Comprehensive Cardiac Magnetic Resonance Imaging in Patients With Suspected Myocarditis: The MyoRacer-Trial.

BACKGROUND: Data suggest that T1 and T2 mapping have excellent diagnostic accuracy in patients with suspected myocarditis. However, the true diagnostic performance of comprehensive cardiac magnetic resonance (CMR) mapping versus endomyocardial biopsy (EMB) has not been determined. OBJECTIVES: This study assessed the performance of CMR imaging, including T1 and T2 mapping, compared with EMB in an unselected, consecutive patient cohort with suspected myocarditis. It also examined the potential role of CMR field strength by comparing 1.5-T versus 3.0-T imaging. METHODS: Patients underwent biventricular EMB, cardiac catheterization (for exclusion of coronary artery disease), and CMR imaging on 1.5- and 3-T scanners. The CMR protocol included current standard Lake Louise criteria (LLC) for myocarditis as well as native T1, calculation of extracellular volume fraction (ECV), and T2 mapping (only on 1.5-T). Patients were divided into 2 groups according to symptom duration (acute: ≤14 days vs. chronic: >14 days). RESULTS: A total of 129 patients underwent 1.5-T imaging. In patients with acute symptoms, native T1 yielded the best diagnostic performance as defined by the area under the curve (AUC) of receiver-operating curves (0.82) followed by T2 (0.81), ECV (0.75), and LLC (0.56). In patients with chronic symptoms, only T2 mapping yielded an acceptable AUC (0.77). On 3.0-T, AUCs of native T1, ECV, and LLC were comparable to 1.5-T with no significant differences. CONCLUSIONS: In patients with acute symptoms, mapping techniques provide a useful tool for confirming or rejecting the diagnosis of myocarditis and are superior to the LLC. However, only T2 mapping has acceptable diagnostic performance in patients with chronic symptoms. (Magnetic Resonance Imaging in Myocarditis [MyoRacer]; NCT02177630).

Outbreak of Ralstonia pickettii bacteremia in a neonatal intensive care unit.

BACKGROUND: Ralstonia pickettii is a Gram-negative bacillus commonly found in soil and moist environments; however, R. pickettii is rarely isolated from clinical specimens. In August 2001, a cluster of R. pickettii bacteremia occurred among neonatal intensive care unit (NICU) infants at a California hospital. METHODS: A case-control study was conducted to determine risk factors for infection. A case was a NICU patient with R. pickettii bacteremia. Controls were NICU infants with negative blood cultures drawn during the same time period. A detailed environmental investigation was also conducted. RESULTS: We identified 18 patients with 19 distinct episodes of R. pickettii bacteremia from July 30 through August 30, 2001. All cases had intravascular access at the time of bacteremia. Although the case-control study did not implicate any statistically significant risk factors, the most likely source of the outbreak was the heparin flush prepared in the hospital pharmacy. This is supported by the following: (1) the heparin flush was the only substance introduced directly into the bloodstream of all case infants; (2) the heparin flush was used exclusively by the NICU; and (3) no further cases were identified after the heparin flush was discontinued. Cultures of remaining heparin flush and environmental cultures from the NICU were negative for R. pickettii. CONCLUSIONS: This unusual outbreak of R. pickettii bacteremia was most likely caused by contaminated heparin flush and ended after the heparin flush was discontinued.