A systematic review of the effects of disclosing carrier results generated through newborn screening

Evidence on the effects of disclosing carrier results identified through newborn screening (NBS) is needed to develop effective strategies for managing these results, and to inform debate about contradictory policies governing genetic testing in minors in the context of NBS relative to clinical care. This is likely to be even more important as technological opportunities for carrier identification through NBS increase. We report the results of a systematic review of evidence related to the generation of carrier results through NBS to summarize what is known about: (1) the outcomes associated with these results; (2) the best strategies for providing information and follow-up care to parents; and (3) the impact they have on reproductive decision-making. Our study expands the existing body of knowledge and identifies gaps in the evidence base. As key players in the management of carrier results clinically, genetic counselors are well positioned to engage in formative research and policy development in this area.

'Hypersynchronisation' by tissue velocity imaging in patients with cardiac amyloidosis

OBJECTIVE

It is unknown if some patients with cardiac amyloidosis (CA) have mechanical dyssynchrony, as has been demonstrated in patients with ischaemic and dilated cardiomyopathies. The aim of this study was to assess mechanical dyssynchrony in patients with CA using tissue velocity imaging (TVI) and to define its usefulness for risk stratification.

DESIGN AND PATIENTS

We included 121 patients with primary amyloidosis and 37 age-matched and sex-matched controls. Patients were divided into two groups: 60 with advanced-CA and 61 with no-advanced-CA, according to left ventricular (LV) wall thickness and diastolic dysfunction. Dyssynchrony assessment included: (1) atrioventricular dyssynchrony (dys), (2) interventricular dys, (3) intraventricular dys assessed longitudinally, using the standard deviation of time to systolic peak velocity (Ts-SD) of the 12 basal and mid level LV segments, and (4) intraventricular dys assessed radially, using the difference in radial Ts between mid anteroseptal and mid posterior segments.

OUTCOME

Primary end-point was all-cause death. During a median follow-up of 13 months there were 35 events among patients.

RESULTS

Contrary to the hypothesis, the intraventricular dys indices in advanced-CA patients were reduced compared to either the no-advanced-CA group or to controls (Ts-SD: 12.1 (9.0); 35.1 (18.6); 24.5 (14.1), respectively, p<0.001). This reduction was primarily the result of decreased ejection time (ET). Moreover, ET was the most significant predictor of survival (HR = 0.98, p<0.001).

CONCLUSIONS

The regional timing of systolic motion measured by TVI was abnormally synchronised in the patients with advanced-CA. ET reduction plays a prominent part in this process and should be considered an essential parameter for assessment of patients with cardiac amyloidosis.

Duty to disclose what? Querying the putative obligation to return research results to participants

Many research ethics guidelines now oblige researchers to offer research participants the results of research in which they participated. This practice is intended to uphold respect for persons and ensure that participants are not treated as mere means to an end. Yet some scholars have begun to question a generalised duty to disclose research results, highlighting the potential harms arising from disclosure and questioning the ethical justification for a duty to disclose, especially with respect to individual results. In support of this view, we argue that current rationales for a duty of disclosure do not form an adequate basis for an ethical imperative. We review policy guidance and scholarly commentary regarding the duty to communicate the results of biomedical, epidemiological and genetic research to research participants and show that there is wide variation in opinion regarding what should be disclosed and under what circumstance. Moreover, we argue that there is fundamental confusion about the notion of "research results," specifically regarding three core concepts: the distinction between aggregate and individual results, amongst different types of research, and across different degrees of result veracity. Even where policy guidance and scholarly commentary have been most forceful in support of an ethical imperative to disclose research results, ambiguity regarding what is to be disclosed confounds ethical action.

When research seems like clinical care: a qualitative study of the communication of individual cancer genetic research results

Background

Research ethicists have recently declared a new ethical imperative: that researchers should communicate the results of research to participants. For some analysts, the obligation is restricted to the communication of the general findings or conclusions of the study. However, other analysts extend the obligation to the disclosure of individual research results, especially where these results are perceived to have clinical relevance. Several scholars have advanced cogent critiques of the putative obligation to disclose individual research results. They question whether ethical goals are served by disclosure or violated by non-disclosure, and whether the communication of research results respects ethically salient differences between research practices and clinical care. Empirical data on these questions are limited. Available evidence suggests, on the one hand, growing support for disclosure, and on the other, the potential for significant harm.

