Biomedical subjects

K R Bailey

Publications and source records attributed to K R Bailey.

At least 91 records · Page 5Linked to original sources

PubMed1997

Variability in anticoagulation control predicts thromboembolism after mechanical cardiac valve replacement: a 23-year population-based study.

OBJECTIVE: To assess optimal control of blood anticoagulation to maximize antithrombotic protection after mechanical cardiac valve replacement. DESIGN: A population-based study of 96 patients with a mean follow-up of 7.7 years (range, 1 month to 23 years) was performed in Olmsted County, Minnesota, and 10,301 prothrombin time (PT) ratios were determined after mechanical heart valve replacement. MATERIAL AND METHODS: PT ratios were analyzed in a new time-dependent Cox proportional-hazards model by defining an algorithm for comparing variability in PT ratios at each month of follow-up and relating these to thromboembolic events. The new method was compared with several conventional time-independent definitions. RESULTS: During 740 person-years of follow-up, 19 of 96 patients (20%) had 27 thromboembolic events. Of these 19 patients, 8 (42%) had events within 3 months after valve replacement. Freedom from any thromboembolic event was 72% at 15 years. The event rate was high (7.5% per year) during high variability and low (0.9% per year) during low variability in the PT ratio. This relationship was lost when time dependence was removed. More PT ratios were less than 1.5 during high (27%) than during low (19%) variability. Several conventional definitions of adequacy of anticoagulation that averaged PT ratios before a thromboembolic event or throughout follow-up or that compared the proportion of PT ratios above or below a fixed ratio did not define or only partially defined different thromboembolic risks. CONCLUSION: Periods of high and low variability of PT ratios define high and low risk of thromboembolism, respectively.

Adult↗

PubMed1997

Effect of infarct-related artery patency and late potentials on late mortality after acute myocardial infarction.

OBJECTIVE: To assess the effect of patency of the infarct-related artery and the presence of late potentials on late cardiac mortality after myocardial infarction. MATERIAL AND METHODS: We studied the influence of the infarct-related artery patency and the presence of late potentials during signal-averaged electrocardiography on late mortality in 124 survivors of acute myocardial infarction. In addition, we assessed predictive factors of cardiac mortality by univariate and multivariate statistical analysis. RESULTS: A study group of 98 men and 26 women (mean age, 59 years) who were survivors of acute myocardial infarction underwent follow-up for a mean of 3.6 +/- 1.0 years. Immediate reperfusion therapy (thrombolysis or direct angioplasty) was accomplished in 71 patients (57%). During follow-up, 13 cardiac-associated deaths occurred. Infarct-related artery patency was strongly associated with improved survival, but the presence of late potentials did not correlate with increased mortality, even among patients with impaired left ventricular function. Univariate and multivariate analyses identified occluded infarct-related arteries, prior myocardial infarction, reduced left ventricular ejection fraction, and advanced age, but not late potentials, as predictors of increased late cardiac mortality. CONCLUSION: These data suggest that coronary angiography may, but signal-averaged electrocardiography may not, identify patients with increased late risk of cardiac-related death after myocardial infarction. The low mortality among patients who have undergone successful reperfusion therapy may reduce the ability of noninvasive tests to distinguish between high- and low-risk patients.

Analysis of Variance↗

PubMed1997

Outcome after surgery for mitral regurgitation. Determinants of postoperative morbidity and mortality.

BACKGROUND AND AIMS OF THE STUDY: The incidence and impact of congestive heart failure and coronary artery disease on late survival after surgical correction of mitral regurgitation are poorly defined. In addition to the uncertainty about the frequency of this complication, the mechanisms of heart failure have not been fully analyzed. METHODS: To determine survival and the incidence and mechanisms of congestive heart failure after mitral valve surgery for mitral regurgitation, we analyzed the long-term outcome of 576 consecutive postoperative survivors. RESULTS: The analysis demonstrated that preserved preoperative left ventricular function (ejection fraction > or = 60%) was associated with improved survival (adjusted risk ratio 0.49; 95% C.I. 0.36-0.661) and reduced incidence of congestive heart failure (adjusted risk ratio 0.30; 95% C.I. 0.20-0.441), while concomitant coronary artery disease was associated with an excess mortality (adjusted risk ratio 1.80; 95% C.I. 1.34-2.41) and incidence of congestive heart failure (adjusted risk ratio 2.12; 95% C.I. 1.48-3.031). CONCLUSIONS: These results suggest that left ventricular dysfunction and coronary artery disease are major determinants of mortality and morbidity after surgical correction of mitral regurgitation. For the prevention of postoperative congestive heart failure, early surgical correction of mitral regurgitation should be considered before left ventricular dysfunction occurs.

