Stroke after coronary artery bypass grafting: are we forgetting atrial fibrillation?
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Age Factors↗
Biomedical subjects
J L Blackshear
Publications and source records attributed to J L Blackshear.
Epidemiology and natural history of atrial fibrillation: clinical implications.
With a substantial impact on morbidity and mortality, the growing "epidemic" of atrial fibrillation (AF) intersects with a number of conditions, including aging, thromboembolism, hemorrhage, hypertension and left ventricular dysfunction. Currently, the epidemiology and natural history of AF govern all aspects of its clinical management. The ongoing global investigative efforts toward understanding AF are also driven by epidemiologic findings. New developments, by affecting the natural history of the disease, could eventually alter the nature of decision making in patients with AF. The crucial issue of rate versus rhythm control awaits completion of the AF Follow-up Investigation of Rhythm Management trial. The processes of electrical and structural remodeling that perpetuate AF appear to be reversible. In the era of functional genomics, the molecular basis of this ubiquitous arrhythmia is in the process of being defined. Unraveling the molecular genetics of AF might provide new insights into the structural and electrical phenotypes resulting from genetic mutations and, as such, new approaches to treatment of this arrhythmia at the ion channel and cellular levels. Thus, current adverse trends are superimposed on a background of a rapidly developing knowledge base and potentially exciting new therapeutic options. Consequently, an understanding of the epidemiology and natural history of AF is crucial to the future allocation of resources and the utilization of an expanding range of therapies aimed at reducing the impact of this disease on a changing patient population.
Atrial Fibrillation↗
Step care therapy for hypertension in diabetic patients.
For diabetic patients, a goal blood pressure lower than 130/80-85 mm Hg is strongly supported by clinical trial results. We review the agents, sequence, and dosing used in clinical trials and propose a treatment algorithm. Multiagent antihypertensive therapy is required to attain goal blood pressure in most patients. Step sequences to obtain this goal are suggested. In general, we favor initial therapy with an angiotensin-converting enzyme inhibitor, followed by the addition of a diuretic. The presence of comorbid conditions may dictate variation from this scheme. The effect of antihypertensive agents on established cardiovascular diseases, proteinuria, renal function, and metabolic factors is discussed. Tailored recommendations for specific clinical scenarios are described.
Adrenergic beta-Antagonists↗
An economic analysis of an aggressive diagnostic strategy with single photon emission computed tomography myocardial perfusion imaging and early exercise stress testing in emergency department patients who present with chest pain but nondiagnostic electrocardiograms: results from a randomized trial.
STUDY OBJECTIVE: Conventional emergency department testing strategies for patients with chest pain often do not provide unequivocal diagnosis of acute coronary syndromes. This study was conducted to determine whether the routine use of single photon emission computed tomography (SPECT) imaging at rest and early exercise stress testing to assess intermediate-risk patients with chest pain and no ECG evidence of acute ischemia will lead to earlier discharges, more discriminate use of coronary angiography, and an overall reduction in average costs of care with no adverse clinical outcomes. METHODS: All patients in this study had technetium 99m tetrofosmin SPECT imaging at rest and were randomly assigned to either a conventional (results of the imaging test blinded to the physician) or perfusion imaging-guided (results of the imaging test unblinded to the physician) strategy. Patients in the conventional arm were treated at their physician's discretion. Patients in the perfusion imaging-guided arm were treated according to a predefined protocol based on SPECT imaging test results: coronary angiography after a positive scan result and exercise treadmill testing after a negative scan result. Study endpoints consisted of total in-hospital costs and length of stay. Hospital costs were calculated using hospital department-specific Medicare cost/charge ratios. Length of stay was calculated as total hospital room days billed (regular and intensive care). RESULTS: We enrolled 46 patients, 9 with acute myocardial infarctions. Patients randomly assigned to the perfusion imaging-guided arm had $1,843 (95% confidence interval [CI] $431 to $6,171) lower median in-hospital costs and 2.0-day (95% CI 1.0 to 3.0 days) shorter median lengths of stay but similar rates of in-hospital and 30-day follow up events as patients in the conventional arm. CONCLUSION: An ED chest pain diagnostic strategy incorporating acute resting (99m)Tc tetrofosmin SPECT imaging and early exercise stress testing may lead to reduced in-hospital costs and decreased length of stay for patients with acute chest pain and nondiagnostic ECGs.
Aged↗
Development of a decision aid for atrial fibrillation who are considering antithrombotic therapy.
