Biomedical subjects

K R Bailey

Publications and source records attributed to K R Bailey.

At least 55 records · Page 3Linked to original sources

PubMed1999

An algorithm for noninvasive identification of angiographic three-vessel and/or left main coronary artery disease in symptomatic patients on the basis of cardiac risk and electron-beam computed tomographic calcium scores.

OBJECTIVES: We sought to model an algorithm for noninvasive identification of angiographically obstructive three-vessel and/or left main disease based on conventional cardiac risk assessment and site and extent of coronary calcium determined by electron-beam computed tomography (EBCT). BACKGROUND: Such an algorithm would greatly facilitate clinical triage in symptomatic patients with no previous diagnosis of coronary artery disease (CAD). METHODS: We examined 291 patients with suspected, but not previously diagnosed, CAD who underwent coronary angiography for clinical indications. Cardiac risk factors were determined as defined by the National Cholesterol Education Program. An EBCT scan was performed in all patients, and a coronary calcium score (Agatston method) was computed. Total per-patient calcium scores and separate scores for the major coronary arteries were generated. These scores were also analyzed for localization of coronary calcium in the more distal versus proximal tomographic sections. These parameters and the risk factors were considered for the model described in the following section. RESULTS: Sixty-eight patients (23%) had angiographic three-vessel and/or left main CAD. Multiple logistic regression analysis determined male sex, presence of diabetes and left anterior descending (LAD) and circumflex (LCx) coronary calcium scores, independent from more distal calcium localization, as independent predictors for identification of three-vessel and/or left main CAD. Based on this four variable model, a simple noninvasive index (NI) was constructed as the following: loge(LAD score) + log(e)(LCx score) + 2[if diabetic] + 3[if male]. Receiver operating characteristic curve analysis for this NI yielded an area under the curve of 0.88+/-0.03 (p < 0.0001) for separating patients with, versus without, angiographic three-vessel and/or left main CAD. Various NI cutpoints demonstrated sensitivities from 87-97% and specificities from 46-74%. The NI values >14 increased the probability of angiographic three-vessel and/or left main CAD from 23% (pretest) to 65-100% (posttest), and NI values <10 increased the probability of no three-vessel and/or left main CAD from 77% (pretest) to 95-100% (posttest). CONCLUSIONS: On the basis of a simple algorithm ("noninvasive index"), EBCT calcium scanning in conjunction with risk factor analysis can rule in or rule out angiographically severe disease, i.e., three-vessel and/or left main CAD, in symptomatic patients.

Algorithms↗

PubMed1999

Independent and incremental value of coronary artery calcium for predicting the extent of angiographic coronary artery disease: comparison with cardiac risk factors and radionuclide perfusion imaging.

OBJECTIVES: The study was done to test the ability to predict the extent of angiographically determined coronary artery disease (CAD) by quantification of coronary calcium using electron-beam computed tomography (EBCT) and to compare it with more conventional parameters for delineating the angiographic extent of CAD, that is, cardiovascular risk factors and radionuclide single-photon emission computed tomography (SPECT). BACKGROUND: The angiographic extent of CAD is a powerful predictor of subsequent events. Use of EBCT may be able to define it by virtue of its ability to determine plaque burden. METHODS: We examined 308 patients presenting with suspected but not previously known CAD who underwent selective coronary angiography. As measures of the angiographic extent of CAD, coronary artery greater even 20 (CAGE > or =20) and CAGE > or =50 scores represented the total number of coronary segments with > or =20% or > or =50% stenoses, respectively. The EBCT-derived total calcium scores were obtained in 291 patients, risk factors as defined by the National Cholesterol Education Program in 239 patients, and SPECT scans in 136 patients. RESULTS: Using multiple linear regression analysis, total calcium scores were better independent predictors of both CAGE > or =20 and CAGE > or =50 scores than either a SPECT-derived radionuclide perfusion score or the risk factors age, male gender and ratio of total/high-density lipoprotein (HDL) cholesterol. The association between EBCT and angiographic scores remained highly significant after excluding the influence of all interrelated risk factors and SPECT variables (r = 0.65; p < 0.001 for CAGE > or =20 scores, r = 0.50; p < 0.001 for CAGE > or =50 scores). CONCLUSIONS: Coronary calcium predicts the angiographic extent of CAD in symptomatic patients and provides independent and incremental information to the more conventional clinical parameters derived from SPECT or risk assessment.

