Percutaneous intervention in peripheral artery disease improves calf muscle phosphocreatine recovery kinetics: a pilot study.

We hypothesized that percutaneous intervention in the affected lower extremity artery would improve calf muscle perfusion and cellular metabolism in patients with claudication and peripheral artery disease (PAD) as measured by magnetic resonance imaging (MRI) and spectroscopy (MRS). Ten patients with symptomatic PAD (mean ± SD: age 57 ± 9 years; ankle-brachial index (ABI) 0.62 ± 0.17; seven males) were studied 2 months before and 10 months after lower extremity percutaneous intervention. Calf muscle phosphocreatine recovery time constant (PCr) in the revascularized leg was measured by (31)P MRS immediately after symptom-limited exercise on a 1.5-T scanner. Calf muscle perfusion was measured using first-pass gadolinium-enhanced MRI at peak exercise. A 6-minute walk and treadmill test were performed. The PCr recovery time constant improved significantly following intervention (91 ± 33 s to 52 ± 34 s, p < 0.003). Rest ABI also improved (0.62 ± 0.17 to 0.93 ± 0.25, p < 0.003). There was no difference in MRI-measured tissue perfusion or exercise parameters, although the study was underpowered for these endpoints. In conclusion, in this pilot study, successful large vessel percutaneous intervention in patients with symptomatic claudication, results in improved ABI and calf muscle phosphocreatine recovery kinetics.

Strength and Motion in the Shoulder, Elbow, and Hip in Softball Windmill Pitchers.

BACKGROUND: Softball pitching is a ballistic, complex movement that requires an underhand windmill motion to create force and ball velocity. In addition to proper pitch biomechanics, upper and lower extremity strength and joint motion likely contribute to ball location accuracy and velocity. Yet, the number of studies reporting muscle strength and joint range of motion among softball pitchers is scarce. OBJECTIVE: To assess differences between throwing and nonthrowing shoulder, elbow, and hip (lead and trail leg) strength and range of motion (ROM) in high school and collegiate level softball windmill pitchers. DESIGN: Cross-sectional study. PARTICIPANTS: Thirty-three female softball pitchers (24 high school, 9 collegiate) were recruited from local teams. METHODS: Goniometric joint ROM and handheld dynamometer strength measurements of the bilateral shoulders, elbows, and hips were measured. MAIN OUTCOME MEASUREMENTS: Goniometric joint ROM of the bilateral elbows (flexion, extension), shoulders, and hips (flexion, extension, internal rotation [IR], external rotation [ER]). Handheld dynamometer strength measurements of the bilateral shoulders (flexion, extension, abduction, IR, ER), elbows (flexion, extension), and hips (flexion, extension, IR, ER, abduction). RESULTS: Across all pitchers, there was greater shoulder flexion ROM in the nonthrowing limb than in the throwing limb (P = .004). There was greater hip extension in the lead leg than trail leg. Among high school pitchers, there was greater shoulder ER (x = 105.792 ± 7.11) than collegiate pitchers (x = 100.1 ± 6.92), P = .05. There was no difference in total arc of shoulder rotational motion (ER+ IR) between throwing and nonthrowing limbs across all pitchers, nor between high school and collegiate pitchers. Strength measures demonstrated greater throwing limb shoulder abduction (P = .006) and IR strength (P = .001) than the nonthrowing shoulder across all pitchers. Elbow flexion strength was significantly greater than the nonthrowing side (P = .001). No difference was noted in hip strength between lead and trail lower extremities. CONCLUSIONS: Developing normative data for softball pitchers upper and lower extremity strength and range of motion may allow providers to assess players more comprehensively and identify athletes out of the expected value range. This information may help in guiding strength and conditioning programs for softball pitchers. LEVEL OF EVIDENCE: III.

Diagnostic Accuracy of Magnetic Resonance Imaging and Computed Tomography Scan in Young Athletes With Spondylolysis.

