Real-Time Patient Portal Use Among Emergency Department Patients: An Open Results Study

OBJECTIVES

We characterized real-time patient portal test result viewing among emergency department (ED) patients and described patient characteristics overall and among those not enrolled in the portal at ED arrival.

METHODS

Our observational study at an academic ED used portal log data to trend the proportion of adult patients who viewed results during their visit from May 04, 2021 to April 04, 2022. Correlation was assessed visually and with Kendall's τ. Covariate analysis using binary logistic regression assessed result(s) viewed as a function of time accounting for age, sex, ethnicity, race, language, insurance status, disposition, and social vulnerability index (SVI). A second model only included patients not enrolled in the portal at arrival. We used random forest imputation to account for missingness and Huber-White heteroskedasticity-robust standard errors for patients with multiple encounters (α = 0.05).

RESULTS

There were 60,314 ED encounters (31,164 unique patients). In 7,377 (12.2%) encounters, patients viewed results while still in the ED. Patients were not enrolled for portal use at arrival in 21,158 (35.2%) encounters, and 927 (4.4% of not enrolled, 1.5% overall) subsequently enrolled and viewed results in the ED. Visual inspection suggests an increasing proportion of patients who viewed results from roughly 5 to 15% over the study (Kendall's τ = 0.61 [p <0.0001]). Overall and not-enrolled models yielded concordance indices (C) of 0.68 and 0.72, respectively, with significant overall likelihood ratio χ 2 (p <0.0001). Time was independently associated with viewing results in both models after adjustment. Models revealed disparate use between age, race, ethnicity, SVI, sex, insurance status, and disposition groups.

CONCLUSION

We observed increased portal-based test result viewing among ED patients over the year since the 21st Century Cures act went into effect, even among those not enrolled at arrival. We observed disparities in those who viewed results.

Rolling Up the Sleeve: Equitable, Efficient, and Safe COVID-19 Mass Immunization for Academic Medical Center Employees

BACKGROUND

Novel coronavirus disease 2019 (COVID-19) vaccine administration has faced distribution barriers across the United States. We sought to delineate our vaccine delivery experience in the first week of vaccine availability, and our effort to prioritize employees based on risk with a goal of providing an efficient infrastructure to optimize speed and efficiency of vaccine delivery while minimizing risk of infection during the immunization process.

OBJECTIVE

This article aims to evaluate an employee prioritization/invitation/scheduling system, leveraging an integrated electronic health record patient portal framework for employee COVID-19 immunizations at an academic medical center.

METHODS

We conducted an observational cross-sectional study during January 2021 at a single urban academic center. All employees who met COVID-19 allocation vaccine criteria for phase 1a.1 to 1a.4 were included. We implemented a prioritization/invitation/scheduling framework and evaluated time from invitation to scheduling as a proxy for vaccine interest and arrival to vaccine administration to measure operational throughput.

RESULTS

We allotted vaccines for 13,753 employees but only 10,662 employees with an active patient portal account received an invitation. Of those with an active account, 6,483 (61%) scheduled an appointment and 6,251 (59%) were immunized in the first 7 days. About 66% of invited providers were vaccinated in the first 7 days. In contrast, only 41% of invited facility/food service employees received the first dose of the vaccine in the first 7 days (p < 0.001). At the vaccination site, employees waited 5.6 minutes (interquartile range [IQR]: 3.9-8.3) from arrival to vaccination.

CONCLUSION

We developed a system of early COVID-19 vaccine prioritization and administration in our health care system. We saw strong early acceptance in those with proximal exposure to COVID-19 but noticed significant difference in the willingness of different employee groups to receive the vaccine.

Electronic Health Records-Based Cardio-Oncology Registry for Care Gap Identification and Pragmatic Research: Procedure and Observational Study

Background

Professional society guidelines are emerging for cardiovascular care in cancer patients. However, it is not yet clear how effectively the cancer survivor population is screened and treated for cardiomyopathy in contemporary clinical practice. As electronic health records (EHRs) are now widely used in clinical practice, we tested the hypothesis that an EHR-based cardio-oncology registry can address these questions.

Objective

The aim of this study was to develop an EHR-based pragmatic cardio-oncology registry and, as proof of principle, to investigate care gaps in the cardiovascular care of cancer patients.