Aged↗

PubMed1999

Progression of mitral regurgitation: a prospective Doppler echocardiographic study.

OBJECTIVES: This study was performed to define the rates and determinants of progression of organic mitral regurgitation (MR). BACKGROUND: Severe MR has major clinical consequences, but the rates and determinants of progression of the degree of regurgitation are unknown. Quantitative Doppler echocardiographic methods allow the quantitation of regurgitant volume (RVol), regurgitant fraction (RF) and effective regurgitant orifice (ERO) to define progression of MR. METHODS: In a prospective study of MR progression, 74 patients had two quantitative Doppler echocardiographic examinations of MR (with at least two methods) 561 +/- 423 days apart without an intervening event. RESULTS: Progression of MR was observed, with increase in RVol (77 +/- 46 ml vs. 65 +/- 40 ml, p < 0.0001), RF (47 +/- 16% vs. 43% +/- 15%, p < 0.0001), and ERO (50 +/- 35 mm2 vs. 41 +/- 28 mm2, p < 0.0001). Annual rates (95% confidence interval) were, respectively, 7.4 ml/year (5.1, 9.7), 2.9%/year (1.9, 3.9) and 5.9 mm2/year (3.9, 7.8). However, wide individual variation was observed, and regression and progression of RVol >8 ml was found in 11% and 51%, respectively. In multivariate analysis, independent predictors of progression of RVol were progression of the lesions, particularly a new flail leaflet (p = 0.0003), and progression of mitral annulus diameter (p = 0.0001). Regression of MR was associated with marked changes in afterload, particularly decreased blood pressure (p = 0.008). No significant effect of treatment was detected. CONCLUSIONS: Organic MR tends to progress over time with increase in volume overload (RVol) due to increase in ERO. Progression of MR is variable and determined by progression of lesions or mitral annulus size. These data should help plan follow up of patients with organic MR and future intervention trials.

Adult↗

PubMed1999

Functional anatomy of mitral regurgitation: accuracy and outcome implications of transesophageal echocardiography.

OBJECTIVES: This study was performed to determine the accuracy and outcome implications of mitral regurgitant lesions assessed by echocardiography. BACKGROUND: In patients with mitral regurgitation (MR), valve repair is a major incentive to early surgery and is decided on the basis of the anatomic mitral lesions. These lesions can be observed easily with transesophageal echocardiography (TEE), but the accuracy and implications for outcome and clinical decision-making of these observations are unknown. METHODS: In 248 consecutive patients operated on for MR, the anatomic lesions diagnosed with TEE were compared with those observed by the surgeon and those seen on 216 transthoracic echocardiographic (TTE) studies, and their relationship to postoperative outcome was determined. RESULTS: Compared with surgical diagnosis, the accuracy of TEE was high: 99% for cause and mechanism, presence of vegetations and prolapsed or flail segment, and 88% for ruptured chordae. Diagnostic accuracy was higher for TEE than TTE for all end points (p < 0.001), but the difference was of low magnitude (<10%) except for mediocre TTE imaging or flail leaflets (both p < 0.001). The type of mitral lesions identified by TEE (floppy valve, restricted motion, functional lesion) were determinants of valve repairability and postoperative outcome (operative mortality and long-term survival; all p < 0.001) independent of age, gender, ejection fraction and presence of coronary artery disease. CONCLUSIONS: Transesophageal echocardiography provides a highly accurate anatomic assessment of all types of MR lesions and has incremental diagnostic value if TTE is inconclusive. The functional anatomy of MR defined by TEE is strongly and independently predictive of valve repairability and postoperative outcome. Therefore, the mitral lesions assessed by echocardiography represent essential information for clinical decision making, particularly for the indication of early surgery for MR.

