Biomedical subjects

K R Bailey

Publications and source records attributed to K R Bailey.

At least 127 records · Page 7Linked to original sources

PubMed1994

Long-term survival after pacemaker implantation for heart block in patients > or = 65 years.

Permanent pacing can prevent recurrent symptoms and reduce mortality in elderly patients with symptomatic high-degree atrioventricular (AV) block. However, long-term survival with respect to comparable control subjects has not been well defined. In our study, relative long-term survival and prognostic predictors after permanent pacemaker implantation for symptomatic high-degree AV block were assessed among all residents of Olmsted County, Minnesota, who were > or = 65 years old. Of the 154 patients, 77 were men and 77 were women (mean age 80 +/- 7 years). Follow-up was 0.1 to 19.8 years (mean 4.2 +/- 2.8). Sixty-nine patients had isolated AV block and 85 had coexisting heart disease. Observed survival at 1, 3, 5, and 10 years was 85%, 68%, 52%, 21%, and 72%, 50%, 31%, 11% for patients with isolated AV block and patients with coexisting heart disease, respectively (p = 0.006). Observed survival in patients 65 to 79 years old with isolated AV block was comparable to age- and sex-matched cohorts (p = 0.53), but in patients aged > or = 80 years, it was less than that for control subjects (p = 0.014). In patients with coexisting heart disease, observed survival was less than that for control subjects in patients 65 to 79 years old (p < 0.001) and > or = 80 years (p < 0.001). Multivariate analysis identified congestive heart failure, chronic obstructive pulmonary disease, age, syncope, insulin-dependent diabetes mellitus, and male gender as independent predictors of increased mortality.

Age Factors↗

PubMed1994

Generalizing the results of randomized clinical trials.

Many scientific and statistical issues are involved in generalizing the results of randomized clinical trials. This paper examines the issues of heterogeneity of risk and heterogeneity of effect, as well as quantitative vs. qualitative heterogeneity. Generalization of quantitative results to populations at different risk is shown to be problematic, independent of any other considerations. Issues of heterogeneity as they relate to target population and choice of therapy are discussed. A few proposals are offered regarding the design and report of trials.

Combined Modality Therapy↗

PubMed1994

Myocardium at risk and infarct size after thrombolytic therapy for acute myocardial infarction: implications for the design of randomized trials of acute intervention.

OBJECTIVES: The purpose of this study was to estimate the effect of an improved reperfusion therapy for acute myocardial infarction on myocardial salvage and ventricular function for anterior and inferior infarctions and to ascertain the sample size required to detect such an effect. BACKGROUND: There are significant differences in myocardium at risk between anterior and inferior infarctions that affect the benefit of reperfusion therapy. METHODS: We studied 58 patients with acute myocardial infarction (24 anterior, 34 inferior) treated with intravenous recombinant tissue-type plasminogen activator and angioplasty when necessary. Tomographic imaging with technetium-99m sestamibi was performed to measure myocardium at risk, final infarct size and myocardial salvage and to estimate the beneficial effects of an improved therapy. RESULTS: A new therapy that was 30% more effective than existing therapy (with respect to salvage) would increase salvage (and reduce mean infarct size) by 5.2% of the left ventricle and increase late ejection fraction by only 0.012 (95% confidence interval [CI] 0.009 to 0.015) in inferior infarction and by 0.038 (95% CI 0.027 to 0.047) in anterior infarction. If anterior and inferior infarctions occurred with equal frequency, a sample size of 140 patients in each treatment group would be required to detect such a change with 80% power. In a trial of interior infarctions alone, a sample size of 236 patients in each treatment group would be required compared with only 98 patients in a trial of anterior infarctions alone. CONCLUSIONS: The anticipated mean benefit from an improved reperfusion therapy in individual patients with inferior infarction is very small and of questionable clinical significance. The anticipated benefit in anterior infarction is greater and easier to detect. Future randomized trials should be stratified for infarct location and should consider the greater absolute benefit of treatment in anterior infarction.

Adult↗

PubMed1994

Effective regurgitant orifice area: a noninvasive Doppler development of an old hemodynamic concept.