With patients demanding a greater role in the clinical decision-making process, many researchers are developing and disseminating decision aids for various medical conditions. In this article, we outline the essential elements in the development and evaluation of a decision aid to help patients with atrial fibrillation choose, in consultation with their physicians, appropriate antithrombotic therapy (warfarin, aspirin, or no therapy) to prevent stroke. We also outline possible future directions regarding the implementation and evaluation of this decision aid. This information should enable clinicians to better understand the role that decision aids may have in their interactions with patients.
Anticoagulants↗
Onset and termination of atrial fibrillation.
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Aged↗
70-year-old woman with chest pain and new diastolic murmur 6 months after coronary artery bypass grafting.
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Aged↗
Warfarin safety and efficacy in patients with thoracic aortic plaque and atrial fibrillation. SPAF TEE Investigators. Stroke Prevention and Atrial Fibrillation. Transesophageal echocardiography.
Patients with atrial fibrillation and with documented aortic plaque who were assigned to adjusted-dose warfarin therapy (international normalized ratio 2.0 to 3.0) had an annual rate of cholesterol embolization of 0.7% (95% confidence interval [CI] 0.1% to 5.3%/patient-year). Warfarin-assigned patients with plaque had a lower rate of embolic events (5.9%/year; 95% CI 3.0 to 12) than those on combination low-dose warfarin (international normalized ratio <1.5) plus aspirin (17.3%/year; 95% CI 11 to 27; p = 0.01).
Aged↗
Pathophysiologic correlates of thromboembolism in nonvalvular atrial fibrillation: II. Dense spontaneous echocardiographic contrast (The Stroke Prevention in Atrial Fibrillation [SPAF-III] study).
We analyzed transesophageal echocardiograms from 772 participants in the Stroke Prevention in Atrial Fibrillation (SPAF-III) study, characterizing spontaneous echocardiographic contrast (SEC) in the left atrium or appendage as faint or dense. The association of dense SEC with stroke risk factors and anatomic, hemodynamic, and hemostatic parameters related to specific thromboembolic mechanisms was evaluated by multivariate analysis. Spontaneous echocardiographic contrast was present in 55% of patients and was dense in 13%. Age (odds ratio [OR] 2.4/decade, P <.001), constant atrial fibrillation (OR 6.9, P <.001), history of hypertension (OR 3. 2, P <.001), and current tobacco smoking (OR 2.6, P =.04) were independent clinical predictors of dense SEC. Multivariate analysis of clinical, echocardiographic, and hemostatic parameters yielded age as the sole independent clinical predictor of dense SEC (OR 2. 4/decade, P <.001). Other independent predictors were measures of left atrial/appendage flow dynamics, left atrial size (OR 2.4/cm diameter, M-mode, P <.001), atherosclerotic aortic plaque (OR 2.8, P =.002), and plasma fibrinogen >350 mg/dL (P <.001). Results were similar when SEC of any density was analyzed. In conclusion, SEC occurred in more than half of these patients with prospectively defined nonvalvular atrial fibrillation but was usually faint. Dense SEC was strongly associated with previously reported clinical predictors of stroke, linking them to thromboembolism through atrial stasis. Diverse pathophysiologic factors including atrial stasis, fibrinogen level, and aortic plaque influence SEC.
Aged↗
Aortic plaque in atrial fibrillation: prevalence, predictors, and thromboembolic implications.
BACKGROUND AND PURPOSE: Thoracic aortic plaque identified by transesophageal echocardiography heightens the risk of stroke associated with atrial fibrillation (AF). We sought to identify the prevalence, predictors, and implications of aortic plaque in patients with nonvalvular AF. METHODS: Thoracic aortic plaque was prospectively sought in 770 persons with AF with the use of transesophageal echocardiography and classified as simple or complex on the basis of thickness >/=4 mm, ulceration, or mobility. Clinical and echocardiographic features of thromboembolism were correlated by multivariate analysis. RESULTS: Aortic plaque was detected in 57% of the cohort, and complex plaque was detected in 25%. Both were found more frequently in the descending than in the proximal aorta. Potentially etiologic patient characteristics independently associated with complex plaque included advanced age, history of hypertension, diabetes, and past or present tobacco use. Comorbidities associated with aortic plaque were prior thromboembolism, increased pulse pressure, ischemic heart disease, stenosis or sclerosis of the aortic valve, mitral annular calcification (>10%), elevated serum creatinine concentration, spontaneous echo contrast in the left atrium or appendage, and left atrial appendage thrombus. The prevalence of complex plaque in patients aged <70 years with <10% mitral annular calcification, without ischemic heart disease, or without pulse pressure >/=65 mm Hg was 4% (95% CI, 1% to 6%). CONCLUSIONS: Aortic plaque is prevalent in patients with AF and is associated with atherosclerosis risk factors and with left atrial stasis or thrombosis, which are themselves independent stroke risk factors. Since the predominant location of complex plaque was in the descending aorta, the role of aortic plaque as a source of embolism in AF is uncertain.