Aged↗

PubMed1999

Sudden death in mitral regurgitation due to flail leaflet.

OBJECTIVES: We sought to assess the incidence and determinants of sudden death (SUD) in mitral regurgitation due to flail leaflet (MR-FL). BACKGROUND: Sudden death is a catastrophic complication of MR-FL. Its incidence and predictability are undefined. METHODS: The occurrence of SUD was analyzed in 348 patients (age 67 +/- 12 years) with MR-FL diagnosed echocardiographically from 1980 through 1994. RESULTS: During a mean follow-up of 48 +/- 41 months, 99 deaths occurred under medical treatment. Sudden death occurred in 25 patients, three of whom were resuscitated. The sudden death rates at five and 10 years were 8.6 +/- 2% and 18.8 +/- 4%, respectively, and the linearized rate was 1.8% per year. By multivariate analysis, the independent baseline predictors of SUD were New York Heart Association (NYHA) functional class (p = 0.006), ejection fraction (p = 0.0001) and atrial fibrillation (p = 0.059). The yearly linearized rate of sudden death was 1% in patients in functional class I, 3.1% in class II and 7.8% in classes III and IV. However, of 25 patients who had SUD, at baseline, 10 (40%) were in functional class I, 9 (36%) were in class II and only 6 (24%) in class III or IV. In five patients (20%), no evidence of risk factors developed until SUD. In patients with an ejection fraction > or =60% and sinus rhythm, the linearized rate of SUD was not different in functional classes I and II (0.8% per year). Surgical correction of MR (n = 186) was independently associated with a reduced incidence of SUD (adjusted hazard ratio [95% confidence interval] 0.29 [0.11 to 0.72], p = 0.007). CONCLUSIONS: Sudden death is relatively common in patients with MR-FL who are conservatively managed. Patients with severe symptoms, atrial fibrillation and reduced systolic function are at higher risk, but notable rates of SUD have been observed without these risk factors. Correction of MR appears to be associated with a reduced incidence of SUD, warranting early consideration of surgical repair.

Aged↗

PubMed1999

The human fetal retinal pigment epithelium: A target tissue for thyroid hormones.

Thyroid hormone (T(3)) has previously been shown to regulate visual function in experimental animals and humans. To determine if T(3) exerts direct effects on retinal function, cultured human fetal retinal pigment epithelial (RPE) cells were tested for the presence of thyroid hormone receptors (TRs) and T(3) responses. Using TR-isoform-specific reverse-transcriptase polymerase chain reaction techniques, mRNA was detected for alpha1, alpha2 and beta1 TR isoforms. Immunohistochemistry using a polyclonal antibody that simultaneously recognizes alpha1, alpha2 and beta1 TRs showed nuclear staining of the fetal RPE. Specific binding of (125)I-T(3) to RPE cell nuclear extracts was detected, and Scatchard analysis revealed a K(d) of 110 pM. To determine if RPE cells can respond to T(3), hyaluronic acid (HA) levels in cell culture media were measured after 2, 4 or 6 days of growth in medium containing 10(-7) M T(3). T(3) inhibited accumulation of HA in the cell culture medium of RPE cells. This effect was not evident at 2 days, but at 4 days there was 42.8% less HA in cell culture medium of RPE cells grown in 10(-7) M T(3) (p < 0.01, t test). The effect persisted through 6 days, when there was 46.3% less HA in cell culture medium of RPE cells grown in 10(-7) M T(3) (p < 0.001, t test). The data indicate that human fetal RPE cells are a direct target for thyroid hormones.

