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Biomedical subjects

C Maynard

Publications and source records attributed to C Maynard.

At least 37 records · Page 2Linked to original sources
PubMed2000

Relation between evolutionary ST segment and T-wave direction and electrocardiographic prediction of mycardial infarct size and left ventricular function among patients with anterior wall Q-wave acute myocardial infarction who received reperfusion therapy.

In the prethrombolytic era it was found that infarct size and left ventricular ejection fraction could be predicted using the Selvester QRS score. We evaluated whether infarct size and left ventricular ejection fraction could be predicted by the predischarge QRS score in patients who had received reperfusion therapy and whether considering the configuration of the ST segments and T waves would increase the accuracy of these predictions. We evaluated 51 patients with first anterior wall myocardial infarction who had received reperfusion therapy and predischarge resting technetium-99m-sestamibi scan. The electrocardiograms recorded on the same day of the scan were analyzed for the QRS score and were divided into 3 groups: A, isoelectric ST and negative T waves; B, ST elevation (> or =0.1 mV) and negative T waves; and C, ST elevation (> or =0.1 mV) and positive T waves. Groups A, B, and C included 12, 23, and 16 patients, respectively. The myocardial perfusion defect extent increased from groups A to C (median 21%, 37%, and 43.5% in groups A, B, and C, respectively; p = 0.023). Similarly, left ventricular ejection fraction decreased (44%, 38%, and 34%, respectively; p = 0.042) from groups A to C. Overall, the correlation between the QRS score and the myocardial perfusion defect extent (rho 0.249; p = 0.08) and ejection fraction (rho -0.229; p = 0.11) was poor. A statistically significant correlation between myocardial perfusion defect size and QRS score was found only in group A (rho 0.599, p = 0.04). Among patients with anterior myocardial infarction who received reperfusion therapy, the predischarge QRS score was predictive of infarct size only in those in whom ST elevation resolved completely. In patients with residual ST elevation there was no correlation between QRS score and infarct size.

Angioplasty, Balloon, Coronary↗
PubMed2000

Healthcare charges and use in commercially insured children enrolled in managed care health plans in Washington State.

OBJECTIVE: To determine the relative importance of enrollee, physician, medical group, and healthcare plan characteristics as determinants of healthcare use and expenditures in commercially insured children < 18 years of age enrolled in managed care health plans. We focused on the effects of age and benefit level, the two most important predictors of cost and utilization in our study of adults. METHODS: This study included 67,432 commercially insured children who were between 1 and 18 years of age, and were cared for by 790 primary care physicians, who practiced in 60 medical care groups in Washington State. Plan enrollment and utilization data for 1994 were linked to a survey of medical care groups contracting with three managed care health plans. Benefit level for each enrollee was defined as low, medium, or high and was based on cost sharing by the health plan for hospitalization, outpatient care, and emergency department services. The three outcome measures included estimated total per member per year charges, number of ambulatory visits, and hospital days. RESULTS: In multivariate analysis, enrollee age was the most important determinant of total charges, with younger children incurring higher charges and utilization. For children 5 years and younger, mean total per member per year charges were $617 in the low-benefit category and $878 in the high category (p < .0001). These differences were less apparent for children 6-12 years ($355 versus $420, p = .012), and were not statistically significant for children 13 years and older ($503 versus $552, p = .14). The annual number of visits increased with benefit level for children of all ages. CONCLUSIONS: Enrollee age and benefit level were the most important determinants of healthcare use and expenditures in children enrolled in managed care health plans.

Adolescent↗
PubMed2000

A physician survey of the effect of drug sample availability on physicians' behavior.