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PubMed1996

Surgery for aortic regurgitation in women. Contrasting indications and outcomes compared with men.

BACKGROUND: Indications for surgical correction of aortic regurgitation have been established mostly in men and have not been validated in women. The outcome of this surgical correction in women is unknown. METHODS AND RESULTS: Baseline characteristics and postoperative outcomes were compared between 51 women and 198 men undergoing surgery for isolated aortic regurgitation between 1980 and 1989. Compared with men, women had surgery rarely for severe left ventricular enlargement (systolic diameter > or = 55 mm in 11% versus 27%, P = .031; diastolic diameter > or = 80 mm in 0% versus 16%, P < .0001) and more often for class III to IV symptoms (59% versus 32%, P < .0001). Operative mortalities were similar in women and men (3.9% and 4.5%, respectively). Among operative survivors, 10-year survival was worse for women than for men (39 +/- 9% versus 72 +/- 4%, P = .0002) and, in contrast with men, was worse than expected for women (P < .0001). Independent predictors of late survival were different for men (age and ejection fraction) and women (age and concomitant coronary bypass grafting). By multivariate analysis, female sex was an independent predictor of worse late survival (adjusted relative risk, 1.80; 95% CI, 1.04 to 3.11). CONCLUSIONS: The generalization to women of the unadjusted left ventricular diameter surgical criteria established in men results in irrelevant criteria almost never reached in women, who often undergo surgery after developing severe symptoms. After surgery, women exhibit an excess late mortality, suggesting that surgical correction of aortic regurgitation should be considered at an earlier stage in women.

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PubMed1996

Clinical outcome of mitral regurgitation due to flail leaflet.

BACKGROUND: Mitral regurgitation due to flail leaflet is difficult to manage, because it is frequently asymptomatic yet carries a high risk of left ventricular dysfunction and because the natural history of the condition is poorly defined. METHODS: We obtained clinical follow-up data through 1994-1995 in 229 patients with isolated mitral regurgitation due to flail leaflet; this condition was first diagnosed by echocardiography between 1980 and 1989. RESULTS: The 86 patients who were treated medically had a mortality rate significantly higher than expected (6.3 percent yearly, P=0.016 for the comparison with the expected rate in the U.S. population according to the 1990 census). Independent determinants of mortality were an older age, the presence of symptoms, and a lower ejection fraction. Patients who were even transiently in New York Heart Association functional class III or IV had a high mortality rate (34 percent yearly), but the rate was also notable (4.1 percent yearly) among those in class I or II. At 10 years, the mean (+/- SE) rates of heart failure, atrial fibrillation, and death or surgery were 63 +/- 8, 30 +/- 12, and 90 +/- 3 percent, respectively. In a multivariate analysis, surgical correction of mitral regurgitation (performed in 143 patients) was associated with a reduced mortality rate (hazard ratio, 0.29; 95 percent confidence interval, 0.15 to 0.56; P<0.001). CONCLUSIONS: When treated medically, mitral regurgitation due to flail leaflet is associated with excess mortality and high morbidity. Surgery is almost unavoidable within 10 years after the diagnosis and appears to be associated with an improved prognosis; this finding suggests that surgery should be considered early in the course of the disease.

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PubMed1996

Predictors of reversibility of pulmonary hypertension in cardiac transplant recipients in the first postoperative year.

