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6408 citation(s) found for "Ma, Christopher".

Outcome of 622 Adults With Asymptomatic, Hemodynamically Significant Aortic Stenosis During Prolonged Follow-Up
Pellikka, Patricia A. , Malouf, Joseph F., Bailey, Kent R. , Scott, Christopher G. , Barnes, Marion E. , Tajik, A. Jamil , Enriquez‐Sarano, Maurice , Nishimura, Rick A. , Scott, Christopher , Pellikka, Patricia A , Enriquez-Sarano, Maurice

Mayo Clinic

Circulation | June 14, 2005 | Volume: 111 | Issue: 24 | Pages: 3290-3295

10.1161/circulationaha.104.495903 | PMID 15956131 Get It

Background— This study assessed the long-term outcome of a large, asymptomatic population with hemodynamically significant aortic stenosis (AS). Methods and Results— We identified 622 patients with isolated, asymptomatic AS and peak systolic velocity ≥4 m/s by Doppler echocardiography who did not undergo surgery at the initial evaluation and obtained follow-up (5.4±4.0 years) in all. Mean age (±SD) was 72±11 years; there were 384 (62%) men. The probability of remaining free of cardiac symptoms while unoperated was 82%, 67%, and 33% at 1, 2, and 5 years, respectively. Aortic valve area and left ventricular hypertrophy predicted symptom development. During follow-up, 352 (57%) patients were referred for aortic valve surgery and 265 (43%) patients died, including cardiac death in 117 (19%). The 1-, 2-, and 5-year probabilities of remaining free of surgery or cardiac death were 80%, 63%, and 25%, respectively. Multivariate predictors of all-cause mortality were age (hazard ratio [HR], 1.05; P <0.0001), chronic renal failure (HR, 2.41; P =0.004), inactivity (HR, 2.00; P =0.001), and aortic valve velocity (HR, 1.46; P =0.03). Sudden death without preceding symptoms occurred in 11 (4.1%) of 270 unoperated patients. Patients with peak velocity ≥4.5 m/s had a higher likelihood of developing symptoms (relative risk, 1.34) or having surgery or cardiac death (relative risk, 1.48). Conclusions— Most patients with asymptomatic, hemodynamically significant AS will develop symptoms within 5 years. Sudden death occurs in ≈1%/y. Age, chronic renal failure, inactivity, and aortic valve velocity are independently predictive of all-cause mortality.
Barriers to Diabetes Education in Urban Patients Perceptions, Patterns, and Associated Factors
Rhee, Mary K. , El‐Kebbi, Imad M., Lyles, Robert H. , Dunbar, Virginia G., Panayioto, Rita M., Berkowitz, Kathy J., Boyd, Barbara, Broussard, Sandra, Cook, Curtiss B. , George, Christopher D.

Mayo Clinic

The Diabetes Educator | May 25, 2005 | Volume: 31 | Issue: 3 | Pages: 410-417

10.1177/0145721705277022 | PMID 15919641 Get It

Purpose This study explored patients’ perceptions of barriers to diabetes education among a mostly African American population of adults with diabetes. Methods A survey was conducted among 605 new patients attending an urban outpatient diabetes clinic. The questionnaire gathered information on issues patients believed would adversely affect their ability to learn about diabetes. The type and frequency of education barriers were evaluated, and variables associated with reporting an obstacle were analyzed. Results Average patient age was 50 years, diabetes duration was 5.6 years, body mass index was 32 kg/m2, and hemoglobin A1C was 9.1%. The majority (56%) were women, 89% were African American, and 95% had type 2 diabetes. Most respondents (96%) had received some prior instruction in diabetes care; however, 53% anticipated future difficulties learning about diabetes. The most commonly cited concerns were poor vision (74%) and reading problems (29%). Patients with a perceived barrier to diabetes education were older (P < .001) than were persons without a barrier, and they differed in both employment and educational status (both P < .001). In adjusted analyses, older age, male gender, being disabled, and having an elementary education or less were associated with a significantly increased likelihood of having a barrier to diabetes education, whereas having a college education decreased the odds. Higher hemoglobin A1C levels also tended to be associated with a greater chance of reporting an education barrier (P = .05). Conclusions A substantial number of persons anticipated a barrier to diabetes education. Interventions at multiple levels that address the demographic and socioeconomic obstacles to diabetes education are needed to ensure successful self-management training.
B-Type Natriuretic Peptide in Organic Mitral Regurgitation
Détaint, Delphine, Messika–Zeitoun, David , Scott, Christopher G. , Chen, Horng, Burnett, John C. , Aviérinos, Jean-François , Enriquez‐Sarano, Maurice , Scott, Christopher , Enriquez-Sarano, Maurice , Messika-Zeitoun, David

