Amiodarone therapy does not compromise subsequent heart transplantation

OBJECTIVES

The objective of this study was to determine the frequency of pulmonary complications, feasibility of early hospital discharge and requirements for postoperative inotropic and chronotropic support in patients receiving amiodarone therapy before heart transplantation.

BACKGROUND

Although many patients waiting for heart transplantation will die of arrhythmias before a donor heart is found, the use of amiodarone has been limited by concern about increased complications in the perioperative period.

METHODS

The 29 patients receiving amiodarone at the time of heart transplantation at University of California, Los Angeles Medical Center between October 1986 and September 1990 were compared with 29 control recipients to evaluate postoperative morbidity. Patients were receiving amiodarone for recurrent ventricular tachyarrhythmias (n = 11), atrial fibrillation (n = 2) or complex ventricular ectopic activity (n = 16). The average daily dose was 360 +/- 230 mg/day for an average of 11 +/- 22 months before transplantation. Amiodarone and control groups had a similar ejection fraction (0.18 +/- 0.07 vs. 0.20 +/- 0.08), frequency of coronary disease, age and gender. There were three more status I patients in the control group. OKT3 was given to only two patients receiving amiodarone and 12 control patients at high risk for renal dysfunction.

RESULTS

Postoperatively, the duration of assisted ventilation was 21 +/- 19 h after amiodarone therapy versus 26 +/- 2 h in the control group (20 +/- 18 h vs. 15 +/- 9 h after excluding patients receiving OKT3), discharge arterial oxygen saturation was > 95% in both groups. Two patients in the amiodarone group with a smoking history of > 100 pack-years developed bilateral pulmonary infiltrates of brief duration. Although patients receiving amiodarone required atrial pacing more frequently (eight vs. two patients) and had a lower heart rate at discharge (75 +/- 18 vs. 86 +/- 11 beats/min), the duration of inotropic support (2.1 +/- 1.5 vs. 3.5 +/- 2.5 days) and of hospital stay (10 +/- 3 vs. 15 +/- 10 days) was not higher in the amiodarone than in the control group. The mortality rate at 30 days was similar in the two groups (6.8% vs. 3.4%, p = NS).

CONCLUSIONS

Amiodarone therapy before heart transplantation may contribute to occasional pulmonary complications but does not significantly increase perioperative morbidity or mortality with the regimens used in this retrospective study.

Modeling distribution of donor hearts to maximize early candidate survival

BACKGROUND

Priority for cardiac transplantation should reflect the relative waiting list mortality and operative mortality of outpatient candidates and critical candidates.

METHODS AND RESULTS

To determine how to distribute donor hearts for maximal overall survival, a Markov model of eight states was constructed from current statistics for outpatient sudden death, deterioration to critical status, operative mortality for outpatients, and operative mortality for critical candidates. Because the fraction of hearts offered to critical candidates varied, expected survival at 1 year was calculated. To determine the factors most critical in determining priority policy, current conditions were then varied over a fourfold range. Priority for critical candidates maximized overall candidate survival (with and without transplantation), increasing 1-year survival to 78% compared with 66% if hearts were offered only to outpatients. The benefit of giving priority to critical patients persisted when current group mortality rates were individually halved or doubled because these rates were still small compared with the 100% expected mortality of critical patients without transplantation. If the outpatient sudden death rate and the operative mortality for critical patients were doubled simultaneously, however, there was a slight negative impact on survival if critical candidates received priority. Regardless of changes in subgroup outcomes, the distribution of donor hearts had a relatively modest impact on survival because of the large excess of candidates.

CONCLUSIONS

Critical candidates for transplantation should continue to receive priority even if their operative mortality increases above current levels. However, postoperative outcomes must be assessed in relation to changing pretransplantation risks. Distribution of donor hearts will be most beneficial when it is possible to identify the waiting patients at greatest risk for sudden death and deterioration without transplantation.

