-infarct-related LGE may signify fibrosis from LV hypertrophy and/or an infiltrative process. Further studies in this patient population will not be possible due to the risk of nephrogenic systemic fibrosis.

Can late gadolinium enhancement by cardiovascular magnetic resonance identify coronary artery disease as the etiology of new onset congestive heart failure?

BACKGROUND: New left ventricular systolic dysfunction affects 500,000 Americans and coronary artery disease (CAD) is responsible for two-thirds of cases. Identifying CAD has both prognostic and therapeutic implications. We evaluated the ability of late gadolinium enhancement (LGE) by cardiovascular magnetic resonance imaging (CMR) to detect CAD as the etiology of recent onset congestive heart failure (CHF). METHODS: CMR and LGE were performed in 26 patients with new onset left ventricular systolic dysfunction. All patients received an x-ray angiography for identification of CAD. Patients with an acute coronary syndrome with troponin I > 1.0 ng/ml or a history of CAD were excluded. The presence and distribution of LGE was evaluated. RESULTS: Significant coronary stenoses were present in 5 of 26 patients (19%). LGE in an infarct pattern was found in 2 of the 5 patients with CAD. Of the 21 patients without CAD, 2 had midwall enhancement but none had evidence of LGE in an infarct pattern. CONCLUSIONS: When present, LGE in an infarct pattern suggests CAD as the etiology of new onset CHF. However, the absence of LGE does not exclude CAD as the underlying etiology. A small proportion of patients with a nonischemic cause of new onset CHF have LGE limited to the midwall.