OBJECTIVE: Pharmaceutical companies often use drug samples as a marketing strategy in the ambulatory care setting. Little is known about how the availability of drug samples affects physicians' prescribing practices. Our goal was to assess: (1) under what circumstances and why physicians dispense drug samples, (2) if drug samples lead physicians to use medications other than their preferred drug choice, and (3) the physician characteristics that are associated with drug sample use. DESIGN: Cross-sectional survey. SETTING: University-based clinics at one academic medical center. PARTICIPANTS: 154 general medicine and family physicians. MEASUREMENTS AND MAIN RESULTS: Physicians' self-reported prescribing patterns for 3 clinical scenarios, including their preferred drug choice, whether they would use a drug sample and subsequently prescribe the sampled medication, and the importance of factors involved in the decision to dispense a drug sample. A total of 131 (85%) of 154 physicians responded. When presented with an insured woman with an uncomplicated lower urinary tract infection, 22 (17%) respondents reported that they would dispense a drug sample; 21 (95%) of 22 sample users stated that they would dispense a drug sample that differed from their preferred drug choice. For an uninsured man with hypertension, 35 (27%) respondents reported that they would dispense a drug sample; 32 (91%) of 35 sample users indicated that they would dispense a drug sample instead of their preferred drug choice. For an uninsured woman with depression, 108 (82%) respondents reported that they would dispense a drug sample; 53 (49%) of 108 sample users indicated that they would dispense a drug sample that differed from their preferred drug choice. Avoiding cost to the patient was the most consistent motivator for dispensing a drug sample for all 3 scenarios. For 2 scenarios, residents were more likely to report using drug samples than attendings (P <.05). When respondents who chose a drug sample for 2 or 3 scenarios were compared to those who never chose to use a drug sample, or chose a drug sample for only one scenario, only younger age was independently associated with drug sample use. CONCLUSION: In self-reports, the availability of drug samples led physicians to dispense and subsequently prescribe drugs that differ from their preferred drug choice. Physicians most often report using drug samples to avoid cost to the patient.

Adult↗
PubMed2000

Comparison of an automated thrombolytic predictive instrument to both diagnostic software and an expert cardiologist for diagnosis of an ST elevation acute myocardial infarction.

Because the electrocardiograms (ECGs) of patients with symptoms suggesting an acute thrombotic coronary occlusion are typically read by physicians relatively inexperienced in this skill, it is important to develop automated decision support. A Thrombolytic Predictive Instrument (TPI) is now available along with the standard diagnostic software in a commercially available electrocardiograph. This study evaluates the performance of the predictive software in comparison to both an expert cardiologist and standard diagnostic software. True sensitivity and specificity cannot be determined because acute coronary angiography was not performed. The specificities determined by this study were excellent (98% and 99%), and the sensitivities were very good (72% and 78%). These results that the TPI will be only rarely applied to patients who do not indeed have an acute coronary thrombosis. However, the reasons for even this small number of presumably falsely TPI positive patients should be determined and analyzed. It is unlikely that alterations of the thresholds for TPI activation will significantly improve on this very good level of sensitivity, without prohibitively decreasing specificity.

Clinical Competence↗
PubMed2000

The correlation between presenting ST-segment depression and the final size of acute myocardial infarcts in patients with acute coronary syndromes.

The use of reperfusion therapy in patients with ST elevation acute coronary syndromes had been established. However, reperfusion therapy is usually considered contra-indicated in those with ST depression, despite the knowledge that regional posterior infarction is typically indicated by ST depression maximal in leads V1 to V3 and nonregional subendocardial infarction is typically indicated by marked ST depression maximal in other leads. This study of patients with non-ST-elevation acute coronary syndromes investigates the quantitative relationship between presenting ST depression and final QRS changes in both of these subgroups. The final QRS score was significantly higher (2.44 points) than that of a control group with not ST depression, (1.55 points) in the group with maximal ST depression in V1 to V3 (P = 0.04). However, in the entire population, there was a highly significant correlation (P = .003) between the sum of the presenting ST depression and the final QRS score. Trials of reperfusion therapy will be required to determine if such evolution to electrocardiogram documented acute myocardial infarction can be prevented in patient with marked ST depression acute coronary syndromes.

Case-Control Studies↗
PubMed2000

Interobserver agreement in the electrocardiographic diagnosis of acute myocardial infarction in patients with left bundle branch block.

