Kurt Amplatz

Bio: Kurt Amplatz is an academic researcher from University of Minnesota. The author has contributed to research in topics: Percutaneous & Embolization. The author has an hindex of 57, co-authored 470 publications receiving 14202 citations. Previous affiliations of Kurt Amplatz include University of Nebraska Omaha & West Virginia University.

Effect of partial ileal bypass surgery on mortality and morbidity from coronary heart disease in patients with hypercholesterolemia. Report of the Program on the Surgical Control of the Hyperlipidemias (POSCH)

Abstract: Background and Methods The Program on the Surgical Control of the Hyperlipidemias (POSCH), a randomized clinical trial, was designed to test whether cholesterol lowering induced by the partial ileal bypass operation would favorably affect overall mortality or mortality due to coronary heart disease. The study population consisted of 838 patients (417 in the control group and 421 in the surgery group), both men (90.7 percent) and women, with an average age of 51 years, who had survived a first myocardial infarction. The mean follow-up period was 9.7 years. Results When compared with the control group at five years, the surgery group had a total plasma cholesterol level 23.3 percent lower (4.71±0.91 vs. 6.14±0.89 mmol per liter [mean ±SD]; P<0.0001), a low-density lipoprotein cholesterol level 37.7 percent lower (2.68±0.78 vs. 4.30±0.89 mmol per liter; P<0.0001), and a high-density lipoprotein cholesterol level 4.3 percent higher (1.08±0.26 vs. 1.04±0.25 mmol per liter; P = 0.02). Overall mortality...

Left retrograde cardioangiography in acquired cardiac disease: Technic, indications and interpretations in 700 cases∗

Abstract: Application of retrograde left cardioangiography to 700 patients, both adults and children, with acquired valvular diseases is described. The technic employed for the test is described. Pressures from the aorta and left ventricle are obtained during the same procedure as angiography to determine whether stenosis of the aortic valve is present. The method may be used to estimate the degree of aortic or mitral insufficiency or both. Mitral stenosis may be identified by a fixed filling defect of the left ventricular cavity. The value of this information in the surgical management of many forms of cardiac disease is emphasized. Complications have occurred infrequently and, in most instances, the patients have responded to appropriate therapy. Three deaths occurred. These were caused by ventricular fibrillation in 1 patient and cardiac tamponade in 2. The most common complication was thrombosis of the femoral artery at the site of arteriotomy. This complication occurred in about 4 per cent of cases; but in none did gangrene occur, and pulsatile flow was restored in all cases by immediate re-exploration of the femoral artery as soon as the diagnosis was made.

The mechanism of balloon angioplasty.

Abstract: A new theory of the mechanism of percutaneous arterial angioplasty is advanced. For this study, abdominal aortas and coronary, renal, superior mesenteric, and iliac arteries were obtained from cadavers. In addition, the iliac arteries of dogs were dilated and studied. No evidence of significant compression or redistribution of plaques could be found, supporting the theory that atheromatous material is incompressible. Cracking of the intima and separation of it from the media were histologically demonstrated following angioplasty. It is proposed that the stretched media distends following dilatation, carrying with the intima and atheromatous material. Once the media is freed from the encasing effect of the intima, it adapts to the circulatory needs of the body. Beyond a certain point, the arterial widening becomes permanent, due to an overstretching of the muscle fibers, which is demonstrated by a corkscrew deformity of the muscle cell nuclei.

Snare-type probe

Abstract: The present invention provides a snare for intravascular use having an elongate proximal member and a loop-shaped distal segment oriented at an angle to the adjacent portion of the proximal member. The snare may be formed of a superelastic shape memory alloy, which permits the distal segment to be collapsed for passage through a catheter and yet automatically open into its original, unrestrained configuration upon emerging from the distal tip of the catheter.

Balloon dilation angioplasty of aortic coarctations in infants and children.