Cells, Cultured↗

PubMed1999

Detection and control of high blood pressure in the community : Do we need a wake-up call?

At the community level, the effect of national programs in increasing hypertension awareness, prevention, treatment, and control is unclear. This study evaluated the degree of detection and control of high blood pressure in a random population-based sample of Olmsted County, Minnesota, residents >/=45 years old, of whom 636 subjects among 1245 eligible residents agreed to participate. Home interview and home and office measurements of blood pressure were used to estimate awareness, treatment, and control rates for hypertension in the community. Mean blood pressures (+/-SD) were 138/80+/-20/12 mm Hg for men and 137/76+/-23/11 mm Hg for women. The overall prevalence of hypertension was 53%. The percentage of subjects with treated and controlled hypertension was 16.6%. Thirty-nine percent of subjects were unaware of their hypertension. Despite clinical trial evidence of reduced morbidity and mortality with antihypertensive therapy, recently reported national data suggest a leveling-off trend for treatment and control of hypertension. This population-based study supports these observations and suggests that at a community level, hypertension awareness and blood pressure control rates are suboptimal, presumably because of decreased attention to the detection and control of hypertension.

Aged↗

PubMed1999

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.

Adrenergic Agents↗

PubMed1999

Trends in heart disease deaths in Olmsted County, Minnesota, 1979-1994.

BACKGROUND: Although age-adjusted heart disease mortality has declined since the 1960s, this decline may not have applied equally to all subgroups. OBJECTIVE: To examine recent trends in heart disease mortality, specifically in women and in the elderly. METHODS: Age- and sex-specific heart disease mortality (International Classification of Diseases, Ninth Edition, Clinical Modification [ICD-9-CM] codes 390-398, 402, 404-429) in Olmsted County, Minnesota, between 1979 and 1994 were studied. RESULTS: The total number of heart disease deaths was 3095; 1578 (51%) occurred in women and 1984 (64%) in persons aged 75 years or older. Most heart disease deaths (77%) were coronary disease deaths (ICD-9-CM codes 410-414). Age-adjusted heart disease mortality rates declined from 123 per 100,000 (95% confidence interval [CI], 102-144/100,000) in 1979 to 81 per 100,000 (95% CI, 67-95/100,000) in 1994. Poisson regression analyses indicated that the trends differed according to sex and age. For women, the relative risk (RR) of heart disease death in 1994 compared with 1979 was 0.69 vs 0.53 for men (P = .06). This equates to a decline in heart disease mortality of 2.5% per year in women or 32% over the period and 4.2% per year in men or 47% over the period. The decline was less pronounced as age increased (P < .001). For 60-year-old women, the RR for 1994 compared with 1979 was 0.59, whereas for 80-year-old women, the RR for 1994 compared with 1979 was 0.76. For men, the RR for 1994 compared with 1979 was 0.60 for 80-year-old men vs 0.46 for 60-year-old men. CONCLUSIONS: Between 1979 and 1994, in Olmsted County, the decline in heart disease mortality was of lesser magnitude in women and in the elderly, emphasizing the importance of age- and sex-specific trends to characterize time patterns in heart disease deaths to target preventive measures.

Age Distribution↗

PubMed1999

Telemedicine consultations in congenital heart disease: assessment of advanced technical capabilities.

OBJECTIVE: To assess the value of adding remote pointer and dynamic display capabilities to a telemedicine system designed to provide consultative services for patients with congenital heart disease. MATERIAL AND METHODS: Independent observations by the referring physician and the consulting physician provided the data for the assessment. Fifty-four teleconsultations involving 38 patients with 21 different congenital heart diseases were analyzed. The teleconsultations were based on previously obtained cineangiograms that were digitized and then transmitted by combined satellite and terrestrial-based technology. The observations, recorded by each physician at his workstation at the time of each teleconsultation, were summarized and analyzed statistically. RESULTS: In 108 observations, the pointer was believed to be helpful in 72 (67%), and dynamic display was helpful in 96 (89%). CONCLUSION: This study suggests that use of a pointer and dynamic display enhances teleconsultations for patients with congenital heart disease.