STUDY OBJECTIVE: To determine the interobserver agreement between cardiologists and emergency physicians in the ECG diagnosis of acute myocardial infarction (AMI) in patients with left bundle branch block (LBBB) using the ECG algorithm previously described by Sgarbossa et al. METHODS: Using the Sgarbossa ECG algorithm, 4 cardiologists and 4 emergency physicians independently interpreted a test set of 224 ECGs with LBBB, of which 100 ECGs were from patients with an evolving AMI. A subset of 25 ECGs was reinterpreted by each reader to test intraobserver agreement for AMI as well as interobserver agreement for the degree of ST-segment deviation. Agreement rates for AMI were estimated using the kappa statistic. In addition, the sensitivity and specificity for diagnosing AMI were determined for each reader, using the Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries (GUSTO I) enzyme criteria for AMI as the gold standard. The study was conducted at 3 university-affiliated medical centers. The test set contained ECGs from 100 patients enrolled in the GUSTO I trial with LBBB on their initial ECG and an evolving AMI confirmed by serum cardiac enzyme changes, and 124 control patients from the Duke Databank for Cardiovascular Disease who had stable, angiographically documented coronary artery disease and LBBB. RESULTS: There was excellent interobserver agreement (kappa=0.81, 95% confidence interval [CI] 0.80 to 0.83) between cardiologists and emergency physicians for diagnosing AMI. Intraobserver agreement kappa values for AMI diagnosis by cardiologists and emergency physicians were 0.81 (95% CI 0.67 to 0.94) and 0.71 (95% CI 0.54 to 0.89). The median sensitivity for diagnosing AMI by cardiologists and emergency physicians was 73% (range 66% to 80%) versus 67% (range 61% to 75%); median specificity was 98% (range 97% to 99%) versus 99% (range 98% to 99%). Spearman rank correlation coefficients for the degree of ST-segment deviation in all 12 leads was 0.86 (95% CI 0.85 to 0.87) among all readers. CONCLUSION: There is excellent interobserver agreement between cardiologists and emergency physicians for diagnosing AMI when applying the Sgarbossa ECG algorithm to patients with LBBB. Emergency physicians should be able to reliably use this algorithm when evaluating patients.

Adult↗
PubMed2000

Spatial, individual, and temporal variation of the high-frequency QRS amplitudes in the 12 standard electrocardiographic leads.

BACKGROUND: Analysis of high-frequency QRS amplitudes (HF-QRS) may provide an additional diagnostic tool in patients with heart disease, but the basic properties of these waveforms have not been sufficiently investigated. This study describes the spatial, individual, and temporal variation at rest of HF-QRS recorded with the 12 standard electrocardiographic leads in patients with ischemic heart disease. METHODS AND RESULTS: Two consecutive electrocardiographic recordings from 67 patients were signal averaged and analyzed within a bandwidth of 150 to 250 Hz. The HF-QRS values were expressed as root mean square values. There was a spatial variation in HF-QRS among the 12 leads, with higher amplitudes in V(2) through V(4), II, aVF, and III. The individual variation among the patients was large for all leads. The sum of the HF-QRS for all 12 leads in each patient ranged from 20 to 75 microV (mean 36 +/- 11 microV). The mean of the temporal variation in HF-QRS for all 12 leads between the 2 recordings was only 0.10 +/- 0. 09 microV. CONCLUSIONS: Because of the large individual variation, analysis of HF-QRS is probably most applicable in monitoring situations when it is possible to track changes in a patient over time. The temporal variation in HF-QRS at rest is small, both in patients with and those without prior myocardial infarction.

Adult↗
PubMed2000

Association between week of the month and death from acute myocardial infarction in Washington state, 1988 to 1997.

BACKGROUND: Deaths caused by substance abuse, circulatory disorders, and external causes such as suicide, homicide, and accidents are more likely to occur during the first week of the month than the last week of the preceding month. The purpose of this report is to determine if death caused by acute myocardial infarction occurs more often in the first 7 days of the month than in the last 7 days of the preceding month. METHODS AND RESULTS: This study used computerized death records for Washington state from 1988 to 1997. There were 401,314 deaths, of which 33,436 (8.3%) had an underlying cause of acute myocardial infarction. The week of the month during which death occurred was defined as occurring during the first 7 days of the month or the last 7 days of the preceding month. R, the ratio of the number of deaths during the first 7 days of the month to the number of deaths in the last 7 days of the preceding month multiplied by 100, was calculated, as were 95% confidence intervals. R values for other cardiac causes and substance abuse-related causes were also calculated. Deaths caused by acute myocardial infarction occurred more often in the first week of the month than in the last week of the previous month (R = 104.4, 95% confidence interval 101. 7-107.8). This pattern of death was most apparent for individuals > or =75 years of age (R = 107.3, 95% confidence interval 102.1-111.1) and was not evident for other cardiac causes, including congestive heart failure or myocardial ischemia. By comparison, substance abuse-related deaths occurred much more frequently during the first week of the month (R = 117.6, 95% confidence interval 110.0-125.8). CONCLUSIONS: This pattern of death for acute myocardial infarction may be in part caused by stressful events associated with the first week of the month.

