The power of (un)natural selection.
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Angioplasty, Balloon, Coronary↗
Biomedical subjects
G S Reeder
Publications and source records attributed to G S Reeder.
Modern management of acute myocardial infarction.
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Angioplasty, Balloon, Coronary↗
Decreasing mortality with primary percutaneous coronary intervention in patients with acute myocardial infarction: the Mayo Clinic experience from 1991 through 1997.
OBJECTIVE: To characterize and determine the overall impact of changes in primary percutaneous coronary intervention (PCI) on the clinical outcome of patients presenting within 24 hours of acute myocardial infarction (AMI). PATIENTS AND METHODS: We retrospectively analyzed a prospective PCI registry for 1073 consecutive patients undergoing primary PCI for AMI at the Mayo Clinic in Rochester, Minn, from 1991 through 1997. The primary outcome measure was mortality from any cause within 30 days and 1 year. RESULTS: The number of patients treated for AMI by primary PCI per year increased from 119 in 1991 to 193 in 1997. Intracoronary stent use increased from 1.7% in 1991 to 64.8% in 1997 (P < .001). This coincided with an increase in ticlopidine use from 3.6% in 1994 to 62.1% in 1997 (P < .001) and in abciximab use from 2.7% in 1995 to 63.2% in 1997 (P < .001). An increase in beta-blocker (58.3% to 75.3%; P < .001), angiotensin-converting enzyme inhibitor (0.9% to 40.0%; P < .001), and 3-hydroxy-3-methylglutaryl coenzyme A reductase use (1.9% to 40.5%; P < .001) as well as a decrease in calcium channel antagonist (34.3% to 8.4%; P < .001) use occurred on discharge. From 1991 through 1997, there was a significant decrease in the 30-day mortality rate (10.1% to 5.2%; P = .05). The 1-year mortality rate also decreased (13.4% in 1991 to 10.4% in 1997) (P = .09). After adjustment for other confounding variables, treatment in more recent years was associated with a significant decrease in death at 30 days (odds ratio, 0.89; 95% confidence interval, 0.79-1.00; P = .05) and during long-term follow-up (odds ratio, 0.93; 95% confidence interval, 0.87-1.00; P = .04). CONCLUSIONS: Percutaneous coronary intervention methods of reperfusion for AMI, along with adjuvant pharmacotherapy, have changed over recent years and have been associated with improved short- and long-term survival.
Abciximab↗
Update on intravenous fibrinolytic therapy for acute myocardial infarction.
Intravenous fibrinolytic therapy is used widely in the treatment of ST-elevation acute myocardial infarction. Advances in this therapeutic modality during the past 5 years include new third-generation fibrinolytic agents and creative strategies to enhance administration and efficacy of fibrinolytic therapy. Several of the new agents allow for single- or double-bolus injection. A number of ongoing large randomized trials are attempting to determine whether the combination of fibrinolytic therapy with low-molecular-weight heparin or a glycoprotein IIb/IIIa antagonist enhances coronary reperfusion and reduces mortality and late reocclusion. One large prospective trial is investigating the potential benefit of prehospital administration of fibrinolytic therapy. This article summarizes recent safety and efficacy data on fibrinolytic therapy, with particular emphasis on the new third-generation fibrin-specific agents; reviews the preliminary data on facilitated fibrinolysis; and discusses the rationale for prehospital administration of fibrinolytic therapy.
Clinical Trials as Topic↗
Contemporary diagnosis and management of unstable angina.
Unstable angina (UA) is one of the acute coronary syndromes, a group of conditions that also includes non-ST elevation myocardial infarction (MI) and ST elevation MI. The underlying pathogenic substrate of all these entities is the unstable coronary plaque with an overlying intracoronary thrombus. Initial management for the patient with suspected UA includes a resting electrocardiogram and oral administration of aspirin. ST-segment elevation indicates acute MI with the need for urgent reperfusion therapy. Patients without ST-segment elevation commonly have a mixture of UA and non-ST elevation MI; initial management is similar with assessment of near-term risk of MI or death as the next step. Features of UA indicating high risk include persistent ST-segment depression, persistent ischemic pain, elevated troponin level, or features of heart failure. Such patients undergo intensive medical therapy with heparin (unfractionated or low-molecular-weight), beta-blockade, and IIb/IIa antiplatelet agents, usually followed by coronary angiography and percutaneous intervention. The timing of intervention depends on the patient's response to therapy. Intermediate- or low-risk patients (including those presenting to the emergency department) can be managed with a chest pain unit strategy, and those with normal results on serial electrocardiograms, cardiac marker studies, and functional testing can be safely discharged home. Others are admitted for elective angiography, intensive medical therapy, or both. Assessment of coronary risk factors and their modification is an important component of long-term therapy for both high-risk and low-risk patients with UA, as well as those determined to have had non-ST elevation MI.
