Anthon Fuisz

Subclinical Brain Embolization in Left-Sided Infective Endocarditis Results From the Evaluation by MRI of the Brains of Patients With Left-Sided Intracardiac Solid Masses (EMBOLISM) Pilot Study

Background— Acute brain embolization (ABE) in left-sided infective endocarditis has significant implications for clinical decision making. The true incidence of ABE, including subclinical brain embolization, is unknown. Methods and Results— We prospectively studied 56 patients with definite left-sided infective endocarditis. Patients were examined by a study neurologist, and those without contraindication had magnetic resonance imaging of the brain. Patients without clinical evidence of acute stroke but with magnetic resonance imaging evidence of ABE were considered to have subclinical brain embolization. Clinical stroke was present in 14 of 56 patients (25%). Among 40 patients undergoing magnetic resonance imaging, the incidence rates of subclinical brain embolization and any ABE were 48% and 80%, respectively. ABE was present in 18 of 19 patients (95%) with Staphylococcus aureus infection. At 3 months, mortality was similar among patients with clinical stroke and subclinical brain embolization (62% versus 53%; P=NS) and was higher among patients with any ABE than among those without ABE (56% versus 12%; P=0.046). Valvular surgery was performed in 25 patients (45%), including 16 with ABE, at a median of 4 days. No patient suffered a postoperative neurological complication. Surgery was independently associated with a lower risk of mortality at 3 months (odds ratio, 0.1; 95% confidence interval, 0.03 to 0.6; P=0.008). Conclusions— Magnetic resonance imaging detected subclinical brain embolization in a substantial number of patients with left-sided infective endocarditis, suggesting that the incidence of ABE may be significantly higher than reports based on clinical and computed tomography findings have indicated. Brain magnetic resonance imaging may play a role in the complex decision about surgical intervention in infective endocarditis.

The impact of myocardial flow reserve on the detection of coronary artery disease by perfusion imaging methods: an NHLBI WISE study.

Myocardial flow reserve (MFR) is not routinely assessed in myocardial perfusion imaging (MPI) studies but has been hypothesized to affect test accuracy when assessing disease severity by coronary vessel lumenography. Magnetic resonance imaging (MRI) is an emerging diagnostic technique that can both perform MPI and assess MFR. We studied women (n = 184) enrolled in the Womens Ischemia Syndrome Evaluation (WISE) study with symptoms suggesting ischemic heart disease. Tests performed were coronary angiography and MPI by both MR and gated radionuclide single photon emission computed tomography (gated-SPECT). The MFR index was calculated using the MR data acquired at baseline and under vasodilation (dipyridamole) conditions. The study was structured with a pilot and an implementation phase. During the pilot phase (n = 46) data were unmasked and an MFR threshold was defined to divide patients into those with an adequate (AMFRI) or inadequate (IMFRI) MFR index. During the implementation phase, the MFR index threshold was prospectively applied to patients (n = 138). In the implementation phase, MPI ischemia detection accuracy compared to severe (> or = 70%) coronary artery diameter narrowing by angiography was higher in the AMFRI vs. the IMFRI group for MRI (86% vs. 70%, p < 0.05) and gated-SPECT (89% vs. 67%, p < 0.01). The IMFRI group (n = 55, 30% of study population) had a higher resting rate-pressure product compared with the AMFRI group (10,599 +/- 2871 vs. 9378 +/- 2447 bpm mm Hg, p < 0.01), consistent with higher resting myocardial flow. When compared with each other, MRI and gated-SPECT MPI showed no difference in accuracy among MFR groups. Myocardial perfusion patterns in the IMFRI group may have resulted in atypical perfusion patterns, which either masked or mimicked epicardial coronary artery disease.