Adult↗
PubMed2000

Validation of cardiologists' decisions to initiate reperfusion therapy for acute myocardial infarction with electrocardiograms viewed on liquid crystal displays of cellular telephones.

BACKGROUND: The transmission of 12-lead electrocardiograms from remote locations to hand-held computers of cardiologists is now possible with the development of wireless technology and computer software. This investigation determined whether the cardiologist's decisions regarding reperfusion therapy for patients with symptoms suggestive of an acute myocardial infarction are the same when given electrocardiograms displayed on a cellular telephone as on a standard paper recording. METHODS: Cardiologists were given 20 electrocardiograms of patients with acute chest pain suggestive of acute myocardial infarction to test the diagnostic reliability of the Nokia 9000i cellular telephone liquid crystal display (LCD) screen. The cardiologists made their decision to initiate or not initiate reperfusion therapy for the patients after viewing their electrocardiograms displayed on both 5-mm and 1-mm formatted grids and twice on traditional printout electrocardiograms. The control level of intraobserver agreement between the responses from the 2 sets of paper display electrocardiograms was compared with the experimental level of intraobserver agreement between the 1-mm LCD electrocardiograms and both sets of paper display electrocardiograms to determine whether the viewing medium affected the cardiologist's decisions. The 1-mm and 5-mm LCD screen electrocardiograms were compared to determine if the grid size affected the cardiologist's decisions. RESULTS: Ninety-three percent of the 2 sets of paper-guided decisions were in agreement. When comparing the 1-mm LCD-guided decisions with both sets of paper-guided decisions, 94% and 89% of the decisions, respectively, were in agreement. The differences between the control and experimental degrees of intraobserver agreement of 1% and 4% were not statistically significant (P1 =.81, P2 =.29). Ninety-one percent of the 1-mm LCD-guided decisions were in agreement with the 5-mm LCD-guided decisions. CONCLUSIONS: Cardiologists' decisions did not vary significantly when viewing either traditional paper electrocardiograms or LCD screen electrocardiograms. Even though there was not a significant difference in the cardiologists' decisions when they viewed electrocardiograms displayed on both the 1-mm and 5-mm grid, it is recommended that the 1-mm grid be used for clinical implementation of the LCD screen.

Computer Terminals↗
PubMed2000

Mother and father self-reports of corporal punishment and severe physical aggression toward clinic-referred youth.

Examined the extent to which 359 mothers and 140 fathers of clinic-referred youth (ages 2 to 17) reported using corporal punishment and severe physical aggression when asked directly via intake screening questionnaires at a community mental health center; higher prevalence rates emerged compared to families in the general population. Clinic-referred parents reported greater use of corporal punishment for younger relative to older youth, sons relative to daughters, and by single relative to married mothers. In cases with reports from both parents, mothers used corporal punishment more frequently than fathers. Demographic factors were not linked to severe physical aggression, except for mothers' treatment of sons versus daughters. After controlling for demographic factors, maternal and paternal reports of child externalizing behavior accounted for significant variance in their own and their partner's use of corporal punishment, and in mothers' use of severe physical aggression.

Adolescent↗
PubMed2000

Utilization of services by persons discharged from involuntary chemical dependency treatment.

This report compares services utilization pre-admission and post-discharge in 735 consecutive persons involuntarily committed to a chemical dependency treatment program in Washington State. Patients entering treatment were in their late 30s, had multiple health problems, previous arrests for misdemeanors or felonies, and minimal structured daily activities. Post discharge, there were decreases in the use of costly acute care services including detox, psychiatric hospitalization, and mental health crisis services. Patients who completed the program were less likely to use acute care services and were more likely to participate in outpatient treatment after discharge. The overall death rate of 29.4 per 1000 persons per year was 4 times greater than the age adjusted death rate for the US adult population. Further studies of other involuntary chemical dependency treatment programs are needed to evaluate the results of this report.

Adult↗
PubMed2000

The association between institutional primary angioplasty procedure volume and outcome in elderly Americans.