Arizona↗

PubMed1999

A randomized double-blind controlled trial of automated term dissection.

OBJECTIVE: To compare the accuracy of an automated mechanism for term dissection to represent the semantic dependencies within a compositional expression, with the accuracy of a practicing Internist to perform this same task. We also compare the results of four evaluators to determine the inter-observer variability and the variance between term sets, with respect to the accuracy of the mappings and the consistency of the failure analysis. METHODS: 500 terms, which required a compositional expression to effect an exact match, were randomly distributed into two sets of 250 terms (Set A and Set B). Set A was dissected using the Automated Term Dissection (ATD) Algorithm. A physician specializing in Internal Medicine dissected set B. He had no prior knowledge of the dissection algorithm or how it functioned. In this manuscript, the authors use Human Term Dissection (HTD) to refer to this method. Set A was randomized to two sets of 125 terms (Set A1 and Set A2). Set B was randomized to two sets of 125 terms (Set B1 and Set B2). A new set of 250 terms Set C was created from Set A1 and Set B2. A second new set of 250 terms Set D was created from Set A2 and Set B1. Two expert Indexers reviewed Set C and another two expert Indexers reviewed Set D. They were blinded to which terms were dissected by the clinician and which terms were dissected by the automated term dissection algorithm. The person providing the files for review to the Indexers was also unaware of which terms were dissected by ATD vs. the HTD method. The Indexers recorded whether or not the dissection was the best possible representation of the input concept. If not, a failure analysis was conducted. They recorded whether or not the dissection was in error and if so was a modifier not subsumed or was a Kernel concept subsumed when it should not have been. If a concept was missing, the Indexers recorded whether it was a Kernel concept, a modifier, a qualifier or a negative qualifier. RESULTS: The ATD method was judged to be accurate and readable in 265 out of the 424 terms with adequate content (62.7%). The HTD method was judged to be accurate in 272 out of 414 terms with adequate content (65.7%). There was no statistically significant difference between the rates of acceptability of the ATD and HTD methods (p = 0.33). There was a non-significant trend toward greater acceptability of the ATD method in the subgroup of terms with three or more compositional elements. ATD was acceptable in 53.6% of the terms where the HTD was only acceptable in 43.6% (p = 0.11). The failure analysis showed that both methods misrepresented kernel concepts and modifiers much more commonly than qualifiers (p < 0.001). CONCLUSIONS: There is no statistically significant difference in the accuracy and readability of terms dissected using the automated term dissection method when compared with human term dissection, as judged by four expert medical indexers. There is a non-significant trend toward improved performance of the ATD method in the subset of more complex terms. The authors submit that this may be due to a tendency for users to be less compulsive when the time to complete the task is long. Automated term dissection is a useful and perhaps preferable method for representing readable and accurate compound terminological expressions.

Abstracting and Indexing↗

PubMed1998

Congestive heart failure in the community: a study of all incident cases in Olmsted County, Minnesota, in 1991.

BACKGROUND: Data are limited regarding the classification and prognosis of patients with congestive heart failure (CHF) in the community. METHODS AND RESULTS: Using the resources of the Rochester Epidemiology Project, we evaluated all patients receiving a first diagnosis of CHF in Olmsted County, Minnesota, in 1991 (n=216). Among these patients, 88% were >/=65 years and 49% were >/=80 years of age. The prognosis of patients with a new diagnosis of CHF was poor; survival was 86+/-2% at 3 months, 76+/-3% at 1 year, and 35+/-3% at 5 years. Of the 216 patients, 137 (63%) had an assessment of ejection fraction. In these patients, systolic function was preserved (ejection fraction >/=50%) in 59 (43%) and reduced (ejection fraction <50%) in 78 (57%). Survival adjusted for age, sex, NYHA class, and coronary artery disease was not significantly different between patients with preserved and those with reduced systolic function (relative risk, 0.80; P=0.369). ACE inhibitors were used in only 44% of the total population with CHF. CONCLUSIONS: The present study reports the clinical characteristics and natural history of CHF as it presents in the community in the vasodilator era. CHF is a disease of the "very elderly," frequently occurs in the setting of normal ejection fraction, and has a poor prognosis, regardless of the level of systolic function. Diagnostic and therapeutic methods are underused in the community.

