Importance of echocardiography in patients with severe nonischemic heart failure: the second Prospective Randomized Amlodipine Survival Evaluation (PRAISE-2) echocardiographic study

BACKGROUND

Echocardiography is used commonly in clinical practice when caring for patients with heart failure. It is unknown whether the presence of certain findings provides an incremental ability to predict survival beyond the use of baseline clinical findings alone. The second PRAISE-2 echocardiographic study was prospectively designed to identify echocardiographic predictors of survival among patients with nonischemic cardiomyopathy and heart failure and to determine if components of the echocardiographic examination add prognostic information to baseline demographic and clinical information.

METHODS

One hundred patients participated in the second Prospective Randomized Amlodipine Survival Evaluation Study (PRAISE-2) echocardiographic study; of these, 93 had full and interpretable echocardiographic examinations. Cox proportional hazards modeling was used to assess the relation between various characteristics and survival as well as to assess the incremental prognostic information gained by echocardiography beyond the clinical examination.

RESULTS

Seven of 10 routine echocardiographic measures were significantly associated with death. These included mitral regurgitation (hazard ratio [HR], 2.31; 95% CI, 1.02, 5.27), left ventricular ejection fraction <20% (HR, 2.59; 95% CI, 1.14, 5.88), restrictive left ventricular filling pattern (HR, 2.37; 95% CI, 1.05, 5.32), and peak D velocity (HR, 1.62; 95% CI, 0.38, 0.87). The only statistically significant clinical predictor of survival was dyspnea at rest. The addition any of several echocardiographic parameters to baseline clinical information significantly improved the ability to predict survival.

CONCLUSIONS

Several readily available echocardiographic parameters are predictive of death and when added to clinical examination findings significantly improve the ability to determine prognosis among patients with nonischemic cardiomyopathy and heart failure.

Medication errors in hospitalized cardiovascular patients

BACKGROUND

The Institute of Medicine's report To Err Is Human: Building a Safer Health System recommends pharmacist participation in patient rounds as an immediate approach to reducing medical errors. In the same report and in prior publications, cardiovascular drugs have been commonly associated with severe adverse drug events.

METHODS

We systematically reviewed the experience of a clinical pharmacist on the cardiology wards between September 1, 1995, and February 18, 2000. We classified medication errors according to the type of error, medications involved, personnel involved, stages of drug administration involved, and time of year most frequently associated with errors.

RESULTS

Among 14983 pharmacist interventions, 4768 were related to medication errors, or 24 medication errors per 100 admissions. The most common errors involved the wrong drug (36.0%) or wrong dose (35.3%), and cardiovascular medications were involved in 41.2% of the errors. Prescribers were associated with most of the errors, and the transition from outpatient to inpatient was the most common point in the system for the occurrence of these medication errors. Higher numbers of errors were also identified during the transition period of house staff, and the total number of errors increased during the study period.

CONCLUSIONS

Through the clinical pharmacist's identification and correction of medication errors, 2 areas of improvement that may reduce medication errors were identified. The first is ensuring accurate knowledge of a patient's outpatient medication regimen. The second involves improving the education and support of new interns during their initial months of training. This work exemplifies the approach recommended by the Institute of Medicine to reduce medical errors through systematic analyses rather than ascribing fault to individuals.

Imaging techniques for diagnosis of infective endocarditis

Cardiac imaging, specifically echocardiography, has greatly enhanced the ability of clinicians to effectively diagnose and manage IE. Echocardiograms should generally be obtained in all patients suspected of having IE, both to establish the diagnosis and to identify complicated cardiac involvement that may warrant surgical intervention. Transesophageal imaging is more sensitive and specific than the transthoracic approach and currently represents the optimal approach to echocardiographic imaging. Manifestations of endocardial involvement include vegetations, abscesses, aneurysms, fistulae, leaflet perforations, and valvular dehiscence. The roles of other imaging modalities including CT, MRI, and nuclear imaging have yet to be fully established.

The influence of left ventricular hypertrophy on survival in patients with coronary artery disease: do race and gender matter?

OBJECTIVES

We sought to determine the overall prognostic importance of left ventricular hypertrophy (LVH) among patients with coronary artery disease (CAD), as well as to determine whether this risk varies as a function of race or gender.

BACKGROUND

Left ventricular hypertrophy is more prevalent among blacks and women than their counterparts. Blacks and women also have higher mortality with coronary disease.

