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Biomedical subjects

F W Smart

Publications and source records attributed to F W Smart.

At least 55 records · Page 3Linked to original sources
PubMed1994

Influence of donor and recipient gender on cardiac allograft vasculopathy. An intravascular ultrasound study.

BACKGROUND: Cardiac allograft vasculopathy remains the leading limitation to long-term survival after cardiac transplantation. While the influence of donor and recipient gender in the pathogenesis of cardiac vasculopathy is still poorly understood, studies have indicated that female allografts may be at higher risk for the development of cardiac allograft vasculopathy. The purpose of this study was to characterize the influence of donor and recipient gender on the early genesis of cardiac allograft vasculopathy by using intravascular ultrasound. METHODS AND RESULTS: Thirty-six consecutive cardiac transplant recipients were divided into three groups on the basis of donor and recipient gender as follows: group 1, female donor and male recipient (n = 8); group 2, male donor and female recipient (n = 7); and group 3, male donor and male recipient (n = 21). The three groups were similar with regard to donor and recipient age, weight, body surface area, serum lipids, left ventricular function, histocompatibility, cellular and vascular rejection, and cytomegalovirus infection. To precisely quantitate the extent of cardiac allograft vasculopathy, intravascular ultrasound was performed in all patients at the time of first annual angiography. Intimal thickening and intimal index were accurately quantitated by intravascular ultrasound. Intimal thickening was significantly greater in group 1 (0.55 +/- 0.15 mm) than in group 2 (0.18 +/- 0.04 mm) or group 3 (0.29 +/- 0.05 mm) (P < .05). In addition, the intimal index was greater in group 1 (0.20 +/- 0.04) than in group 2 (0.07 +/- 0.02) or group 3 (0.15 +/- 0.02) (P < .01, group 1 versus group 2). CONCLUSIONS: Male recipients of female allografts have a higher degree of vascular intimal hyperplasia detected by intravascular ultrasound at 1 year after heart transplantation. These findings indicate that donor and recipient gender influences the early genesis of cardiac allograft vasculopathy.

Age Factors↗
PubMed1994

Cardiovascular adaptation to cyclosporine-induced hypertension.

Arterial hypertension is a complication of cyclosporine therapy in heart transplant recipients. We studied cardiovascular adaptation to cyclosporine-induced hypertension by determining haemodynamic and echocardiographic indexes in 25 cardiac transplant recipients matched by mean arterial pressure, age, sex, height and weight to 25 patients with established essential hypertension. Twenty-five normotensive subjects matched by age, sex and body habitus were used as controls. Systemic vascular resistance was 15% higher (P = 0.07) and cardiac and stroke volume indices were 20% and 25% lower (P < 0.01), respectively, in the hypertensive cardiac transplant recipients compared with patients with essential hypertension. Patients with essential hypertension and hypertensive cardiac transplant recipients had greater posterior wall thickness and left ventricular mass index than normotensive subjects (P < 0.01); however, hypertensive cardiac transplant recipients had a greater left ventricular mass (245 +/- 7 vs. 223 +/- 8 g, P < 0.05) than patients with markedly established essential hypertension. Left ventricular ejection fraction was significantly lower in hypertensive cardiac transplant recipients when compared with either normotensives or patients with established essential hypertension. These results indicate that established essential and cardiac transplant hypertension are associated with markedly increased systemic vascular resistance. However, after heart transplantation, hypertension is associated with higher systemic vascular resistance, lower cardiac output, stroke volume and stroke work compared with patients with established essential hypertension at the same level of mean arterial pressure. The cardiac adaptation to cyclosporine-induced hypertension has more severe concentric left ventricular hypertrophy and impaired left ventricular systolic performance.(ABSTRACT TRUNCATED AT 250 WORDS)

Adaptation, Physiological↗
PubMed1993

Assessment of intracoronary morphology in cardiac transplant recipients by angioscopy and intravascular ultrasound.