Age Distribution↗

PubMed1998

Excess mortality due to coronary artery disease after valve surgery. Secular trends in valvular regurgitation and effect of internal mammary artery bypass.

BACKGROUND: During the 1980s, mortality from coronary artery disease (CAD) decreased markedly in the United States. This raises the question of whether a parallel decrease occurred in excess mortality due to CAD in patients undergoing surgical correction of valvular regurgitation. METHODS AND RESULTS: Survival of 752 patients (age, 64 +/- 13 years) with isolated left-sided valvular regurgitation operated on from 1980 to 1991 was analyzed. Of 242 patients with CAD (stenosis > or = 70%), 208 had coronary artery bypass grafting. Multivariate analysis identified CAD as an independent predictor of operative mortality (odds ratio [OR] = 2.35, P = 0.012), overall (hazard ratio [HR] = 1.65, P < 0.0001) and late mortality (HR = 1.57, P = 0.0006), and postoperative congestive heart failure (HR = 2.35, P = 0.0001). Comparison of patients operated on in 1980 to 1985 with those operated on in 1986 to 1991, excess of operative, overall, and late mortality and postoperative congestive heart failure (adjusted for age and gender) related to associated CAD did not decrease significantly (P = 0.23, P = 0.64, P = 0.90, and P = 0.61, respectively). Overall survival was better for patients receiving an internal mammary artery graft than those receiving vein grafts only (HR = 0.57, P = 0.011). CONCLUSIONS: In contrast to the secular trend for decreased mortality from CAD, excess mortality related to associated CAD after surgery for valvular regurgitation has not decreased. Internal mammary artery grafts were associated with improved outcome. In patients with valvular regurgitations, these results support continued active search of associated CAD, wide use of internal mammary artery graft, and vigorous efforts for secondary prevention of complications of CAD.

Aged↗

PubMed1998

Agreement and coding reliability of the Minnesota and Mayo electrocardiographic coding systems.

PROBLEM: To determine whether diagnoses of myocardial infarction assigned by a system that uses Marquette 12SL electrocardiographic (ECG) codes with manual over-reading agree with diagnoses assigned by Minnesota ECG codes. STUDIES UNDERTAKEN: Agreement and recode reliability of Minnesota and Mayo coding systems based on 768 ECGs plus chest pain history and serum enzyme values were analyzed for a stratified random sample of 141 patients with an event in 1990 or 1991 coded as HICDA 410.x, 411, 413 or 796.9. The population was reconstructed from the stratified random sample so that population-based inferences could be made from the analysis. RESULTS: For the stratified random sample, exact agreement on 4 categories (evolving diagnostic, diagnostic, equivocal, or other ECG) between Mayo and Minnesota ECG coding was 53.9% (kappa = 0.37 +/- 0.05). Code-recode agreement was higher for Minnesota coding (83.0%; kappa = 0.74 +/- 0.05) compared with Mayo coding (73.8%; kappa = 0.64 +/- 0.05). The same pattern was present for the reconstructed population. For coding myocardial infarction based on the ECG, serum enzyme levels, and the presence or absence of ischemic chest pain, agreement between Mayo and Minnesota coding was 84.4% (kappa = 0.72 +/- 0.05) based on the stratified random sample and 81.7% (kappa = 0.67 +/- 0.06) based on the reconstructed population. For the stratified random sample, reliability of diagnosis of myocardial infarction was 93.6% (kappa = 0.88 +/- 0.04) for the Minnesota system and 94.3% (kappa = 0.90 +/- 0.03) for the Mayo system. CONCLUSION: ECG interpretation by the Mayo and Minnesota coding systems differs significantly, and Mayo ECG coding is less reliable than Minnesota ECG coding. Coding of myocardial infarction on the basis of ECGs, serum enzymes, and ischemic chest pain, however, is equally reliable for both systems.