OBJECTIVES: The purpose of this study was to determine the feasibility, relation to other methods and significance of the effective regurgitant orifice area measurement. BACKGROUND: Assessment of the severity of valvular regurgitation (effective regurgitant orifice area) has not been implemented in clinical practice but can be made by Doppler echocardiography. METHODS: Effective regurgitant orifice area was calculated by Doppler echocardiography as the ratio of regurgitant volume/regurgitant jet time-velocity integral and compared with color flow Doppler mapping, angiography, surgical classification, regurgitant fraction and variables of volume overload. RESULTS: In 210 consecutive patients examined prospectively, feasibility improved from the early to the late experience (65% to 95%). Effective regurgitant orifice area was 28 +/- 23 mm2 (mean +/- SD) for aortic regurgitation (32 patients), 22 +/- 13 mm2 for ischemic/functional mitral regurgitation (50 patients) and 41 +/- 32 mm2 for organic mitral regurgitation (82 patients). Significant correlations were found between effective regurgitant orifice and mitral jet area by color flow Doppler mapping (r = 0.68 and r = 0.63, p < 0.0001, respectively) and angiographic grade (r = 0.77, p = 0.0004). Effective regurgitant orifice area in surgically determined moderate and severe lesions was markedly different in mitral regurgitation (35 +/- 12 and 75 +/- 33 mm2, respectively, p = 0.009) and in aortic regurgitation (21 +/- 8 and 38 +/- 5 mm2, respectively, p = 0.08). Strong correlations were found between effective regurgitant orifice area and variables reflecting volume overload. A logarithmic regression was found between effective regurgitant orifice area and regurgitant fraction, underlining the complementarity of these indexes. CONCLUSIONS: Calculation of effective regurgitant orifice area is a noninvasive Doppler development of an old hemodynamic concept, allowing assessment of the lesion severity of valvular regurgitation. Feasibility is excellent with experience. Effective regurgitant orifice area is an important and clinically significant index of regurgitation severity. It brings additive information to other quantitative indexes and its measurement should be implemented in the comprehensive assessment of valvular regurgitation.

Aged↗

PubMed1994

Identification of multivessel coronary artery disease by exercise echocardiography.

OBJECTIVES: This study examined the ability of exercise echocardiography to identify multivessel coronary artery disease and ascertain its incremental value when combined with clinical and exercise test variables. BACKGROUND: Although exercise echocardiography has been shown to be accurate for the detection of coronary artery disease, little is known about its utility for identifying multivessel involvement, and its incremental value when combined with clinical and exercise test variables has not been studied. METHODS: One hundred fifty consecutive patients were selected on the basis of having had an exercise echocardiographic and a coronary angiographic study within 6 months without any revascularization procedure. Significant coronary artery disease (> or = 50% diameter stenosis in any major coronary artery) was present in 117 patients, and multivessel (two- or three-vessel) disease was present in 90 patients. The exercise echocardiographic studies were reviewed by an experienced observer unaware of the results of the coronary angiogram. RESULTS: The overall sensitivity and specificity of exercise echocardiography for the identification of multivessel disease were 73% and 70%, respectively. A stepwise logistic regression analysis identified the number of abnormal regions on the postexercise images as the strongest independent predictor of multivessel disease; also significant were a history of myocardial infarction and ST segment depression of at least 2 mm on the peak exercise electrocardiogram. CONCLUSIONS: Exercise echocardiography adds independent and incremental information to clinical and exercise test variables for identifying multivessel coronary artery disease.

Aged↗

PubMed1994

Determination of left ventricular mass by echocardiography in a normal population: effect of age and sex in addition to body size.

OBJECTIVE: In this study, we determined the effect of age, sex, and body size on left ventricular mass. DESIGN: Two-dimensional-guided M-mode echocardiography was used in an assessment of 111 healthy, normal adults. MATERIAL AND METHODS: Left ventricular mass was calculated with the cube function formula corrected by a regression equation to agree with autopsy estimates of left ventricular mass. Calculated left ventricular mass, indexed by body surface area and by height, was analyzed on the basis of sex and age of the study participants. Age was analyzed as a dichotomous, trichotomous, and continuous variable. The effects of age, sex, and obesity, as well as interactions, were tested within a multiple linear regression model framework. RESULTS: Left ventricular mass, when indexed for either body surface area or height, was greater in men than in women. For women, but not men, we found a small but significant increase in left ventricular mass with advancing age. Body mass index, an indicator of obesity, increased with aging in women but not in men and affected left ventricular mass. No significant changes were noted in left ventricular cavity size with advancing age, and the increase in left ventricular mass in women was due to increased ventricular wall thickness. CONCLUSION: The findings in this study suggest that left ventricular mass, as assessed by two-dimensional-guided M-mode echocardiography, is affected not only by sex and body size but also by age in women. This phenomenon may be related to an increase in body mass index with advancing age in women. In clinical studies that use echocardiographic left ventricular mass to diagnose left ventricular hypertrophy, these observations should be considered.