Abciximab↗
Clinical characteristics and outcome in postinfarction pseudoaneurysm.
The clinical characteristics and outcome in 22 patients with postinfarction pseudoaneurysm were studied. The medium-term outcome was poor (median follow-up 3.6 years), but cardiac rupture was uncommon in patients treated conservatively.
Adult↗
Clinical correlates of the initial and long-term cost of coronary bypass surgery and coronary angioplasty.
BACKGROUND: Medical costs vary substantially among patients. Understanding the baseline factors that predict subsequent cost may allow better selection of therapy for individual patients. Understanding the postprocedure events that increase cost should help to improve efficiency and effectiveness of coronary revascularization. METHODS: Data on 4-year costs were collected from patients randomly assigned to coronary angioplasty or bypass surgery as part of the BARI (Bypass Angioplasty Revascularization Investigation) trial. Regression models first examined factors known at the time of randomization that prospectively predicted initial procedure cost and long-term cost. Subsequent models tested the value of postrandomization events as explanatory variables for cost. RESULTS: The independent baseline predictors of higher initial percutaneous transluminal coronary angioplasty cost included 3-vessel disease (+12%) and acute presentations (+22%), whereas the independent predictors of higher initial coronary artery bypass grafting cost included the number of comorbid conditions (+5% per condition) and female sex (+7%). The independent baseline predictors of 4-year cost included heart failure (+26%), diabetes (+22%), comorbidity (+10%), and angioplasty assignment in patients with 2-vessel disease (-15%). Postrandomization models showed higher initial and long-term costs were strongly correlated with the number of repeat revascularization procedures (+30% to +128%) and the occurrence of clinical complications (+8% to +131%). CONCLUSIONS: Two-vessel disease identifies patients likely to have lower costs after angioplasty, whereas heart failure, comorbid conditions, and diabetes identify patients likely to accrue higher costs after either angioplasty or bypass surgery. Long-term costs can be potentially reduced by interventions that decrease procedural complications or reduce the need for repeat revascularization.
Aged↗
Elevation of creatine kinase, MB fraction after elective coronary intervention: a valid surrogate end point of poor late outcome?
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Angioplasty, Balloon, Coronary↗
Digoxin, hypercalcaemia, and cardiac conduction.
The cardiac effects of hypercalcaemia are usually manifest as a shortening of the QT-interval. Hypercalcaemia is infrequently associated with a clinically manifest arrhythmia. However, concomitant therapy with digoxin or underlying cardiac disease can potentiate the arrhythmogenic effects of hypercalcaemia, leading to a symptomatic rhythm disorder. We describe a symptomatic arrhythmia, which developed in a patient with hypercalcaemia secondary to squamous cell carcinoma of the bronchus. The patient was on digoxin therapy at the time. The arrhythmia did not recur after discontinuation of digoxin therapy and correction of the hypercalcaemia. Because of its effect on cardiac conduction, hypercalcaemia should be considered in the evaluation of any patient with an unexplained bradyarrhythmia. Conversely, patients with hypercalcaemia should discontinue digoxin therapy and be evaluated for the presence of rhythm disorders while receiving appropriate treatment for hypercalcaemia.
Aged↗
Transmyocardial and percutaneous myocardial revascularization: current and future role in the treatment of coronary artery disease.
Transmyocardial revascularization (TMR) is a new treatment modality under evaluation in patients with severely symptomatic, diffuse coronary artery disease, in whom the potential for medical or interventional management has been exhausted. Preliminary clinical trials show improved ischemic symptoms within the first 3 months in about 70% of TMR-treated patients. The original proposed mechanism of surgical or catheter-based TMR (percutaneous myocardial revascularization [PMR]) was that channels mediate direct blood flow between the left ventricular cavity and ischemic myocardium. However, several alternative explanations for the clinical success of TMR have recently been suggested, including improved perfusion by angiogenesis, an anesthetic effect by nerve destruction, and a potential placebo effect. This article reviews the clinical role of TMR/PMR, its possible pathophysiologic mechanisms, and its controversies. It provides an overview of the actual scientific and clinical status of TMR and details future directions.