New imaging techniques for diagnosing coronary artery disease

New tomographic cardiovascular imaging tests, such as intravascular ultrasonography (IVUS), coronary computed tomography (CT) angiography and magnetic resonance imaging (MRI), can be used to assess atherosclerotic plaques for the characterization and early staging of coronary artery disease (CAD). Although IVUS images have very high resolution capable of revealing very early preclinical CAD, it is an invasive technique used clinically only in conjunction with a coronary intervention. Multiple-slice coronary CT angiography, which is noninvasive, shows promise as a diagnostic method for CAD. New 64-slice cardiac CT technology has high accuracy for the detection of lesions obstructing more than 50% of the lumen, with sensitivity, specificity, and positive and negative predictive values all better than 90% in patients without known CAD. Cardiac MRI is also improving accuracy in coronary plaque detection and offers a better opportunity for plaque characterization. With further advances in tomographic imaging of coronary atheromas, the goal will be to detect plaques earlier in the development of CAD and to characterize the plaques most likely to generate a clinical event.

Prognostic value of global MR myocardial perfusion imaging in women with suspected myocardial ischemia and no obstructive coronary disease: results from the NHLBI-sponsored WISE (Women's Ischemia Syndrome Evaluation) study.

OBJECTIVES The purpose of this study was to assess the prognostic value of global magnetic resonance (MR) myocardial perfusion imaging (MPI) in women with suspected myocardial ischemia and no obstructive (stenosis <50%) coronary artery disease (CAD). BACKGROUND The prognostic value of global MR-MPI in women without obstructive CAD remains unknown. METHODS Women (n = 100, mean age 57 ± 11 years, age range 31 to 76 years), with symptoms of myocardial ischemia and with no obstructive CAD, as assessed by coronary angiography, underwent MR-MPI and standard functional assessment. During follow-up (34 ± 16 months), time to first adverse event (death, myocardial infarction, or hospitalization for worsening anginal symptoms) was analyzed using global MPI and left ventricular ejection fraction (EF) data. RESULTS Adverse events occurred in 23 (23%) women. Using univariable Cox proportional hazards regression modeling, variables found to be predictive of adverse events were global MR-MPI average uptake slope (p < 0.05), the ratio of MR-MPI peak signal amplitude to uptake slope (p < 0.05), and EF (p < 0.05). Two multivariable Cox models were formed, 1 using variables that were performance site dependent: ratio of MR-MPI peak amplitude to uptake slope together with EF (chi square: 13, p < 0.005); and a model using variables that were performance site independent: MR-MPI slope and EF (chi square: 12, p < 0.005). Each of the 2 multivariable models remained predictive of adverse events after adjustment for age, disease history, and Framingham risk score. For each of the Cox models, patients were categorized as high risk if they were in the upper quartile of the model and as not high risk otherwise. Kaplan-Meier analysis of time to event was performed for high risk versus not high risk for site-dependent (log rank: 15.2, p < 0.001) and site-independent (log rank: 13.0, p < 001) models. CONCLUSIONS Among women with suspected myocardial ischemia and no obstructive CAD, MR-MPI-determined global measurements of normalized uptake slope and peak signal uptake, together with global functional assessment of EF, appear to predict prognosis.

Imaging cardiac structure and pump function.

This article describes magnetic resonance imaging approaches for assessing cardiac structure and myocardial pump function. The article is divided into cardiac structure and ventricular function. Throughout, representative images are included. There are numerous applications of magnetic resonance imaging for assessing cardiac structure and function, and magnetic resonance imaging compared favorably to other imaging modalities.