Methods

We generated a programmatically deidentified, real-time EHR-based cardio-oncology registry from all patients in our institutional Cancer Population Registry (N=8275, 2011-2017). We investigated: (1) left ventricular ejection fraction (LVEF) assessment before and after treatment with potentially cardiotoxic agents; and (2) guideline-directed medical therapy (GDMT) for left ventricular dysfunction (LVD), defined as LVEF<50%, and symptomatic heart failure with reduced LVEF (HFrEF), defined as LVEF<50% and Problem List documentation of systolic congestive heart failure or dilated cardiomyopathy.

Results

Rapid development of an EHR-based cardio-oncology registry was feasible. Identification of tests and outcomes was similar using the EHR-based cardio-oncology registry and manual chart abstraction (100% sensitivity and 83% specificity for LVD). LVEF was documented prior to initiation of cancer therapy in 19.8% of patients. Prevalence of postchemotherapy LVD and HFrEF was relatively low (9.4% and 2.5%, respectively). Among patients with postchemotherapy LVD or HFrEF, those referred to cardiology had a significantly higher prescription rate of a GDMT.

Conclusions

EHR data can efficiently populate a real-time, pragmatic cardio-oncology registry as a byproduct of clinical care for health care delivery investigations.

Algorithmic Detection of Boolean Logic Errors in Clinical Decision Support Statements

OBJECTIVE

Clinical decision support (CDS) can contribute to quality and safety. Prior work has shown that errors in CDS systems are common and can lead to unintended consequences. Many CDS systems use Boolean logic, which can be difficult for CDS analysts to specify accurately. We set out to determine the prevalence of certain types of Boolean logic errors in CDS statements.

METHODS

Nine health care organizations extracted Boolean logic statements from their Epic electronic health record (EHR). We developed an open-source software tool, which implemented the Espresso logic minimization algorithm, to identify three classes of logic errors.

RESULTS

Participating organizations submitted 260,698 logic statements, of which 44,890 were minimized by Espresso. We found errors in 209 of them. Every participating organization had at least two errors, and all organizations reported that they would act on the feedback.

DISCUSSION

An automated algorithm can readily detect specific categories of Boolean CDS logic errors. These errors represent a minority of CDS errors, but very likely require correction to avoid patient safety issues. This process found only a few errors at each site, but the problem appears to be widespread, affecting all participating organizations.

CONCLUSION

Both CDS implementers and EHR vendors should consider implementing similar algorithms as part of the CDS authoring process to reduce the number of errors in their CDS interventions.

The use of automated data extraction tools to develop a solid organ transplant registry: Proof of concept study of bloodstream infections

BACKGROUND

We created an electronic health record-based registry using automated data extraction tools to study the epidemiology of bloodstream infections (BSI) in solid organ transplant recipients. The overarching goal was to determine the usefulness of an electronic health record-based registry using data extraction tools for clinical research in solid organ transplantation.

METHODS

We performed a retrospective single-center cohort study of adult solid organ transplant recipients from 2010 to 2015. Extraction tools were used to retrieve data from the electronic health record, which was integrated with national data sources. Electronic health records of subjects with positive blood cultures were manually adjudicated using consensus definitions. One-year cumulative incidence, risk factors for BSI acquisition, and 1-year mortality were analyzed by Kaplan-Meier method and Cox modeling, and 30-day mortality with logistic regression.

RESULTS

In 917 solid organ transplant recipients the cumulative incidence of BSI was 8.4% (95% confidence interval 6.8-10.4) with central line-associated BSI as the most common source. The proportion of multidrug-resistant isolates increased from 0% in 2010 to 47% in 2015 (p = 0.03). BSI was the strongest risk factor for 1-year mortality (HR=8.44; 4.99-14.27; p<0.001). In 11 of 14 deaths, BSI was the main cause or contributory in patients with non-rapidly fatal underlying conditions.

CONCLUSIONS

Our study illustrates the usefulness of an electronic health record-based registry using automated extraction tools for clinical research in the field of solid organ transplantation. A BSI reduces the 1-year survival of solid organ transplant recipients. The most common sources of BSIs in our studies are preventable.

