2,155 research outputs found
969-99 Biocompatible Mechanical Left Ventricular Support: Potential Alternative to Transplantation
Use of mechanical circulatory support has been limited by its associated bleeding and thrombotic complications. Blood contact with an artificial surface results in a well-deined pattern of hematologic alterations. The TCI HeartMate® left ventricular assist device (LVAD) is an implantable circulatory support pump currently used as a bridge to transplantation. Its textured blood contacting surfaces result in a formation of an adherent pseudoneointimal lining which eliminates the direct interaction of blood elements with the artificial surface. To determine if this biological lining could mitigate the stereotypical blood-synthetic surface interactions, we studied eight patients who underwent implantation at our institution over a 10 month period from 5/93 to 3/94. Seven of the 8 patients were bridged to transplantation. Three patients were transplanted within 10 days and one month data could not be obtained. Hemodynamic and hemostatic parameters (mean±sd) were studied as follows:Pre-implantPOD 7POD 28Cardiac index (I/min/m2)1.8±0.73.2±0.43.1±0.5Systolic BP (mmHg)759±6.8125.8±9.7130.4±8.1Hemoglobin (mg/dl)7.4±1.88.2±1.69.6±2.0Plasma free hemoglobin (mg/dl)15.4±1.76.4±2.36.8±1.9Prothrombin time (sec)14.2±1.113.4±0.713.3±0.7Partial thromboplastin time (sec)56.7±15.931.8±4.837.6±11.9Platelet count (× 103lcu mm)250±81269±63325±37In vitro platelet reactivity to the agonist ADP remained normal pre and post implantation. Average perioperative blood requirements included PRBC, 3.3±1.3 units; platelets, 2.3±4.5 units; fresh frozen plasma, 2±1.9 units. No blood products were required after postoperative day 2.We conclude that TCI LVAD support improves hemodynamics and can bridge patients in pre-implant cardiogenic shock to transplantation. Furthermore, no red cell destruction or hemostatic and thrombotic complications were observed despite one month of support without anticoagulation therapy. Therefore, as the donor shortage continues, LVADs with biocompatible surfaces may provide an alternative to cardiac transplantation
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Eating Pattern Response to a Low-Fat Diet Intervention and Cardiovascular Outcomes in Normotensive Women: The Women's Health Initiative.
BackgroundWomen without cardiovascular disease (CVD) or hypertension at baseline assigned to intervention in the Women's Health Initiative Dietary Modification (DM) trial experienced 30% lower risk of coronary heart disease (CHD), whereas results in women with hypertension or prior CVD could have been confounded by postrandomization use of statins.ObjectivesIntervention participants reported various self-selected changes to achieve the 20% total fat goals. Reviewed are intervention compared with comparison group HRs for CHD, stroke, and total CVD in relation to specific dietary changes in normotensive participants.MethodsDietary change was assessed by comparing baseline with year 1 FFQ data in women (n = 10,371) without hypertension or CVD at baseline with intake of total fat above the median to minimize biases due to use of the FFQ in trial eligibility screening.ResultsIntervention participants self-reported compensating reduced energy intake from total fat by increasing carbohydrate and protein. Specifically they increased plant protein, with those in the upper quartile (increased total protein by ≥3.3% of energy) having a CHD HR of 0.39 (95% CI: 0.22, 0.71), compared with 0.92 (95% CI: 0.57, 1.48) for those in the lower quartile of change (decreased total protein ≥0.6% of energy), with P-trend of 0.04. CHD HR did not vary significantly with change in percentage energy from carbohydrate, and stroke HR did not vary significantly with any macronutrient changes. Scores reflecting adherence to recommended dietary patterns including the Dietary Approaches to Stop Hypertension Trial and the Healthy Eating Index showed favorable changes in the intervention group.ConclusionsIntervention group total fat reduction replaced with increased carbohydrate and some protein, especially plant-based protein, was related to lower CHD risk in normotensive women without CVD who reported high baseline total fat intake. This trial was registered at clinicaltrials.gov as NCT00000611. Link to the WHI trial protocol: https://www.whi.org/about/SitePages/Dietary%20Trial.aspx