Mayo Clinic

Circulation | May 9, 2005 | Volume: 111 | Issue: 18 | Pages: 2391-2397

10.1161/01.cir.0000164269.80908.9d | PMID 15883225 Get It

Background— B-type natriuretic peptide (BNP) activation observed in cardiac diseases is a predictor of poor outcome; however, in organic mitral regurgitation (MR), BNP determinants and prognostic value are unknown. Methods and Results— We prospectively enrolled 124 patients with chronic organic MR (aged 63±15 years, 60% males) in whom we measured BNP level and simultaneously quantified MR degree, left ventricular (LV) remodeling, and left atrial (LA) volumes and analyzed long-term outcome. Baseline BNP level (54±67 pg/mL, median 31 pg/mL) was associated univariately with multiple clinical and echocardiographic characteristics, but in multivariate analysis, independent determinants of BNP, beyond age and sex (both P ≤0.01), were LV end-systolic volume index, LA volume, atrial fibrillation, and symptoms (all P <0.02). Conversely, MR degree was not independently associated with BNP. During follow-up, patients with high versus low BNP (≥31 versus <31 pg/mL) displayed lower survival rates (at 5 years, 72±10% versus 95±5%, P =0.03) and higher rates of the combined end point of death and heart failure (at 5 years, 42±10% versus 16±7%, P =0.03). In multivariate analysis, with adjustment for age, sex, functional class, MR severity, and ejection fraction, BNP was independently predictive of mortality (hazard ratio per 10 pg/mL, 1.23 [95% CI 1.07 to 1.48], P =0.004) and of death or heart failure (hazard ratio per 10 pg/mL, 1.09 [95% CI 1.001 to 1.19], P =0.04). Conclusions— BNP activation in organic MR reflects primarily ventricular and atrial consequences rather than degree of MR. Higher BNP level in patients with organic MR independently predicts adverse events under conservative management. Therefore, BNP activation in organic MR is an emerging biomarker of severity of MR consequences and of poor clinical outcome, and its assessment should be considered in the clinical evaluation and risk stratification of patients with MR.
Recent advances in medical imaging: Surgery planning and simulation
McEwan, Christopher, Fukuta, Keizo

Mayo Clinic

World Journal of Surgery | May 8, 2005 | Volume: 13 | Issue: 4 | Pages: 343-348

10.1007/bf01660746 | PMID 2773493 Get It

AbstractThree‐dimensional display of medical image data has under gone rapid development since its introduction. This article explores the current state‐of‐the‐art of 3‐dimensional imaging applied to surgery planning and discusses the various image acquisition sources: computed tomography (CT), cine CT, magnetic resonance imaging, and ultrasound. Since increased physician involvement is the goal of the surgery planning software described, the future directions discussed emphasize the inclusion of “expert“ knowledge and ways to facilitate realistic interaction for surgery simulation.
Long‐term evaluation following resection of apparently benign pheochromocytoma(s)/paraganglioma(s)
Heerden, Jonathan A. van, Roland, Christopher F., Carney, J. Aidan, Sheps, Sheldon G., Grant, Clive S.

Mayo Clinic

World Journal of Surgery | May 8, 2005 | Volume: 14 | Issue: 3 | Pages: 325-329

10.1007/bf01658516 | PMID 1973322 Get It

AbstractIn the absence of distant disease, the pathologic diagnosis of malignancy in pheochromocytoma or paraganglioma is impossible. In an effort to establish the true incidence of recurrence in this disease, we have analyzed long‐term follow‐up (average, 15.8 years) of 98 patients who underwent complete resection of localized, noninvasive, histologically‐benign pheochromocytomas and paragangliomas at our institution between 1960 and 1976.Eighty‐eight patients had nonfamilial, sporadic pheochromoctyoma/ paraganglioma. Nine had multiple endocrine neoplasia (MEN) type 2 (2A: 7, 2B: 2), and 1 had familial pheochromocytoma. Seventy‐nine patients had single pheochromocytomas; 10 had single extraadrenal tumors (paragangliomas); and 9 had multicentric or bilateral adrenal tumors.Six patients (6.5%) developed recurrent pheochromocytoma after documentation of normal postoperative urinary catecholamine levels. One of these patients had MEN 2A. The recurrences developed at intervals from 5 to 13 years following initial resection. These were distant in 3 patients, local in 2, and both local and distant in a single patient. None of the recurrences occurred in the 13 patients who, on pathologic rereview, had either local or vascular invasion. No paraganglioma recurred.Life‐long follow‐up of all patients who have had pheochromocytomas or paragangliomas resected is mandatory.
The Radiologist's role in acute endocrine problems
May, Gerald R., James, E M, Johnson, Christopher M.

Mayo Clinic

World Journal of Surgery | May 8, 2005 | Volume: 6 | Issue: 6 | Pages: 725-734

10.1007/bf01655365 | PMID 6295001 Get It

AbstractUltrasound and computed tomography have had an enormous impact on the imaging procedures used in the detection of tumors of the parathyroids, pancreas, and adrenals. Ultrasound is now the examination of choice in localizing parathyroid adenomas in the neck prior to cervical exploration or after unsuccessful exploration. Its role as a screening test in patients without biochemical confirmation of hyperparathyroidism awaits further study. Computed tomography is useful in identifying mediastinal parathyroid adenomas in patients who have had unsuccessful neck explorations and islet‐cell tumors of the pancreas if they are sufficiently large (greater than 2 cm). Angiography remains the most accurate method of localizing insulinomas prior to surgery. Computed tomography scanning has become the procedure of choice in localizing adrenal tumors and has sufficient sensitivity to be used as a screening test in patients without biochemical confirmation of an adrenal abnormality.
Safety Evaluation of Titanium Middle Ear Prostheses at 3.0 Tesla
Martin, Angela D., Driscoll, Colin L. W., Wood, Christopher P. , Felmlee, Joel P.