Angioplasty, Balloon, Coronary↗
A clinical trial of a chest-pain observation unit for patients with unstable angina. Chest Pain Evaluation in the Emergency Room (CHEER) Investigators.
BACKGROUND: Nearly half of patients hospitalized with unstable angina eventually receive a non-cardiac-related diagnosis, yet 5 percent of patients with myocardial infarction are inappropriately discharged from the emergency department. We evaluated the safety, efficacy, and cost of admission to a chest-pain observation unit (CPU) located in the emergency department for such patients. METHODS: We performed a community-based, prospective, randomized trial of the safety, efficacy, and cost of admission to a CPU as compared with those of regular hospital admission for patients with unstable angina who were considered to be at intermediate risk for cardiovascular events in the short term. A total of 424 eligible patients were randomly assigned to routine hospital admission (a monitored bed under the care of the cardiology service) or admission to the CPU (where patients were cared for according to a strict protocol including aspirin, heparin, continuous ST-segment monitoring, determination of creatine kinase isoenzyme levels, six hours of observation, and a study of cardiac function). The CPU was managed by the emergency department staff. Patients whose test results were negative were discharged, and the others were hospitalized. Primary outcomes (nonfatal myocardial infarction, death, acute congestive heart failure, stroke, or out-of-hospital cardiac arrest) and use of resources were compared between the two groups. RESULTS: The 212 patients in the hospital-admission group had 15 primary events (13 myocardial infarctions and 2 cases of congestive heart failure), and the 212 patients in the CPU group had 7 events (5 myocardial infarctions, 1 death from cardiovascular causes, and 1 case of congestive heart failure). There was no significant difference in the rate of cardiac events between the two groups (odds ratio for the CPU group as compared with the hospital-admission group, 0.50; 95 percent confidence interval, 0.20 to 1.24). No primary events occurred among the 97 patients who were assigned to the CPU and discharged. Resource use during the first six months was greater among patients assigned to hospital admission than among those assigned to the CPU (P<0.01 by the rank-sum test). CONCLUSIONS: A CPU located in the emergency department can be a safe, effective, and cost-saving means of ensuring that patients with unstable angina who are considered to be at intermediate risk of cardiovascular events receive appropriate care.
Adult↗
Rescue echocardiographically guided pericardiocentesis for cardiac perforation complicating catheter-based procedures. The Mayo Clinic experience.
OBJECTIVES: The purpose of this study was to determine the safety and efficacy of rescue echocardiographically guided pericardiocentesis as a primary strategy for the management of acute cardiac perforation and tamponade complicating catheter-based procedures. BACKGROUND: In this era of interventional catheterization, acute tamponade from cardiac perforation as a complication is encountered more frequently. The safety and efficacy of echocardiographically guided pericardiocentesis in this life-threatening situation and outcomes of patients managed by this technique are unknown. METHODS: Of the 960 consecutive echocardiographically guided pericardiocenteses performed at the Mayo Clinic (1979 to 1997), 92 (9.6%) were undertaken in 88 patients with acute tamponade that developed in association with a diagnostic or interventional catheter-based procedure. Most of the patients were hemodynamically unstable at the time of pericardiocentesis, with clinically overt tamponade in 40% and frank hemodynamic collapse (systolic blood pressure <60 mm Hg) in 57%. Clinical end points of interest were the success and complication rates of rescue pericardiocentesis and patient outcomes, including the need for other interventions, clinical and echocardiographic follow-up findings and survival. RESULTS: Rescue pericardiocentesis was successful in relieving tamponade in 91 cases (99%) and was the only and definitive therapy in 82% of the cases. Major complications (3%) included pneumothorax (n=1), right ventricular laceration (n=1) and intercostal vessel injury with right ventricular laceration (n=1); all were treated successfully. Minor complications (2%) included a small pneumothorax and an instance of transient nonsustained ventricular tachycardia; all were resolved spontaneously. Further surgical intervention was performed in 16 patients (18%). No deaths resulted from the rescue pericardiocentesis procedure itself. Early death (<30 days) in this series was due to injuries from cardiac catheter-based procedures (n=3), perioperative complications (n=2) and underlying cardiac diseases (n=2). Clinical or echocardiographic follow-up for a minimum of 3 months or until death (if <3 months) for recurrent effusion or development of pericardial constriction was achieved in 87 (99%) of the patients. CONCLUSIONS: Echocardiographically guided pericardiocentesis was safe and effective for rescuing patients from tamponade and reversing hemodynamic instability complicating invasive cardiac catheter-based procedures. For most patients, this was the definitive and only therapy necessary.
