Biomedical subjects

D J Cohen

Publications and source records attributed to D J Cohen.

At least 55 records · Page 3Linked to original sources

PubMed2000

Impact of smoking on health-related quality of life after percutaneous coronary revascularization.

BACKGROUND: PTCA is performed primarily to improve health-related quality of life (HRQOL) in patients with symptomatic coronary artery disease. In patients undergoing PTCA, smoking has been shown to increase risks of late myocardial infarction and death. Whether smoking also affects HRQOL after PTCA is currently unknown. METHODS AND RESULTS: We examined the relation between smoking status and HRQOL among 1432 patients who underwent PTCA as part of 2 multicenter clinical trials. HRQOL was assessed with the use of the Medical Outcomes Study SF-36 questionnaire. Patients were classified as smokers (n=301), quitters (n=141), or nonsmokers (n=990) on the basis of their smoking status at the time of their index procedure and during the first year of follow-up. For the overall population, HRQOL improved significantly after PTCA for all scales except general health perception, with improvements ranging from 5.5 points for mental health to 23.2 points for role-physical functioning. After adjustment for baseline characteristics and initial HRQOL, nonsmokers had gains at 6 months that were larger than those of smokers for all health domains: physical function (15.4 versus 10.4 points), role-physical (24.5 versus 13.9), pain (18.4 versus 13.3), general health perception (1.7 versus -4.5), vitality (11.0 versus 4. 7), social function (12.8 versus 3.5), role-emotional (13.5 versus 6. 7), and mental health (6.8 versus 0.8; P:<0.02 for all comparisons). Quitters had 6-month HRQOL improvements that were greater than those in smokers for all domains as well. Findings were similar at 1 year. CONCLUSIONS: Quality-of-life benefits of PTCA are diminished by continued smoking. Efforts to promote smoking cessation at the time of PTCA may substantially improve the health outcomes of these procedures.

Age Factors↗

PubMed2000

Impact of patient characteristics, complications, and facility volume on the costs and time of cardiac catheterization and coronary angioplasty in 70 catheterization laboratories.

Although over 1 million procedures are performed in cardiac catheterization laboratories (CCLs) annually, little comparative data exist on costs or resource use in these settings. In this study, data from 70 CCLs were used to profile CCL times and total direct costs for 2 high-volume procedures: left heart catheterization (LHC) and percutaneous transluminal coronary angioplasty (PTCA) with or without stent placement. In total, 70,677 consecutive patient examinations for a 12-month period from January 1, 1998 to December 31, 1998 were analyzed. For LHC mean total direct costs averaged $306, whereas for PTCA catheterization laboratory costs averaged $3,172. The average total times for these procedures were 63 and 108 minutes, respectively. Seventy-two percent of the PTCA patients underwent coronary stenting with an associated incremental cost of $1,244. By multivariate linear regression, baseline patient characteristics such as age, gender, and clinical factors had little impact on total time and total costs. The major determinants of CCL time and cost were procedural factors (e.g., number and type of interventions) and in-lab complications, including profound hypotension, abrupt vessel closure, and emergency bypass surgery. Using facility procedure volume as a proxy for potential economies of scale, we found no relation between CCL volume and total direct CCL costs. There did appear to be a significant inverse relation between facility volume and total procedural time with CCLs that performed the highest volumes of LHC and PTCA procedures saving an average of 5 to 9 minutes per procedure. These findings may be useful in defining specific time and cost benchmarks for these commonly performed procedures and serve to underscore the critical role of reducing complications in both quality improvement and cost-saving efforts.

Aged↗

PubMed2000

Clinical trials in coronary angiogenesis: issues, problems, consensus: An expert panel summary.

The rapid development of angiogenic growth factor therapy for patients with advanced ischemic heart disease over the last 5 years offers hope of a new treatment strategy based on generation of new blood supply in the diseased heart. However, as the field of therapeutic coronary angiogenesis is maturing from basic and preclinical investigations to clinical trials, many new and presently unresolved issues are coming into focus. These include in-depth understanding of the biology of angiogenesis, selection of appropriate patient populations for clinical trials, choice of therapeutic end points and means of their assessment, choice of therapeutic strategy (gene versus protein delivery), route of administration, and the side effect profile. The present article presents a summary statement of a panel of experts actively working in the field, convened by the Angiogenesis Foundation and the Angiogenesis Research Center during the 72nd meeting of the American Heart Association to define and achieve a consensus on the challenges facing development of therapeutic angiogenesis for coronary disease.