Abstract: Balloon dilation angioplasty (BDA) was attempted nine times in eight infants and children with aortic coarctation. In three infants (all with associated ventricular septal defect or atrioventricular canal and marked hemodynamic instability) dilation was attempted at a site of aortic narrowing that had not been operated on previously. Although the coarctation gradient fell 40% or more over the short term in two of the three, there was no angiographic or late gradient evidence of improvement. All three underwent subsequent coarctation surgery. Five dilations were performed in four infants and children who had previously undergone coarctation surgery (end-to-end anastomosis, attempted jump graft, and subclavian flap) and had residual gradients. Dilation was successful in all five cases, resulting in an increase in the diameter at the coarctation site (4.7 +/- 2.6 to 7.7 +/- 4.0 mm, p less than .05) and a decrease in the gradient measured 24 hr after dilation (42.0 +/- 15.5 to 11.8 +/- 11.2 mm Hg, p less than .05). In one child with a long area of hypoplasia of the thoracic aorta and similar lesions of the brachiocephalic vessels, a preliminary attempt to dilate a severely narrowed subclavian artery was unsuccessful. Postdilation angiography demonstrated evidence of intimal tears in three of five successful dilations. Follow-up (1 to 6 months) has demonstrated continued gradient relief in four of five children. BDA is frequently, but not always, a successful treatment for human aortic coarctation. The chief determinant of success appears to be the nature of the lesion; short-term changes in coarctation gradient are unreliable indicators of success of failure. Although BDA was not associated with mortality or significant morbidity in this group of patients, its role in the management of children with coarctation is yet to be determined.

Recommendations for cardiac chamber quantification by echocardiography in adults: an update from the American Society of Echocardiography and the European Association of Cardiovascular Imaging.

Abstract: The rapid technological developments of the past decade and the changes in echocardiographic practice brought about by these developments have resulted in the need for updated recommendations to the previously published guidelines for cardiac chamber quantification, which was the goal of the joint writing group assembled by the American Society of Echocardiography and the European Association of Cardiovascular Imaging. This document provides updated normal values for all four cardiac chambers, including three-dimensional echocardiography and myocardial deformation, when possible, on the basis of considerably larger numbers of normal subjects, compiled from multiple databases. In addition, this document attempts to eliminate several minor discrepancies that existed between previously published guidelines.

Bariatric surgery: a systematic review and meta-analysis.

Abstract: ContextAbout 5% of the US population is morbidly obese. This disease remains largely refractory to diet and drug therapy, but generally responds well to bariatric surgery.ObjectiveTo determine the impact of bariatric surgery on weight loss, operative mortality outcome, and 4 obesity comorbidities (diabetes, hyperlipidemia, hypertension, and obstructive sleep apnea).Data Sources and Study SelectionElectronic literature search of MEDLINE, Current Contents, and the Cochrane Library databases plus manual reference checks of all articles on bariatric surgery published in the English language between 1990 and 2003. Two levels of screening were used on 2738 citations.Data ExtractionA total of 136 fully extracted studies, which included 91 overlapping patient populations (kin studies), were included for a total of 22 094 patients. Nineteen percent of the patients were men and 72.6% were women, with a mean age of 39 years (range, 16-64 years). Sex was not reported for 1537 patients (8%). The baseline mean body mass index for 16 944 patients was 46.9 (range, 32.3-68.8).Data SynthesisA random effects model was used in the meta-analysis. The mean (95% confidence interval) percentage of excess weight loss was 61.2% (58.1%-64.4%) for all patients; 47.5% (40.7%-54.2%) for patients who underwent gastric banding; 61.6% (56.7%-66.5%), gastric bypass; 68.2% (61.5%-74.8%), gastroplasty; and 70.1% (66.3%-73.9%), biliopancreatic diversion or duodenal switch. Operative mortality (≤30 days) in the extracted studies was 0.1% for the purely restrictive procedures, 0.5% for gastric bypass, and 1.1% for biliopancreatic diversion or duodenal switch. Diabetes was completely resolved in 76.8% of patients and resolved or improved in 86.0%. Hyperlipidemia improved in 70% or more of patients. Hypertension was resolved in 61.7% of patients and resolved or improved in 78.5%. Obstructive sleep apnea was resolved in 85.7% of patients and was resolved or improved in 83.6% of patients.ConclusionsEffective weight loss was achieved in morbidly obese patients after undergoing bariatric surgery. A substantial majority of patients with diabetes, hyperlipidemia, hypertension, and obstructive sleep apnea experienced complete resolution or improvement.