Methods

This paper explores the implications of the disclosure of individual research results for the relationship between research and clinical care through analysis of research-based cancer genetic testing in Ontario, Canada in the late 1990s. We analyze a set of 30 interviews with key informants involved with research-based cancer genetic testing before the publicly funded clinical service became available in 2000.

Results

We advance three insights: First, the communication of individual research results makes research practices seem like clinical services for our respondents. Second, while valuing the way in which research enables a form of clinical access, our respondents experience these quasi-clinical services as inadequate. Finally, our respondents recognize the ways in which their experience with these quasi-clinical services is influenced by research imperatives, but understand and interpret the significance and appropriateness of these influences in different ways.

Conclusion

Our findings suggest that the hybrid state created through the disclosure of research results about individuals that are perceived to be clinically relevant may produce neither sufficiently adequate clinical care nor sufficiently ethical research practices. These findings raise questions about the extent to which research can, and should, be made to serve clinical purposes, and suggest the need for further deliberation regarding any ethical obligation to communicate individual research results.

Incorporating documents into qualitative nursing research

PURPOSE

To present an overview of how documents can be incorporated as key sources of data in qualitative nursing research.

METHODS

Analysis of the nature of documents and the distinctive features of any research strategy to analyze documents.

CONCLUSIONS

Many different strategies can be used in the analysis of documentary sources that are relevant to nursing practice. A systematic approach to the analysis of these textual resources, using one or several of the analytic strategies described here, can support and advance nursing scholarship.

Calcific retinal embolism as an indicator of severe unrecognised cardiovascular disease

OBJECTIVE

To describe the association between calcific retinal embolism (CRE) and cardiac valve stenosis.

DESIGN AND SETTING

Retrospective chart review of patients with clinical criteria for CRE.

PATIENTS

24 patients with CRE who underwent two dimensional echocardiography between 1976 and 1998.

RESULTS

Nine patients (38%) had calcific valve stenosis, which was haemodynamically severe in five patients (four aortic and one mitral), four of whom had no cardiac symptoms. Six patients underwent surgical intervention (aortic valve replacement in three patients, mitral and aortic valve replacement in one patient, removal of calcific cardiac pseudotumour in one patient, and carotid endarterectomy in one patient).

CONCLUSIONS

CRE may be the presenting feature of otherwise asymptomatic, clinically important underlying cardiovascular disease and, in particular, haemodynamically severe calcific valve stenosis.

Progression of familial and non-familial dilated cardiomyopathy: long term follow up

BACKGROUND

It is unknown whether progression of familial idiopathic dilated cardiomyopathy differs from progression in the non-familial form. It has been suggested that familial disease indicates a worse prognosis, and that this should be considered when planning the timing of heart transplantation.

OBJECTIVE

To compare five year survival or time to heart transplantation in an unselected series of patients with dilated cardiomyopathy who had been evaluated for familial v non-familial disease through the echocardiographic investigation of first degree relatives.

DESIGN

Medical records were reviewed and questionnaires were mailed to all patients who had previously participated in a family based study of dilated cardiomyopathy. Information was gathered about survival, heart transplantation, and left ventricular ejection fraction (LVEF) measurements. Survival data were censored at the time of cardiac transplantation.

RESULTS

Follow up data were obtained for 99 of 101 patients (69 with non-familial and 30 with familial disease). Five year survival was 55% for non-familial and 51% for familial patients (NS). The main predictor of mortality was an LVEF of < 30%. Familial status did not predict mortality. There was no significant difference in follow up LVEF values between the groups.

CONCLUSIONS

Five year survival is not significantly different in the familial and non-familial forms of dilated cardiomyopathy.

Eustachian valve cyst

Transesophageal echocardiography provides high resolution of intracardiac structures. One potential problem is the misdiagnosis of previously unrecognized benign cardiac structures as malignant processes, leading to unnecessary surgical procedures. We describe an unusual case of benign intracardiac eustachian valve cyst monitored over 2 years.

Patent foramen ovale transcatheter closure device thrombosis

The role of patent foramen ovale (PFO) in patients with cryptogenic stroke (stroke of unknown cause) remains controversial, although an association seems likely in younger patients with atrial septal aneurysms and PFO. The mechanism of cryptogenic stroke in these patients is presumed to be paradoxical embolism via right-to-left shunt across the PFO. The available options for treatment include medical therapy with antiplatelet or anticoagulant therapy or closure of the PFO surgically or with use of transcatheter PFO closure devices. We describe 2 cases of bilateral device thrombosis associated with use of a transcatheter PFO closure device (CardioSEAL). To our knowledge, only 1 other case of thrombosis associated with use of this device has been reported.