Angiogenesis Inducing Agents↗

PubMed2000

Short- and intermediate-term clinical outcomes from direct myocardial laser revascularization guided by biosense left ventricular electromechanical mapping.

BACKGROUND: Direct myocardial revascularization (DMR) has been examined as an alternative treatment for patients with chronic refractory myocardial ischemic syndromes who are not candidates for conventional coronary revascularization. Methods and Results-We used left ventricular electromagnetic guidance in 77 patients with chronic refractory angina (56 men, mean age 61+/-11 years, ejection fraction 0.48+/-0.11) to perform percutaneous DMR with an Ho:YAG laser at 2 J/pulse. Procedural success (laser channels placed in prespecified target zones) was achieved in 76 of 77 patients with an average of 26+/-10 channels (range 11 to 50 channels). The rate of major in-hospital cardiac adverse events was 2.6%, with no deaths or emergency operations, 1 patient with postprocedural pericardiocentesis, and 1 patient with minor embolic stroke. The rate of out-of-hospital adverse cardiac events (up to 6 months) was 2.6%, with 1 patient with myocardial infarction and 1 patient with stroke. Exercise duration after DMR increased from 387+/-179 to 454+/-166 seconds at 1 month and to 479+/-161 seconds at 6 months (P=0.0001). The time to onset of angina increased from 293+/-167 to 377+/-176 seconds at 1 month and to 414+/-169 seconds at 6 months (P=0.0001). Importantly, the time to ST-segment depression (>/=1 mm) also increased from 327+/-178 to 400+/-172 seconds at 1 month and to 436+/-175 seconds at 6 months (P=0.001). Angina (Canadian Cardiovascular Society classification) improved from 3.3+/-0.5 to 2.0+/-1.2 at 6 months (P<0.001). Nuclear perfusion imaging studies with a dual-isotope technique, however, showed no significant improvements at 1 or 6 months. CONCLUSIONS: Percutaneous DMR guided by left ventricular mapping is feasible and safe and reveals improved angina and prolonged exercise duration for up to a 6-month follow-up.

Adult↗

PubMed2000

Impact of end-stage renal disease on clinical and angiographic outcomes after coronary stenting.

Although patients with end-stage renal disease (ESRD) are at high risk for restenosis that requires repeat revascularization after balloon angioplasty, their restenosis rate after coronary stenting is still unknown. Over a 4-year period, we performed coronary stenting on 40 lesions in 34 patients with ESRD. We compared these lesions with 80 lesions from patients without renal disease who underwent coronary stenting in the STARS and WINS clinical trials, matched for treatment site, diabetes, lesion length, and reference vessel diameter. Quantitative coronary angiography was performed on all lesions and clinical outcomes were assessed at 9-month follow-up. Clinical and angiographic characteristics were well matched between the 2 groups and acute clinical success rates were similar. Despite comparable initial angiographic results over the 9-month follow-up period, repeat target lesion revascularization was twice as frequent in the ESRD group compared with the control group (35% vs 16%, p <0.05). After adjusting for differences in postprocedural minimum lumen diameter and other angiographic and clinical characteristics, ESRD remained the most important predictor of late target lesion revascularization (relative risk = 2.3, p = 0.04). In addition, overall 9-month mortality was higher for ESRD patients than for the control population (18% vs 2%, p <0.01). Thus, despite similar angiographic results, patients with ESRD are at higher risk for target lesion revascularization after coronary stenting than controls. Nonetheless, most patients with ESRD do not develop restenosis after stent placement, suggesting an important role for stenting in the management of this challenging population.

Aged↗

PubMed2000

Optimum percutaneous transluminal coronary angioplasty compared with routine stent strategy trial (OPUS-1): a randomised trial.