BACKGROUND: The association between greater procedure volume and improved patient outcome in cardiac procedures has been established in percutaneous transluminal coronary angioplasty (PTCA), coronary stent placement and coronary bypass surgery. The association between primary angioplasty volume and outcome has not been evaluated. METHODS: We evaluated the association between the volume of primary angioplasty procedures with short- and long-term outcome in 6,124 patients with documented acute myocardial infarction. Patients without shock on presentation treated with primary coronary angioplasty within 12 hours of hospital admission were selected from consecutive infarct patients included in the Cooperative Cardiovascular Project database. Patients were divided into quartiles based on the volume of primary PTCA procedures performed at their admitting hospital. RESULTS: The majority of United States (US) hospitals performed less than three primary PTCA procedures per month. Patients admitted to hospitals in the lowest volume quartile of primary PTCA had 31% higher 30-day mortality than those admitted to the highest volume quartile. After adjustment for baseline differences in patient characteristics, there was an association between admission to higher volume primary PTCA hospitals and lower 30-day mortality (odds ratio per volume quartile = 0.91; 95% confidence interval = 0.83-0.99). CONCLUSION: Eighty-two percent of US hospitals perform less than three primary PTCA procedures per month. In elderly Americans treated with primary PTCA, we observed an association between admission to higher volume hospitals and lower short- and long-term mortality. This association was independent of total PTCA volumes.

Aged↗
PubMed1999

Early use of ACE inhibitors in the treatment of acute myocardial infarction in the United States: experience from the National Registry of Myocardial Infarction 2. National Registry of Myocardial Infarction 2 participants.

This study was undertaken to examine recent trends in the use of angiotensin-converting enzyme (ACE) inhibitors within 24 hours of admission in patients hospitalized for acute myocardial infarction (AMI) and to identify clinical factors associated with ACE inhibitor-prescribing patterns. Demographic, procedural, and acute medication use from 202,438 patients with AMI were collected at 1,470 US hospitals participating in the National Registry of Myocardial Infarction 2 from June 1994 through June 1996. Acute ACE inhibitor use increased from 14.0% in 1994 to 17.3% in 1996. After controlling for all important clinical variables, we found that there was a significant increase in the odds of acute ACE inhibitor treatment over time (odds ratio [OR]1.07 for each 180-day period; 95% confidence intervals [CI] 1.06 to 1.08; p<0.0001). Univariate data suggested that patients treated acutely with ACE inhibitors tended to be older (70.9 vs. 67.2 years) and had lower rates of in-hospital mortality (8.8% vs. 11.0%). Independent predictors of receiving an ACE inhibitor acutely included anterior wall infarction (OR 1.36; 95% CI 1.32 to 1.40), Killip class 2 or 3 (OR 1.77; 95% CI 1.72 to 1.83), prior myocardial infarction (OR 1.33; 95% CI 1.30 to 1.37), prior history of congestive heart failure (OR 1.88; 95% CI 1.82 to 1.95), and diabetes mellitus (OR 1.34; 95% CI 1.30 to 1.38). Physicians are prescribing ACE inhibitors acutely in patients with AMI with increasing frequency. Patients with evidence of congestive heart failure and those with anterior myocardial infarction have the greatest expected benefit from such therapy, and these persons receive such treatment most often. However, most patients hospitalized with AMI do not receive this potentially life-saving therapy.

Aged↗
PubMed1999

Terminal QRS distortion on admission is better than ST-segment measurements in predicting final infarct size and assessing the Potential effect of thrombolytic therapy in anterior wall acute myocardial infarction.

We assessed predicting final infarct size (using predischarge Selvester score) by 3 electrocardiographic variables in 267 patients with first anterior wall acute myocardial infarction (AMI) undergoing (n = 86) or not undergoing (n = 181) thrombolysis. Patients with previous AMI or inverted T waves in leads with ST elevation were excluded. The sum (sigma) of ST elevation, the number of leads with ST elevation, and the initial electrocardiographic pattern were determined on the admission electrocardiogram (absence (QRS-) or presence (QRS+) of distortion of the terminal portion of the QRS in > or =2 leads (J point > or =0.5 of the R-wave amplitude in leads I, aVL, V4 to V6, or presence of ST elevation without S waves in leads V1 to V3). There was no association between sigmaST elevation and final infarct size in patients who did or did not receive thrombolytic therapy. Analysis of covariance showed that the number of leads with ST elevation (F = 19.6), thrombolysis (F = 25.2), and QRS+ initial pattern (F = 19.5) were all associated with final infarct size (p <0.0001 for all). Among patients who did not receive thrombolytic therapy, the average Selvester score was 19.7+/-9.9 for the QRS- patients and 26.1+/-10.4 for the QRS+ patients (p = 0.02). Among patients who received thrombolytic therapy, the average Selvester score was 11.7+/-9.8 for the QRS- patients and 24.2+/-10.1 for the QRS+ patients (p <0.0001). Thrombolysis reduced final Selvester score only in the QRS- group (p <0.00001), but not in the QRS+ group (p = 0.45). It is concluded that (1) final Selvester score in anterior wall AMI can be predicted by the number of leads with ST elevation, the initial electrocardiographic pattern, and thrombolysis, and (2) thrombolysis reduces final Selvester score only in patients with QRS- pattern.