Aged↗
Transesophageal echocardiography in source-of-embolism evaluation: the search for a better therapeutic rationale.
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Aortic Diseases↗
Transesophageal echocardiographic correlates of clinical risk of thromboembolism in nonvalvular atrial fibrillation. Stroke Prevention in Atrial Fibrillation III Investigators.
OBJECTIVES: This study explored the mechanisms linking clinical and precordial echocardiographic predictors to thromboembolism in atrial fibrillation (AF) by assessing transesophageal echocardiographic (TEE) correlations. BACKGROUND: Clinical predictors of thromboembolism in patients with nonvalvular AF have been identified, but their mechanistic links remain unclear. TEE provides imaging of the left atrium, its appendage and the proximal thoracic aorta, potentially clarifying stroke mechanisms in patients with AF. METHODS: Cross-sectional analysis of TEE features correlated with low, moderate and high thromboembolic risk during aspirin therapy among 786 participants undergoing TEE on entry into the Stroke Prevention in Atrial Fibrillation III trial. RESULTS: TEE features independently associated with increased thromboembolic risk were appendage thrombi (relative risk [RR] 2.5, p = 0.04), dense spontaneous echo contrast (RR 3.7, p < 0.001), left atrial appendage peak flow velocities < or = 20 cm/s (RR 1.7, p = 0.008) and complex aortic plaque (RR 2.1, p < 0.001). Patients with AF with a history of hypertension (conferring moderate risk) more frequently had atrial appendage thrombi (RR 2.6, p < 0.001) and reduced flow velocity (RR 1.8, p = 0.003) than low risk patients. Among low risk patients, those with intermittent AF had similar TEE features to those with constant AF. CONCLUSIONS: TEE findings indicative of atrial stasis or thrombosis and of aortic atheroma were independently associated with high thromboembolic risk in patients with AF. The increased stroke risk associated with a history of hypertension in AF appears to be mediated primarily through left atrial stasis and thrombi. The presence of complex aortic plaque distinguished patients with AF at high risk from those at moderate risk of thromboembolism.
Aged↗
Angiosarcoma of the aorta: report of a case and review of the literature.
Primary malignant tumors of the thoracic and abdominal aortas are extremely rare. In most cases, a diagnosis is established either postmortem or after an emergency operation for embolic complications. We present the case of a thoracic aortic angiosarcoma in a 71-year-old man who initially was seen with peripheral embolization. The management of these tumors and the world literature are reviewed.
Aged↗
Valvular and coronary heart disease. When is it time for surgical referral?
Decisions about when to refer patients for cardiac surgery remain dynamic in the face of rapidly advancing technology. Coexisting health problems obviously play an important role, as do the natural history of the cardiovascular disorder, the indications for surgery, and the risks associated with the operative procedure. Nonetheless, many patients can be offered the possibility of improved cardiovascular function and survival through cardiac interventions.
Coronary Disease↗
Control of heart rate during transition from intravenous to oral diltiazem in atrial fibrillation or flutter.
We tested whether patients presenting with atrial fibrillation (AF) or flutter (AFl) with a rapid ventricular response could maintain control of heart rate while transferring from a bolus and continuous infusion of intravenous diltiazem to oral diltiazem. Forty patients with AF or AFI and sustained ventricular rate > or = 120 beats/min received intravenous diltiazem "bolus" (20 to 25 mg for 2 minutes) and "infusion" (5 to 15 mg/hour for 6 to 20 hours). Oral long-acting diltiazem (diltiazem CD 180, 300, or 360 mg/24 hours) was administered in patients in whom stable heart rate control was attained during constant infusion. Intravenous diltiazem infusion was discontinued 4 hours after the first oral dose, and patients were monitored during 48 subsequent hours of "transition" to oral therapy. Response to diltiazem was defined as heart rate <100 beats/min, > or = 20% decrease in heart rate from baseline, or conversion to sinus rhythm. Other rate control or antiarrhythmic medications were not allowed during the study period. Thirty-seven of 40 patients maintained heart rate control during the bolus, and 35 of the remaining 37 maintained control during the infusion of intravenous diltiazem. Of the 35 patients achieving heart rate control with intravenous diltiazem who entered the transition to oral therapy, 27 maintained heart rate control (response rate of 77%/, 95% confidence interval 63% to 91%). The median infusion rate of intravenous diltiazem was 10 mg/hour, and the median dose of oral diltiazem CD was 300 mg/day. Oral long-acting diltiazem was 77% effective in controlling ventricular response over 48 hours in patients with AF or AFl in whom ventricular response was initially controlled with intravenous diltiazem.