Activities of Daily Living↗

PubMed1994

Effects of age on left ventricular dimensions and filling dynamics in 117 normal persons.

OBJECTIVE: To determine standard left ventricular Doppler measurements in a large reference group of various ages to reflect the senescence process. DESIGN: We prospectively studied the influence of aging on left ventricular diastolic filling by performing Doppler echocardiography in 117 normal healthy volunteers. MATERIAL AND METHODS: Transthoracic pulsed-wave Doppler echocardiographic studies of pulmonary venous flow and left ventricular inflow were done in the 53 male and 64 female study subjects. For analysis, the study subjects were arbitrarily classified into two groups: those younger than 50 years of age (group 1; N = 61) and those 50 years old or older (group 2; N = 56). RESULTS: A striking difference was found in pulmonary venous flow and left ventricular inflow between group 1 and group 2 subjects. Group 2 had increased pulmonary venous peak systolic flow velocity (71 +/- 9 versus 48 +/- 9 cm/s), decreased peak diastolic flow velocity (38 +/- 9 versus 50 +/- 10 cm/s), increased peak atrial reversal flow velocity (23 +/- 4 versus 19 +/- 4 cm/s), and increased percentage of forward flow in systole (65 +/- 7 versus 55 +/- 8%) in comparison with group 1. In group 2, peak early filling velocity (62 +/- 14 versus 72 +/- 14 cm/s) and ratio of early filling to atrial filling (1.1 +/- 0.3 versus 1.9 +/- 0.6) were lower and peak atrial filling velocity (59 +/- 14 versus 40 +/- 10 cm/s) was higher than in group 1. Deceleration time (210 +/- 36 versus 179 +/- 20 ms) and isovolumic relaxation time (90 +/- 17 versus 76 +/- 11 ms) were prolonged in group 2 in comparison with group 1. CONCLUSION: This study confirms the major influence of the aging process on left ventricular diastolic function in a large series of normal subjects. This physiologic factor should be considered in Doppler assessment of left ventricular diastolic filling in future studies.

Adult↗

PubMed1994

Cost comparison of immediate angioplasty versus thrombolysis followed by conservative therapy for acute myocardial infarction: a randomized prospective trial. Mayo Coronary Care Unit and Catheterization Laboratory Groups.

OBJECTIVE: Immediate angioplasty and thrombolysis followed by conservative therapy are treatment strategies for acute myocardial infarction. The objective of this study was to compare the costs of these two strategies during a 12-month period. METHODS: Of 103 patients with acute myocardial infarction who sought medical assistance within 12 hours after onset of symptoms, 4 were excluded from analysis for various reasons, 51 received tissue plasminogen activator, and 48 underwent immediate angioplasty as the initial revascularization strategy. The main outcome determinants were direct monetary costs and indirect measures of costs, including duration of hospital stay and return to work. RESULTS: No significant difference in monetary costs between the two initial treatment strategies could be demonstrated. A trend was noted toward a briefer hospital stay and fewer late in-hospital procedures for patients treated initially with immediate angioplasty. Other measures of indirect costs were not statistically different. CONCLUSION: The hypothesis that thrombolysis followed by conservative therapy would be more cost-effective than immediate angioplasty in the treatment of patients with acute myocardial infarction could not be substantiated. The two strategies seem to have similar cost-effectiveness.

Adult↗

PubMed1994

Lipids and Lp(a) lipoprotein levels and coronary artery disease in subjects with non-insulin-dependent diabetes mellitus.