Reoperation for prosthetic aortic valve obstruction in the era of echocardiography: trends in diagnostic testing and comparison with surgical findings

OBJECTIVES

We sought to: 1) identify trends in the diagnostic testing of patients with prosthetic aortic valve (AVR) obstruction who undergo reoperation and 2) compare diagnostic test results with pathologic findings at surgery.

BACKGROUND

It is unclear whether Doppler transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) have reduced hemodynamic catheterization rates.

METHODS

We reviewed 92 consecutive cases ofAVR reoperation at a single center from 1989 to 1998, comparing 49 cases of mechanical AVR obstruction (group A) to 43 cases of bioprosthetic obstruction (group B). Preoperative Doppler TTE was performed in all cases.

RESULTS

In group A cases, there was a marginally significant trend towards lower catheterization rates for the Gorlin AVR area, from 36% in 1989 to 1990 to 10% in 1997 to 1998 (p = 0.07), but diagnostic TEE utilization (47% of cases) did not vary. The cause of mechanical AVR obstruction was pannus in 26 cases (53%), mismatch (P-PM) in 19 (39%) and thrombosis in 4 (8%). The mechanism (pannus/thrombus vs. mismatch) was identified in 10% by TTE and 49% by TEE (p < 0.001). In group B cases, hemodynamic catheterization rates (21%) and diagnostic TEE utilization (21%) did not vary with time. Obstruction was caused by structural degeneration in 37 cases (86%), thrombosis in 3 (7%), mismatch in 2 (5%) and pannus in 1 (2%). The mechanism was correctly identified in 63% by TTE and in 81% by TEE (p = 0.18).

CONCLUSIONS

Doppler TTE is the primary means to diagnose AVR obstruction; hemodynamic catheterization is not routinely needed. In unselected patients with mechanical AVR obstruction, TEE differentiation of pannus or thrombus from mismatch is challenging.

Doppler hemodynamics of 51 clinically and echocardiographically normal pulmonary valve prostheses

OBJECTIVE

To determine the normal Doppler hemodynamics of various pulmonary valve prostheses (PVPs).

PATIENTS AND METHODS

We retrospectively analyzed comprehensive Doppler echocardiographic examinations of 51 patients (mean age, 27.8 years; range, 1-59 years) with PVPs that were normal on clinical and 2-dimensional echocardiographic examinations to establish the normal hemodynamics of various types and sizes of PVPs. The earliest complete postoperative transthoracic echocardiogram was identified for each patient. Doppler examinations were analyzed for peak instantaneous velocity, right ventricular outflow tract velocity, and peak and mean systolic gradient. The frequency of prosthetic regurgitation was also noted.

RESULTS

The average +/- SD peak instantaneous velocity for all PVPs was 2.24+/-0.6 m/s, with an average peak systolic gradient of 20.4+/-10.4 mm Hg and an average mean systolic gradient of 11.0+/-5.1 mm Hg. The mean right ventricular outflow tract velocity was 1.0+/-0.2 m/s. Pulmonary homografts were found to have significantly lower peak velocities (average, 1.8+/-0.6 m/s) than all heterografts combined (average, 2.4+/-0.5 m/s; P=.002). Prosthetic regurgitation was more common in pulmonary homografts (88%) than in heterografts combined (29%; P<.001).

CONCLUSION

This study establishes the normal range for Doppler hemodynamics of various PVPs, specifically homografts and heterografts, in both pediatric and adult patients.

Outcome of reoperation for aortic valve prosthesis-patient mismatch

We report a single center's 10-year experience with 21 consecutive cases of repeat aortic valve replacement for prosthesis-patient mismatch (P-PM) in which there was no hospital mortality among 12 patients treated for isolated P-PM. With an overall survival of 92% at a median follow-up of 4.5 years and functional class I symptoms in most survivors (73%), we conclude that repeat surgery for isolated P-PM has a relatively low mortality and a good intermediate-term clinical outcome.

Clinical utility of Doppler echocardiography and tissue Doppler imaging in the estimation of left ventricular filling pressures: A comparative simultaneous Doppler-catheterization study

BACKGROUND

Noninvasive assessment of diastolic filling by Doppler echocardiography provides important information about left ventricular (LV) status in selected subsets of patients. This study was designed to assess whether mitral annular velocities as assessed by tissue Doppler imaging are associated with invasive measures of diastolic LV performance and whether additional information is gained over traditional Doppler variables.