Effect of direct vasodilation with hydralazine versus angiotensin-converting enzyme inhibition with captopril on mortality in advanced heart failure: the Hy-C trial

To compare the benefit of angiotensin-converting enzyme inhibition and direct vasodilation on the prognosis of advanced heart failure, 117 patients evaluated for cardiac transplantation who had severe symptoms and abnormal hemodynamic status at rest were randomized to treatment with either captopril or hydralazine plus isosorbide dinitrate (Hy-C Trial). Comparable hemodynamic effects of the two regimens were sought by titrating vasodilator doses to match the hemodynamic status achieved with nitroprusside and diuretic agents, attempting to achieve a pulmonary capillary wedge pressure of 15 mm Hg and a systemic vascular resistance of 1,200 dynes.s.cm-5. Treatment with the alternate vasodilator was started because of poor hemodynamic response or side effects (40% of patients in the captopril group and 22% in the hydralazine group). Adequate hemodynamic response in patients with a serum sodium level less than 135 mg/dl was more likely with hydralazine than with captopril (71% vs. 33%, p = 0.04). Isosorbide dinitrate was prescribed in 88% of the hydralazine-treated patients and 84% of the captopril-treated patients. The hemodynamic improvements from each regimen were equivalent. After 8 +/- 7 months of follow-up, the actuarial 1-year survival rate was 81% in the captopril-treated patients and 51% in the hydralazine-treated patients (p = 0.05). The improved survival with captopril resulted from a lower rate of sudden death, which occurred in only 3 of 44 captopril-treated patients compared with 17 of 60 hydralazine-treated patients (p = 0.01). In the subset of patients who continued treatment with the initial vasodilator, results were similar to those for the entire treatment group.(ABSTRACT TRUNCATED AT 250 WORDS)

Dentists evaluate their patients: an empirical investigation of preferences

Dental treatment is a dyadic encounter. Yet research on the dentist-patient dyad has tended to focus on patient perceptions of dentist, to the neglect of dentist perceptions of patient. Previous theoretic and qualitative work on caregiver perceptions of patients suggested three dimensions of evaluation. Dentists (N = 618) rated their patients on items taken from two prior studies. Dentists' responses were subjected to confirmatory factor analysis. The analysis substantiated the existence of three evaluative dimensions: compliance, tractability, and likability. Further analysis showed that the three dimensions formed a Guttman simplex, revealing a second-order factor of selectivity and allowing a classification of dentists on the basis of patient selectivity.

Ischemic cardiomyopathy. Criteria for coronary revascularization and cardiac transplantation

Because of the shortage of donor hearts, 16 (33%) of 48 patients with ischemic cardiomyopathy died awaiting transplantation. Determining factors that predict effective coronary revascularization and identifying patients who may benefit from revascularization is crucial. From 1984 to 1990, 207 ischemic cardiomyopathy patients were evaluated for heart transplantation; 131 were accepted (83 transplanted), 54 were not accepted, and 22 were revascularized (19 underwent bypass graft surgery and three underwent percutaneous transluminal coronary angioplasty). Four bypass patients failed early (less than or equal to 30 days, three deaths and one urgent heart transplant) and two late deaths (greater than or equal to 1 year) occurred. Overall mortality was 27%. Three-year survival of revascularized and transplanted patients was 72 +/- 10% and 73 +/- 6%, respectively. Successfully revascularized patients had preoperative ejection fraction, left ventricular end-diastolic dimension, and New York Heart Association functional class of 26 +/- 9%, 68 +/- 3 mm, and 3.9 +/- 0.4, respectively, compared with 36 +/- 9% (p less than 0.05), 64 +/- 6 mm (p = NS), and 1.2 +/- 0.4 (p less than 0.05) after revascularization. Preoperative ejection fraction of patients failing revascularization was 15 +/- 4% (p = NS compared with successful revascularization), and left ventricular end-diastolic dimension was 81 +/- 4 mm (p less than 0.05). Preoperative positron emission tomography imaging myocardial blood flow and glucose metabolism was performed in 12 patients: 10 patients with scans predicting reversible ischemia were successfully revascularized, and two patients with negative scans had failed revascularization.(ABSTRACT TRUNCATED AT 250 WORDS)

