Progression of human carotid and femoral atherosclerosis: a prospective follow-up study by magnetic resonance vessel wall imaging.

AIMS: The time course of atherosclerosis burden in distinct vascular territories remains poorly understood. We longitudinally evaluated the natural history of atherosclerotic progression in two different arterial territories using high spatial resolution magnetic resonance imaging (HR-MRI), a powerful, safe, and non-invasive tool. METHODS AND RESULTS: We prospectively studied a cohort of 30 patients (mean age 68.3, n = 9 females) with high Framingham general cardiovascular disease 10-year risk score (29.5%) and standard medical therapy with mild-to-moderate atherosclerosis intra-individually at the level of both carotid and femoral arteries. A total of 178 HR-MRI studies of carotid and femoral arteries performed at baseline and at 1- and 2-year follow-up were evaluated in consensus reading by two experienced readers for lumen area (LA), total vessel area (TVA), vessel wall area (VWA = TVA - LA), and normalized wall area index (NWI = VWA/TVA). At the carotid level, LA decreased (-3.19%/year, P = 0.018), VWA increased (+3.83%/year, P = 0.019), and TVA remained unchanged. At the femoral level, LA remained unchanged, VWA and TVA increased (+5.23%/year and +3.11%/year, both P < 0.01), and NWI increased for both carotid and femoral arteries (+2.28%/year, P = 0.01, and +1.8%/year, P = 0.033). CONCLUSION: The atherosclerotic burden increased significantly in both carotid and femoral arteries. However, carotid plaque progression was associated with negative remodelling, whereas the increase in femoral plaque burden was compensated by positive remodelling. This finding could be related to anatomic and flow differences and/or to the distinct degree of obstruction in the two arterial territories.

Prospective, intraindividual comparison of MRI versus MDCT for endoleak detection after endovascular repair of abdominal aortic aneurysms.

This study compares MRI and MDCT for endoleak detection after endovascular repair of abdominal aortic aneurysms (EVAR). Forty-three patients with previous EVAR underwent both MRI (2D T1-FFE unenhanced and contrast-enhanced; 3D triphasic contrast-enhanced) and 16-slice MDCT (unenhanced and biphasic contrast-enhanced) within 1 week of each other for endoleak detection. MRI was performed by using a high-relaxivity contrast medium (gadobenate dimeglumine, MultiHance). Two blinded, independent observers evaluated MRI and MDCT separately. Consensus reading of MRI and MDCT studies was defined as reference standard. Sensitivity, specificity, and accuracy were calculated and Cohen's k statistics were used to estimate agreement between readers. Twenty endoleaks were detected in 18 patients at consensus reading (12 type II and 8 indeterminate endoleaks). Sensitivity, specificity, and accuracy for endoleak detection were 100%, 92%, and 96%, respectively, for reader 1 (95%, 81%, 87% for reader 2) for MRI and 55%, 100%, and 80% for reader 1 (60%, 100%, 82% for reader 2) for MDCT. Interobserver agreement was excellent for MDCT (k = 0.96) and good for MRI (k = 0.81). MRI with the use of a high-relaxivity contrast agent is significantly superior in the detection of endoleaks after EVAR compared with MDCT. MRI may therefore become the preferred technique for patient follow-up after EVAR.

A phase I-II study to determine the maximum tolerated infusion rate of rituximab with special emphasis on monitoring the effect of rituximab on cardiac function.

PURPOSE: This phase I infusion rate escalation trial was undertaken to evaluate the maximum applicable infusion rate for rituximab without steroid premedication in patients having received one previous rituximab infusion. EXPERIMENTAL DESIGN: Cohorts of at least three patients were assigned to rituximab with or without concomitant chemotherapy. The initial infusion rate was 200 mg/h in the first cohort, and was increased by 100 mg/h in each subsequent cohort to a maximum of 700 mg/h. In each patient the infusion rate was increased by 100 mg/h every 30 minutes to the total dose (375 mg/m2). In the first six cohorts (21 patients), two well-tolerated rituximab administrations were required; in the 7th cohort (11 patients) one previously well-tolerated rituximab infusion was required. Patients did not receive steroid premedication and were monitored with electrocardiograms (ECG), echocardiograms, Holter ECGs, troponin, and brain natriuretic peptide (BNP). RESULTS: Thirty-two patients were included and 128 cycles were done, 85 at a rate of 700 mg/h. Patients tolerated infusion rates without major side effects. There were no new clinically relevant ECG alterations. Troponin (< 0.1 ng/L) and mean cardiac ejection fraction (65%) remained in the reference range; BNP baseline level increased significantly 24 hours after rituximab administration (from 30.4 to 64.1 ng/L; P < 0.0001). CONCLUSIONS: Rituximab can be administered safely at 700 mg/h without steroid premedication in patients having received at least one rituximab dose in the previous 3 months.