Rapid Development of Specialty Population Registries and Quality Measures from Electronic Health Record Data*. An Agile Framework

BACKGROUND

Creation of a new electronic health record (EHR)-based registry often can be a "one-off" complex endeavor: first developing new EHR data collection and clinical decision support tools, followed by developing registry-specific data extractions from the EHR for analysis. Each development phase typically has its own long development and testing time, leading to a prolonged overall cycle time for delivering one functioning registry with companion reporting into production. The next registry request then starts from scratch. Such an approach will not scale to meet the emerging demand for specialty registries to support population health and value-based care.

OBJECTIVE

To determine if the creation of EHR-based specialty registries could be markedly accelerated by employing (a) a finite core set of EHR data collection principles and methods, (b) concurrent engineering of data extraction and data warehouse design using a common dimensional data model for all registries, and (c) agile development methods commonly employed in new product development.

METHODS

We adopted as guiding principles to (a) capture data as a byproduct of care of the patient, (b) reinforce optimal EHR use by clinicians, (c) employ a finite but robust set of EHR data capture tool types, and (d) leverage our existing technology toolkit. Registries were defined by a shared condition (recorded on the Problem List) or a shared exposure to a procedure (recorded on the Surgical History) or to a medication (recorded on the Medication List). Any EHR fields needed - either to determine registry membership or to calculate a registry-associated clinical quality measure (CQM) - were included in the enterprise data warehouse (EDW) shared dimensional data model. Extract-transform-load (ETL) code was written to pull data at defined "grains" from the EHR into the EDW model. All calculated CQM values were stored in a single Fact table in the EDW crossing all registries. Registry-specific dashboards were created in the EHR to display both (a) real-time patient lists of registry patients and (b) EDW-generated CQM data. Agile project management methods were employed, including co-development, lightweight requirements documentation with User Stories and acceptance criteria, and time-boxed iterative development of EHR features in 2-week "sprints" for rapid-cycle feedback and refinement.

RESULTS

Using this approach, in calendar year 2015 we developed a total of 43 specialty chronic disease registries, with 111 new EHR data collection and clinical decision support tools, 163 new clinical quality measures, and 30 clinic-specific dashboards reporting on both real-time patient care gaps and summarized and vetted CQM measure performance trends.

CONCLUSIONS

This study suggests concurrent design of EHR data collection tools and reporting can quickly yield useful EHR structured data for chronic disease registries, and bodes well for efforts to migrate away from manual abstraction. This work also supports the view that in new EHR-based registry development, as in new product development, adopting agile principles and practices can help deliver valued, high-quality features early and often.

Agile Model Driven Development of Electronic Health Record-Based Specialty Population Registries

The transformation of the American healthcare payment system from fee-for-service to value-based care increasingly makes it valuable to develop patient registries for specialized populations, to better assess healthcare quality and costs. Recent widespread adoption of Electronic Health Records (EHRs) in the U.S. now makes possible construction of EHR-based specialty registry data collection tools and reports, previously unfeasible using manual chart abstraction. But the complexities of specialty registry EHR tools and measures, along with the variety of stakeholders involved, can result in misunderstood requirements and frequent product change requests, as users first experience the tools in their actual clinical workflows. Such requirements churn could easily stall progress in specialty registry rollout. Modeling a system's requirements and solution design can be a powerful way to remove ambiguities, facilitate shared understanding, and help evolve a design to meet newly-discovered needs. "Agile Modeling" retains these values while avoiding excessive unused up-front modeling in favor of iterative incremental modeling. Using Agile Modeling principles and practices, in calendar year 2015 one institution developed 58 EHR-based specialty registries, with 111 new data collection tools, supporting 134 clinical process and outcome measures, and enrolling over 16,000 patients. The subset of UML and non-UML models found most consistently useful in designing, building, and iteratively evolving EHR-based specialty registries included User Stories, Domain Models, Use Case Diagrams, Decision Trees, Graphical User Interface Storyboards, Use Case text descriptions, and Solution Class Diagrams.

