Delayed contrast-enhanced magnetic resonance imaging for the detection of autoimmune myocarditis and long-term follow-up.

MRI proved to be a valuable tool for the evaluation and monitoring of myocarditis. We report the case of a 36 year old caucasian male with an undifferentiated collagenosis who presented first four years ago with unspecific symptoms and impaired exercise capacity. On echocardiography left ventricular function was impaired as well as on MRI. In addition, after administration of Gd-DTPA an intramyocardial pathological signal enhancement was observed on TSE T1 weighted and contrast enhanced FLASH 3D IR sequences. Based on several diagnostic tests including myocardial biopsy an autoimmune myocarditis due to an undifferentiated collagenosis was diagnosed. On long time follow up over almost 3 years with repeated MRI examinations, the delayed hyper enhancement (dHE) decreased or disappeared with successful treatment, respectively. However, in the area of recurrent inflammation, a persisting area of dHE developed with a subsequent perfusion defect. This area represents myocardial fibrosis due to recurrent inflammation.

Intracoronary autologous bone-marrow cell transfer after myocardial infarction: the BOOST randomised controlled clinical trial.

BACKGROUND: Emerging evidence suggests that stem cells and progenitor cells derived from bone marrow can be used to improve cardiac function in patients after acute myocardial infarction. In this randomised trial, we aimed to assess whether intracoronary transfer of autologous bone-marrow cells could improve global left-ventricular ejection fraction (LVEF) at 6 months' follow-up. METHODS: After successful percutaneous coronary intervention (PCI) for acute ST-segment elevation myocardial infarction, 60 patients were randomly assigned to either a control group (n=30) that received optimum postinfarction medical treatment, or a bone-marrow-cell group (n=30) that received optimum medical treatment and intracoronary transfer of autologous bone-marrow cells 4.8 days (SD 1.3) after PCI. Primary endpoint was global left-ventricular ejection fraction (LVEF) change from baseline to 6 months' follow-up, as determined by cardiac MRI. Image analyses were done by two investigators blinded for treatment assignment. Analysis was per protocol. FINDINGS: Global LVEF at baseline (determined 3.5 days [SD 1.5] after PCI) was 51.3 (9.3%) in controls and 50.0 (10.0%) in the bone-marrow cell group (p=0.59). After 6 months, mean global LVEF had increased by 0.7 percentage points in the control group and 6.7 percentage points in the bone-marrow-cell group (p=0.0026). Transfer of bone-marrow cells enhanced left-ventricular systolic function primarily in myocardial segments adjacent to the infarcted area. Cell transfer did not increase the risk of adverse clinical events, in-stent restenosis, or proarrhythmic effects. INTERPRETATION: Intracoronary transfer of autologous bone-marrow-cells promotes improvement of left-ventricular systolic function in patients after acute myocardial infarction.

Pulmonary vein diameter reduction after radiofrequency catheter ablation for paroxysmal atrial fibrillation evaluated by contrast-enhanced three-dimensional magnetic resonance imaging.

BACKGROUND: Radiofrequency catheter ablation (RFCA) is a promising intervention to treat atrial fibrillation. However, pulmonary vein (PV) stenosis after RFCA has been reported. The aim of this study was to investigate the incidence and time course of pulmonary vein stenosis after RFCA within a period of 3 months. Contrast-enhanced magnetic resonance angiography (MRA) was used to visualize pulmonary veins and was compared with radiographic angiography. METHODS AND RESULTS: Forty-six consecutive patients with symptomatic paroxysmal atrial fibrillation had RFCA in the orifice of 138 pulmonary veins. Comparison of diameters measured in 44 untreated vessels either by radiographic angiography or with MRA established the reliability of MRA (r=0.934). MRA measurements revealed an incidence of relevant diameter reductions of > or =25% or stenosis of > or =50% after RFCA of 25 of 138 (18.1%) treated vessels 1 day and/or 3 months after ablation. A progression of diameter reduction after RFCA was observed in 8.3% (maximum 75%), whereas a regression was observed in 6.3% of treated PVs. Ablation at a radial angle of >180 degrees of a pulmonary vein orifice increased the risk of diameter reduction significantly compared with ablation at a radial angle < or =180 degrees (P=0.002). CONCLUSIONS: The occurrence and progression of PV stenosis is a potential significant complication of RFCA in the orifice of pulmonary veins. These findings may have an impact on the technical performance of this intervention. In addition, long-term studies will be necessary to evaluate lumen reduction over time. MRA is a noninvasive, reproducible imaging modality for this purpose.