Adult↗
PubMed1999

Combined historical and electrocardiographic timing of acute anterior and inferior myocardial infarcts for prediction of reperfusion achievable size limitation.

The historical time of acute symptom onset is not always an accurate indication of the timing of onset of an acute myocardial infarction (AMI). Consideration of electrocardiographic (ECG) timing parameters could supplement historical timing alone as a clinical guide for decisions regarding the use of reperfusion therapy. Three hundred ninety-five patients from 4 trials of thrombolytic therapy conducted in the northwestern United States and western Canada are included in the present study. A total of 316 patients received either streptokinase or tissue plasminogen activator, and 79 received no reperfusion therapy. Historical time of symptom onset was acquired by emergency or cardiology department personnel and recorded on patient report forms. An ECG method for estimating the timing of the AMI, the Anderson-Wilkins (AW) acuteness score, was calculated from the initial standard 12-lead recording by investigators blinded to the knowledge of symptom duration or any other study variables. Tomographic thallium-201 imaging 7 weeks after hospital admission was used to measure final AMI size. The ECG timing method achieved a relation with final AMI size similar to that previously reported for historical timing. The AW acuteness score proved most useful for anterior AMI location when there was a > or = 2 hour delay following symptom onset, but was most useful for the inferior AMI location when there was a < 2 hour delay. Despite a longer delay, patients with high AW acuteness scores had 50% lower final anterior AMI size than those with low scores; and despite a shorter delay, those with low ECG acuteness scores had 50% greater final inferior AMI size than those with high scores. The AW acuteness score combined with the historical estimation of symptom duration should provide a more accurate basis for predicting the potential for limitation of final AMI size than either method alone. These results could potentially provide the basis for developing a new method for noninvasive guidance of clinical decisions regarding administration of reperfusion therapy in the initial evaluation of patients with AMI.

Electrocardiography↗
PubMed1999

Association between percutaneous transluminal coronary angioplasty volumes and outcomes in the Healthcare Cost and Utilization Project 1993-1994.

Studies from a variety of settings have indicated that outcomes for coronary angioplasty are improved when performed in institutions with high caseloads (> 400/year). The purpose of this investigation was to examine the volume outcome hypothesis for coronary angioplasty in a 20% stratified sample of acute care, non-federal hospitals in 17 states. Data were derived from the Nationwide Inpatient Sample from the Health Care Cost and Utilization Project releases 2 and 3. From these records, 163,527 angioplasties from 214 hospitals were selected. Outcomes included hospital mortality, same-admission coronary artery bypass surgery, and a combined end point of either death or same-admission surgery, or both. Hospital volumes were defined as low (< or = 200 cases/year), medium (201 to 400), and high (> 400). Analyses were conducted separately for patients with and without a principal discharge diagnosis of acute myocardial infarction (AMI). For both AMI and no-AMI groups, the rates of adverse outcomes were generally lower in high-volume institutions, and this finding was true in both univariate and multivariate analyses. Although 27% of hospitals were in the low-volume category, only 5% of all procedures were performed in these institutions. Projecting to all United States hospitals for the 2 years, if all procedures performed in low-volume centers had been done in high-volume institutions, 137 deaths could have been averted (90 AMIs, 47 no-AMIs) as well as 404 (46 AMIs, 358 no-AMIs) same-admission surgeries. The results of this study support the hypothesis that better results are obtained in higher volume institutions, but also show that in 1993 and 1994, relatively few patients had their procedures performed in low-volume institutions.

Angioplasty, Balloon, Coronary↗