Decreasing survival benefit from cardiac transplantation for outpatients as the waiting list lengthens

Many patients are accepted for cardiac transplantation during a period of clinical instability associated with a high risk of death, even though most can be discharged home to await transplantation. As the waiting lists lengthen, priority is awarded solely on the basis of the waiting time of outpatients, who now usually undergo transplantation after they have already survived a major period of jeopardy. To determine the impact of the current waiting times and priority system on the previously expected benefit offered by transplantation, 1-year actuarial survival without transplantation was recalculated after each month without transplantation for 214 potential candidates with an ejection fraction of 0.17 +/- 0.05 discharged on tailored medical therapy after evaluation. These data were compared with the 1-year survival data of 88 outpatients who underwent transplantation. Actuarial survival after 1 year was 67% on tailored therapy compared with 88% after transplantation (p = 0.009). Death without transplantation was sudden in 43 of 51 patients, resulting from hemodynamic decompensation in 8. For outpatients already surviving 6 months without transplantation, actuarial survival over the next 12 months was 83% without transplantation. Thus, the expected improvement in survival after transplantation would be only 5% over the subsequent year for patients waiting 6 months, which is the waiting time for many outpatients. Such patients should be reevaluated to determine whether transplantation remains indicated during the next year.

Altered thyroid hormone metabolism in advanced heart failure

To determine the prevalence and significance of abnormal thyroid hormone metabolism in congestive heart failure, free thyroxine (T4) index, free triiodothyronine (T3) index, reverse T3 and thyrotropin levels were obtained in 84 hospitalized patients with chronic advanced heart failure. Free T4 index was normal in all patients. Free T3 index was reduced or reverse T3 elevated, or both, leading to a low free T3 index/reverse T3 ratio in 49 (58%) of the 84 patients. A low free T3 index/reverse T3 ratio was associated with higher right atrial, pulmonary artery and pulmonary capillary wedge pressures and lower ejection fraction, cardiac index, serum sodium, albumin and total lymphocyte count. In multivariate analysis, the free T3 index/reverse T3 ratio was the only independent predictor of poor 6 week outcome (p less than 0.001); the actuarial 1 year survival rate was 100% for patients with a normal ratio and only 37% for those with a low ratio (p less than 0.0001). A low free T3 index/reverse T3 ratio is associated with poor ventricular function and nutritional status and is the strongest predictor yet identified for short-term outcome in patients with advanced heart failure.

Dentists' technical competence, communication, and personality as predictors of dental patient anxiety

Previous research has found that many factors influence patients' dental anxiety, many of which are related to the practitioner's technical and interpersonal skill. Unfortunately, a confirmatory factor analysis of scales used in dental anxiety research revealed numerous problems with the measurement devices. The Spielberger State-Trait Anxiety Inventory (STAI) split into two subscales: calmness and anxiety. The Corah Dental Anxiety Scale (CDAS) was unidimensional but was unable to detect relationships between anxiety and interpersonal or communication factors. Interestingly, patient satisfaction, dentist behavior, and empathy items did not load on independent scales, as previously reported in the literature. Instead, five clusters were detected: positive and negative communication, positive and negative interpersonalness, and perceived technical competence.