Percutaneous coronary angioscopy and intravascular ultrasound are sensitive intravascular imaging methods for detecting early changes in coronary morphology in cardiac transplant recipients. To compare the 2 imaging modalities, 29 consecutive cardiac transplant recipients underwent percutaneous coronary angioscopy and intravascular ultrasound during annual coronary angiography. Surface morphology, presence of plaque, and percent area stenosis were determined with each procedure. Percutaneous coronary angioscopy was more sensitive in detecting the presence of plaque and stenosis than was coronary angiography (plaque: 79 vs 10% [p < 0.001]; and stenosis: 24 vs 3% [p < 0.01]). Intravascular ultrasound was also more sensitive in detecting plaque (76 vs 10%; p < 0.001) and stenosis (45 vs 3%; p < 0.001) than was coronary angiography. Although both angioscopy and ultrasound identified atherosclerotic plaque, only percutaneous coronary angioscopy could show luminal surface morphology and pigmentation of the plaque. Conversely, ultrasound could detect calcification and presence of intimal thickening, and was more accurate in assessing the severity of stenosis (45 vs 24%; p < 0.01). In conclusion, percutaneous coronary angioscopy and intravascular ultrasound, in conjunction, provide information not only regarding the appearance of the luminal surface, but also quantitative information regarding the structure and extent of the disease in the coronary artery wall.

Adult↗
PubMed1993

Induction immunosuppression with the monoclonal antibody OKT3 after cardiac transplantation.

The routine use of monoclonal induction immunosuppression with OKT3 after orthotopic heart transplantation remains controversial. This study examined the clinical response of prophylactic monoclonal induction immunosuppression versus standard triple-drug immunosuppression in 41 patients who underwent orthotopic heart transplantation from January 1989 to December 1990 at this institution. Of these, eight received monoclonal induction immunosuppression for a period of 10 to 14 days. All patients received identical triple-drug immunosuppression with the exception of cyclosporine starting on the fifth postoperative day in those who received OKT3. At 6 months the duration of hospitalization, freedom from rejection, incidence of infection requiring hospitalization, and serum creatinine in the monoclonal induction immunosuppression and triple-drug groups were compared. It was found that the length of hospital stay in the OKT3 group was 14.3 +/- 4.5 days, compared with 14.7 +/- 4.7 days in the triple-drug group and that freedom from rejection was 66% in the OKT3 group compared with 75% in the triple-drug group. In addition, it was found that the incidence of infection was 36% in the OKT3 group compared with 38% in the triple-drug group and that serum creatinine at 6 months was 1.36 +/- 0.26 mg/dl in the OKT3 group compared with 1.45 +/- 0.73 mg/dl in the triple-drug group. Finally, patient survival at 1 year for the monoclonal induction immunosuppression group was 100% compared with 91% for the triple-drug group.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Cortex Hormones↗
PubMed1993

Valvular regurgitation and right-sided cardiac pressures in heart transplant recipients by complete Doppler and color flow evaluation.

OBJECTIVE: To define normal profiles of cardiac structure, function, and hemodynamics postcardiac transplantation using Doppler echocardiography. DESIGN: Retrospective clinical case series with mean follow-up of 5.1 months. SETTING: Institutional tertiary care center, ambulatory setting. PATIENTS: A consecutive sample of 48 orthotopic cardiac transplant recipients. RESULTS: Aortic regurgitation was present in two patients, and was trivial in both cases. Mitral regurgitation was present in 29 of 48 patients, was trivial in 19 of 29 patients, and was mild in 10 of 29 patients. Tricuspid regurgitation was present in 41 of 48 patients and was graded as follows: trivial, 23 of 41; mild, 12 of 41; and moderate, 6 of 41. Septal hypokinesis was present in 33 of 49 patients, and no patient had evidence of other wall motion abnormalities. A pericardial effusion was present in 13 of 48 patients. Hemodynamic values were comparable to those of a nontransplant, normal population with pulmonary artery systolic pressures having a mean value of 31 +/- 6 mm Hg (range, 15 to 45 mm Hg) and estimates of right atrial pressure being 0 to 5 mm Hg in 12 of 48, 5 to 10 mm Hg in 32 of 48, and 10 to 15 mm Hg in 1 patient. There was no correlation between the degree of mitral or tricuspid regurgitation and sex, transplant interval, hemodynamic indices, or endomyocardial biopsy specimen grade. Right ventricular enlargement was associated with the presence of moderate tricuspid regurgitation. CONCLUSIONS: Cardiac transplantation recipients commonly display the following: (1) trivial or mild degrees of mitral regurgitation; (2) as much as moderate tricuspid regurgitation; (3) septal hypokinesis; and (4) small pericardial effusions. There is an association between the presence of right ventricular enlargement and moderate tricuspid regurgitation.