Haptoglobin phenotype is an independent risk factor for cardiovascular disease in individuals with diabetes the strong heart study
AbstractObjectivesThe goal of this study was to determine if the haptoglobin phenotype was predictive of cardiovascular disease (CVD) in diabetic mellitus (DM).BackgroundCardiovascular disease is the most frequent, severe, and costly complication of type 2 DM. There are clear geographic and ethnic differences in the risk of CVD among diabetic patients that cannot be fully explained by differences in conventional CVD risk factors. We have demonstrated that a functional allelic polymorphism in the haptoglobin gene acts as a major determinant of susceptibility for the development of diabetic microvascular complications.MethodsWe sought to determine if this paradigm concerning the haptoglobin gene could be extended to CVD in DM. We tested this hypothesis in a case-control sample from the Strong Heart study, a population-based longitudinal study of CVD in American Indians. Haptoglobin phenotype was determined by polyacrylamide gel electrophoresis in 206 CVD cases and 206 matched controls age 45 to 74 years. Median follow-up was six years.ResultsIn multivariate analyses controlling for conventional CVD risk factors, haptoglobin phenotype was a highly statistically significant, independent predictor of CVD in DM. The odds ratio of having CVD in DM with the haptoglobin 2-2 phenotype was 5.0 times greater than in DM with the haptoglobin 1-1 phenotype (p = 0.002). An intermediate risk of CVD was associated with the haptoglobin 2-1 phenotype.ConclusionsThis study suggests that determination of haptoglobin phenotype may contribute to the algorithm used in CVD risk stratification, and in evaluation of new therapies to prevent CVD in the diabetic patient
Depressed Myocardial Energetic Efficiency Increases Risk of Incident Heart Failure: The Strong Heart Study
An estimation of myocardial mechano-energetic efficiency (MEE) per unit of left ventricular (LV) mass (MEEi) can significantly predict composite cardiovascular (CV) events in treated hypertensive patients with normal ejection fraction (EF), after adjustment for LV hypertrophy (LVH). We have tested whether MEEi predicts incident heart failure (HF), after adjustment for LVH, in the population-based cohort of a "Strong Heart Study" (SHS) with normal EF. We included 1,912 SHS participants (age 59 ± 8 years; 64% women) with preserved EF (≥50%) and without prevalent CV disease. MEE was estimated as the ratio of stroke work to the "double product" of heart rate times systolic blood pressure. MEEi was calculated as MEE/LV mass, and analyzed in quartiles. During a follow-up study of 9.2 ± 2.3 years, 126 participants developed HF (7%). HF was preceded by acute myocardial infarction (AMI) in 94 participants. A Kaplan-Meier plot, in quartiles of MEEi, demonstrated significant differences, substantially due to the deviation of the lowest quartile (p < 0.0001). Using AMI as a competing risk event, sequential models of Cox regression for incident HF (including significant confounders), demonstrated that low MEEi predicted incident HF not due to AMI (p = 0.026), after adjustment for significant effect of age, LVH, prolonged LV relaxation, diabetes, and smoking habits with negligible effects for sex, hypertension, antihypertensive therapy, obesity, and hyperlipemia. Low LV mechano-energetic efficiency per unit of LVM, is a predictor of incident, non-AMI related, HF in subjects with initially normal EF
Using HbA1c to improve efficacy of the American Diabetes Association fasting plasma glucose criterion in screening for new type 2 diabetes in American Indians. The Strong Heart Study
WSTĘP. Celem badania jest określenie optymalnej krytycznej linii
FPG-HbA1c, umożliwiającej rozpoznanie cukrzycy w grupie chorych z nieprawidłowym
stężeniem glukozy na czczo (IFG, impaired fasting glucose) i poprawa
skuteczności oznaczenia glikemii na czczo (FPG, fasting plasma glucose),
stosowanego jako samodzielne badanie przesiewowe w kierunku cukrzycy u Indian
amerykańskich.