BACKGROUND: Whether routine implantation of coronary stents is the best strategy to treat flow-limiting coronary stenoses is unclear. An alternative approach is to do balloon angioplasty and provisionally use stents only to treat suboptimum results. We did a multicentre trial to compare the outcomes of patients treated with these strategies. METHODS: We randomly assigned 479 patients undergoing single-vessel coronary angioplasty routine stent implantation or initial balloon angioplasty and provisional stenting. We followed up patients for 6 months to determine the composite rate of death, myocardial infarction, cardiac surgery, and target-vessel revascularisation. RESULTS: Stents were implanted in 227 (98.7%) of the patients assigned routine stenting. 93 (37%) patients assigned balloon angioplasty had at least one stent placed because of suboptimum angioplasty results. At 6 months the composite endpoint was significantly lower in the routine stent strategy (14 events, 6.1%) than with the strategy of balloon angioplasty with provisional stenting (37 events, 14.9%, p=0.003). The cost of the initial revascularisation procedure was higher than when a routine stent strategy was used (US$389 vs $339, p<0.001) but at 6 months, average per-patient hospital costs did not differ ($10,206 vs $10,490). Bootstrap replication of 6-month cost data showed continued economic benefit of the routine stent strategy. INTERPRETATION: Routine stent implantation leads to better acute and long-term clinical outcomes at a cost similar to that of initial balloon angioplasty with provisional stenting.

Adult↗

PubMed2000

Percutaneous coronary revascularization in elderly patients: impact on functional status and quality of life.

BACKGROUND: Percutaneous coronary intervention (PCI) is frequently performed in elderly patients, but little is known about its impact on overall health and quality of life. OBJECTIVE: To examine changes in health-related quality of life among elderly patients after PCI. DESIGN: Observational study. SETTING: 75 U.S. hospitals. PATIENTS: Participants in two clinical trials of PCI. MEASUREMENTS: Health-related quality of life was assessed by using the Medical Outcomes Study Short Form (SF-36) survey and the Seattle Angina Questionnaire at baseline, 6 months, and 1 year. RESULTS: Serial data on health-related quality of life were available for 295 elderly (> or =70 years) and 1150 nonelderly (<70 years) patients. At 6 months, physical health had improved in 51% of elderly patients and mental health had improved in 29%. Cardiovascular-specific health status had improved in 58% to 75% of elderly patients. Improvement did not significantly differ between elderly and non-elderly patients at 6 months or 1 year. CONCLUSIONS: Elderly patients selected for participation in a trial of PCI had substantial improvements in health-related quality of life after PCI that were similar to those in younger patients.

Activities of Daily Living↗

PubMed2000

Administration of equine anti-thymocyte globulin via peripheral vein in renal transplant recipients.

BACKGROUND: Anti-thymocyte globulin (ATG) is used frequently as induction therapy in renal transplant recipients. It has been standard practice that the various polyclonal anti-lymphocyte preparations be administered via central line, vascular shunt, or arteriovenous fistula to avoid thrombophlebitis. METHODS: We have safely administered equine ATG (Atgam) via peripheral veins since 1978. We now retrospectively review recent experience with 83 patients transplanted between 1993 and 1998 who received Atgam induction via peripheral vein. Heparin 1000 U and Solucortef 20 mg were added to the infusion. Acetaminophen and diphenhydramine were given before infusion. RESULTS: Only two of 83 patients developed mild edema/erythema at or around the i.v. site. These reactions responded promptly to local management with warm soaks. No phlebitis or symptomatic venous thrombosis occurred in any patients. CONCLUSIONS: Equine ATG can be safely administered via peripheral vein infusion. Its use does not require continued hospitalization or placement of a central line. Peripheral vein infusion is safe, convenient, and economical.

Acetaminophen↗

PubMed2000

8-Aminocyclazocine analogues: synthesis and structure-activity relationships.

Opioid binding affinities were assessed for a series of cyclazocine analogues where the prototypic 8-OH substituent of cyclazocine was replaced by amino and substituted-amino groups. For mu and kappa opioid receptors, secondary amine derivatives having the (2R,6R,11R)-configuration had the highest affinity. Most targets were efficiently synthesized from the triflate of cyclazocine or its enantiomers using Pd-catalyzed amination procedures.

Analgesics↗

PubMed2000

Synthesis and opioid receptor affinity of morphinan and benzomorphan derivatives: mixed kappa agonists and mu agonists/antagonists as potential pharmacotherapeutics for cocaine dependence.