METHODS

We studied records of 2,461 patients (19% black, 42% women) diagnosed with CAD at cardiac catheterization between 1990 and 1998 from a single academic center. Left ventricular hypertrophy was defined using standard echocardiographic measures. Cox proportional hazards models were used for adjusted survival analyses. Mean patient follow-up was three years.

RESULTS

Patients with LVH were older (68 vs. 65 years, p < 0.01), more often women (54% vs. 36%, p < 0.01), and black (25% vs. 16%, p < 0.01), and had higher unadjusted three-year mortality rates than patients without LVH (42% vs. 34%, p < 0.01). Left ventricular hypertrophy remained an independent predictor of mortality after adjusting for other clinical risk factors (hazard ratio 1.56, 95% confidence interval 1.35 to 1.80) with prognostic importance equivalent to that of left ventricular ejection fraction. Although the relative risk of LVH did not vary by race or gender, the attributable risk of LVH was greater in blacks and women.

CONCLUSIONS

Clinicians should consider the prognostic importance of LVH when assessing risk in patients with CAD. Because LVH is more common among black and women patients with CAD, it partially accounts for racial and gender differences in survival.

Assessing quality in the cardiac catheterization laboratory

Quality assurance and improvement have increasingly been the focus of health care providers, third-party payers, and patients. Because cardiovascular procedures are common, easily identifiable with claims data, and account for a relatively large proportion of health care expenditures, particular attention has been paid to quality assurance in the setting of the diagnostic and interventional cardiac catheterization laboratory. The structure, process, and outcomes domains of quality measurement in the interventional laboratory involve the maintenance of volume standards, the availability of surgical backup, consistent tracking of procedural outcomes and complications so they can be compared with national standards, and the application of evidence-based therapy. Quality assurance i the diagnostic laboratory revolves around the clinical proficiency of the operators, the maintenance and management of catheterization laboratory equipment, and the presence of a continuous quality improvement program. The evolution of interventional equipment and techniques along with the establishment of national registries has led to a gradual improvement in the quality of percutaneous coronary intervention. Given the dynamic nature of cardiology, adaptable quality assurance and quality improvement programs will remain the foundation of successful catheterization labs.

Effect of fenfluramine-derivative diet pills on cardiac valves: a meta-analysis of observational studies

BACKGROUND

Fenfluramine-derivative diet pills were withdrawn from the market in 1997 because of an association with valvular regurgitation, but subsequent estimates of the prevalence of this condition have varied widely. We systematically reviewed evidence regarding the prevalence of valvular disease after fenfluramine exposure.

METHODS

We searched multiple databases with multiple search terms. Conference proceedings from 1997 onward were searched by index. Authors of eligible studies were contacted to identify unpublished works. Selection criteria were liberally determined. Ten of the identified 11 articles met these criteria. Reviewers assessed the studies' methodologic quality by use of a standard form to evaluate selection, attrition, performance, and detection bias. The studies were analyzed in 2 groups on the basis of length of exposure (<90 days or >90 days). The Mantel-Haenszel method was used to summarize data. Quantitative and qualitative tests for heterogeneity were performed. Tests for publication bias were also done.

RESULTS

Tests for heterogeneity were nonsignificant after removing 1 outlier trial. The pooled prevalence of valvular regurgitation meeting Food and Drug Administration criteria (at least mild aortic regurgitation or at least moderate mitral regurgitation) among patients treated for >90 days was 12.0% compared with 5.9% for the unexposed group (prevalence odds ratio 2.2, 95% CI 1.7-2.7). The combined analyses also identified a small but statistically significant increase in mitral regurgitation not previously identified by individual studies (exposed 3.5%, unexposed 1.8%, prevalence odds ratio 1.6, 95% CI 1.05-2.3). Among patients exposed for <90 days, a trend toward more regurgitation was not statistically significant by either combined Food and Drug Administration criteria (exposed 6.8%, unexposed 5.8%, prevalence odds ratio 1.4, 95% CI 0.8-2.4) or by individual valve.

CONCLUSIONS

These data indicate that fenfluramine-associated valvular regurgitation is less common than initially reported, but still present in 1 of 8 patients treated for >90 days.

Imaging techniques for diagnosis of infective endocarditis

With the ability to structurally characterize cardiac manifestations, echocardiography is used for the diagnosis and management of infective endocarditis. In establishing the diagnosis according to the Duke criteria, the findings of endocardial involvement (vegetation, abscess, prosthetic valve dehiscence) or new valvular regurgitation represent "major" diagnostic criteria. As echocardiography cannot reliably differentiate noninfective from infective lesions, however, proper diagnosis lies in correlating echocardiography with clinical findings. The more invasive transesophageal approach provides substantially greater image resolution; this approach should be considered first in the evaluation of patients with higher prior probabilities of endocarditis and those with potential endocardial complications.