BACKGROUND: Pulmonary hypertension remains a risk factor for early postoperative mortality in heart transplantation and may reduce the long-term benefits of the procedure. This study was undertaken to assess the value of baseline hemodynamic studies with nitroprusside used to predict the degree of postoperative reversibility of pulmonary hypertension in cardiac transplant recipients and to identify clinical risk factors for fixed pulmonary hypertension. METHODS AND RESULTS: Hemodynamic data from 55 consecutive patients who underwent orthotopic cardiac transplantation from June 1988 through September 1993 were analyzed. The effects of nitroprusside and transplantation on pulmonary artery pressure, cardiac output, and pulmonary vascular resistance were compared. Multiple regression analysis was used to identify the predictors of reversibility of pulmonary hypertension. Nitroprusside reduced pulmonary vascular resistance by increasing cardiac output and, to a lesser extent, by reducing the transpulmonary gradient. Pulmonary hypertension was less reversible in patients with ischemic heart disease (versus dilated cardiomyopathy) and in former smokers (versus nonsmokers). Patients with nonischemic heart failure and no smoking history had significantly lower posttransplant pulmonary vascular resistance (1.24 +/- 0.45 Wood units) than ischemic patients (who were all former smokers; 2.20 +/- 1.01 wood units) or nonischemic former smokers (1.72 +/- 0.70 Wood units). The correlation of pulmonary vascular resistance during nitroprusside challenge with posttransplant pulmonary vascular resistance was better than that of baseline pulmonary vascular resistance with posttransplant pulmonary vascular resistance. CONCLUSIONS: Nitroprusside testing improves the prediction of late posttransplant pulmonary vascular resistance; hence, it provides data that may be relevant to both early operative risk and later long-term effectiveness of cardiac transplantation. The finding of increased risk of fixed pulmonary hypertension associated with ischemic heart disease and smoking suggests that underlying atherosclerotic vascular disease may contribute to the irreversibility of pulmonary vascular resistance.

Adult↗

PubMed1996

Survival and functional independence after implantation of a permanent pacemaker in octogenarians and nonagenarians. A population-based study.

BACKGROUND: The number of very elderly persons who are candidates for implantation of a permanent pacemaker is increasing, but the effect of cardiac pacing on long-term survival and functional variables has not been determined. OBJECTIVE: To determine long-term survival after implantation of a permanent pacemaker in octogenarians and nonagenarians and to assess functional independence after such implantation. DESIGN: Retrospective, population-based cohort study. SETTING: Epidemiologic setting from an unselected population. PATIENTS: 157 octogenarians and nonagenarians who initially received a pacemaker between 1962 and 1988 and were followed through 1992. MAIN OUTCOME MEASURES: Overall mortality rate, functional capabilities, and placement in a nursing home. RESULTS: Observed survival in patients with heart disease was significantly worse than that in age-and sex-matched controls (P < 0.001). Observed survival in community residents without heart disease was similar to that in controls (P > 0.2). Multivariable analysis identified congestive heart failure, chronic obstructive pulmonary disease, old age, syncope, cancer, and atrioventricular block as independent predictors of increased mortality. Symptoms decreased in 118 patients (75%) after pacemaker implantation. After implantation, 70 patients (45%) were permanently placed in nursing homes; this number is similar to the estimated probability of lifetime use of nursing homes from the National Mortality Followback Survey. Dementia developed or worsened in 51 patients (32%), and orthopedic disability occurred in 41 patients (26%). CONCLUSIONS: Normal relative survival in octogenarians and nonagenarians without heart disease is reassuring; the poor prognosis in patients with heart disease warrants careful evaluation of the methods and indications for cardiac pacing. Permanent pacing alleviates bradycardia-related symptoms. Placement in a nursing home and development or worsening of cardiac, neurologic, or orthopedic disabilities frequently occur after implantation of a permanent pacemaker in the very elderly.

Activities of Daily Living↗

PubMed1996

Secular trends in coronary atherosclerosis--analysis in patients with valvular regurgitation.