The Dallas Heart Study: a population-based probability sample for the multidisciplinary study of ethnic differences in cardiovascular health

The decrease in cardiovascular death rates in the United States has been slower in blacks than whites, especially in patients <65 years of age. The Dallas Heart Study was designed as a single-site, multiethnic, population-based probability sample to (1) produce unbiased population estimates of biologic and social variables that pinpoint ethnic differences in cardiovascular health at the community level and (2) support hypothesis-driven research on the mechanisms causing these differences using genetics, advanced imaging modalities, social sciences, and clinical research center methods. A probability-based sample of Dallas County residents aged 18 to 65 years was surveyed with an extensive household health interview. The subset of participants 30 to 65 years of age provided in-home fasting blood and urine samples and underwent multiple imaging studies, including cardiac magnetic resonance imaging and electron beam computed tomography. Completed interviews were obtained for 6,101 subjects (54% black), phlebotomy visits for 3,398 (52% black), and clinic visits for 2,971 (50% black). Participation rates were 80.4% for interviews, 75.1% for phlebotomy visits, and 87.4% for clinic visits. Weighted population estimates of many measured variables agreed closely with those of the United States census and were relatively stable from the interview sample to the phlebotomy and clinic subsamples. Thus, the Dallas Heart Study provides a phenotypically well-characterized probability sample for multidisciplinary research that will be used to improve the mechanistic understanding and prevention of cardiovascular disease, especially in black Americans.

Assessment of aortic regurgitation by transesophageal color Doppler imaging of the vena contracta: validation against an intraoperative aortic flow probe

OBJECTIVES

This study was performed to validate the accuracy of color flow vena contracta (VC) measurements of aortic regurgitation (AR) severity by comparing them to simultaneous intraoperative flow probe measurements of regurgitant fraction (RgF) and regurgitant volume (RgV).

BACKGROUND

Color Doppler imaging of the vena contracta has emerged as a simple and reliable measure of the severity of valvular regurgitation. This study evaluated the accuracy of VC imaging of AR by transesophageal echocardiography (TEE).

METHODS

A transit-time flow probe was placed on the ascending aorta during cardiac surgery in 24 patients with AR. The flow probe was used to measure RgF and RgV simultaneously during VC imaging by TEE. Flow probe and VC imaging were interpreted separately and in blinded fashion.

RESULTS

A good correlation was found between VC width and RgF (r = 0.85) and RgV (r = 0.79). All six patients with VC width >6 mm had a RgF >0.50. All 18 patients with VC width <5 mm had a RgF <0.50. Vena contracta area also correlated well with both RgF (r = 0.81) and RgV (r = 0.84). All six patients with VC area >7.5 mm2 had a RgF >0.50, and all 18 patients with a VC area <7.5 mm2 had a RgF <0.50. In a subset of nine patients who underwent afterload manipulation to increase diastolic blood pressure, RgV increased significantly (34 +/- 26 ml to 41 +/- 27 ml, p = 0.042) while VC width remained unchanged (5.4 +/- 2.8 mm to 5.4 +/- 2.8 mm, p = 0.41).

CONCLUSIONS

Vena contracta imaging by TEE color flow mapping is an accurate marker of AR severity. Vena contracta width and VC area correlate well with RgF and RgV obtained by intraoperative flow probe. Vena contracta width appears to be less afterload-dependent than RgV.

Dobutamine magnetic resonance imaging with myocardial tagging quantitatively predicts improvement in regional function after revascularization

Segmental contractile reserve measured by dobutamine magnetic resonance imaging quantitatively predicts improvement in end-systolic wall thickness after revascularization. Segments with end-systolic wall thickness <7 mm at rest do not demonstrate contractile reserve or improve after revascularization.

Effects of afterload reduction on vena contracta width in mitral regurgitation

OBJECTIVES

We used color Doppler flow mapping to determine whether vena contracta width (VCW) is a load-independent measure of the severity of mitral regurgitation.

BACKGROUND

VCW has been proposed to be a relatively load-independent measure of mitral regurgitation severity in flow models using a fixed orifice. However, in patients with mitral regurgitation, VCW may not be load independent because of a dynamic regurgitant orifice.

METHODS

VCW, effective regurgitant orifice area and regurgitant volume were measured by quantitative Doppler mapping in 31 patients with chronic mitral regurgitation at baseline and during nitroprusside infusion. Patients with rheumatic heart disease, annular calcification or endocarditis were considered to have a fixed regurgitant orifice, whereas patients with mitral valve prolapse, dilated cardiomyopathy or ischemia were considered to have a dynamic regurgitant orifice.