OBJECTIVE: To determine whether increased Lp(a) lipoprotein levels are associated with either non-insulin-dependent diabetes mellitus (NIDDM) or coronary artery disease (CAD) in patients with NIDDM and to examine the relationship between Lp(a) levels and glycemic control. DESIGN: We conducted a cross-sectional study of subjects with NIDDM who were participants in the Rochester Diabetic Neuropathy Study and healthy control subjects from the population of Rochester, Minnesota. MATERIAL AND METHODS: Lipids and Lp(a) lipoprotein levels were compared in 227 subjects with NIDDM and 163 control subjects and, among the subjects with NIDDM, in those with (N = 96) and without (N = 131) CAD. The correlation between Lp(a) levels and glycosylated hemoglobin was investigated. RESULTS: Subjects with NIDDM had higher triglyceride and lower high-density lipoprotein cholesterol levels than did control subjects. Subjects with NIDDM and CAD had higher total cholesterol, triglyceride, and low-density lipoprotein cholesterol levels and lower high-density lipoprotein cholesterol levels than did subjects with NIDDM without CAD. Subjects with NIDDM had significantly higher Lp(a) levels than did control subjects, but subjects with NIDDM and CAD did not have significantly higher Lp(a) levels than did those without CAD. Among subjects with NIDDM, the level of Lp(a) was not significantly correlated with glycosylated hemoglobin. CONCLUSION: Although subjects with NIDDM have higher Lp(a) levels than do control subjects, Lp(a) does not seem to be associated with CAD in subjects with NIDDM. In this study, no association was found between Lp(a) level and glycemic control.

Adult↗

PubMed1994

Effects of exercise and therapy on ventricular emptying and filling in mildly hypertensive patients.

Left ventricular (LV) filling was studied in 18 healthy subjects and 19 mildly hypertensive patients before and after 50% and 70% of maximal supine exercise using radionuclide ventriculography. In addition, in the hypertensive patients, the effects of oral verapamil and lisinopril treatment on LV filling before and after exercise were studied. At rest, hypertensive patients compared with healthy subjects had a lower peak filling rate, ratio of peak filling to peak emptying rate, first-half filling fraction, and a longer isovolumic duration. With exercise, LV filling measures were not different between healthy subjects and hypertensive patients. In the hypertensive patients at rest, compared with before treatment, lisinopril prolonged isovolumic duration and verapamil had no effect on LV filling; at 50% maximal exercise compared with before treatment, verapamil shortened the time to peak filling rate and isovolumic duration and increased first-half filling fraction but, at 70% maximal exercise, verapamil had no effect, whereas lisinopril did not alter exercise LV filling at either exercise level. Thus, the early abnormal LV filling in mildly hypertensive patients is influenced by therapeutic interventions both at rest and with exercise.

Adult↗

PubMed1994

Differential neointimal response to coronary artery injury in pigs and dogs. Implications for restenosis models.

Neointimal hyperplasia occurs in the coronary arteries after percutaneous revascularization procedures and is a reparative response that frequently causes recurrent stenosis. Prior animal studies have shown that neointimal tissue thickness is proportional to the depth of arterial injury. Because animal models are increasingly used to test therapeutic strategies against restenosis, the purpose of this study was to evaluate the degree of neointimal thickening formed in the coronary arteries of pigs compared with dogs in response to severe injury. Fourteen coronary arteries in six mongrel dogs and 18 coronary arteries in nine pigs underwent severe arterial injury using tantalum metal coils delivered on oversized angioplasty balloons. Animals were killed after 4 weeks, and all coronary arteries were pressure perfusion fixed. Mean histological injury scores and neointimal thicknesses for dogs were 1.9 +/- 0.3 and 0.30 +/- 0.11, respectively, compared with 2.1 +/- 0.7 and 0.71 +/- 0.36 for pigs. Thus, there was significantly less neointimal thickening in dogs compared with pigs (P < .001) despite no differences in injury (P = NS). The neointimal thickening differences translated into significantly different percent area stenoses: 55 +/- 24% for pigs versus 27 +/- 13% for dogs (P < .001). Linear regression modeled neointimal thickness versus injury assessed by an ordinal injury score proportional to the depth of injury for each species. This analysis confirmed the differences across multiple injury levels. The slope of the regression line for dogs was small, suggesting that no relation may exist between injury and neointimal thickness in this species. The pig may be a more appropriate model for the study of the genesis of stenosing neointima.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1994

Echocardiographic prediction of survival after surgical correction of organic mitral regurgitation.