BACKGROUND: Between 1980 and 1989, mortality due to coronary artery disease decreased considerably in the United States, suggesting a possible decrease in the prevalence of coronary atherosclerosis. We examined this possibility in patients with valvular regurgitation who, often in the absence of angina, underwent coronary angiography before valve-replacement surgery. METHODS: We studied 601 patients with isolated, nonischemic valvular regurgitation who were operated on between 1980 and 1989 and who had undergone preoperative coronary angiography. From the angiograms we determined the prevalence of clinically significant coronary artery disease and of multivessel disease, assessed the mean degree of stenosis, and analyzed the trends in the data over the years of the study. RESULTS: The prevalence of coronary artery disease (35 percent in 1980-1981, 37 percent in 1982-1983, 34 percent in 1984-1985, 37 percent in 1986-1987, and 35 percent in 1988-1989; P = 0.97) did not change significantly during the study period. We found no significant change in the prevalence of multivessel disease (24 percent in 1980-1981 and 23 percent in 1988-1989, P = 0.99) or in the mean ( +/- SD) degree of stenosis (11 +/- 13 percent in 1980-1981 and 13 +/- 14 percent in 1988-1989, P = 0.07). When these measures of coronary atherosclerosis were adjusted for age and sex, there were still no significant changes over time (P = 0.39 for the prevalence of coronary artery disease, P = 0.81 for that of multivessel disease, and P = 0.57 for the mean degree of stenosis). The patients' mean total cholesterol level decreased from 219 +/- 48 mg per deciliter (5.66 +/- 1.24 mmol per liter) to 206 +/- 44 mg per deciliter (5.33 +/- 1.14 mmol per liter) between 1980 and 1989 (P = 0.04). CONCLUSIONS: From 1980 to 1989, no significant change was observed in angiographic measures of coronary atherosclerosis in patients with nonischemic valvular regurgitation, in contrast to the marked decrease in mortality due to coronary disease in the general population. These findings suggest that the well-documented reduction in mortality due to coronary disease may not be due to a reduction in the prevalence of coronary atherosclerosis.

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PubMed1996

Aortic regurgitation complicated by extreme left ventricular dilation: long-term outcome after surgical correction.

OBJECTIVES: This study sought to determine the outcome of aortic valve replacement for aortic regurgitation complicated by extreme left ventricular dilation. BACKGROUND: Aortic valve replacement has been recommended in aortic regurgitation with extreme left ventricular dilation (diastolic dimension >/= 80 mm), but extreme left ventricular dilation raises concern about irreversible left ventricular dysfunction. METHODS: Thirty-one patients with a preoperative echocardiographic diastolic dimension >/= 80 mm (group 1) undergoing operation for severe isolated aortic regurgitation between 1980 and 1989 were compared with 188 patients with a diastolic dimension <80 mm operated on during the same period (group 2). RESULTS: Preoperatively, extreme left ventricular dilation was seen only in male patients and was associated with a reduced ejection fraction (43 +/- 12% vs. 53 +/- 11% [mean +/- SD], p < 0.0001). The postoperative outcome of group 1 was compared with that of male patients in group 2 (group 2M, n = 144). The operative mortality rates for groups 1 and 2M were 0% and 5.6%, respectively (p = 0.35). Late survival in operative survivors was similar in groups 1 and 2M, but compared with expected survival, an excess mortality was observed for group 1 (p = 0.024). Preoperative ejection fraction, but not diastolic dimension, independently predicted late survival and postoperative ejection fraction. Postoperatively, groups 1 and 2M showed a similar improvement in ejection fraction, but persistent left ventricular enlargement was more frequent in group 1. CONCLUSIONS: Extreme left ventricular dilation due to aortic regurgitation is observed in male patients and is frequently associated preoperatively with a reduced ejection fraction but is not a marker of irreversible left ventricular dysfunction. Operative risk and late postoperative survival are acceptable in these patients, although a late excess mortality, predicted best by preoperative ejection fraction, is observed. Therefore, extreme left ventricular dilation is not a contraindication to operation, which should be performed before left ventricular dysfunction occurs.

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PubMed1996

Impact of stent size and indication for stent placement on immediate outcome.

The immediate outcome of 271 procedures involving the intracoronary implantation of 305 stents was determined. Data were analyzed with regard to indication for stenting and stent size. Elective indication was associated with a higher success rate than emergency indication (95.6% vs. 86.6%, P = 0.013) and a lower Q-wave infarction rate (0 vs. 6.4%, P = 0.006). Univariate analysis showed that the odds ratio for procedural success was significantly favored by elective indication (3.37, P = 0.018) but was unrelated to stent size (1.10, P = 0.087). These findings were confirmed on multivariate analysis. The likelihood of Q-wave infarction was lower for elective placement (P = 0.0008) but was not related to size. Requirement for emergency bypass surgery, incidence of subacute closure, and death were not related to indication or to stent size on either univariate or multivariate analysis. Therefore, the immediate outcome of stent placement is related to the indication for stenting, but not to the size of stent implanted. Procedural success is significantly favored by elective indication.