Adolescent↗
Myxoma of the left atrial appendage mimicking thrombus during aortic valve replacement.
Echocardiographic characterization of cardiac masses involving the left atrium are defined by morphologic shape and appearance, site of attachment, type of margins, and presence or absence in the left atrial appendage. Most reports use location in the LAA as strong supportive evidence of thrombus, especially if associated with other suggestive findings (i.e., atrial fibrillation, spontaneous echo contrast, or both). Other reported masses (non-thrombi) in the left atrial appendage are considered extremely rare. We report a case of a patient with coexisting aortic stenosis and atrial fibrillation diagnosed intraoperatively by transesophageal echocardiography with myxoma of the left atrial appendage.
Aged↗
Intravenous adenosine and lidocaine in patients with acute myocardial infarction.
OBJECTIVES: A pilot study was designed to assess the safety of combined intravenous adenosine and lidocaine in patients with acute myocardial infarction and to estimate the likelihood of a beneficial effect on final infarct size. BACKGROUND: Adenosine plus lidocaine reduces infarct size in animals, but the safety and efficacy in human beings is unknown. METHODS AND RESULTS: Adenosine (70 microg/kg per minute intravenous infusion) plus lidocaine (1 mg/kg intravenous bolus injection and 2 mg/kg per minute infusion) was given to 45 patients with acute myocardial infarction. Patients underwent immediate balloon angioplasty without preceding thrombolytic therapy. Myocardial perfusion defects were measured with serial technetium 99m sestamibi studies. One patient developed persisting hypotension in conjunction with a large inferolateral myocardial infarction. Transient hypotension in three other patients resolved with a reduction in adenosine. Advanced atrioventricular block was never observed. Other adverse events (including atrial fibrillation, ventricular tachyarrhythmia, bradycardia, and respiratory distress) occurred at low frequencies, as expected for patients with acute myocardial infarction. An initial median perfusion defect of 45% of the left ventricle (60% for anterior infarction, 17% for nonanterior infarction) was observed. At hospital discharge (mean +/- SD = 4.3 +/- 2.1 days) the median value was 12%, and at 8 +/- 4 weeks it was 3% (7% for anterior infarction, 0% for nonanterior infarction); 14 patients had no measurable follow-up. Compared with historical control patients, prehospital discharge measurements were not different but late perfusion defects were improved. CONCLUSIONS: Treatment with intravenous adenosine and lidocaine during acute myocardial infarction has sufficient safety and potential for improved myocardial salvage. Randomized studies are justified.
Adenosine↗
A simplified, practical approach to assessment of severity of mitral regurgitation by Doppler color flow imaging with proximal convergence: validation with concomitant cardiac catheterization.
OBJECTIVE: To compare the proximal convergence method for quantification of mitral regurgitation with findings on concomitant left ventriculography. MATERIAL AND METHODS: In 41 patients (22 men and 19 women, 63 +/- 13 years of age), mitral regurgitation was evaluated concomitantly by Doppler color flow jet area, proximal convergence method, and left ventriculography. A simplified measurement of the proximal convergence, consisting of the aliasing radius and velocity of the proximal isosurface (r2 x V), was used. RESULTS: Angiographic grade correlated well with the proximal convergence method (r2 x V) but had poor correlation with the Doppler color flow jet area method. All patients with a proximal convergence flow rate of less than 10 cm3/s had grade 1 or 2 mitral regurgitation, whereas patients with a proximal convergence flow rate of more than 20 cm3/s had grade 3 or 4 mitral regurgitation. The severity of mitral regurgitation was indeterminate in patients with proximal convergence flow rates from 10 to 20 cm3/s. CONCLUSION: Doppler color flow jet area correlates poorly with angiographic grade of mitral regurgitation. A simplified proximal convergence method is useful for separating grade 3 and 4 from grade 1 and 2 mitral regurgitation in most patients. A group of patients with indeterminate severity of mitral regurgitation remains, however, in whom further assessment is necessary.