MATERIAŁ I METODY. Analizowano oznaczenia stężenia glukozy na
czczo i 2 godziny po doustnym obciążeniu glukozą (2hPG) oraz HbA1c
w grupie 2389 Indian amerykańskich w wieku 45-74 lat, którzy dotychczas nie byli
leczeni z powodu cukrzycy, u których wcześniej nie rozpoznawano cukrzycy, a których poddano wyjściowej i powtórnej ocenie w ramach badania SHS (Strong
Heart Study). Zgodnie z kryteriami American Diabetes Association
cukrzycę rozpoznawano, gdy stężenie glukozy na czczo było równe lub wyższe niż
126 mg/dl lub gdy wartość 2hPG wynosiła 200 mg/dl lub więcej. Nieprawidłowe stężenie
glukozy na czczo rozpoznawano, gdy mieściło się ono w przedziale 110 Ł
FPG < 126 mg/dl, a jako wartość prawidłową (NFG, normal fasting glucose)
przyjęto stężenie glukozy na czczo niższe niż 110 mg/dl. Do rozpoznawania cukrzycy
w grupie badanych z IFG (2hPG ł 200 mg/dl) zastosowano
modele regresji logistycznej. Najlepszy model wybrano na podstawie porównania
pól pod krzywymi ROC (receiver operating characteristic) utworzonymi
w oparciu o różne modele regresji logistycznej. Do wyznaczenia optymalnych wartości
krytycznych użyto funkcji przydatności opartej na najlepszym modelu oraz współczynniku
koszt/korzyść. Dane z drugiego badania wykorzystano do oceny wpływu czasu, jaki
upłynął pomiędzy dwoma kolejnymi badaniami przesiewowymi, zarówno na kryterium
FPG, jak i na optymalną krytyczną linię FPG-HbA1c.
WYNIKI. W grupie chorych z nowo rozpoznaną cukrzycą, u 37% w
badaniu wyjściowym oraz u 55,2% w badaniu powtórnym stwierdzono wartości 2hPG
większe bądź równe 200 mg/dl, przy wartościach FPG mniejszych niż 126 mg/dl. Zarówno
w wyjściowym, jak i w drugim oznaczeniu u znacznej części pacjentów z IFG rozpoznano
cukrzycę (odpowiednio: 19,3 i 22,9%). Porównanie pól pod krzywymi ROC dla poszczególnych
modeli regresji logistycznej wykazało, że największa wartość pola odpowiada łącznemu
oznaczeniu FPG i HbA1c. Wartość ta była znamiennie wyższa od wartości
pola dla oznaczenia FPG (p = 0,0008). Dla współczynnika koszt/korzyść = 0,23888
optymalna linia krytyczna o największej użyteczności miała wartość równą 0,89 × HbA1c + 0,11 × FPG = 17,92. U chorych, u których wartości FPG i HbA1c
znajdowały się na tej linii lub powyżej, zalecano wykonanie doustnego testu tolerancji
glukozy (OGTT, oral glucose tolerance test) w celu rozpoznania lub wykluczenia
cukrzycy. Optymalne wartości krytyczne w badaniu powtórzonym po 4 latach były
mniejsze.