RESULTS

Systolic blood pressure (148 +/- 27 to 115 +/- 25 mm Hg) and end-systolic wall stress (121 +/- 50 to 89 +/- 36) decreased with nitroprusside (p < 0.05). Although nitroprusside did not significantly change mean values for VCW (0.5 +/- 0.2 to 0.5 +/- 0.2 cm), regurgitant volume (69 +/- 47 to 69 +/- 56 ml) or effective regurgitant orifice area (0.5 +/- 0.4 to 0.5 +/- 0.6 cm2), individual patients exhibited marked directional variability. Specifically, VCW decreased in 16 patients (improved mitral regurgitation), remained unchanged in 7 patients and increased in 8 patients (worsened mitral regurgitation) with nitroprusside. Also, the VCW response to nitroprusside was concordant with changes in effective regurgitant orifice area and regurgitant volume, and was not different between dynamic and fixed orifice groups.

CONCLUSIONS

Contrary to the results from in vitro studies, VCW is not load independent in patients with mitral regurgitation caused by dynamic changes in the regurgitant orifice. The origin of mitral regurgitation does not predict accurately whether the regurgitant orifice is fixed or dynamic. Finally, short-term vasodilation with nitroprusside may significantly worsen the severity of mitral regurgitation in some patients.

Comparison of quantitative Doppler with magnetic resonance imaging for assessment of the severity of mitral regurgitation

We compared quantitative Doppler echocardiography and cine magnetic resonance imaging for calculation of regurgitant volume and regurgitant fraction in mitral regurgitation. A good correlation was present between the 2 methods with some scatter in patients with severe mitral regurgitation and high regurgitant volumes.

Comparison of vena contracta width by multiplane transesophageal echocardiography with quantitative Doppler assessment of mitral regurgitation

Mitral regurgitation (MR) severity is routinely assessed by Doppler color flow mapping, which is subject to technical and hemodynamic variables. Vena contracta width may be less influenced by hemodynamic variables and has previously been shown to correlate with angiographic estimates of MR severity. This study was performed to compare mitral vena contracta width by multiplane transesophageal echocardiography (TEE) with simultaneous quantitative Doppler echocardiography in 35 patients with MR. The vena contracta width was measured at the narrowest portion of the MR jet as it emerged through the coaptation of the leaflets; it was identified in 97% of the patients. Vena contracta width correlated well with regurgitant volume (R2 = 0.81) and regurgitant orifice area (R2 = 0.81) by quantitative Doppler technique. A vena contracta width > or = 0.5 cm always predicted a regurgitant volume >60 ml and an effective regurgitant orifice area > or = 0.4 cm2 in all patients. A vena contracta width < or = 0.3 cm always predicted a regurgitant volume <45 ml and a regurgitant orifice area < or = 0.35 cm2. Thus, vena contracta width by multiplane TEE correlates well with mitral regurgitant volume and regurgitant orifice area by quantitative Doppler echocardiography and provides a simple method for the identification of patients with severe MR.

Usefulness of transesophageal echocardiography in determining the source of emboli in patients with acute limb ischemia

A potential cardiovascular source of embolism was demonstrated by transesophageal echocardiography in 20 of 33 patients (61%) with acute limb ischemia. The percentage was higher in patients with large artery occlusions (9 of 11, 82%) than in those with small artery occlusions (9 of 22, 41%) (p = 0.026).

Assessment of mitral regurgitation severity by Doppler color flow mapping of the vena contracta

BACKGROUND

Although Doppler color flow mapping is widely used to assess the severity of mitral regurgitation (MR), a simple, accurate, and quantitative marker of MR by color flow mapping remains elusive. We hypothesized that vena contracta width by color flow mapping would accurately predict the severity of MR.