Acute reduction of atrial overload during vasodilator and diuretic therapy in advanced congestive heart failure

Although acute afterload reduction is known to improve cardiac output in patients with congestive heart failure (CHF), the effect of therapy on the atrial overload directly causing congestive symptoms has not been systematically studied. Atrial volumes and mitral and tricuspid regurgitation, in addition to left ventricular ejection fraction and indexes of left ventricular contractility (mean acceleration, ejection time and peak systolic pressure/end-systolic volume index), were measured using 2-dimensional and Doppler echocardiography and color flow imaging in 30 patients with advanced CHF, before and after acute vasodilator and diuretic therapy tailored to hemodynamic goals. Therapy increased stroke volume by 64% (36 +/- 10 to 55 +/- 14 cc), decreased right atrial pressure by 45% (15 +/- 5 to 8 +/- 4 mm Hg), systemic vascular resistance by 36% (1,700 +/- 400 to 1,030 +/- 300 dynes s cm-5) and pulmonary capillary wedge pressure by 37% (31 +/- 6 to 19 +/- 6 mm Hg) (all p less than 0.001). Echocardiography showed simultaneous reductions in left and right atrial volumes: 24 +/- 19 and 18 +/- 12%, respectively (p less than 0.001). Mitral and tricuspid regurgitation measured by color flow fraction both decreased by a mean of 44% (p less than 0.001). While ejection fraction increased from 15 +/- 5 to 19 +/- 7% (p less than 0.001), there were no changes in relatively load-independent indexes of contractility. Therefore, acute therapy with vasodilators and diuretics in advanced CHF causes reductions in atrial volumes and atrioventricular valve regurgitation that are evident from serial noninvasive studies and may play a major role in the improvement of congestive symptoms.

Estimating the power of the two-sample Wilcoxon test for location shift

Traditional methods for calculating the power of a statistical test for location shift require knowledge of the shape of the underlying probability distribution. The distribution shape, however, may be unknown. This paper describes a bootstrap method for using observed data (or pilot data) to approximate the power. No assumptions need be made about the shape of the underlying continuous probability distribution. Simulation evidence shows that, when applied to the Wilcoxon two-sample test for location shift, the suggested method is reliable. The evidence also shows that it is more accurate than a benchmark traditional approach. The bootstrap method is applied to a real-data example. The analysis demonstrates how the method can be used to determine sample sizes and how to choose the more powerful of two alternative tests for location shift.

Descriptive statistical analyses of serial dilution data

The serial dilution assay (for example, an in vitro antimicrobic susceptibility test or a serum antibody titer assay) is an important technique in biomedical research. The structure of the experiment forces grouping of the threshold concentrations into intervals. Statistical methods to analyse threshold concentrations from a batch of serial dilution assays should account for the grouping of the data. Many traditional subject area analyses, however, ignore the grouped nature of the data. This article discusses the discrepancy between the traditional subject area approach and the usual statistical approach for analysing such grouped data.

Interval estimation of the density of organisms using a serial-dilution experiment

The serial-dilution assay is a standard microbiological method for estimating the density of organisms in a solution. The commonly used interval-estimation procedures of Woodward and deMan are described and compared. A new method for the calculation of two-sided confidence intervals, which is superior to the standard procedures, is presented. The computations are illustrated for a decimal dilution assay with three samples at each of three dilutions.

Prospective payment's impact on ancillary services. Pastoral care, social services: role in reducing medical costs

Under the prospective payment system, costs for medical social services, as well as for other inpatient services, are reimbursed at a fixed rate according to the patient's diagnosis. Thus hospitals, under the incentives to reduce costs by limiting services and increasing patient volume, will examine ancillary services to determine whether the services increase or decrease costs. Social and pastoral care workers will likely play an important role in hospitals' cost reduction efforts in several ways: Begin forming a discharge plan early in a patient's care, especially for patients who are at high risk for delayed discharge. Evaluate patients and their families to detect problems that may impede treatment and recovery and refer patients to community and hospital resources for help. In the emergency room, guide persons who do not need to be hospitalized to community resources. Record patient information that may help health professionals improve treatment and speed discharge. Such data include patients' financial status, use of community agencies, and rehabilitation. Counsel patients and families as they make treatment decisions.