METHODS AND RESULTS

One hundred consecutive patients referred for cardiac catheterization underwent simultaneous Doppler interrogation. Invasive measurements of LV pressures were obtained with micromanometer-tipped catheters, and the mean LV diastolic pressure (M-LVDP) was used as a surrogate for mean left atrial pressure. Doppler signals from the mitral inflow, pulmonary venous inflow, and TDI of the mitral annulus were obtained. Isolated parameters of transmitral flow correlated with M-LVDP only when ejection fraction <50%. The ratio of mitral velocity to early diastolic velocity of the mitral annulus (E/E') showed a better correlation with M-LVDP than did other Doppler variables for all levels of systolic function. E/E' <8 accurately predicted normal M-LVDP, and E/E' >15 identified increased M-LVDP. Wide variability was present in those with E/E' of 8 to 15. A subset of those patients with E/E' 8 to 15 could be further defined by use of other Doppler data.

CONCLUSIONS

The combination of tissue Doppler imaging of the mitral annulus and mitral inflow velocity curves provides better estimates of LV filling pressures than other methods (pulmonary vein, preload reduction). However, accurate prediction of filling pressures for an individual patient requires a stepwise approach incorporating all available data.

Diet drug-related cardiac valve disease: the Mayo Clinic echocardiographic laboratory experience

OBJECTIVE

To describe the prevalence of diet drug-related valvular disease among our referral population and the association of valvular disease with duration of exposure to fenfluramine and phentermine in combination and to dexfenfluramine alone.

PATIENTS AND METHODS

In this retrospective review of clinical and echocardiographic data, charts of patients referred for treatment of toxic effects of diet drugs were reviewed, and telephone interviews were conducted.

RESULTS

Between June and December 1997, 191 patients (164 women, 27 men; mean age, 47 years) were referred for possible diet drug-related valvular disease. Twenty-eight (28%) of the 99 asymptomatic patients and 40 (43%) of the 92 symptomatic patients had abnormal echocardiographic findings. Valvular lesions among the 68 patients with abnormal echocardiographic findings included mild (or greater) aortic regurgitation in 55 patients (81%), moderate (or greater) mitral regurgitation in 12 (18%), and moderate (or greater) tricuspid regurgitation in 7 (10%). The Food and Drug Administration case definition of diet drug-related valvulopathy was noted in 31 % of this referral population. Of patients with valvulopathy, mean duration of therapy with fenfluramine and phentermine in combination and dexfenfluramine alone was 9 months and 5 months, respectively. Duration of therapy was not associated with presence or absence of disease. Five patients had surgical intervention for severe valvulopathy: 3 had mitral valve repair, 1 had mitral valve replacement, and 1 had aortic valve replacement. Pulmonary hypertension (>40 mm Hg) was found in 24 patients (13%), and 17 (71 %) had pulmonary hypertension in association with valvulopathy.

CONCLUSION

This study demonstrated a 31% (60/191) prevalence of valvulopathy in patients with a history of diet drug exposure who were referred for echocardiographic evaluation. The most common finding was mild aortic regurgitation. Twenty-eight percent of asymptomatic patients had abnormal echocardiographic findings. This study emphasizes the spectrum of diet drug-related cardiac disease and the potential for valvulopathy in asymptomatic patients.

Echocardiographic improvement over time after cessation of use of fenfluramine and phentermine

OBJECTIVE

To determine the echocardiographic changes over time of valvular heart lesions in patients who took the weight loss drugs fenfluramine and phentermine.

SUBJECTS AND METHODS

This prospective cohort study began at the termination of a randomized, double-blind, placebo-controlled weight loss trial of 18 obese women and 13 obese men (mean age, 42 years; mean body mass index, 33.4 kg/m2) who had been assigned randomly to treatment with fenfluramine and phentermine or to placebo. Echocardiograms were obtained at termination of the trial when fenfluramine was withdrawn from the market and 6 months later. They were interpreted independently by 3 cardiologists blinded to treatment assignment and temporal sequence of the echocardiograms. The main outcome measure was the change in drug-related valvular disease over time.