Changing patient characteristics and the effect on mortality in endocarditis

BACKGROUND

Limited data exist on recent demographic and microbiological changes in infective endocarditis (IE) and the impact of these changes on patient survival.

METHODS

Data were collected from all patients with definite or possible IE at Duke University Medical Center, Durham, NC, from 1993 to 1999. Logistic regression analysis was used to identify demographic and microbiological changes that occurred in patients with IE over the study period. The impact of these changes on survival was evaluated using Cox proportional hazards modeling.

RESULTS

Among the 329 study patients, rates of hemodialysis dependence, immunosuppression, and Staphylococcus aureus infection increased during the study period (P=.04, P=.008, and P<.001, respectively), while rates of infection due to viridans group streptococci decreased (P=.007). Hemodialysis was independently associated with S aureus infection (odds ratio, 3.1; 95% confidence interval, 1.6-5.9). Patients with S aureus IE had a higher 1-year mortality rate (43.9% vs 32.5%; P=.04) that persisted after adjustment for other illness severity characteristics (hazard ratio, 1.5; 95% confidence interval, 1.03-2.3).

CONCLUSIONS

The demographic and microbiological characteristics of IE at our institution have changed over the past decade in ways that suggest a link between medical practice and IE characteristics. Staphylococcus aureus has emerged as a dominant cause of IE, and is an independent predictor of mortality. These findings identify clinical settings that may warrant closer surveillance and more aggressive measures in the identification and prevention of endocarditis.

Cost implications of closure of atrial septal defect

We sought to evaluate the relative cost of surgical and device closure of atrial septal defect. Device closure for atrial septal defects is becoming an alternative to surgical closure. We examined the hospital-generated cost data in 13 patients who underwent surgical repair and 15 patients who underwent device closure of an atrial septal defects (ASD) or patent foramen ovale (PFO) during a prospective clinical trial of the device. The cost of device closure of ASD was 7,837 dollars less on average than surgical closure when the cost of the occlusion device was excluded (device closure cost 7,397 dollars +/- 2,822 dollars, surgical closure cost 15,234 dollars +/- 3,851 dollars; P < 0.001). When adjusted for a 5% failure rate of device closure, the cost savings was 7,076 dollars. Device closure of ASD results in substantial hospital-related cost savings that will be an important consideration once new devices are approved for clinical use.

Advanced coronary artery disease: Appropriate end points for trials of novel therapies

BACKGROUND

The segment of patients with advanced coronary artery disease, or disease that is not amenable to conventional revascularization therapies, continues to grow. Because the natural history of these patients is less defined, the appropriate end points for trials of novel revascularization therapies involving patients with advanced coronary artery disease are not certain.

METHODS AND RESULTS

The Mediators of Social Support Study (MOSS) prospectively followed up outcomes of long-term survival, quality of life, resource use, and costs for 1189 patients and compared outcomes of patients with advanced coronary artery disease with those of a reference group who underwent bypass surgery or angioplasty.

CONCLUSIONS

Despite greater disease burden, cost, and mortality for patients with advanced coronary artery disease, a number of self-reported measures of general health status improved in a similar fashion to that of patients eligible for angioplasty or bypass surgery. These findings should inform the design of trials involving novel therapies, suggesting that angina status and mortality be included as primary end points in the consideration of efficacy. This work also suggests that additional studies of novel therapies involving larger sample sizes may be required to confidently characterize efficacy.

Post-myocardial infarction risk stratification in elderly patients

BACKGROUND

The purpose of this study was to examine the use of post-myocardial infarction (MI) risk stratification in the elderly. Although expert panels have recommended risk stratification after MI, limited data are available on whether patients actually undergo suggested testing. In particular, concern has been raised that the elderly, who are at high risk for recurrent ischemia and short-term death, are not referred as often as younger patients for post-MI testing.

METHODS

We studied the records of 192,311 Medicare patients (age > or = 65 years) admitted with MI between January 1992 and November 1992. By combining Medicare part A and part B data, we created a longitudinal record of patient care within 60 days of an MI admission. We describe the pattern of post-MI testing for ischemia and left ventricular function and outcomes as a function of patient age.