The objective of this study was to determine diagnostic accuracy of magnetic resonance imaging (MRI) and computed tomography (CT) scans in young athletes diagnosed with spondylolysis. A cross-sectional study was used. Twenty-two young athletes (14.7 ± 1.5 years) were diagnosed as spondylolysis based on a single-photon emission CT. Following the diagnosis, participants underwent MRI and CT scan imaging tests on the same day. The sensitivity and false-negative rate of the MRI and CT scans were analyzed. MRI test confirmed 13 (+) and 9 (-) results while CT test showed 17 (+) and 5 (-) results. The sensitivity and false-negative rate of MRI were, respectively, 59.1% (95% confidence interval [CI] = 36.7% to 78.5%) and 40.9% (95% CI = 21.5% to 63.3%). Furthermore, the sensitivity and false-negative rate of CT scan were 77.3% (95% CI = 54.2% to 91.3%) and 22.7% (95% CI = 0.09% to 45.8%). Our results indicated that CT scan is a more accurate imaging modality to diagnose spondylolysis compared with MRI in young athletes.

Unusual Iliac Crest Stress Fracture in a Marathoner: A Case Presentation.

This case presentation describes a 50-year-old healthy woman who developed left-sided hip pain while training for the Boston Marathon. Magnetic resonance imaging demonstrated a stress fracture of the left iliac body. This injury was unique in that it did not occur in the setting of low bone mineral density and it did not fall into the current published radiographic categorization based on location of injury. This case illustrates an uncommon and atypical bone stress injury in an endurance athlete. It should be considered in the differential diagnosis of runners presenting with hip or lumbopelvic pain. LEVEL OF EVIDENCE: V.

The effects of preoperative, video-assisted anesthesia education in Spanish on Spanish-speaking patients' anxiety, knowledge, and satisfaction: a pilot study.

We studied the effect of an instructional video in Spanish on self-reported anxiety, knowledge about general anesthesia procedures, and satisfaction with the preoperative anesthesia process in patients requiring a Spanish interpreter. This prospective, randomized, nonblinded pilot study took place at Massachusetts General Hospital (MGH), a university-affiliated tertiary-care hospital. Twenty adult, ASA physical status 1, 2, and 3 patients, scheduled for elective surgery (gynecological, orthopedic, and intrabdominal surgery) during general anesthesia were studied. Anxiety, knowledge, and patient satisfaction were assessed using a visual analog scale (VAS). There was a significant reduction in anxiety score in patients who viewed the video compared with those who did not (median reduction 2 vs 0; P = 0.020). There was an increase in satisfaction score in the video group (median increase 2 vs 0; P = 0.046). There was no difference in reported knowledge-improvement scores between the two groups (3.5 vs 4; P = 0.908). In Spanish-speaking patients, the addition of an instructional video in Spanish to a preanesthesia interview decreased anxiety and increased patient satisfaction.

Low-density lipoprotein lowering does not improve calf muscle perfusion, energetics, or exercise performance in peripheral arterial disease.

OBJECTIVES: We hypothesized that low-density lipoprotein (LDL) reduction regardless of mechanism would improve calf muscle perfusion, energetics, or walking performance in peripheral arterial disease (PAD) as measured by magnetic resonance imaging and magnetic resonance spectroscopy. BACKGROUND: Statins improve cardiovascular outcome in PAD, and some studies suggest improved walking performance. METHODS: Sixty-eight patients with mild to moderate symptomatic PAD (age 65 ± 11 years; ankle-brachial index [ABI] 0.69 ± 0.14) were studied at baseline and annually for 2 years after beginning simvastatin 40 mg (n = 20) or simvastatin 40 mg/ezetimibe 10 mg (n = 18) if statin naïve, or ezetimibe 10 mg (n = 30) if taking a statin. Phosphocreatine recovery time was measured by (31)P magnetic resonance spectroscopy immediately after symptom-limited calf exercise on a 1.5-T scanner. Calf perfusion was measured using first-pass contrast-enhanced magnetic resonance imaging with 0.1 mM/kg gadolinium at peak exercise. Gadolinium-enhanced magnetic resonance angiography was graded. A 6-min walk and a standardized graded Skinner-Gardner exercise treadmill test with peak Vo(2) were performed. A repeated-measures model compared changes over time. RESULTS: LDL reduction from baseline to year 2 was greater in the simvastatin 40 mg/ezetimibe 10 mg group (116 ± 42 mg/dl to 56 ± 21 mg/dl) than in the simvastatin 40 mg group (129 ± 40 mg/dl to 90 ± 30 mg/dl, p < 0.01). LDL also decreased in the ezetimibe 10 mg group (102 ± 28 mg/dl to 79 ± 27 mg/dl, p < 0.01). Despite this, there was no difference in perfusion, metabolism, or exercise parameters between groups or over time. Resting ABI did improve over time in the ezetimibe 10 mg group and the entire study group of patients. CONCLUSIONS: Despite effective LDL reduction in PAD, neither tissue perfusion, metabolism, nor exercise parameters improved, although rest ABI did. Thus, LDL lowering does not improve calf muscle physiology or functional capacity in PAD. (Comprehensive Magnetic Resonance of Peripheral Arterial Disease; NCT00587678).

