Objectives The objective of this study was to test the hypothesis that gastric bypass surgery (GBS) would favorably impact cardiac remodeling and function. Background GBS is increasingly used to treat severe obesity, but there are limited outcome data. Methods We prospectively studied 423 severely obese patients undergoing GBS and a reference group of severely obese subjects that did not have surgery (n = 733). Results At a 2-year follow up, GBS subjects had a large reduction in body mass index compared with the reference group (−15.4 ± 7.2 kg/m2 vs. −0.03 ± 4.0 kg/m2; p < 0.0001), as well as significant reductions in waist circumference, systolic blood pressure, heart rate, triglycerides, low-density lipoprotein cholesterol, and insulin resistance. High-density lipoprotein cholesterol increased. The GBS group had reductions in left ventricular (LV) mass index and right ventricular (RV) cavity area. Left atrial volume did not change in GBS but increased in reference subjects. In conjunction with reduced chamber sizes, GBS subjects also had increased LV midwall fractional shortening and RV fractional area change. In multivariable analysis, age, change in body mass index, severity of nocturnal hypoxemia, E/E', and sex were independently associated with LV mass index, whereas surgical status, change in waist circumference, and change in insulin resistance were not. Conclusions Marked weight loss in patients undergoing GBS was associated with reverse cardiac remodeling and improved LV and RV function. These data support the use of bariatric surgery to prevent cardiovascular complications in severe obesity.

Objectives We hypothesized that arterial spin labeling (ASL) magnetic resonance imaging (MRI) at 3 Tesla (T) would be a reliable non-contrast technique for measuring peak exercise calf muscle blood flow in both healthy volunteers and patients with peripheral arterial disease (PAD) and will discriminate between these groups. Background Prior work demonstrated the utility of first-pass gadolinium-enhanced calf muscle perfusion MRI in patients with PAD. However, patients with PAD often have advanced renal disease and cannot receive gadolinium. Methods PAD patients had claudication and an ankle brachial index 0.4–0.9. Age-matched normal subjects (NL) had no PAD risk factors and were symptom-free with exercise. All performed supine plantar flexion exercise in a 3T MRI scanner using a pedal ergometer until exhaustion or limiting symptoms and were imaged at peak exercise with 15 averaged ASL images. Peak perfusion was measured from ASL blood flow images by placing a region of interest in the calf muscle region with the greatest signal intensity. Perfusion was compared between PAD and NL and repeat testing was performed in 12 subjects (5 NL, 7 PAD) for assessment of reproducibility. Results Peak exercise calf perfusion (mean±SD) of 15 NL (age 54±9 years) was higher than in 15 PAD (age 64±5 years, ABI 0.70±0.14) (80±23mL/min-100g vs. 49±16mL/min-100g, p<0.001). Five NL performed exercise matched to PAD and again demonstrated higher perfusion (84±25mL/min-100g, p<0.002). As a measure of reproducibility, intra-class correlation coefficient between repeated studies was 0.87 (95% CI 0.61–0.96). Inter-observer reproducibility was 0.96 (95% CI 0.84–0.99). Conclusions ASL is a reproducible non-contrast technique for quantifying peak exercise blood flow in calf muscle. Independent of exercise time, ASL discriminates between NL and PAD. This technique may prove useful for clinical trials of therapies for improving muscle perfusion, especially in patients unable to receive gadolinium.

Cardiotoxicity due to administration of cancer therapeutic agents such as anthracyclines and herceptin are well described. Established guidelines to screen for chemotherapy-related cardiotoxicity (CRC) are primarily based on serial assessment of left ventricular (LV) ejection fraction (EF). However, other parameters such as LV volume, diastolic function, and strain may also be useful in screening for cardiotoxicity. More recent advances in molecular imaging of apoptosis and tissue characterization by cardiac MRI are techniques which might allow early detection of patients at high risk for developing cardiotoxicity prior to a drop in EF. This comprehensive multi-modality review will discuss both the current established imaging techniques as well as the emerging technologies which may revolutionize the future of screening and evaluation for CRC.