BACKGROUND: Left ventricular dysfunction is a frequent cause of death after successful surgical repair of mitral regurgitation. The role of preoperative echocardiographic left ventricular variables in the prediction of postoperative survival and thus their clinical implications remain uncertain. METHODS AND RESULTS: The survival of 409 patients operated on between 1980 and 1989 for pure, isolated, organic mitral regurgitation and with a preoperative echocardiogram (within 6 months of operation) was analyzed. The overall survival was 75% at 5 years (90% of expected), 58% at 10 years (88% of expected), and 44% at 12 years (73% of expected). Operative mortality was 6.6% and markedly improved from 1980 to 1984 (10.7%) to 1985 to 1989 (3.7%). Multivariate analysis showed that age (P = .0003), date of operation (P = .003), and functional class (P = .016) but not left ventricular function were predictors of operative mortality. In the most recent period (1985 to 1989), operative mortality was 12.3% in patients age 75 years or older and 1.1% in patients younger than 75 years. Late survival was analyzed in the operative survivors. Multivariate analysis showed that the most powerful predictor was echocardiographic ejection fraction (EF) (P = .0004), followed by age (P = .0031), creatinine level (P = .0062), systolic blood pressure (P = .0164), and presence of coronary artery disease (P = .0237). The late survival at 10 years was 32 +/- 12% for patients with EF < 50%, 53 +/- 9% for EF 50% to 60%, and 72 +/- 4% for EF > or = 60%. The hazard ratio compared with EF > or = 60% was 2.79 (95% confidence interval, 1.65 to 4.72) for EF < 50% and 1.81 (95% confidence interval, 1.11 to 2.95) for EF 50% to 60%. Echocardiographic EF remained the best predictor of late survival, even when combined with left ventricular angiographic variables. The survival of patients with EF > or = 60% was 100% of expected at 10 years but was better in patients in class I or II than in those in class III or IV (82 +/- 6% versus 59 +/- 6%, respectively, at 10 years; P = .0021). The preoperative predictors of operative and late mortality remained significant independent of the type of surgical correction performed in combined multivariate analyses. CONCLUSIONS: In organic mitral regurgitation, (1) operative mortality has markedly decreased recently, being at a low 1.1% in patients younger than 75 years, and is predicted by age and symptoms and not by left ventricular function, and (2) left ventricular EF measured by echocardiography is the most powerful predictor of late survival. These results suggest that surgical treatment should be considered early, even in the absence of severe symptoms, in patients with severe mitral regurgitation, before left ventricular dysfunction occurs.

Echocardiography↗

PubMed1994

Systolic and diastolic dysfunction in patients with clinical diagnosis of dilated cardiomyopathy. Relation to symptoms and prognosis.

BACKGROUND: Dilated cardiomyopathy is an important cause of morbidity and mortality among patients with congestive heart failure. Hemodynamic and prognostic characterization are critical in guiding selection of medical and surgical therapies. METHODS AND RESULTS: A cohort of 102 patients with the clinical diagnosis of dilated cardiomyopathy who underwent echocardiographic examination between 1986 and 1990 was identified and followed up through July 1, 1991. Patients with moderate or severe symptoms had lower indices of systolic function and greater left atrial and right ventricular dilation. Mitral inflow Doppler signals were characterized by a restrictive left ventricular filling pattern. In multivariate logistic regression analysis, deceleration time, ejection fraction, and peak E velocity were independently associated with symptom status. Over a mean follow-up of 36 months, 35 patients died. Kaplan-Meier estimated survival at 1, 2, and 4 years was 84%, 73%, and 61%, respectively, and was significantly poorer than that of an age- and sex-matched population. The subgroup with an ejection fraction < 0.25 and deceleration time < 130 milliseconds had a 2-year survival of only 35%. The subgroup with ejection fraction < 0.25 and deceleration time > 130 milliseconds had an intermediate 2-year survival of 72%, whereas patients with an ejection fraction > or = 0.25 had 2-year survivals > or = 95% regardless of deceleration time. In multivariate analysis, ejection fraction and systolic blood pressure were independently predictive of subsequent mortality. Mitral deceleration time was significant in univariate analysis. CONCLUSIONS: In patients with the clinical diagnosis of dilated cardiomyopathy, markers of diastolic dysfunction correlated strongly with congestive symptoms, whereas variables of systolic function were the strongest predictors of survival. Consideration of both ejection fraction and deceleration time allowed identification of subgroups with divergent long-term prognoses.