Adult↗
PubMed1993

Cyclosporine-induced hypertension. Efficacy of omega-3 fatty acids in patients after cardiac transplantation.

BACKGROUND: Cyclosporine-induced hypertension may be related to vasoconstriction of the afferent arterioles in the glomeruli caused by changes in the prostaglandin profile. omega-3 Fatty acids have demonstrated vasodilatory properties related to a favorable effect in the prostaglandin profile. The purpose of this study was to evaluate the antihypertensive effects of oral supplementation with omega-3 fatty acids in cyclosporine-treated cardiac transplant recipients. METHODS AND RESULTS: The study consisted of 20 orthotopic cardiac transplant recipients with hypertension who were prospectively randomized in a double-blind fashion to receive either omega-6 fatty acids (placebo group, n = 10) or omega-3 fatty acids (treatment group, n = 10). Blood pressure, systemic hemodynamics, two-dimensional guided M-mode and Doppler echocardiography, and laboratory values (serum creatinine, lipid profile) were recorded at baseline and at 12 weeks. The treatment group demonstrated a significant reduction in mean arterial pressure (120 +/- 7 versus 102 +/- 7 mm Hg; P = .0001) associated with a decrease in systemic vascular resistance (2107 +/- 45 versus 1426 +/- 60 dynes.sec.cm-5; P = .0001). No changes in indexes of left ventricular structure and function occurred, except for a modest decrease in deceleration time (211 +/- 10 versus 182 +/- 12 milliseconds; P = .05), an index of left ventricular diastolic function. CONCLUSIONS: omega-3 Fatty acids (3 g/d) reduce blood pressure by decreasing systemic vascular resistance and, therefore, can be used as an adjuvant for the treatment of hypertension in cyclosporine-treated cardiac transplant recipients. Their vasodilatory effect may be related to a beneficial change in the prostaglandin profile.

Antihypertensive Agents↗
PubMed1993

Cardiac transplantation: role of endomyocardial biopsy and immunosuppressive agents.

The field of cardiac transplantation has made tremendous strides since the first transplant procedure in 1967. This paper reviews the role of endomyocardial biopsy to diagnose and follow rejection as well as the standard immunosuppressive regimens employed. With continued refinements in immunosuppressive therapy, further improvements in mortality and morbidity rates should be realized.

Biopsy↗
PubMed1993

Cardiac transplantation: an overview of recipient selection.

Cardiac transplantation is an accepted treatment for end-stage heart disease. Potential recipients are carefully screened in order to best place the short supply of donor organs with the best recipient. The success of heart transplantation in the United States today is directly related to careful donor and recipient selection criteria and improvements in immunosuppression.

Age Factors↗
PubMed1993

Cardiac assist devices: bridging and beyond.

Due to the high incidence of death while awaiting cardiac transplantation today, most major transplant centers have adopted the use of left ventricular assist devices in order to stave off the complications of end-stage heart failure and allow patients to maintain a good physiologic state going into heart transplantation. These devices are safe and may one day prove to be a substitute for the short supply of donor organs.

Equipment Design↗
PubMed1993

Cardiac allograft vasculopathy: current concepts.