The health status of fourth form students in Northland

A random sample of fourth form students throughout Northland was studied. Uncorrected visual defects were found in 4.5% and significant hearing loss in 9.1%. Appreciable numbers were overweight; 6.2% of boys and 22.5% of girls exceeded the desirable bulk index range. Levels of total cholesterol appear decreased compared to earlier New Zealand studies and were significantly lower than the Wairoa College survey levels. There was a strong correlation between total cholesterol and low density lipoprotein cholesterol. High density lipoprotein cholesterol was significantly higher in non-Maori than in Maori girls. Overall systolic blood pressure for boys at 114.3 mmHg (15.2 kPa) was significantly higher than for girls at 109.5 mm Hg (14.56 kPa). One-third of boys exceeded the adult uric acid reference range; a significantly higher proportion than for girls. Fifteen point one percent of boys and 23.5% of girls reported smoking seven or more cigarettes per week; 19.1% of boys and 9% of girls reported taking regular amounts of alcohol at least every weekend.

Estimating proportionate changes in rates

Quantitative measures are defined for use in health policy formulation. Consider a dichotomized risk factor for a specific disease or a protective factor known to promote health. A health policy that alters the prevalence of exposure to the factor will create corresponding proportionate changes in the disease rate and in the health rate. Statistical formulas are presented for estimating such proportionate changes. Formulas are given for cohort, case-control, and some hybrid study designs, but only for those studies where it is appropriate to present the data in a 2 X 2 table. It is assumed that the population is stable and that all subjects are observed over the same fixed time interval. Formulas for estimating the standard error of the estimate are also provided.

Effect of neonatal intrahypothalamic testosterone implants on cyclicity and adult sexual behavior in the female hamster

To localize the neural sites of hormone action for sexual differentiation in the hamster, pellets containing 3 microgram testosterone were implanted directly in the preoptic area-anterior hypothalamus (POA-AH) and the ventromedial hypothalamus-arcuate regions of the hypothalamus of 3-day-old female hamsters. The POA-AH implants strongly enhanced the potential for ectopic mounts, rear mounts, and intromission patterns after adult testosterone treatment. 50% of the females with neonatal POA-AH implants demonstrated vaginal acyclicity in adulthood, suggesting a significant disruption of normal gonadotropin release. Tests for female sexual behavior revealed that implants in both POA-AH and ventromedial arcuate had no significant effect on latency to lordosis or total lordosis duration with estrogen and progesterone priming, but did reduce the longest single bout of lordosis. In conjunction with other recent investigations, these findings suggest that in the hamster, as in other species, androgenization involves several independent processes in terms of both location and sensitivity to hormone exposure.

Aural health in 227 Northland school and preschool children

Two hundred and seventy-seven Northland school and preschool children were examined to determine the current incidence of chronic suppurative otitis media and middle ear effusion in the child population of one area. A reduction in incidence of CSOM from 10.5 percent in 1974 to 2.7 percent in 1978 is attributed to the successful mobile ear clinic's child health hearing conservation programme. The incidence of middle ear effusion would indicate that this condition may be less uncommon in Maori children than is generally believed. The value of impedance audiometry as a screening procedure is considered.

Statistical tests for recessive lethal-carriers

This paper presents a statistical method for testing whether a male mouse is a recessive lethal-carrier. The analysis is based on a back-cross experiment in which the male mouse is mated with some of his daughters. The numbers of total implantations and intrauterine deaths in each litter are recorded. It is assumed that, conditional on the number of total implantations, the number of intrauterine deaths follows a binomial distribution. Using computer-simulated experimentation it is shown that the proposed statistical method, which is sensitive to the pattern of intrauterine death rates, is more powerful than a test based only on the total number of implant deaths. The proposed test requires relatively simple calculations and can be used for a wide range of values of total implantations and background implant mortality rates. For computer-simulated experiments, there was no practical difference between the empirical error rate and the nominal error rate.