WNIOSKI. Według kryteriów American Diabetes Association cukrzycę
rozpoznaje się, gdy wartość FPG jest większa lub równa 126 mg/dl albo gdy wartość
2hPG wynosi 200 mg/dl lub więcej. Wykonanie badania FPG jest proste i zaleca się
je jako badanie przesiewowe. Natomiast stosowanie w praktyce OGTT w celu uzyskania
wartości 2hPG jest kłopotliwe, szczególnie u chorych, u których stwierdza się
wartość FPG poniżej 126 mg/dl. Wykonywanie OGTT jako badania przesiewowego u każdego
pacjenta również jest niepraktyczne. Uzyskane dane wskazują, że u 37% osób z nowo
wykrytą cukrzycą w badaniu wyjściowym i u 55,2% w oznaczeniu drugim stężenie glukozy
w OGTT wynosiło 200 mg/dl lub więcej, podczas gdy wartość FPG była niższa niż
126 mg/dl. W takich wypadkach, na podstawie oznaczenia wyłącznie FPG jako badania
przesiewowego, cukrzyca nie zostałaby rozpoznana. Mimo że odsetek chorych na cukrzycę
w grupie NFG jest mały i może zostać zignorowany (4,7% w pierwszym i 6,5% w drugim
oznaczeniu), to częstość przypadków cukrzycy stwierdzonych w grupie IFG w trakcie
niniejszego badania (ok. 20%) wymaga uwzględnienia w dyskusji na temat metody
badań przesiewowych. Wydaje się, że u części chorych z nieprawidłowym stężeniem
glukozy na czczo, wybranych na podstawie optymalnych krytycznych wartości FPG-HbA1c,
warto wykonać OGTT. Wyznaczenie optymalnej linii krytycznej i odstępu między kolejnymi
testami przesiewowymi wymaga dalszych badań.INTRODUCTION. To find an optimal critical line in the
fasting plasma glucose (FPG)-HbA1c plane for identifying
diabetes in participants with impaired fasting
glucose (IFG) and thereby improve the efficacy of
using FPG alone in diabetes screening among American
Indians.
RESEARCH DESIGN AND METHODS. We used FPG, 2-h
postload glucose (2hPG), and HbA1c measured in the
2,389 American Indians (aged 45–74 years, without
diabetes treatment or prior history of diabetes) in
the Strong Heart Study (SHS) baseline (second) examination.
Participants were classified as having diabetes
if they had either FPG £ 126 mg/dl or 2hPG
≥ 200 mg/dl, as having IFG if they had 110 £ FPG
< 126 mg/dl, and as having normal fasting glucose
(NFG) if they had FPG < 110, according to the American
Diabetes Association (ADA) definition. Logistic
regression models were used for identifying diabetes
(2hPG ≥ 200 mg/dl) in IFG participants. The areas
under the receiver operating characteristic (ROC) curves
generated by different logistic regression models
were evaluated and compared to select the best
model. A utility function based on the best model
and the cost-to-benefit ratio was used to find the
optimal critical line. The data from the second examination
were used to study the effect of the time
interval between the successive diabetes screenings
on both the FPG criterion and the optimal critical line.
RESULTS. A total of 37% of all subjects with new
diabetes at baseline and 55.2% of those in the second
exam had 2hPG ≥ 200 but FPG < 126. There
was a very large portion of IFG participants with diabetes
(19.3 and 22.9% in the baseline and second
exam, respectively). Among the areas under the ROC
curves, the area generated by the logistic regression
model on FPG plus HbA1c is the largest and is
significantly larger than that based on FPG (P =
= 0.0008). For a cost-to-benefit ratio of 0.23888, the
optimal critical line that has the highest utility is:
0.89 × HbA1c + 0.11 × FPG = 17.92. Those IFG participants
whose FPG and HbA1c were above or on the
line were referred to take an oral glucose tolerance
test (OGTT) to diagnose diabetes. The optimal critical
line is lower if a successive diabetes screening will be
conducted 4 years after the previous screening.
CONCLUSIONS. FPG ≥ 126 and 2hPG ≥ 200, as suggested
by the ADA, are used in-dependently to define diabetes. The FPG level is easy to obtain, and using
FPG alone is suggested for diabetes screening. It is
difficult to get physicians and patients to perform
an OGTT to get a 2hPG level because of the many
drawbacks of the OGTT, especially in those patients
who already have FPG < 126. It is also impractical
to conduct an OGTT for everyone in a diabetes screening.
Our data show that 37% of all subjects with
new diabetes in the SHS baseline exam and 55.2%
of those in the second exam have 2hPG ≥ 200 but
FPG < 126. These cases of diabetes cannot be detected
if FPG is used alone in a diabetes screening.
Therefore, although the small portion of diabetes in
the NFG group (4.7% in the base-line and 6.9% in
the second exam) may be ignored, those cases of
diabetes among IFG participants (~20% in our data)
need further consideration in a diabetes screening.
It may be worthwhile for those IFG participants identified
by the optimal critical line to take an OGTT.
The optimal critical line and time interval between
successive diabetes screenings need further study
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