Adult↗

PubMed1996

Changing outcome of angioplasty in the elderly.

OBJECTIVES: This study sought to determine whether in-hospital and intermediate-term posthospital outcomes have changed in elderly patients undergoing percutaneous transluminal coronary angioplasty from the period 1980 through 1989 to the period 1990 through 1992. BACKGROUND: Although elderly patients have a higher incidence of procedure-related deaths and late recurrence of angina after coronary angioplasty, recent complication rates for angioplasty seem to be lower. METHODS: From 1980 to 1989, 982 patients > or = 65 years old underwent nonemergent coronary angioplasty (group A). They were compared with 768 similar patients who had coronary angioplasty from 1990 to 1992 (group B). RESULTS: Patients in group B were older than those in group A and had a higher mean concomitant disease score, a higher proportion of men and a greater proportion of patients with a previous myocardial infarction and previous coronary artery bypass surgery. Despite the increased complexity of the group B cohort, procedural success rates were higher, and rates of important in-hospital complications were much lower than those in group A. For group A versus group B, respectively, the technical success rate was 88.1% versus 93.5% (p < 0.001), in-hospital death rate 3.3% versus 1.4% (p = 0.014), emergency bypass surgery rate 5.5% versus 0.65% (p < 0.001) and incidence of in-hospital death or myocardial infarction 6.3% versus 3.4% (p < 0.005). However, intermediate-term posthospital event-free rates in hospital survivors did not decrease. The rate of death or myocardial infarction at 6 months was 4.7% in group A versus 7.1% in group B (p < 0.05). Survival free of acute myocardial infarction, bypass surgery, repeat coronary angioplasty or severe angina at 1 year was 66.7% in group A versus 54.9% in group B (p < 0.001). The combined in-hospital death/myocardial infarction rate plus that for the first 6 months after hospital dismissal was essentially equivalent for the two groups (10.3% vs. 9.9%, p = NS). CONCLUSIONS: An increase in technical success rates and a reduction in short-term complication rates for coronary angioplasty in the elderly in recent years have not translated into an improved event-free survival rate, which continues to be influenced by important baseline characteristics of these high risk patients.

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PubMed1996

Hypertrophic obstructive cardiomyopathy: preoperative echocardiographic predictors of outcome after septal myectomy.

OBJECTIVES: The purpose of this study was to determine whether two-dimensional and Doppler echocardiography are predictive of clinical outcome in patients with hypertrophic obstructive cardiomyopathy who undergo septal myectomy. BACKGROUND: Surgical myectomy provides excellent relief of symptoms in most patients with hypertrophic obstructive cardiomyopathy who are severely symptomatic despite medical therapy. There is a subset of patients who will remain symptomatic even after operation. Because comprehensive two-dimensional and Doppler echocardiography can define the range of anatomic and associated pathophysiologic abnormalities, it was hypothesized that preoperative echocardiographic variables may be predictive of clinical outcome after septal myectomy. METHODS: The clinical, electrocardiographic (ECG), echocardiographic and surgical data of 47 adult patients with hypertrophic cardiomyopathy who underwent isolated septal myectomy from 1986 to 1992 were analyzed. Specific symptoms were evaluated both preoperatively and at 1 year postoperatively. Electrocardiography and echocardiography were performed preoperatively and postoperatively. The ECG and echocardiographic variables were analyzed to determine whether any were predictive of residual symptoms 1 year postoperatively. RESULTS: The mean [+/-SD] age of the patients was 47 +/- 15 years. All were New York Heart Association functional class III or IV. Dyspnea was present in all 47 patients and was severe in 70%. Most patients experienced symptomatic improvement at 1 year; dyspnea persisted in 26 patients (55%). The preoperative echocardiographic variables of asymmetric hypertrophy, severe systolic anterior motion of the mitral leaflet(s) and prolonged isovolumetric relaxation time were independent predictors of mild or no residual dyspnea postoperatively. CONCLUSIONS: This initial study shows that the preoperative echocardiographic variables of asymmetric hypertrophy, severe systolic anterior motion of the mitral leaflet(s) and prolonged isovolumetric relaxation time can identify patients who are most likely to benefit from septal myectomy.