Chest Pain↗

PubMed1998

Measuring the effect of risk factors on coronary atherosclerosis: coronary calcium score versus angiographic disease severity.

OBJECTIVES: This study sought to determine whether noninvasive quantification of coronary calcium is comparable to selective coronary angiography in measuring the effect of cardiovascular risk factors on coronary atherosclerosis. BACKGROUND: Electron beam computed tomography (EBCT) allows the delineation of anatomic coronary atherosclerotic disease and may be useful for noninvasively defining the role of established and new cardiovascular risk factors in selected patient groups. METHODS: A total of 211 consecutive patients, 26 to 79 years old, referred for evaluation of suspected or recently diagnosed coronary artery disease were examined. Selective coronary angiography was used to define five angiographic disease categories: normal coronary arteries, nonobstructive disease and one-, two- or three-vessel disease. EBCT was used to calculate coronary calcium scores, and cardiovascular risk, including lipid variables and fibrinogen levels, was assessed. RESULTS: Coronary calcium score and angiographic disease severity categories were largely predicted by identical risk factors (i.e., age, male gender, total/high density lipoprotein cholesterol ratio, fibrinogen) and, to a lesser degree, hypertension. Only smoking predicted angiographic disease severity but not calcium scores. The risk factors together explained a comparable proportion of the variability in angiographic disease categories and in calcium score quintiles (33% vs. 41%, p=0.16 by bootstrap analysis). An overall risk score composed of these risk factors separated angiographic disease categories and calcium score quintiles with a similar area under the receiver operating characteristic curve ([mean+/-SE] 0.81+/-0.03 vs. 0.83+/-0.03, p=NS). CONCLUSIONS: Quantification of coronary calcium is comparable to selective coronary angiography in measuring the effect of established cardiovascular risk factors on coronary atherosclerosis. Thus, EBCT may be useful for the noninvasive evaluation of the relations between conventional or developing cardiovascular risk factors and coronary atherosclerosis.

Adult↗

PubMed1998

Gender differences in use of stress testing and coronary heart disease mortality: a population-based study in Olmsted County, Minnesota.

OBJECTIVES: We sought to examine the utilization of exercise stress testing in relation to age and gender in a population-based setting. BACKGROUND: The utilization of noninvasive procedures has been shown to be associated with the subsequent use of invasive procedures. Yet, there are no population-based data on the utilization of stress testing; in particular, although gender differences in the use of invasive procedures have been reported, the use of noninvasive procedures has not been examined in relation to gender. METHODS: In Olmsted County, Minnesota, passive surveillance of the medical care of the community is provided through the Rochester Epidemiology Project. A population-based cohort of Olmsted County residents undergoing exercise tests was identified. The medical records of residents with prevalent and incident exercise tests in 1987 and 1988 were reviewed. For persons with an initial test (incidence cohort), data on clinical presentation, test indications and results were abstracted. Stress test utilization rates were calculated, and crude rates were directly adjusted to the age distribution of the 1980 U.S. population. To help interpret patterns of use at the population level, coronary heart disease mortality rates (International Classification of Diseases, 9th revision, codes 410 to 414) were calculated (crude and directly adjusted to the overall age distribution of the 1980 U.S. population) and used as an indicator of coronary disease burden. RESULTS: A total of 2,624 tests were performed. The crude utilization rate (per 100,000) was 1,888 for men and 703 for women (rate ratio for men over women 2.7, 95% confidence interval [CI] 2.5 to 2.9); it remained significantly higher in men across all age strata. The crude incidence rate (per 100,000) of initial stress tests was 1,112 for men and 517 for women (rate ratio 2.2, 95% CI 1.9 to 2.4). For both men and women, the incidence increased with age; however, incidence remained lower in women in all age strata. At the time that they underwent an initial test, women were more symptomatic and had poorer exercise performance than men. The rate ratio of men over women for coronary heart disease mortality was 1.1 (95% CI 0.9 to 1.2). The age-adjusted rate ratios for stress test utilization were 2.8 (95% CI 2.5 to 3.0), and that for coronary heart disease mortality was 1.9 (95% CI 1.7 to 2.2). CONCLUSIONS: These population-based data show that during the study period, the utilization of stress testing in Olmsted County was lower in women than in men. Women in the incidence cohort were older and more symptomatic and had poorer exercise performance than men. Such differences should be considered when examining the utilization of subsequent invasive procedures according to gender.