Administration, Oral↗
Fecal hemoglobin excretion in elderly patients with atrial fibrillation: combined aspirin and low-dose warfarin vs conventional warfarin therapy.
BACKGROUND: Antithrombotic prophylaxis using combined aspirin and low-dose warfarin is under evaluation in several clinical trials. However, therapy may result in increased gastrointestinal blood loss and clinical bleeding vs conventional single-agent antithrombotic therapy. METHODS: To assess differences in gastrointestinal blood loss, we measured quantitative fecal hemoglobin equivalents (HemoQuant, Mayo Medical Laboratory, Rochester, Minn) in 117 patients, mean age 71 years, 1 month after initiation of assigned therapy in the Stroke Prevention in Atrial Fibrillation III Study. Sixty-three of these patients who had characteristics for high risk of stroke were randomly assigned to conventional adjusted-dose warfarin therapy (international normalized ratio, 2.0 to 3.0) or low-dose combined therapy (warfarin [international normalization ratio,<1.5] plus 325 mg/d of enteric-coated aspirin). The remaining 54 patients with low risk of stroke received 325 mg/d of enteric-coated aspirin. RESULTS: Among the 63 at high risk of stroke, abnormal values (>2mg of hemoglobin per gram of stool) were detected in 11% and values greater than 4 mg of hemoglobin per gram of stool were found in 8%. Mean ( +/- SD) values were more for those randomly assigned to receive combined therapy (1.7 +/- 3.3 mg of hemoglobin per gram of stool vs adjusted-dose warfarin therapy, 1.0 +/- 1.9 mg/g; P=.003). The 54 nonrandomized patients with low risk of stroke receiving aspirin alone had a mean (+/- SD) HemoQuant value of 0.8 +/- 0.7mg of hemoglobin per gram of stool 1 month after entry in the study. CONCLUSIONS: Abnormal levels of fecal hemoglobin excretion were common in elderly patients with high risk of atrial fibrillation 1 month after randomization to prophylactic antithrombotic therapy. Combined warfarin and aspirin therapy was associated with greater fecal hemoglobin excretion than standard warfarin therapy, suggesting the potential for increased gastrointestinal hemorrhage.
Aged↗
F-amplitude, left atrial appendage velocity, and thromboembolic risk in nonrheumatic atrial fibrillation. Stroke Prevention in Atrial Fibrillation Investigators.
BACKGROUND: Reduced left atrial appendage velocity (LAAV) has been identified as a marker for thromboembolism in patients with atrial fibrillation. HYPOTHESIS: It was postulated that electrocardiographic (ECG) F-wave amplitude would correlate with LAAV, and inversely with the risk of thromboembolism in patients with atrial fibrillation. METHODS: In all, 53 patients with nonrheumatic (NRAF) and 7 patients with rheumatic (RAF) atrial fibrillation underwent assessment of maximum LAAV, which was correlated to the maximum ECG F-wave voltage from lead V1 (F(max)). In 450 NRAF patients on neither aspirin nor warfarin, the relationship between F(max) and thromboembolic risk was assessed over an average follow-up of 1.3 years. RESULTS: F(max) did not correlate with LAAV (r = 0.2, p = 0.07). Patients with intermittent atrial fibrillation (n = 123) had smaller F(max) amplitude than patients with constant atrial fibrillation (n = 327) (mean 0.73 vs. 0.88 mV-1, p = 0.001). F(max) amplitude was not related to a history of hypertension, systolic blood pressure, duration of NRAF, abnormal transthoracic echocardiographic left ventricular (LV) systolic function or left atrial (LA) diameter. There was a strong trend for increased LV mass being related to smaller F(max) amplitude after adjusting for body surface area (p = 0.06). F(max) amplitude was not correlated with risk of embolic events, including only those events presumed by a panel of case-blinded neurologists to be cardioembolic. CONCLUSIONS: F(max) amplitude in NRAF is smaller in patients with intermittent versus constant AF. It does not correlate with LAAV, LA size, increased LV mass, or systolic dysfunction, hypertension, or risk of embolism. Therefore, F(max) amplitude may not be used as a surrogate for LAAV, or as a measure of thromboembolic risk in NRAF.
Aged↗
Directional coronary atherectomy for coronary artery spasm refractory to medical therapy.
A patient with severe medically refractory coronary artery spasm was treated successfully with coronary atherectomy of a mild (40%) left anterior descending artery stenosis. Before the procedure, the patient was dependent on intravenous nitroglycerin because of daily episodes of angina with ST-segment elevation despite receiving multiple combinations of antianginal therapies. Clinical response to coronary atherectomy was prompt and dramatic.
Adult↗