Adult↗

PubMed1996

Adenosine: potential modulator for vasovagal syncope.

OBJECTIVES: This study examined the hypothesis that adenosine could provoke a vasovagal response in susceptible patients. Mechanisms of the vasovagal response were further explored by studying the adenosine-mediated reactions. BACKGROUND: Increased sympathetic activity is frequently observed before vasovagal syncope. Recent studies have demonstrated that adenosine, in addition to its direct bradycardiac and vasodilatory effects, can increase sympathetic discharge by activating cardiovascular afferent nerves. METHODS: The effects of adenosine and head-up tilt-table testing with or without isoproterenol were prospectively evaluated in 85 patients examined for syncope after negative results of electrophysiologic testing (51 men and 34 women, mean [+/- SD] age 61 +/- 17 years). Adenosine bolus injections of 6 mg and 12 mg were sequentially administered to patients in the upright position. The same protocol was implemented in 14 normal control subjects (7 men and 7 women, mean [+/- SD] age 38 +/- 10 years). RESULTS: Transient hypertension or tachycardia was observed in 57 (67%) and 20 (24%) patients after administration of 6 mg and 12 mg of adenosine, respectively, during the immediate phase (first 15 s), suggesting direct sympathetic activation. Hypotension and reflex tachycardia were observed in all patients during the delayed phase (15 to 60 s after adenosine injection), suggesting baroreceptor unloading. A vasovagal response was induced in 22 (26%) and 29 (34%) patients after adenosine administration and during tilt-table testing. Inducibility of a vasovagal response by these two methods was comparable (p = 0.12). Of the control subjects, one (7%) had a vasovagal response after adenosine administration and one (7%) had a positive response during tilt-table testing. CONCLUSIONS: These observations support the idea that adenosine is an endogenous modulator of the cardiac excitatory afferent nerves. Sympathetic activation by adenosine can be direct (i.e., cardiac excitatory afferent nerves) and indirect (i.e., vasodilation and reflex sympathetic activation). Adenosine could be an important modulator in triggering a vasovagal response in susceptible patients during examination for syncope.

Adenosine↗

PubMed1996

Intensity of murmurs correlates with severity of valvular regurgitation.

PURPOSE: To evaluate the relationship between the intensity of murmurs and severity of mitral and aortic regurgitation. PATIENTS AND METHODS: Consecutive patients with chronic isolated aortic (n = 40) or mitral (n = 170) regurgitation undergoing echocardiographic quantitation of regurgitation between 1990 and 1991 were studied. Regurgitant volume and fraction were measured using two simultaneous methods (quantitative Doppler echocardiography and quantitative two-dimensional echocardiography); the intensity of the regurgitant murmur (grade 0 to 6) was noted by physicians unaware of the study. RESULTS: Correlations between murmur intensity and regurgitant volume and fraction were good in aortic regurgitation (r = .60 and r = .67, respectively; P < 0.001) and mitral regurgitation (r = .64 and r = .67, respectively; P < 0.001) but weaker (r = .47 and r = .45, respectively) in the subset of mitral regurgitation of ischemic or functional cause. Murmur intensity grades > or = 3 for aortic regurgitation and > or = 4 for mitral regurgitation predicted severe regurgitation (regurgitant fraction > or = 40%) in 71% and 91% of patients, respectively. Murmur grades < or = 1 for aortic regurgitation and < or = 2 for mitral regurgitation predicted "not severe" regurgitation in 100% and 88% of patients, respectively. Murmur grades 2 for aortic regurgitation and 3 for mitral regurgitation were not correlated to degree of regurgitation. The severity of regurgitation was the most powerful determinant of intensity of murmur. CONCLUSIONS: Murmur intensity correlates well with the degree of chronic organic aortic and mitral regurgitation, and can be used as a predictor of regurgitation severity and as a simple guideline for diagnostic testing in these patients.