The effect of ezetimibe on peripheral arterial atherosclerosis depends upon statin use at baseline.

BACKGROUND: Both statins and ezetimibe lower LDL-C, but ezetimibe's effect on atherosclerosis is controversial. We hypothesized that lowering LDL-C cholesterol by adding ezetimibe to statin therapy would regress atherosclerosis measured by magnetic resonance imaging (MRI) in the superficial femoral artery (SFA) in peripheral arterial disease (PAD). METHODS: Atherosclerotic plaque volume was measured in the proximal 15-20 cm of the SFA in 67 PAD patients (age 63 ± 10, ABI 0.69 ± 0.14) at baseline and annually × 2. Statin-naïve patients (n=34) were randomized to simvastatin 40 mg (S, n=16) or simvastatin 40 mg+ezetimibe 10mg (S+E, n=18). Patients already on statins but with LDL-C >80 mg/dl had open-label ezetimibe 10mg added (E, n=33). Repeated measures models estimated changes in plaque parameters over time and between-group differences. RESULTS: LDL-C was lower at year 1 in S+E (67 ± 7 mg/dl) than S (91 ± 8 mg/dl, p<0.05), but similar at year 2 (68 ± 10 mg/dl vs. 83 ± 11 mg/dl, respectively). Plaque volume did not change from baseline to year 2 in either S+E (11.5 ± 1.4-10.5 ± 1.3 cm(3), p=NS) or S (11.0 ± 1.5-10.5 ± 1.4 cm(3), p=NS). In E, plaque progressed from baseline to year 2 (10.0 ± 0.8-10.8 ± 0.9, p<0.01) despite a 22% decrease in LDL-C. CONCLUSIONS: Statin initiation with or without ezetimibe in statin-naïve patients halts progression of peripheral atherosclerosis. When ezetimibe is added to patients previously on statins, peripheral atherosclerosis progressed. Thus, ezetimibe's effect on peripheral atherosclerosis may depend upon relative timing of statin therapy.

Cardiovascular magnetic resonance imaging of myocardial infarction, viability, and cardiomyopathies.

Cardiovascular magnetic resonance provides the opportunity for a truly comprehensive evaluation of patients with a history of myocardial infarction, with regard to characterizing the extent of disease, effect on left ventricular function, and degree of viable myocardium. The use of contrast-enhanced cardiac magnetic resonance (CMR) imaging for first-pass perfusion and late gadolinium enhancement is a powerful technique for delineating areas of myocardial ischemia and infarction. Using a combination of T2-weighted and contrast-enhanced CMR images, information about the acuity of an infarct can be obtained. There is extensive published data using contrast-enhanced CMR to predict myocardial functional recovery with revascularization in patients with ischemic cardiomyopathies. In addition, CMR imaging in patients with cardiomyopathies can distinguish between ischemic and nonischemic etiologies, with the ability to further characterize the underlying pathology of nonischemic cardiomyopathies.

Assessment of advanced coronary artery disease: advantages of quantitative cardiac magnetic resonance perfusion analysis.