This report concerns the synthesis and preliminary pharmacological evaluation of a novel series of kappa agonists related to the morphinan (-)-cyclorphan (3a) and the benzomorphan (-)-cyclazocine (2) as potential agents for the pharmacotherapy of cocaine abuse. Recent evidence suggests that agonists acting at kappa opioid receptors may modulate the activity of dopaminergic neurons and alter the neurochemical and behavioral effects of cocaine. We describe the synthesis and chemical characterization of a series of morphinans 3a-c, structural analogues of cyclorphan [(-)-3-hydroxy-N-cyclopropylmethylmorphinan S(+)-mandelate, 3a], the 10-ketomorphinans 4a,b, and the 8-ketobenzomorphan 1b. Binding experiments demonstrated that the cyclobutyl analogue 3b [(-)-3-hydroxy-N-cyclobutylmethylmorphinan S(+)-mandelate, 3b, MCL-101] of cyclorphan (3a) had a high affinity for mu, delta, and kappa opioid receptors in guinea pig brain membranes. Both 3a,b were approximately 2-fold more selective for the kappa receptor than for the mu receptor. However 3b (the cyclobutyl analogue) was 18-fold more selective for the kappa receptor in comparison to the delta receptor, while cyclorphan (3a) had only 4-fold greater affinity for the kappa receptor in comparison to the delta receptor. These findings were confirmed in the antinociceptive tests (tail-flick and acetic acid writhing) in mice, which demonstrated that cyclorphan (3a) produced antinociception that was mediated by the delta receptor while 3b did not produce agonist or antagonist effects at the delta receptor. Both 3a,b had comparable kappa agonist properties. 3a,b had opposing effects at the mu receptor: 3b was a mu agonist whereas 3a was a mu antagonist.

Acetic Acid↗

PubMed2000

Abnormal ventral temporal cortical activity during face discrimination among individuals with autism and Asperger syndrome.

BACKGROUND: Recognition of individual faces is an integral part of both interpersonal interactions and successful functioning within a social group. Therefore, it is of considerable interest that individuals with autism and related conditions have selective deficits in face recognition (sparing nonface object recognition). METHOD: We used functional magnetic resonance imaging (fMRI) to study face and subordinate-level object perception in 14 high-functioning individuals with autism or Asperger syndrome (the autism group), in comparison with 2 groups of matched normal controls (normal control group ] [NC1] and normal control group 2 [NC2]) (n = 14 for each). Regions of interest (ROIs) were defined in NC1 and then applied in comparisons between NC2 and the autism group. Regions of interest were also defined in NC2 and then applied to comparisons between NC1 and the autism group as a replication study. RESULTS: In the first set of comparisons, we found significant task x group interactions for the size of activation in the right fusiform gyrus (FG) and right inferior temporal gyri (ITG). Post hoc analyses showed that during face (but not object) discrimination, the autism group had significantly greater activation than controls in the right ITG and less activation of the right FG. The replication study showed again that the autism group used the ITG significantly more for processing faces than the control groups, but for these analyses, the effect was now on the left side. Greater ITG activation was the pattern found in both control groups during object processing. CONCLUSIONS: Individuals with autism spectrum disorders demonstrate a pattern of brain activity during face discrimination that is consistent with feature-based strategies that are more typical of nonface object perception.

Adult↗

PubMed2000

Preliminary findings of antistreptococcal antibody titers and basal ganglia volumes in tic, obsessive-compulsive, and attention deficit/hyperactivity disorders.

BACKGROUND: Previous studies have provided preliminary serological evidence supporting the theory that symptoms of tic disorders or obsessive-compulsive disorder (OCD) may be sequelae of prior streptococcal infection. It is unclear, however, whether previously reported associations with streptococcal infection were obscured by the presence of diagnostic comorbidities. It is also unknown whether streptococcal infection is associated in vivo with anatomical alterations of the brain structures that have been implicated in the pathophysiology of these disorders. METHODS: Antistreptococcal antibody titers were measured in 105 people diagnosed as having CTD, OCD, or attention-deficit/hyperactivity disorder (ADHD) and in 37 community controls without a disorder. Subjects were unselected with regard to their history of streptococcal exposure. Basal ganglia volumes were measured in 113 of these subjects (79 patients and 34 controls). RESULTS: A DSM-IV diagnosis of ADHD was associated significantly with titers of 2 distinct antistreptococcal antibodies, antistreptolysin O and anti-deoxyribonuclease B. These associations remained significant after controlling for the effects of CTD and OCD comorbidity. No significant association was seen between antibody titers and a diagnosis of either CTD or OCD. When basal ganglia volumes were included in these analyses, the relationships between antibody titers and basal ganglia volumes were significantly different in OCD and ADHD subjects compared with other diagnostic groups. Higher antibody titers in these subjects were associated with larger volumes of the putamen and globus pallidus nuclei. CONCLUSIONS: These findings suggest that the prior reports of an association between antistreptococcal antibodies and either CTD or OCD may have been confounded by the presence of ADHD. They also support the hypothesis that in susceptible persons who have ADHD or OCD, chronic or recurrent streptococcal infections are associated with structural alterations in basal ganglia nuclei.