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PubMed1996

Superiority of brain natriuretic peptide as a hormonal marker of ventricular systolic and diastolic dysfunction and ventricular hypertrophy.

Atrial and brain natriuretic peptides (ANP and BNP) are produced by the heart, and their plasma concentrations are increased in human chronic congestive heart failure. Although separate studies have suggested that circulating levels of the biologically active C-terminal ANP, the biologically inactive N-terminal ANP, and BNP may have diagnostic utility in the detection of left ventricular systolic dysfunction or left ventricular hypertrophy, no studies have directly assessed the relative value of these peptides prospectively. We therefore designed this study to compare the relative ability of the different natriuretic peptides to detect abnormal left ventricular systolic and diastolic function and left ventricular hypertrophy. Using a prospective study design, we investigated 94 patients referred for cardiac catheterization and 15 age-matched normal subjects. The diagnostic abilities of elevated plasma C-terminal ANP, N-terminal ANP-(1-30), and BNP concentrations to identify systolic dysfunction (ejection fraction < 45%), diastolic dysfunction (time constant of left ventricular relaxation > 55 milliseconds, left ventricular end-diastolic pressure > 18 mm Hg), and left ventricular hypertrophy (left ventricular mass index > 120 g/m2) were objectively compared by receiver operating characteristic analysis. The areas under the receiver operating characteristic curve of BNP for detecting each of these abnormalities ranged from 0.715 to 0.908 and were significantly greater than those of C-terminal ANP or N-terminal ANP-(1-30). The sensitivity and specificity of an elevated plasma BNP, which we defined as greater than the mean + 3 SD of the 15 age-matched normal subjects, were 0.83 and 0.77, respectively, for detecting ejection fraction less than 45%, 0.85 and 0.70 for detecting the time constant of left ventricular relaxation greater than 55 milliseconds, 0.63 and 0.76 for detecting left ventricular end-diastolic pressure greater than 18 mm Hg, and 0.81 and 0.85 for detecting left ventricular mass index greater than 120 g/m2. The use of BNP and one other peptide increased sensitivity (0.90 to 0.96), albeit with lower specificity (0.56 to 0.71). An elevated plasma BNP was a more powerful marker of left ventricular systolic dysfunction, left ventricular diastolic dysfunction, and left ventricular hypertrophy than C-terminal ANP or N-terminal ANP-(1-30) in this population of patients with suspected cardiac disease. Measurement of BNP alone or in combination with C-terminal ANP or N-terminal ANP-(1-30) has potential utility for the detection of altered left ventricular structure and function in a patient population at risk for cardiovascular disease.

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PubMed1996

Effect of Doppler echocardiography on utilization of hemodynamic cardiac catheterization in the preoperative evaluation of aortic stenosis.

OBJECTIVE: To examine the use of Doppler echocardiography in preoperative assessment of aortic stenosis and to determine its effect on subsequent use of hemodynamic cardiac catheterization. MATERIAL AND METHODS: We retrospectively reviewed a consecutive series of 574 adult patients who underwent aortic valve replacement for aortic stenosis between 1990 and 1992 at our institution. The use of Doppler echocardiography and cardiac catheterization and the predictive factors for use of hemodynamic catheterization were analyzed. RESULTS: After Doppler echocardiography in 423 patients, invasive hemodynamic assessment of the severity of aortic stenosis was performed in only 42% (179 patients). The use of cardiac catheterization declined over time (54% in 1990, 40% in 1991, and 35% in 1992) (P = 0.003), whereas no significant change in the baseline clinical characteristics of the population or in severity of stenosis as determined by Doppler echocardiography occurred during that time. Multivariate analysis identified the following variables as independent predictors of use of cardiac catheterization after Doppler echocardiography: clinically not severe aortic stenosis, mean gradient of less than 50 mm Hg determined by Doppler echocardiography, Doppler-determined aortic valve area of more than 0.8 cm2 or not calculated, attending cardiologist not specialized in echocardiography, and earlier year of assessment. CONCLUSION: After Doppler echocardiography, less than 50% of our patients undergoing aortic valve replacement for aortic stenosis have cardiac catheterization preoperatively. The use of cardiac catheterization after Doppler echocardiography--thus, duplication of hemodynamic assessment--declined significantly over time during the study period. Decline in the use of catheterization is related to the degree of diagnostic certainty provided by Doppler echocardiography and to the level of familiarity of the attending cardiologist with the technique.