Aged↗

PubMed1994

Short-term (six hour), ambulatory blood pressure monitoring.

The feasibility of substituting a shorter duration of ambulatory blood pressure monitoring (ABPM) for 24h ambulatory monitoring to evaluate increased office BP measurements was investigated by analysing the records of 126 normal volunteers and 168 mildly hypertensive patients receiving placebo, including 22 studied on two occasions two months apart. The value to be predicted was the long-term awake BP mean for an individual (usual BP). Among the subjects studied on two occasions, there were no systematic differences between the two occasions and there was reasonable correspondence between the hourly patterns. Estimated variance components were substituted in a formula for the standard error of prediction (SEP) of the usual awake mean BP, for various durations and frequencies of monitoring. The lower limit of the SEP was determined by the patient-by-occasion component of variance. As few as six hours of monitoring with two to three readings/hour achieved most of the gain in precision obtainable by going from single BP readings toward continuous measurement during an entire awake period. In the remaining subjects, the influence of the day rhythm of BP on short-term monitoring was examined by measuring the differences in means of 6h periods from the full awake mean BP for starting times from 7 am to 3 pm. Among normotensives and hypertensive patients with near normal office BP (< 144/< 96 mmHg), there was little difference due to starting time. There was, however, a slight positive bias in the more hypertensive subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1993

Amplitude-weighted mean velocity: clinical utilization for quantitation of mitral regurgitation.

OBJECTIVES: The purpose of this study was to determine the clinical usefulness of the amplitude-weighted mean velocity method for quantitation of mitral regurgitation. BACKGROUND: Amplitude-weighted mean velocity is a nonvolumetric method for calculating the mitral regurgitant fraction. Its previous validation at one center mandated an independent assessment of its usefulness and limitations. METHODS: In 56 patients with and 16 patients without mitral regurgitation, the regurgitant fraction was measured simultaneously by amplitude-weighted mean velocity, quantitative Doppler study and quantitative two-dimensional echocardiography. In 16 patients, multiple gain settings were used to determine the influence of this variable on amplitude-weighted mean velocity. RESULTS: In patients without regurgitation, amplitude-weighted mean velocity showed more scattering of regurgitant fraction (-18% to 23%) than Doppler (p = 0.016) or two-dimensional echocardiography (p = 0.022). The absolute value of regurgitant fraction was (mean +/- SD) 8 +/- 6%, 4 +/- 2% and 4 +/- 3%, respectively (p = NS). With increasing gain, the amplitude-weighted mean velocity mitral and aortic integrals increased, but the calculated regurgitant fraction remained unchanged. In patients with mitral regurgitation, significant correlation was found between amplitude-weighted mean velocity and Doppler study (r = 0.79, p = 0.0001) and between amplitude-weighted mean velocity and two-dimensional echocardiography (r = 0.76, p = 0.0001) for calculated regurgitant fraction, but the standard error of the estimate (12%) was large. CONCLUSIONS: The amplitude-weighted mean velocity-calculated regurgitant fraction is gain independent, whereas the aortic and mitral integrals are gain dependent. Compared with Doppler and two-dimensional echocardiography, it shows more scattering of values in patients without regurgitation, but the methods correlate significantly in patients with mitral regurgitation. Amplitude-weighted mean velocity can be used as a simple adjunctive tool for comprehensive, noninvasive quantitation of mitral regurgitation.

Adult↗

PubMed1993

Coronary embolization after balloon angioplasty or thrombolytic therapy: an autopsy study of 32 cases.