RESULTS

Patients > or = 75 years of age were significantly less likely than patients 65 to 74 years of age to have either cardiac catheterization (17% vs 43%) or any test for coronary artery disease severity (24% vs 53%). They were also less likely to have a test of left ventricular function (61% vs 76%). Even after adjustment for baseline characteristics, older patients remained less likely than younger patients to have an assessment of coronary artery disease severity (odds ratio, 0.44) or left ventricular function (odds ratio, 0.65).

CONCLUSIONS

Post-MI risk stratification declines with age and falls short of recommendations in our nation's elderly. This lack of testing may result in lost opportunities for therapeutic interventions in this high-risk group.

Association between selective serotonin-reuptake inhibitor therapy and heart valve regurgitation

The identification of an association between fenfluramines and valvular disease has raised the possibility of a similar association between another class of medications that increases local levels of serotonin, the selective serotonin-reuptake inhibitors (SSRIs). The objective of this study was to examine the association between heart valve regurgitation and treatment with SSRIs. We examined 5,437 consecutive patients who underwent echocardiography. Patients with a similar likelihood of SSRI treatment were identified by propensity models. The prevalence of regurgitation according to treatment was compared after adjusting for clinical characteristics associated with regurgitation. We also blindly reinterpreted a subset of 2,000 echocardiograms to identify characteristics associated with fenfluramine-associated valvular heart disease such as posterior mitral leaflet restriction. Among 5,437 consecutively hospitalized patients, we identified 292 who had taken SSRIs before admission. Patients taking SSRIs tended to be younger, female, Caucasian, unmarried, and more likely to have psychiatric illness and hypertension (p < or = 0.05). The overall prevalence of regurgitation meeting Food and Drug Administration criteria (at least moderate mitral regurgitation or mild aortic regurgitation) was 30%, with no significant difference in prevalence between those receiving SSRIs (26.7%) and controls (30.4%) (p = 0.19). The association remained negative when comparing SSRI-treated patients to controls with similar characteristics. Furthermore, the prevalence of features described in conjunction with fenfluramine exposure, such as posterior mitral leaflet restriction, was not higher in SSRI-treated patients. Among a large consecutive cohort of patients, the prevalence of mitral and aortic regurgitation in patients taking SSRIs was not different from that of controls, suggesting that SSRIs are not associated with valvular disease.

The progression of fenfluramine-associated valvular heart disease assessed by echocardiography

BACKGROUND

An association between the dietary suppressants fenfluramine and dexfenfluramine and valvular heart disease was first described in patients from North Dakota and Minnesota in 1997. Limited data are available on the natural history of this valvulopathy after discontinuation of drug therapy.

OBJECTIVE

To follow the progression of fenfluramine-associated valvular heart disease after discontinuation of therapy by using serial echocardiography.

DESIGN

Retrospective cohort study.

SETTING

Regional medical center in Fargo, North Dakota.

PATIENTS

50 patients with previous exposure to fenfluramines who had at least mild mitral regurgitation or aortic regurgitation after exposure to fenfluramines on serial echocardiography between December 1994 and February 1999 (96% were female, mean body mass index was 36.6 kg/m(2), and mean duration of drug exposure was 447 days).

MEASUREMENTS

Serial echocardiograms were reviewed by two echocardiographers who were blinded to the order of image acquisition. The severity of valvular regurgitation and presence or absence of valve leaflet restriction were assessed.

RESULTS

As described in the initial report, significant valvular disease on initial postexposure echocardiography was common in this cohort; 38 patients (76%) had at least mild mitral regurgitation and 43 patients (86%) had at least mild aortic regurgitation. On serial echocardiograms obtained an average of 356 days apart, mitral regurgitation improved by at least one grade in 17 patients (P = 0.001) and aortic regurgitation improved by at least one grade in 19 patients (P = 0.004). Nineteen and 22 patients, respectively, experienced no change in severity of mitral and aortic regurgitation. Two patients in each group experienced worsening of regurgitation by at least one grade. Results were similar for tricuspid (P = 0.002) and pulmonic (P = 0.012) regurgitation.

CONCLUSION

On serial echocardiography, fenfluramine-associated valvular regurgitation improved or remained stable in most patients after therapy ended. Worsening of valvular regurgitation was uncommon. The potential for stabilization or regression of valvular regurgitation should be taken into account when counseling patients and considering the need for and timing of valve surgery.

Fenfluramine and phentermine and cardiovascular findings: effect of treatment duration on prevalence of valve abnormalities

BACKGROUND

The combination of fenfluramine and phentermine was a widely used obesity treatment before the withdrawal of fenfluramine for an association with heart valve regurgitation. The prevalence and clinical significance of regurgitation among patients treated with these medications has yet to be fully established.