METHODS AND RESULTS

We studied 80 patients with MR. Vena contracta width was measured in multiple views with zoom mode and nonstandard angulation to optimize its visualization. Flow volumes across the left ventricular outflow tract and mitral annulus were calculated by pulsed-Doppler technique to determine regurgitant volume. Effective regurgitant orifice area was calculated by dividing the regurgitant volume by the continuous-wave Doppler velocity-time integral of the MR jet. The cause of MR was ischemia in 24, dilated cardiomyopathy in 34 mitral valve prolapse in 12, endocarditis in 2, rheumatic disease in 2, mitral annular calcification in 1, and uncertain in 5. Regurgitant volumes ranged from 2 to 191 mL. Regurgitant orifice area ranged from 0.01 to 1.47 cm2. Single-plane vena contracta width from the parasternal long-axis view correlated well with regurgitant volume (r = .85, SEE = 20 mL) and regurgitant orifice area (r = .86, SEE = 0.15 cm2). Biplane vena contracta width from apical views correlated well with regurgitant volume (r = .85, SEE = 19 mL) and regurgitant orifice area (r = .88, SEE = 0.14 cm2). A biplane vena contracta width > or = 0.5 cm was always associated with a regurgitant volume > 60 mL and a regurgitant orifice area > 0.4 cm2. A biplane vena contracta width < or = 0.3 cm predicted a regurgitant volume < 60 mL and a regurgitant orifice area < 0.4 cm2 in 24 of 29 patients. No other parameter, including jet area, left atrial size, pulmonary flow reversal, or semiquantitative MR grade, correlated significantly with regurgitant volume or regurgitant orifice area in a multivariate analysis.

CONCLUSIONS

Our results demonstrate that careful color flow mapping of the vena contracta of the MR jet provides a simple quantitative assessment of MR that correlates well with quantitative Doppler techniques.

Comparison of quantitation of left ventricular volume, ejection fraction, and cardiac output in patients with atrial fibrillation by cine magnetic resonance imaging versus invasive measurements

Currently available invasive and noninvasive techniques for the determination of left ventricular end-diastolic and end-systolic volumes, ejection fraction, and cardiac output are more time-consuming and potentially less accurate in patients with atrial fibrillation (AF) than in those with sinus rhythm. Although magnetic resonance imaging (MRI) can rapidly and accurately measure these variables in patients with sinus rhythm, its ability to do so in subjects with AF is not known. To determine if left ventricular volumes, ejection fraction, and cardiac output can be measured accurately in patients with AF using MRI, 26 subjects (13 women and 13 men, aged 15 to 76 years) in sinus rhythm (n = 13) or AF (n = 13) underwent MRI followed immediately by invasive measurements of these indexes. For those in AF, MRI measurements of left ventricular end-diastolic volume, end-systolic volume, stroke volume, ejection fraction, and cardiac output correlated well with catheterization measurements (r = 0.90, 0.90, 0.95, 0.85, and 0.90, respectively). In addition, the mean difference between MRI and catheterization measurements was similar in subjects with AF and in those with sinus rhythm. Compared with standard invasive measurements, MRI provides an accurate noninvasive determination of left ventricular volumes, ejection fraction, and cardiac output in patients with AF.

Quantitative MR imaging of the heart

MR imaging cardiac quantitation is accurate, highly reproducible, and feasible using equipment available in most hospitals. For determination of myocardial mass, evaluation of RV function, and quantitative measurements of flow in the great vessels and peripheral vasculature, MR imaging is the reference method. Availability of methods for rapid scanning and analysis will lead to increased use of cardiac MR imaging in quantifying cardiac function.

Assessment of coronary arterial flow and flow reserve in humans with magnetic resonance imaging

BACKGROUND

The noninvasive measurement of absolute epicardial coronary arterial flow and flow reserve would be useful in the evaluation of patients with coronary circulatory disorders. Phase-contrast magnetic resonance imaging (PC-MRI) has been used to measure coronary arterial flow in animals, but its accuracy in humans is unknown.

METHODS AND RESULTS

Twelve subjects (7 men, 5 women: age 44 to 67 years) underwent PC-MRI measurements of flow in the left anterior descending coronary artery or one of its diagonal branches at rest and after administration of adenosine (140 microgram . kg(-1) . min (-1) IV). Immediately thereafter, intracoronary Doppler velocity (IDV) and flow measurements were made during cardiac catheterization at rest and after intravenous administration of adenosine. For the 12 patients, the correlation between MRI and invasive measurements of coronary arterial flow and coronary arterial flow reserve was excellent: coronary flow (MRI) (mL/min)= 0.85 x coronary flow (IDV) (mL/min)+17 (mL/min), r=.89, and coronary flow reserve (MRI) =0.79 x coronary velocity reserve (IDV) + 0.34, r=.89. For the range of coronary arterial flows (18 to 161 mL/min) measured by MRI, the limit of agreement between MRI and catheterization measurements of flow was -13+/-30 mL/min; for the range of coronary reserves (0.7 to 3.7) measured by MRI, the limit of agreement between the two techniques was 0.1+/-0.4.