OBJECTIVES: This study was undertaken to examine the nature, extent and clinical relevance of coronary embolism after balloon angioplasty or thrombolytic therapy, or both. BACKGROUND: Histopathologic documentation of postinterventional coronary embolization has been reported in only 10 patients from five studies. METHODS: This retrospective autopsy-based study included 32 patients, treated with balloon angioplasty or thrombolysis, or both, who died within 3 weeks of the procedure and underwent autopsy at the Mayo Clinic. Clinical variables included patient age and gender, artery treated, site and type of obstruction, type of intervention, success of the procedure, and postprocedural changes in the electrocardiogram (ECG), cardiac enzymes and hemodynamic status. Histopathologic variables included characteristics of treated plaques, acutely infarcted myocardium and coronary microemboli. Associations between microemboli and clinical and microscopic factors were evaluated by t tests and simple and multiple linear regression. RESULTS: Emboli were observed in 26 (81%) of the 32 patients. Among 83 emboli, 95% were thrombotic or atheromatous. The presence of microemboli was associated statistically with the development of postprocedural infarct extension, new myocardial infarction or new ECG abnormalities. Moreover, the greatest number of microemboli were associated with intervention in the left anterior descending coronary artery, multiple interventional sites, postprocedural medial dissection and plaque rupture or extrusion. CONCLUSIONS: Among patients undergoing balloon angioplasty or thrombolytic therapy who die and undergo autopsy, coronary microemboli occur in a substantial percent. The frequency in survivors is unknown. However, in living patients who develop acute myocardial ischemia or new ECG abnormalities after these interventions, coronary microembolization should be considered a potential cause.

Adult↗

PubMed1993

Late outcome after percutaneous transluminal coronary angioplasty during acute myocardial infarction.

Early reperfusion for acute myocardial infarction (AMI) results in improved ventricular function and survival. There is a dearth of data on long-term survival (> 5 years) after percutaneous transluminal coronary angioplasty (PTCA) performed either as a primary procedure or in conjunction with thrombolytic therapy. We studied 160 patients who underwent PTCA during AMI between 1981 and 1987 either with (n = 101) or without (n = 59) streptokinase therapy. Mean time to reperfusion was 4.6 hours, and patency was achieved in 134 patients (84%). Mean discharge ejection fraction was 46 +/- 14%. Coronary artery bypass grafting was performed before dismissal in 34 patients (21%), including 21 of 130 patients (16%) with 1- or 2-vessel disease and 13 of 30 patients (43%) with 3-vessel disease (p < 0.05). Eleven patients (7%) died in the hospital. The 149 hospital survivors were followed for a mean of 69 +/- 21 months (median 72). During follow-up, 22 patients (15%) died, 21 (14%) had reinfarction, 23 (15%) underwent coronary artery bypass grafting, and 21 (14%) underwent repeat PTCA of the infarct-related artery. On univariate analysis, age > or = 62 years, multivessel disease, ejection fraction < or = 40%, previous AMI, and being a nonsmoker at the time of AMI were predictive of late mortality (p < 0.05 each variable). On multivariate analysis, only ejection fraction < or = 40% and prior AMI were predictive of late death. In patients treated with PTCA for AMI, late survival is excellent. Early surgical revascularization of high-risk patients may contribute to these encouraging results.

Adult↗

PubMed1993

Predictors of major ischemic complications after coronary dissection following angioplasty.

Coronary dissection is a major cause of abrupt arterial closure after coronary angioplasty but may also be associated with no discernible event. Deciding which dissections should receive further treatment is often a dilemma if the artery remains patent. This case-control study examined predictors of major ischemic complications after coronary dissections. Fifty-eight patients with coronary dissections, but a patent artery at the completion of the angioplasty procedure, subsequently had in-hospital abrupt arterial closure, acute myocardial infarction, emergency coronary bypass surgery, or died; they were matched to 58 control subjects with dissection but no event. Analysis of each angiogram was performed with the examiner unaware of patient's history. Baseline angiographic and clinical characteristics of cases and controls were similar except for an excess of current smokers among the cases (31 vs 16%; p = 0.048). Residual luminal diameter at the dissection site was 1.2 +/- 0.6 mm (cases) versus 1.6 +/- 0.6 mm (controls; p = 0.001) with relative stenosis of 59 +/- 21% vs 43 +/- 21%, respectively (p = 0.0001). Dissections among cases were longer than among controls (11 +/- 7 mm vs 7 +/- 4 mm; p = 0.001). No significant difference was found in dissection morphology using 2 classification schemes or in final Thrombolysis in Myocardial Infarction study flow grade. Transient occlusion during the procedure, however, occurred in 47% of cases versus 5% of controls (p = 0.0001). Transient occlusion, residual percent stenosis > or = 70%, and dissections > or = 6 mm were independently predictive of major ischemic events.

Acute Disease↗