Choosing the parameter for a 2 x 2 table or a 2 x 2 x 2 table analysis

Fourteen 2 x 2 table measures of association are compared and six 2 x 2 x 2 table measures of synergism are compared. The presentation is based on a conceptual population model for the true association between the disease and the risk factor(s). Each measure is judged as to potential use and identified with the study designs under which it can be estimated. It is shown that prior information about the correct population model is required to adequately measure synergism.

The treatment and prevention of chronic otorrhoea in the Northland health district

The operation of a mobile ear clinic within the school medical service in Northland is described. The major justification for the use of a sophisticated unit lies in the opportunity which it affords for the education of children and adults on aural health. The higher costs of treatment may well be more than offset by the long-term benefits resulting from increased awareness and better understanding in our population on the causation of supporative otitis media.

New assay of protective activity of Rocky Mountain spotted fever vaccines

Areas under the fever curves of guinea pigs inoculated with Rocky Mountain spotted fever vaccine over a restricted dose range and infected with a standardized dose of Rickettsia rickettsii varied linearly with log10 dose of vaccine. A calculator was programmed to plot fever curves and calculate the vaccine dose that reduced the fever of infected animals by 50%.

Statistical inferences about injury and persistence of environmentally stressed bacteria

A standard technique for ascertaining the survival characteristics of bacteria after being environmentally stressed is to incubate the bacteria on both selective and non-selective media and count the colonies produced. Based on these colony counts, indexes of injury and persistence of the bacteria are calculated. To compare the stress of two different environments, a persistence ratio is calculated. In this paper, methods of statistical inference concerning these indexes and ratios are presented. These statistical methods use well-known procedures for analysis of binomial data and 2 times 2 table data, and are appropriate when the colony counts follow a Possion distribution.

Activation of solubilized steroid-transforming enzymes of adrenal microsomal origin by serum proteins

The reactions which result in the conversion of pregnenolone to progesterone and of progesterone to deoxycorticosterone in undisrupted microsomal preparations from rat adrenal glands were stimulated by homologous serum. The active materials were shown to be firmly associated with serum proteins. The dialysable fraction of serum was either without effect on these transformations or was inhibitory. The enzyme systems involved were partially solubilized by exposure of the microsomal preparation to prolonged sonic treatment or to 1% Triton N-101. After either treatment, 35–40% of the original specific activity of the steroid 21-hydroxylase system responsible for the conversion of progesterone to deoxycorticosterone was found in the supernatant fraction after high-speed centrifugation. However, this solubilized system did not respond to serum preparations. The same procedures also resulted in a supernatant fluid which showed about 50–60% of the initial specific activity of the multi-enzyme system involved in the conversion of pregnenolone to progesterone. In these instances, the stimulatory effect of serum was retained or accentuated. Acetone powders prepared from the adrenal microsomal fraction were also active in the conversion of pregnenolone to progesterone and responded to serum with enhanced activity. Earlier observations that activation of steroid 21-hydroxylase by homologous rat serum was specific for the β-globulin fraction were confirmed in the present investigations. In contrast, stimulation of the conversion of pregnenolone to progesterone was apparently due principally to the albumin fraction. Albumin preparations from a number of other sources, as well as whole human serum protein, were also effective in this regard. The active protein preparations selectively stimulated 4-ene-3β-hydroxysteroid dehydrogenase activity, but did not activate 5-ene-3-oxosteroid isomerase in the microsomal fraction. This finding suggested that activation of 5-ene-3β-hydroxysteroid dehydrogenase was responsible for stimulation of progesterone synthesis from pregnenolone. The results indicate that the protein-bound factor in rat serum which was capable of stimulating the conversion of progesterone to deoxycorticosterone in microsomal preparations from rat adrenal glands was different from that which activates the conversion of pregnenolone to progesterone. Moreover, these diverse factors appeared to act by different mechanisms.