Randomized Trial of Estrogen Plus Progestin for Secondary Prevention of Coronary Heart Disease in Postmenopausal Women

Abstract: Context.—Observational studies have found lower rates of coronary heart disease (CHD) in postmenopausal women who take estrogen than in women who do not, but this potential benefit has not been confirmed in clinical trials.Objective.—To determine if estrogen plus progestin therapy alters the risk for CHD events in postmenopausal women with established coronary disease.Design.—Randomized, blinded, placebo-controlled secondary prevention trial.Setting.—Outpatient and community settings at 20 US clinical centers.Participants.—A total of 2763 women with coronary disease, younger than 80 years, and postmenopausal with an intact uterus. Mean age was 66.7 years.Intervention.—Either 0.625 mg of conjugated equine estrogens plus 2.5 mg of medroxyprogesterone acetate in 1 tablet daily (n=1380) or a placebo of identical appearance (n=1383). Follow-up averaged 4.1 years; 82% of those assigned to hormone treatment were taking it at the end of 1 year, and 75% at the end of 3 years.Main Outcome Measures.—The primary outcome was the occurrence of nonfatal myocardial infarction (MI) or CHD death. Secondary cardiovascular outcomes included coronary revascularization, unstable angina, congestive heart failure, resuscitated cardiac arrest, stroke or transient ischemic attack, and peripheral arterial disease. All-cause mortality was also considered.Results.—Overall, there were no significant differences between groups in the primary outcome or in any of the secondary cardiovascular outcomes: 172 women in the hormone group and 176 women in the placebo group had MI or CHD death (relative hazard [RH], 0.99; 95% confidence interval [CI], 0.80-1.22). The lack of an overall effect occurred despite a net 11% lower low-density lipoprotein cholesterol level and 10% higher high-density lipoprotein cholesterol level in the hormone group compared with the placebo group (each P<.001). Within the overall null effect, there was a statistically significant time trend, with more CHD events in the hormone group than in the placebo group in year 1 and fewer in years 4 and 5. More women in the hormone group than in the placebo group experienced venous thromboembolic events (34 vs 12; RH, 2.89; 95% CI, 1.50-5.58) and gallbladder disease (84 vs 62; RH, 1.38; 95% CI, 1.00-1.92). There were no significant differences in several other end points for which power was limited, including fracture, cancer, and total mortality (131 vs 123 deaths; RH, 1.08; 95% CI, 0.84-1.38).Conclusions.—During an average follow-up of 4.1 years, treatment with oral conjugated equine estrogen plus medroxyprogesterone acetate did not reduce the overall rate of CHD events in postmenopausal women with established coronary disease. The treatment did increase the rate of thromboembolic events and gallbladder disease. Based on the finding of no overall cardiovascular benefit and a pattern of early increase in risk of CHD events, we do not recommend starting this treatment for the purpose of secondary prevention of CHD. However, given the favorable pattern of CHD events after several years of therapy, it could be appropriate for women already receiving this treatment to continue.

Evolocumab and Clinical Outcomes in Patients with Cardiovascular Disease

Abstract: BackgroundEvolocumab is a monoclonal antibody that inhibits proprotein convertase subtilisin–kexin type 9 (PCSK9) and lowers low-density lipoprotein (LDL) cholesterol levels by approximately 60%. Whether it prevents cardiovascular events is uncertain. MethodsWe conducted a randomized, double-blind, placebo-controlled trial involving 27,564 patients with atherosclerotic cardiovascular disease and LDL cholesterol levels of 70 mg per deciliter (1.8 mmol per liter) or higher who were receiving statin therapy. Patients were randomly assigned to receive evolocumab (either 140 mg every 2 weeks or 420 mg monthly) or matching placebo as subcutaneous injections. The primary efficacy end point was the composite of cardiovascular death, myocardial infarction, stroke, hospitalization for unstable angina, or coronary revascularization. The key secondary efficacy end point was the composite of cardiovascular death, myocardial infarction, or stroke. The median duration of follow-up was 2.2 years. ResultsAt 48 weeks, the ...