Adult↗

PubMed2000

Relationship between the association of rat epididymal protein "DE" with spermatozoa and the behavior and function of the protein.

Rat epididymal glycoprotein DE associates with the dorsal region of the sperm head during sperm maturation, migrates to the equatorial segment (ES) with the acrosome reaction (AR), and is involved in gamete membrane fusion. In the present study we examined the association of DE with the sperm surface and the relationship of this interaction with the behavior and function of the protein. Cloning and sequencing of DE revealed a lack of hydrophobic domains and the presence of 16 cysteine residues in the molecule. Experiments in which cauda epididymal sperm were subjected to different extraction procedures indicated that while most of the protein is removable from sperm by mild ionic strength, a low amount of DE, resistant to even 2 M NaCl, can be completely extracted by agents that remove integral proteins. However, the lack of hydrophobic domains in the molecule and the failure of DE to interact with liposomes, does not support a direct insertion of the protein into the lipid bilayer. These results, and the complete extraction of the tightly bound protein by dithiothreitol, suggest that this population would correspond to a peripheral protein bound to a membrane component by strong noncovalent interactions that involve disulfide bonds. While ELISA experiments showed that no protein could be extracted by NaCl from capacitated sperm, indirect immunofluorescence studies revealed the ability of the NaCl-resistant protein to migrate to the ES. Together, these results support the existence of two populations of DE: a major, loosely bound population that is released during capacitation, and a minor strongly bound population that remains after capacitation, migrates to the ES with the AR, and thus would correspond to the one with a role in gamete fusion.

Animals↗

PubMed2000

Outcome of patients with acute myocardial infarction who are ineligible for primary angioplasty trials.

We determined acute outcome in 148 consecutive patients with ST segment elevation myocardial infarction undergoing angioplasty including 72 patients (48.7%) considered ineligible for primary angioplasty trials. Overall, in-hospital mortality for acute infarct angioplasty was 12%, with fivefold higher mortality in the trial-ineligible group (21% vs. 4%, P = 0.003). Thus, primary angioplasty trials continue to exclude nearly 50% of acute infarction patients and reported mortality rates of primary angioplasty trials are likely to be significantly lower than the unselected in-hospital mortality rates. Cathet. Cardiovasc. Intervent. 49:237-243, 2000.

Angioplasty, Balloon, Coronary↗

PubMed2000

Rotational atherectomy or balloon angioplasty in the treatment of intra-stent restenosis: BARASTER multicenter registry.

The BARASTER registry was formed to evaluate the initial success and long-term results of rotational atherectomy in the management of in-stent restenosis. Rotational atherectomy was used in 197 cases of in-stent restenosis: 46 with stand-alone rotational atherectomy or at most 1 atmosphere of balloon inflation (Rota strategy), and 151 with rotational atherectomy and adjunctive balloon angioplasty <1 atmosphere (Combination strategy). These were compared with 107 episodes of in-stent restenosis treated with balloon angioplasty alone. In this observational study, the use of Combination therapy was associated with a slightly higher initial success rate (95% vs. 87% with the Rota strategy and 89% with Balloons, P = 0.08). There was a reduction in one year clinical outcomes (death, myocardial infarction or target lesion revascularization) in the combination group (38% vs. 60% with Rota and 52% with balloons, P = 0.02). These data support a benefit of the strategy of debulking with rotational atherectomy followed by adjunctive balloon angioplasty, in the management of in-stent restenosis.

Aged↗

PubMed2000

Ascending aortic atheroma assessed intraoperatively by epiaortic and transesophageal echocardiography.