Adult↗

PubMed1998

Application of the proximal flow convergence method to calculate the effective regurgitant orifice area in aortic regurgitation.

OBJECTIVES: We sought to determine the reliability of the proximal isovelocity surface area (PISA) method for calculation of effective regurgitant orifice (ERO) of aortic regurgitation (AR). BACKGROUND: The ERO area can be calculated by the PISA method, but this method has not been validated in AR. METHODS: ERO calculation by the PISA method was undertaken prospectively in 71 consecutive patients with isolated AR and achieved in 64 and compared with two simultaneous reference methods (quantitative Doppler and quantitative two-dimensional echocardiography). In addition, this method was compared with angiography in 12 patients, with surgical assessment in 18 patients and with ventricular volumes in all patients. RESULTS: Good correlations between PISA and reference methods were obtained (both r=0.90, both p < 0.0001), but a trend toward underestimation of the ERO by the PISA method was noted (24+/-19 vs. 26+/-22 mm2 and 27+/-23 mm2, respectively, both p=0.04). However, this trend was confined to five patients with an obtuse flow convergence angle (>220 degrees), and on multivariate analysis this variable was the only independent determinant of underestimation of the ERO. In contrast, in 59 patients with a flat flow convergence (< or =220 degrees ), the PISA method, in comparison with reference methods, showed excellent correlations, with a narrow standard error of the estimate (r=0.95, SEE 5.4 mm2, and r=0.95, SEE 5.8 mm2; all p < 0.0001) and no trend toward underestimation (22+/-18 vs. 23+/-16 mm2, p=0.44, and vs. 23+/-18 mm2, p=0.34). CONCLUSIONS: In patients with AR, the PISA method can be used to measure the ERO with reasonable feasibility. Underestimation of the ERO by PISA may occur in patients with an obtuse flow convergence angle. However, in most patients with appropriate flow convergence, PISA provides reliable measurement of the ERO of AR.

Aortic Valve↗

PubMed1998

Rapid estimation of regurgitant volume by the proximal isovelocity surface area method in mitral regurgitation: Can continuous-wave Doppler echocardiography be omitted?

The proximal isovelocity surface area (PISA) method is accurate for quantitating mitral regurgitation but requires recording both mitral maximal and integrated jet velocities using the same continuous-wave Doppler jet signal. In 272 consecutive patients with isolated mitral regurgitation, the mean ratio of maximal to integral of velocity had a narrow range of variation (mean +/- SD, 3.25 +/- 0.47). The estimated regurgitant volume, calculated as regurgitant flow/3.25, showed an excellent correlation with reference regurgitant volumes (r = 0.96 and r = 0.97; standard error of the estimate, 11 ml; both p < 0.0001), with limited overestimation and high sensitivity and specificity for severe mitral regurgitation. The estimated regurgitant volume is a useful measurement in patients in whom the continuous-wave Doppler signal of mitral regurgitation cannot be obtained.

Aged↗