Adult↗

PubMed1995

Changes in effective regurgitant orifice throughout systole in patients with mitral valve prolapse. A clinical study using the proximal isovelocity surface area method.

BACKGROUND: In patients with mitral valve prolapse, spontaneous changes of the effective regurgitant orifice during systole are not well documented. Such changes can now be analyzed by use of the proximal isovelocity surface area method, but the changes raise concern about the reliability of this method for assessing overall severity of regurgitation in these patients. METHODS AND RESULTS: In a prospective study of 42 patients with mitral valve prolapse, the effective mitral regurgitant orifice was calculated at four phases of systole (early, mid, mid-late, and late) as the ratio of regurgitant flow to regurgitant velocity by use of the proximal isovelocity surface area method. Throughout systole, the effective regurgitant orifice increased significantly, from 32 +/- 27 mm2 in early systole to 41 +/- 27 in midsystole, 55 +/- 30 in mid-late systole, and 107 +/- 66 mm2 during late systole (P < .0001). Phasic regurgitant volume increased from early to mid-late systole but decreased in late systole. For quantitation of the overall effective regurgitant orifice, four approaches using the proximal isovelocity surface area were compared with simultaneously performed quantitative Doppler echocardiography (54 +/- 30 mm2) and quantitative two-dimensional echocardiography (51 +/- 29 mm2). All correlations were good (r > .95), but overestimation was considerable when the largest flow convergence was used (70 +/- 39 mm2; both P < .0001), significant when the simple mean of the four phases was used (59 +/- 36 mm2; P = .005 and P = .0007, respectively), mild when a weighted mean of the four phases was used (55 +/- 33 mm2; P = .41 and P = .01, respectively), and no overestimation was observed when the effective regurgitant orifice calculated at maximum regurgitant velocity was used (54 +/- 30 mm2; P = .29 and P = .17, respectively). CONCLUSIONS: Phasic changes of mitral regurgitation are observed in patients with mitral valve prolapse. The effective regurgitant orifice increases throughout systole. Regurgitant volume also increases initially but tends to decrease in late systole. These changes can lead to overestimation of the overall degree of regurgitation, but properly timed measurements made by use of the proximal isovelocity surface area method allow an accurate estimation of the overall effective regurgitant orifice.

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PubMed1995

Normal stroke volume and cardiac output response during dobutamine stress echocardiography in subjects without left ventricular wall motion abnormalities.

Dobutamine stress echocardiography has become widely utilized for evaluation of coronary artery disease, but the expected responses of stroke volume and cardiac output to the high doses of dobutamine administered in these studies are not known. To determine these responses, stroke volume and cardiac output were measured with 2-dimensional Doppler echocardiography at each stage of dobutamine stress echocardiography and after administration of atropine in 47 patients without resting or inducible wall motion abnormalities. Heart rate increased significantly at each stage of dobutamine infusion and after atropine. Mean blood pressure decreased at the 5 micrograms/kg/min dose, then showed little change. Stroke volume increased 27 +/- 18% from baseline, with significant increases occurring at both the 5 and 10 micrograms/kg/min doses (p < 0.00001). With higher doses of dobutamine, stroke volume tended to plateau or decrease. Mean changes in stroke volume were not significant between the doses of 10, 20, and 30 micrograms/kg/min. The mean change in stroke volume from the 30 to the 40 micrograms/kg/min dose was a significant decrease of 6.3% (p = 0.004); the decrease from the 40 micrograms/kg/min dose to atropine approached statistical significance (p = 0.06). Cardiac output increased throughout dobutamine infusion. Stroke volume during dobutamine stress echocardiography is commonly maximum at a dose of 20 micrograms/kg/min and tends to decline at higher infusion rates. At higher doses, increases in cardiac output are mediated primarily by increases in heart rate.

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