METHODS AND RESULTS

To evaluate the potential association between the duration of treatment and the prevalence of heart valve abnormalities, we examined 1163 patients who had taken fenfluramine-phentermine and 672 control patients who had not taken the drug combination within 5 years. Mild or greater aortic regurgitation was present in 8.8% of treated patients and 3.6% of control patients (P<0.001). Moderate or greater mitral regurgitation was present in 2.6% of treated patients and 1.5% of control patients (P=0.18). The adjusted odds ratio compared with controls of aortic regurgitation of mild or greater severity increased according to duration of treatment: 90 to 180 days, 1.5 (P=0.23); 181 to 360 days, 2.4 (P=0.002); 361 to 720 days, 4.6 (P<0.001); >720 days, 6.2 (P<0.001).

CONCLUSIONS

This is the largest study to demonstrate a relation between the length of treatment with fenfluramine-phentermine and the prevalence of valvular abnormalities. These findings suggest that valvular abnormalities in patients who took fenfluramine-phentermine primarily involve those who had taken these medications for >6 months and predominantly results in mild aortic regurgitation. The valve regurgitation identified by this study was not accompanied by significant differences in cardiovascular symptoms nor physical findings other than a higher prevalence of heart murmurs.

Evaluating the potential 'economic attractiveness' of new therapies in patients with non-ST elevation acute coronary syndrome

OBJECTIVE

To evaluate the relationship between how much a new cardiovascular therapy improves clinical outcomes over current therapies and how much more it can cost while still remaining 'economically attractive'.

DESIGN

We developed a decision model to predict the 6-month cumulative cost savings and increased life expectancy that could be associated with new therapies for patients with non-ST elevation acute coronary syndrome.

SETTING

This modelling study used outcome and cost data from US sources.

METHODS

Event probabilities at 30 days and 6 months were estimated from US patients with non-ST elevation in the Global Use of Strategies to Open Occluded Coronary Arteries in Acute Coronary Syndromes (GUSTO) IIb trial; cost estimates were derived from patients enrolled in the Economics and Quality of Life substudy of this trial. Patient life expectancy estimates were calculated using survival estimates for similar patients treated at Duke University Medical Center.

RESULTS

We found that new therapies costing up to $US2000 per episode that reduce 6-month mortality by 0.5%, death and nonfatal myocardial infarction (MI) by 1%, or death, nonfatal MI and revascularisation by 3%, may be cost effective by current standards. When new therapies costing up to $US1000 per episode reduce the absolute rate of death, nonfatal MI and revascularisation at 6 months by 6.5% or more, they may be cost saving.

CONCLUSION

Our analysis suggests that economic constraints should not inhibit the development of effective new therapies.

Calcium channel blockers and mortality in elderly patients with myocardial infarction

BACKGROUND

Although calcium channel blockers are a useful therapy in relieving angina, lowering blood pressure, and slowing conduction of atrial fibrillation, growing evidence has cast doubt on their safety in patients with coronary disease.

OBJECTIVE

To examine the association between calcium channel blocker therapy at hospital discharge and mortality in a population-based sample of elderly patients hospitalized with acute myocardial infarction.

DESIGN

Retrospective cohort study using data from medical charts and administrative files.

SETTING

All acute care hospitals in 46 states.

PATIENTS

All Medicare patients with a principal diagnosis of acute myocardial infarction consecutively discharged from the hospital alive during 8-month periods between 1994 and 1995 (N = 141,041).

MAIN OUTCOME MEASURE

Mortality at 30 days and 1 year.

RESULTS

Calcium channel blockers were widely prescribed at hospital discharge to elderly patients with myocardial infarction between 1994 and 1995 (n = 51,921), the most commonly prescribed being diltiazem (n = 21,175), nifedipine (n = 12,670), amlodipine (n = 11,683), and verapamil (n = 3639). After adjusting for illness severity and concomitant medication use, patients who were prescribed calcium channel blockers at hospital discharge did not have increased risk for 30-day or 1-year mortality, with the exception of the few (n = 116) treated with bepridil. Bepridil differs from other calcium channel blockers because of its tendency to prolong repolarization, and its association with proarrhythmic effects in elderly patients.

CONCLUSION

We did not identify a mortality risk in a large consecutive sample of elderly patients with myocardial infarction, which supports the need for additional prospective trials examining calcium channel blocker therapy for ischemic heart disease.