RESULTS

One subject assigned to receive the drugs was lost to follow-up, and 3 subjects who did not meet a weight loss goal of 10 kg crossed over from placebo to drug treatment. Echocardiograms were obtained in 19 subjects who received the drugs and 11 subjects who received placebo, and 6-month follow-up echocardiograms were obtained in 15 subjects who received the drugs and 3 who received placebo. Subjects had taken fenfluramine and phentermine a mean of 41 weeks (range, 8-73 weeks). Five of 19 subjects who received the drugs (26%; 95% confidence interval, 7%-46%) and 1 of 11 who received placebo (9%) (odds ratio, 3.6; 95% confidence interval, 0.4-35.6) had findings that met criteria established for drug-related valvular disease. All 5 subjects (4 women and 1 man) receiving the drugs had mild aortic regurgitation, and 1 also had pulmonary hypertension (estimated pulmonary artery pressure, 59 mm Hg). Six months later, the echocardiographic findings had improved in all 5 subjects (P=.06), and 3 no longer met the criteria for drug-related valvular disease. Pulmonary artery pressures decreased to near normal in the subject with pulmonary hypertension (37 mm Hg). Overall, the echocardiographic valvular features improved in 8 of 15 subjects who received the drugs and had echocardiograms performed at both time periods (P=.008).

CONCLUSIONS

Valvular heart disease did not appear to progress after cessation of use of fenfluramine and phentermine, and echocardiographic valvular features appeared to improve over time.

Chronotropic response, safety, and accuracy of dobutamine stress echocardiography in patients with atrial fibrillation and known or suspected coronary artery disease

Ninety-two consecutive patients with atrial fibrillation (AF) who underwent dobutamine stress echocardiography were compared with a control group of patients in sinus rhythm matched for age, sex, and resting heart rate. Patients with AF had an increased chronotropic response to dobutamine, but there were no adverse effects and no evidence that the lower doses of dobutamine typically given to patients with AF were insufficient to induce ischemia.

Aneurysms in the left ventricular outflow tract: clinical presentation, causes, and echocardiographic features

We present a descriptive compendium of anatomically interrelated aneurysms and aneurysmal-like structures arising in and around the left ventricular outflow tract. Images selected from the Mayo Clinic echocardiography database illustrate classic or typical examples of each entity. Essential morphologic features of each lesion are described. Clinical presentation, causes, and diagnostic echocardiographic features taken together can improve recognition and clinical management of this diverse group of anomalies.

Safety of dobutamine stress echocardiography supervised by registered nurse sonographers

Dobutamine stress echocardiography (DSE) is widely used for the diagnosis and evaluation of coronary artery disease. Studies examining the safety of this technique typically have involved DSE supervised by physicians. At the Mayo Clinic, experienced registered nurse (RN) sonographers were trained to perform DSE under the direct supervision of a physician. To prove that the safety of DSE was not compromised with the change in supervision, we examined data from 1035 consecutive outpatient studies: 516 patients were monitored by cardiologists or cardiology fellows (group 1) and 519 were monitored by trained RN sonographers (group 2). Risk factors, history of coronary artery disease, stress parameters, and complication rates were similar in both groups. In group 1, one patient experienced sustained ventricular tachycardia requiring treatment. In group 2, one patient experienced ventricular fibrillation during recovery and was successfully resuscitated. Outpatient DSE is safe when supervised by RN sonographers.

Outpatient two-dimensional echocardiography-guided pericardiocentesis

Two-dimensional echocardiography-guided pericardiocentesis is an accepted, safe, and cost-effective procedure. Carefully selected patients can be treated with this technique in an outpatient setting. A consecutive series of outpatient echocardiography-directed pericardiocentesis performed for diagnostic or therapeutic indications is described. Appropriate technique and precautions are discussed.

Short deceleration time of mitral inflow E velocity: prognostic implication with atrial fibrillation versus sinus rhythm

The present study retrospectively identified 367 patients who had restrictive physiology as defined by deceleration time < or = 130 msec; 293 were in sinus rhythm (SR) (194 men and 99 women; mean age 64 +/- 14 years) and 74 were in atrial fibrillation (AF) (51 men and 23 women; mean age 72 +/- 11 years; p < 0.001). Both groups had similar underlying diagnoses and no significant difference in Doppler indices (E wave, 96 +/- 23 vs 99 +/- 22 cm/sec in SR and AF, respectively; deceleration time, 116 +/- 12 vs 116 +/- 13 msec; and left ventricular outflow tract time velocity integral, 14.8 +/- 4.8 vs 14.5 +/- 4.4 cm). Left ventricular ejection fraction was significantly lower in SR patients (29% +/- 16% vs 39% +/- 20%; p = 0.0003). There were 120 deaths (41%) in the SR group and 35 (47%) in the AF group (median follow-up for both groups, 2.2 years). Restrictive physiology as defined by Doppler echocardiography (deceleration time < or = 130 msec) appears to predict a similar poor prognosis with AF as with SR.