Aged↗
Echocardiographic assessment of commissural calcium: a simple predictor of outcome after percutaneous mitral balloon valvotomy.
OBJECTIVES: This study was undertaken to determine whether the presence of calcium in the mitral valve commissures, as demonstrated echocardiographically, could predict outcome and to compare this with an established echocardiographic scoring system. BACKGROUND: Percutaneous mitral balloon valvotomy is an effective form of treatment for mitral valve stenosis. It is important to identify patients who would benefit from this procedure. Commissural splitting is the dominant mechanism by which mitral valve stenosis is relieved by this technique, and thus commissural morphology may predict outcome. METHODS: One hundred forty-nine consecutive patients who underwent percutaneous mitral balloon valvotomy at the Mayo Clinic were evaluated retrospectively. The morphology of the mitral valve apparatus on the baseline echocardiograms was scored in blinded manner using a semiquantitative grading system of leaflet thickening, mobility, calcification and subvalvular thickening (Abascal score). Additionally, each of the medial and lateral commissures was graded for the presence or absence of calcification. End points were death, New York Heart Association functional class, repeat percutaneous mitral balloon valvotomy and mitral valve replacement at follow-up. RESULTS: The mean follow-up period was 1.8 years (maximum 7.9 years). Univariate predictors of death and all events combined included age, the use of a double-balloon technique, the presence of calcium in a commissure and the Abascal score, as continuous variables. Patients with an Abascal score < or = 8 showed a trend toward improved survival at 36 months free of death, repeat percutaneous mitral balloon valvotomy or mitral valve replacement (78 +/- 6% vs. 67 +/- 8%, p = 0.07) and free of all events combined (75 +/- 6% vs. 64 +/- 8%, p = 0.07) versus those patients with a score > 8. However, survival at 36 months free of death, repeat percutaneous mitral balloon valvotomy or mitral valve replacement (86 +/- 4% vs. 40 +/- 4%) and free of all events combined (82 +/- 5% vs. 38 +/- 10%) at follow-up was significantly different between patients without commissural calcium and those with commissural calcium (p < 0.001). In a Cox regression model with Abascal score and commissural calcium and their interaction, calcification emerged as the only significant variable (p < 0.01). CONCLUSIONS: The presence of commissural calcium is a strong predictor of outcome after percutaneous mitral balloon valvotomy. Patients with evidence of calcium in a commissure have a lower survival rate and a higher incidence of mitral valve replacement and all end points combined. Thus, the simple presence or absence of commissural calcification assessed by two-dimensional echocardiography can be used to predict outcome.
Calcinosis↗
Eosinophilic myocarditis manifesting as myocardial infarction: early diagnosis and successful treatment.
OBJECTIVE: To report a case of eosinophilic myocarditis with remarkable initial clinical manifestations and outcome. MATERIAL AND METHODS: A 67-year-old woman with hypertension and a history of asthma and drug hypersensitivity was referred to our institution with a diagnosis of acute myocardial infarction on the basis of severe chest pain, ST elevation on an electrocardiogram, and a slight increase in cardiac enzymes. Further diagnostic studies were performed. RESULTS: Echocardiography disclosed left ventricular dysfunction in conjunction with apical asynergy, thinning, and thrombus. The eosinophil count in the peripheral blood was increased only slightly. Coronary angiography showed normal arteries and prompted the performance of endomyocardial biopsy, which revealed active eosinophilic myocarditis. After corticosteroid therapy, global and regional left ventricular function returned to normal. CONCLUSION: This unusual clinical picture and outcome demonstrate that eosinophilic myocarditis may simulate acute myocardial infarction and should be considered in patients with a history of allergies or acute left ventricular dysfunction, even in the absence of pronounced eosinophilia in the peripheral blood. With appropriate medical therapy, recovery for these patients can be complete.
Acute Disease↗
Giant coronary artery aneurysms and myocardial infarction in a patient with systemic lupus erythematosus.
A 26-year-old woman with systemic lupus erythematosus and end-stage renal disease presented for renal transplantation. She had no findings of cardiac disease. Radiologic evaluation, cardiac magnetic resonance imaging, and coronary angiography showed giant aneurysms of the right and left anterior descending coronary arteries. Despite therapy, acute anterior myocardial infarction developed during follow-up. Giant coronary artery aneurysms associated with systemic lupus erythematosus are unusual and their management is controversial. Antithrombotic therapy probably should be considered for giant coronary artery aneurysms.
Adult↗