Mechanism of Paradoxical Ventricular Septal Motion After Coronary Artery Bypass Grafting

Paradoxical septal motion is commonly noted on echocardiography after coronary artery bypass grafting (CABG), but its mechanism is unclear. Cardiac magnetic resonance imaging was performed before and 3 months after CABG in 23 patients. On a mid-left ventricular short-axis cine image, the motion of myocardial landmarks during the cardiac cycle was ascertained relative to a stationary anterior reference point. Before CABG, the movement of the ventricular septum in systole was either posterior or neutral (median -2 mm) in 19 patients, whereas after CABG, the septum moved anteriorly in all 23 patients (+4 mm; p<0.001). (A positive sign indicates anterior motion in ventricular systole, and a negative sign denotes posterior motion.) The motion of the right ventricular free wall was reduced after CABG (-5 vs -3 mm; p=0.002), whereas anterior movement of the lateral left ventricular wall in systole increased (+4 vs +9 mm; p<0.001). There was a positive correlation between degree of anterior movement of the ventricular septum and right ventricular ejection fraction (r=0.47, p=0.023). In conclusion, after CABG, the entire left ventricle translocated anteriorly in systole. Despite preserved right ventricular function, there was restricted motion of the right ventricular free wall suggestive of postoperative adhesions. The pattern of movement observed offers a sound explanation for postoperative paradoxical septal motion.

Cardiac Magnetic Resonance Appearance of Myocarditis Caused by High Dose IL-2: Similarities to Community-Acquired Myocarditis

The purpose of this study was to describe and compare the cardiac magnetic resonance (CMR) characteristics of myocarditis caused by high dose interleukin-2 (7 patients) with community-acquired myocarditis (14 patients). A total of 21 patients with suspected myocarditis and elevated cardiac enzymes underwent cine CMR followed by delayed enhancement. The mean ejection fraction was mildly decreased in both groups. The location, pattern, and extent of DE were similar in both groups of patients. The CMR similarities between these two populations suggest that cytokine-mediated cytotoxicity may play an important role in community-acquired myocarditis.

Protecting the heart of the American Athlete: Proceedings of the American college of cardiology sports and exercise cardiology think tank October 18, 2012, Washington, DC

Yvette L. Rooks, MD, CAQ, FAAFP[1][1] G. Paul Matherne, MD, FACC[2][2] Jim Whitehead[3][3] Dan Henkel[3][3] Irfan M. Asif, MD[4][4] James C. Dreese, MD[5][5] Rory B. Weiner, MD[6][6] Barbara A. Hutchinson, MD, PhD, FACC[7][7] Linda Tavares, MS, RN, AACC[8][8] Steven Krueger, MD, FACC[9][9

Safety of gadoversetamide in patients with acute and chronic myocardial infarction

To assess the safety data from two large, multicenter, phase 2 trials on the use of gadoversetamide (OptiMARK, Tyco Healthcare/Mallinckrodt, St. Louis, MO) as a contrast agent in delayed hyperenhancement magnetic resonance imaging (DE‐MRI) in patients with acute and chronic myocardial infarction (MI).

Validation of Rapid Velocity Encoded Cine Imaging of a Dynamically Complex Flow Field Using Turbo Block Regional Interpolation Scheme for k Space

AbstractBlock regional interpolation scheme for k space (BRISK) is a sparse sampling approach to allow rapid magnetic resonance imaging of dynamic events. Rapid velocity encoded cine (VEC) imaging with Turbo BRISK is potentially an important clinical diagnostic technique for cardiovascular diseases. Previously we applied BRISK and Turbo BRISK to imaging pulsatile flow in a straight tube. To evaluate the capabilities of Turbo BRISK imaging in more complex dynamic flow fields such as might exist in the human vasculature, an in vitro curved tube model, similar in geometry to the aortic arch, was fabricated and imaged under pulsatile flow conditions. Velocity maps were obtained using conventional VEC and Turbo BRISK (turbo factors 1 through 5). Comparison of the flow fields obtained with each higher order turbo factor showed excellent agreement with conventional VEC with minimal loss of information. Similarly, flow maps showed good agreement with the profiles from a laser Doppler velocimetry model. Turbo-5 BRISK, for example, allowed a 94% savings in imaging time, reducing the conventional imaging time from over 8 min to a near breath-hold imaging period of 31 s. Turbo BRISK shows excellent promise toward the development of a clinical tool to evaluate complex dynamic intravascular flow fields.