OBJECTIVES: The purpose of this paper was to compare quantitative cardiac magnetic resonance (CMR) first-pass contrast-enhanced perfusion imaging to qualitative interpretation for determining the presence and severity of coronary artery disease (CAD). BACKGROUND: Adenosine CMR can detect CAD by measuring perfusion reserve (PR) or by qualitative interpretation (QI). METHODS: Forty-one patients with an abnormal nuclear stress scheduled for X-ray angiography underwent dual-bolus adenosine CMR. Segmental myocardial perfusion analyzed using both QI and PR by Fermi function deconvolution was compared to quantitative coronary angiography. RESULTS: In the 30 patients with complete quantitative data, PR (mean +/- SD) decreased stepwise as coronary artery stenosis (CAS) severity increased: 2.42 +/- 0.94 for <50%, 2.14 +/- 0.87 for 50% to 70%, and 1.85 +/- 0.77 for >70% (p < 0.001). The PR and QI had similar diagnostic accuracies for detection of CAS >50% (83% vs. 80%), and CAS >70% (77% vs. 67%). Agreement between observers was higher for quantitative analysis than for qualitative analysis. Using PR, patients with triple-vessel CAD had a higher burden of detectable ischemia than patients with single-vessel CAD (60% vs. 25%; p = 0.02), whereas no difference was detected by QI (31% vs. 21%; p = 0.26). In segments with myocardial scar (n = 64), PR was 3.10 +/- 1.34 for patients with CAS <50% (n = 18) and 1.91 +/- 0.96 for CAS >50% (p < 0.0001). CONCLUSIONS: Quantitative PR by CMR differentiates moderate from severe stenoses in patients with known or suspected CAD. The PR analysis differentiates triple- from single-vessel CAD, whereas QI does not, and determines the severity of CAS subtending myocardial scar. This has important implications for assessment of prognosis and therapeutic decision making.

Noninvasive imaging of the heart and coronary arteries.

There are multiple imaging modalities currently available to noninvasively evaluate the heart and coronary arteries. Choosing the most appropriate modality depends on the pertinent clinical question and the underlying patient characteristics. This article provides an overview of the fields of echocardiography, myocardial perfusion imaging, cardiac computed tomography, and cardiac magnetic resonance imaging, with particular attention to specific clinical applications for cardiac surgery patients.

Multifactorial determinants of functional capacity in peripheral arterial disease: uncoupling of calf muscle perfusion and metabolism.

OBJECTIVES: We aimed to investigate the pathophysiology of peripheral arterial disease (PAD) by examining magnetic resonance imaging (MRI) and spectroscopic (MRS) correlates of functional capacity. BACKGROUND: Despite the high prevalence, morbidity, and cost of PAD, its pathophysiology is incompletely understood. METHODS: Eighty-five patients (age 68 +/- 10 years) with mild-to-moderate PAD (ankle-brachial index 0.69 +/- 0.14) had their most symptomatic leg studied by MRI/MRS. Percent wall volume in the superficial femoral artery was measured with black blood MRI. First-pass contrast-enhanced MRI calf muscle perfusion and (31)P MRS phosphocreatine recovery time constant (PCr) were measured at peak exercise in calf muscle. All patients underwent magnetic resonance angiography (MRA), treadmill testing with maximal oxygen consumption measurement, and a 6-min walk test. RESULTS: Mean MRA index of number and severity of stenoses was 0.84 +/- 0.68 (normal 0), % wall volume 74 +/- 11% (normal 46 +/- 7%), tissue perfusion 0.039 +/- 0.015 s(-1) (normal 0.065 +/- 0.013 s(-1)), and PCr 87 +/- 54 s (normal 34 +/- 16 s). MRA index, % wall volume, and ankle-brachial index correlated with most functional measures. PCr was the best correlate of treadmill exercise time, whereas calf muscle perfusion was the best correlate of 6-min walk distance. No correlation was noted between PCr and tissue perfusion. CONCLUSIONS: Functional limitations in PAD are multifactorial. As measured by MRI and spectroscopy, atherosclerotic plaque burden, stenosis severity, tissue perfusion, and energetics all play a role. However, cellular metabolism is uncoupled from tissue perfusion. These findings suggest a potential role for therapies that regress plaque, increase tissue perfusion, and/or improve cellular metabolism. (Comprehensive Magnetic Resonance of Peripheral Arterial Disease; NCT00587678).