BACKGROUND: The presence of ascending aortic atheroma is a known risk for systemic emboli or early saphenous vein graft failure if unrecognized at the time of cardiopulmonary bypass. METHODS: This study prospectively compared intraoperative omniplane transesophageal echocardiography (TEE) and epiaortic ultrasound (EAU) images in 22 patients (6 women, 16 men, age 66 +/- 8 years) before surgical manipulation of the ascending aorta. Atheroma lesion severity was scored: 1 = normal, 2 = nonprotruding intimal thickening (> 2 mm), 3 = atheroma less than 4 mm +/- Ca++, 4 = atheroma greater than or equal to 4 mm +/- Ca++, and 5 = any size mobile or ulcerated lesion +/- Ca++. The ascending aorta between the aortic valve and innominate artery was divided into proximal, middle, and distal segments. A total of 66 segments were evaluated. RESULTS: Although the overall agreement of scores between procedures was 75.8%, significantly more lesions were identified by EAU (15) than by TEE (5) (p < 0.03). TEE failed to identify lesions in the middle and distal segments of the aorta with a score of more than 3. CONCLUSIONS: Although atheromatous lesions were identified in the ascending aorta by both ultrasound modalities, the results suggest that intraoperative EAU may have an advantage over TEE for surgeons assessing target sites for surgical procedures involving the ascending aorta.

Aged↗

PubMed2000

A method for mediastinal drainage after cardiac procedures using small silastic drains.

BACKGROUND: It has been standard teaching in cardiac surgery that drainage of the mediastinum following cardiac surgical procedures is best accomplished using rigid large-bore chest tubes. Recent trends in cardiac surgery have suggested less invasive approaches to a variety of diseases. Difficult drainage problems in the field of general surgery including hepatic and pancreatic collections have been drained successfully with smaller flexible drains for many years. Additionally, many difficult to reach collections in the chest have been drained by invasive radiologists using small pigtail catheters. METHODS: We have introduced drainage of the mediastinum using 10-mm flexible, flat, fluted Blake drains. To date, we have used these drains in more than 100 cardiac operations including coronary artery bypass grafting, valve repair/replacements, combined coronary artery bypass grafting/valve operations, heart transplants, septal defects, and mediastinal tumors. RESULTS: We have demonstrated that this form of drainage is as good as using large-bore chest tubes with no significant risk of bleeding or tamponade. Additionally, use of these tubes is less painful, allows more mobility, and earlier discharge with functioning drains in place if necessary. CONCLUSIONS: Larger chest tubes are not necessarily better when it comes to draining the mediastinum. The actual area of ingress through the sideholes is considerably less than the surface area provided by the fluted Blake drain. We believe that this system can replace standard chest tubes.

Cardiac Surgical Procedures↗

PubMed2000

Incidence and predictors of myocardial infarction among patients with atrial fibrillation.

OBJECTIVES: We sought to evaluate the utility of excluding myocardial infarction (MI) in patients presenting to the emergency department (ED) with atrial fibrillation (AF) and to identify predictors of MI in this group. BACKGROUND: Patients with AF are frequently admitted to the hospital, in part, to exclude an associated MI. There are no prospective data on unselected patients to support this common practice. METHODS: We conducted a prospective cohort study of all patients who presented to a single-center ED with the primary diagnosis of AF. RESULTS: Of a total of 255 patients, 190 (75%) were admitted to the hospital, and 109 of them underwent a standard "rule-out MI" protocol. Of these 109 patients, six (5.5%) were identified as having an acute MI at the time of admission. Chest pain was present in 39% of patients, with a sensitivity and specificity for the occurrence of MI of 100% and 65%, respectively. ST segment elevation or depression was present in 43% of patients, with a sensitivity and specificity of 100% and 51%. The presence of either major ST segment depression (>2 mm) or elevation on the admission electrocardiogram (ECG) was present in 6%, with a sensitivity of 100% and a specificity of 99%. The resulting positive and negative predictive values were 86% (95% confidence interval [CI] 42% to 99%) and 100% (95% CI 96% to 100%), respectively. Use of this criterion would have reduced the number of rule-out MIs in our study group by 94%, with no loss of sensitivity. CONCLUSIONS: Chest pain and ST segment depression are extremely common findings in patients presenting to the ED with AF and have limited power to predict MI. In contrast, ECG evidence of ST segment elevation or depression >2 mm appears to be a reliable discriminator of which patients are at risk for MI. Patients without significant ST segment changes are at very low risk for MI and may not require performance of the rule-out MI protocol or hospital admission if clinically stable.

Aged↗