Mayo Clinic

Otolaryngology–Head and Neck Surgery | April 2, 2005 | Volume: 132 | Issue: 4 | Pages: 537-542

10.1016/j.otohns.2004.12.003 | PMID 15806041 Get It

OBJECTIVE:To assess the magnetic resonance imaging (MRI) safety of titanium middle ear prostheses at 3.0 tesla (T).STUDY DESIGN AND SETTING:Titanium middle ear prostheses from 3 commercial vendors were examined for magnetic field interactions at 3 T. Initially, ex vivo studies were performed to test for rotational motion and forward displacement (translational motion) of the prostheses in a static magnetic field. If movement was observed during this screening study, then the prosthesis was tested to determine the translational or rotational force acting upon the prosthesis. In addition to testing for prosthesis displacement, temperature changes of the prostheses were measured to assess for radiofrequency heating during imaging.RESULTS:Twenty‐one of the 24 titanium prostheses tested revealed no movement when tested in the 3 T static magnetic field. Three prostheses revealed minimal movement during the screening study. A translational force test (string test) was performed upon these 3 prostheses, and the measured angle of displacement was used to determine the force. This calculated force acting upon each prosthesis was essentially zero. Therefore, we conclude that the magnetic field interaction is negligible. A positive control with a ferromagnetic stainless steel prosthesis demonstrated obvious displacement during the screening study, as well as deflection of the prosthesis by 90° in the translational force test. Last, heating of the titanium prostheses did not occur in the 7 models tested.CONCLUSIONS:Middle ear prostheses made from titanium are safe, neither deflecting nor heating during magnetic resonance examinations conducted at 3 T. EBM rating: C‐1.
Primary Hyperparathyroidism in Pediatric Patients
Kollars, Josh, Zarroug, Abdalla E., Heerden, Jon van, Lteif, Aida, Stavlo, Penny, Suarez, Luis , Moir, Christopher R. , Ishitani, Michael B., Rodeberg, David A. , Kollars, Joshua P.

Mayo Clinic

Pediatrics | April 1, 2005 | Volume: 115 | Issue: 4 | Pages: 974-980

10.1542/peds.2004-0804 | PMID 15805373 Get It

Objective. Primary hyperparathyroidism (HPT) is unusual in children. We reviewed our experience with HPT to better characterize these children. Methods. The retrospective review of patients &lt;19 years old who underwent parathyroid resection for primary HPT from 1970 to 2000 was performed at a single institution.. Results. Fifty-two patients were identified. Median age was 16.8 years (range: 4–18.9) with a female-to-male ratio of 3:2. Eighty-five percent had an elevated parathyroid hormone (PTH) level, and 15% had an inappropriately normal PTH level during hypercalcemia. Serum calcium was elevated in all patients except for 2 with multiple endocrine neoplasma (MEN)-IIA and 1 with familial non-MEN HPT, but both had elevated PTH levels. Alkaline phosphatase levels were significantly higher in children with documented bone involvement. At presentation 41 patients (79%) were symptomatic and end-organ damage (nephrocalcinosis, nephrolithiasis, acute pancreatitis, or bone involvement) occurred in 23 patients (44%). Thirty-four patients (65%) had a single adenoma; hyperplasia was identified in 16 patients (27%), and of these cases, 57% occurred in patients diagnosed with MEN-I. Short-term complications included transient hypocalcemia in 29 patients (56%) and transient vocal cord paralysis in 2 patients (4%). Long-term complications were significant for permanent hypocalcemia in 2 patients (4%) and no recurrent laryngeal nerve injuries. No parathyroid abnormalities were identified during exploration in 4 (8%) children. Long-term follow-up was achieved in 98% of patients for a mean and median of 13 years. Resolution of hypercalcemia was achieved in 94% of cases. Conclusion. The diagnosis of primary HPT in pediatric patients is frequently delayed, is commonly symptomatic, and has significant morbidity. For children in whom HPT is suspected, evaluation of serum calcium and PTH levels is diagnostic in 100% of children. Parathyroid resection is effective at restoring normal serum calcium, has few complications, and is the treatment of choice for children with primary hyperparathyroidism.
Differentiating Paroxysmal Hemicrania from Cluster Headache
Boes, Christopher J.

Mayo Clinic

Cephalalgia | March 17, 2005 | Volume: 25 | Issue: 4 | Pages: 241-243

10.1111/j.1468-2982.2004.00925.x | PMID 15773820 Get It

In Reply:
Crane, Christopher H. , Sargent, Daniel J. , Sargent, Daniel J

Mayo Clinic

Journal of Clinical Oncology | January 29, 2005 | Volume: 23 | Issue: 4 | Pages: 934-935

10.1200/jco.2005.05.298 Get It