CONCLUSIONS

Cine velocity-encoded PC-MRI can noninvasively measure absolute coronary arterial flow in the left anterior descending artery in humans. PC-MRI can detect pharmacologically induced changes in coronary arterial flow and can reliably distinguish between those subjects with normal and abnormal coronary artery flow reserve.

Comparison of myocardial contrast echocardiography and low-dose dobutamine stress echocardiography in predicting recovery of left ventricular function after coronary revascularization in chronic ischemic heart disease

BACKGROUND

Dobutamine stress echocardiography (DSE) and myocardial contrast echocardiography (MCE) can predict recovery of left ventricular function after myocardial infarction. DSE also has been shown to predict left ventricular functional recovery after revascularization in chronic ischemic heart disease, whereas MCE has not been evaluated in such patients. This study was performed to compare DSE and MCE in the prediction of left ventricular functional recovery after revascularization in patients with chronic ischemic heart disease.

METHODS AND RESULTS

MCE and DSE were performed in 35 patients with chronic coronary artery disease and significant wall motion abnormalities (mean ejection fraction, 0.36 +/- 0.09). Regional wall motion was scored by use of a 16-segment model wherein 1 = normal or hyperkinetic, 2 = hypokinetic, 3 = akinetic, and 4 = dyskinetic. Each segment was evaluated for contractile reserve by DSE and perfusion by MCE. Revascularization (coronary artery bypass graft [n = 13] and percutaneous transluminal coronary angioplasty [n = 10]) was successful in 23 patients. Follow-up echocardiograms were done to assess wall motion 30 to 60 days later. In 238 segments with resting wall motion abnormalities, perfusion was more likely to present than contractile reserve (97% versus 91%, P < .02). Revascularization resulted in functional recovery in 77 of 95 hypokinetic segments (81%) but only 18 of 57 akinetic segments (32%, P < .0001). DSE and MCE were not significantly different in predicting functional recovery of hypokinetic segments. In akinetic segments, DSE and MCE had similar sensitivities (89% versus 94%, respectively) and negative predictive values (93% and 97%, respectively) in predicting functional recovery. However, DSE had a higher specificity (92% versus 67%, P < .02) and positive predictive value (85% versus 55%, P < .02) than MCE in predicting functional recovery.

CONCLUSIONS

Both contractile reserve by DSE and perfusion by MCE are predictive of functional recovery in hypokinetic segments after coronary revascularization in patients with chronic coronary revascularization in patients with chronic coronary artery disease. In akinetic segments, myocardial perfusion by MCE may exist in segments that do not recover contractile function after revascularization. Thus, contractile reserve during low-dose dobutamine infusion is a better predictor of functional recovery after revascularization in akinetic segments than perfusion.

Racial differences in the prevalence of left ventricular hypertrophy among chronic cocaine abusers

There are racial differences in the prevalence and pattern of left ventricular (LV) hypertrophy in hypertension. This study was performed to determine whether racial differences also exist in LV hypertrophy among chronic cocaine users. We studied 112 chronic cocaine abusers < 45 years old in whom normal blood pressures (< or = 140/90 mm Hg) were recorded 3 times daily for 3 weeks. LV wall thickness and mass were measured echocardiographically. Technically adequate studies were obtained in 79 blacks and 33 whites. Self-reported cocaine use was higher in whites than in blacks (688 +/- 516 vs 431 +/- 468 $/week, p = 0.03). There were no group differences in terms of duration of cocaine use, age, height, weight, blood pressure, LV dimensions, or left atrial size. However, posterior wall thickness (1.13 +/- 0.17 vs 1.03 +/- 0.14 cm, p = 0.0035) and LV mass index (113 +/- 25 vs 94 +/- 19 g/m2, p = 0.0001) were significantly greater in blacks. LV hypertrophy, defined as an M-mode LV mass index > or = 134 g/m2, was present in 24 blacks (30%) and 2 whites (6%) (p = 0.011). When defined as a posterior wall thickness > or = 1.2 cm and a 2-dimensional echocardiographic LV mass index > or = 105 g/m2, LV hypertrophy was present in 37 of 79 blacks (47%) and in 6 of 33 whites (18%) (p = 0.0086). Cocaine-related LV hypertrophy is more prevalent in black men than in white men.(ABSTRACT TRUNCATED AT 250 WORDS)