The major cause of late death in cardiac transplant recipients is cardiac allograft vasculopathy also referred to as cardiac transplant atherosclerosis which occurs in 15% to 20% of transplant recipients. It differs from traditional atherosclerosis in that it is a concentric and diffuse intimal hyperplastic process, the internal elastic lamina remains intact, and calcification is rare. The distal portion of the coronary vessel is the earliest to occlude, with occlusion occurring rapidly. Sometimes a low grade vasculitis is also present. There is no definitive reason for cardiac allograft vasculopathy occurring though it has been suggested that it may actually be caused by immunologic and nonimmunologic damage to endothelial cells resulting in myointimal proliferation. Intravascular ultrasound and coronary angioscopy seem to be a more sensitive diagnostic measure of cardiac allograft vasculopathy than coronary angiography. To date, retransplantation seems to be the only definitive therapy for cardiac allograft vasculopathy. But only fair results are being seen with this procedure.

Coronary Artery Disease↗
PubMed1992

Attenuation of waiting time mortality with heterotopic heart transplantation.

As the number of heart transplants and the number of transplant programs has increased, so has the waiting time for a suitable organ. To more accurately assess the magnitude of this increase and the influence of recipient size, we reviewed waiting times for large (body surface area greater than or equal to 1.95 m2) and small (body surface area less than 1.95 m2) patients with respect to era of transplantation. Patients who underwent transplantation early (1984 to December 31, 1986) waited 35 +/- 47 days (mean +/- standard deviation), whereas patients who underwent transplantation in the late era (1987 to September 30, 1989) waited 83 +/- 102 days (p = 0.001). Large patients waited longer (130 +/- 142 days) in the late era than did small patients (60 +/- 67 days; p = 0.008). During the heterotopic era (October 1, 1989 to June 30, 1990), waiting times for large patients who received a heterotopic transplant (67 +/- 46 days) were significantly shorter than those for patients who received an orthotopic transplant (166 +/- 157 days; p = 0.05). Waiting times for small patients remained unchanged. In addition, waiting time mortality decreased from 24% to 9% (p less than 0.05). Comparison of orthotopic and heterotopic procedures performed during the same era revealed no significant differences in recipient age, preoperative status, graft ischemic time, donor age, early and midterm survival, or early postoperative functional status. Heterotopic heart transplantation may effectively increase the size of the donor pool, decrease the waiting time, and decrease waiting time mortality without increasing the morbidity of the procedure.

Body Surface Area↗
PubMed1992

Current issues in advanced heart failure.

In the past 50 years, an increased understanding of the pathophysiologic mechanisms associated with the development of heart failure has produced a more precise treatment of this syndrome. The effects of the agents used for the treatment of patients with advanced heart failure have been summarized in this article and demonstrate the importance of vasodilatory drugs on the survival and progression of dilated cardiomyopathy.

Cardiomegaly↗
PubMed1991

Insensitivity of noninvasive tests to detect coronary artery vasculopathy after heart transplant.

Obstructive coronary artery vasculopathy can be a major problem after cardiac transplant. The use of noninvasive tests to detect coronary artery vasculopathy was studied in 73 consecutive patients after heart transplant. Angiographically or autopsy-proved coronary artery disease was noted in 19 consecutive patients (26%) followed prospectively for 2.5 +/- 1.3 years (mean +/- standard deviation). Patients underwent yearly surveillance echocardiographic, rest/exercise-gated wall motion, oral dipyridamole thallium, ambulatory electrocardiographic monitor and angiographic studies. Positive test results were defined by decrease in ejection fraction, wall motion abnormality, failure to increase ejection fraction, lack of systolic blood pressure increase, and ischemic ST changes at maximal exercise (or on ambulatory monitor). Wall motion abnormalities and depressed ejection fraction on echocardiography were also abnormal studies as were fixed or reversible perfusion defects on thallium scan. Angiograms were considered positive when 50% luminal narrowing was observed and autopsy coronary artery vasculopathy was defined as cross-sectional coronary obstruction greater than or equal to 70%. No procedure that was examined proved to be a sensitive noninvasive detector of heart transplant coronary artery vasculopathy. All except ambulatory electrocardiographic monitoring had positive predictive values less than 50%. Interestingly, of the techniques evaluated, echocardiography was most sensitive (53%). The poor predictive ability of noninvasive testing in this population may be due to the fact that these tests are designed to detect effects of ischemia rather than coronary obstruction alone. Use of these particular noninvasive modalities routinely after heart transplant to detect coronary artery vasculopathy should be reconsidered because of their low sensitivity and predictive value when used as a surveillance screen.

Adult↗
PubMed1991

Heterotopic heart transplantation and native heart ventricular arrhythmias.

Heterotopic heart transplantation has been said to be contraindicated in patients with serious native heart arrhythmias that produce hemodynamic instability. Placement of heterotopic allografts, however, can theoretically act as a biological biventricular assist device to provide hemodynamic support during these unstable rhythms. Further, this operation might beneficially alter the hemodynamic milieu of heart failure such that the arrhythmias are ameliorated. Described is our experience with 4 patients with heart failure receiving heterotopic cardiac allografts, documenting changes in native heart arrhythmia that occurred. These cases demonstrate that heterotopic grafts can adequately sustain hemodynamics during malignant native heart dysrhythmia. We believe native heart ventricular arrhythmias are not a contraindication to heterotopic heart transplantation.

Arrhythmias, Cardiac↗
PubMed1991

Inability of isolated soluble interleukin-2 receptor levels to predict biopsy rejection scores after heart transplantation.

Successful cardiac transplantation requires suppression of rejection, and endomyocardial biopsy is generally used to quantify this and guide immunotherapy. Biopsy, however, is an invasive, costly, cardiac catheterization with repetition limited. Since rejection requires lymphocyte activation, an alternative method of assessing rejection dynamics might be ELISA determination of soluble interleukin-2 receptor (sIL-2R) levels since induction of the interleukin-2 ligand and its receptor is required. Reports suggest that sIL-2R levels rise during kidney, liver, and heart-lung allograft rejection and heart recipients have an adverse prognosis if sIL-2R is elevated postoperatively. It is unclear, however, if serial measurements or single determinations are sufficient or if change from a baseline assessment is important. The purpose of this study was to determine if an isolated sIL-2R level after heart transplant predicted endomyocardial biopsy score at that moment. To do this, we prospectively followed 60 consecutive patients after orthotopic heart transplant and correlated 479 endomyocardial biopsy scores (McAllister scale 0-10) with matched sIL-2R levels. Regression analysis demonstrated minimal relationship between sIL-2R level and biopsy score (r =.11, r2 =.01, P=.009). When the maximum sIL-2R level for each individual patient was compared with the matched biopsy score, regression analysis revealed r=.04, r2=.001, P=.8. Likewise, when all biopsy scores and sIL-2R levels for each patient were meaned, analysis showed r=.14, r2=.02, P=.26. Thus in heart transplant patients, there is poor correlation between an isolated biopsy score and matched sIL-2R level. However, when mean +/- SEM sIL-2R was determined for severe rejection (score 7-10) and compared with sIL-2R for all other grades, it was significantly higher (1600 +/- 257 vs. 423 +/- 57 U/ml; P=.012). Still, the sensitivity, specificity, and predictive value of an sIL-2R level above 1000 U/ml predicting severe rejection was only 52%, 63%, and 8%. It would be difficult, therefore, to use a single sIL-2R determination after heart transplant to foretell the endomyocadial biopsy score. Serial measurements or quantification of a change in sIL-2R level from baseline might be more predictive of rejection severity.

Biomarkers↗
PubMed1990

Complications of flow-directed balloon-tipped catheters.

Acute or short-term complications following the use of flow-directed balloon-tipped catheters are well recognized. Long-term sequelae are rarely reported. We report herein an early complication of pulmonary arterial rupture with infarction followed by the delayed development of a pulmonary arterial aneurysm.

Aged↗