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ABSTRACT: To examine further the relations of plasma von Willebrand factor (vWf, an index of endothelial damage and dysfunction) and soluble P-selectin (sP-sel, an index of platelet activation) concentrations to the presence and onset of clinical congestive heart failure (CHF) and the degree of left ventricular (LV) dysfunction in patients taking part in the SPAF (stroke prevention in atrial fibrillation) study.
Plasma concentrations of vWf and sP-sel were measured by enzyme linked immunosorbent assay (ELISA) in 1321 participants in the SPAF III study and related to the presence and onset of clinical CHF, as well as echocardiographic findings. Of the 1321 patients with atrial fibrillation (AF), 331 (25%) had a documented history of clinical heart failure, of which 168 cases were related to a new or recurrent episode of acute decompensated heart failure occurring within the preceding three months.
Mean plasma vWf was higher among patients with AF and CHF (154 (29) v 144 (31) IU/dl, p < 0.001), particularly those with acute or recent decompensated symptoms. Patients with severe LV dysfunction on two dimensional echocardiography and low fractional shortening also had significantly higher vWf concentrations than those with no LV dysfunction. CHF patients with clinical features--with (156 (28) IU/dl) and without (152 (31) IU/dl) LV dysfunction--also had higher mean vWf concentrations than patients with asymptomatic LV dysfunction (146 (31) IU/dl, p < 0.001). The presence of mitral regurgitation in CHF was associated with lower vWf concentrations. Plasma sP-sel concentrations were not affected by presence, onset, or severity of heart failure.
CHF may contribute to hypercoagulability and thrombotic risk in AF through increased endothelial damage and dysfunction. Patients with acute or recent decompensated features have the highest degree of endothelial damage and dysfunction. The presence of CHF clinical features was an important determinant of plasma vWf concentrations.
Heart (British Cardiac Society) 07/2005; 91(6):759-63. · 4.22 Impact Factor
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ABSTRACT: To quantitatively compare preferences for treatment between persons who enrolled in a randomized controlled trial (RCT) and those who were eligible but chose not to enrol.
Participants' thresholds for treatment were determined using a probability trade-off technique. Pertinent health states were described. If not taking Aspirin, the probabilities of stroke, myocardial infarction (MI), and major bleeding were given. Given the risks and benefits of chronic Aspirin therapy, a systematic approach was used to determine patients' thresholds for treatment (the smallest reduction in stroke or MI risk of which patients were willing to take Aspirin).
Of 54 participants, 42 enrolled in the RCT, and 12 did not. Compared with persons who enrolled, those who did not enrol required significantly greater increments in treatment benefit to be willing to take Aspirin.
This study shows differences in thresholds for treatment between persons who enrolled in a clinical trial and those who chose not to. Such attitudinal differences may lead to difficulty in the interpretation of clinical trials, especially those using health-related quality-of-life measures. More studies are needed to determine whether the attitudinal differences affect the generalization of results from clinical trials.
Annals (Royal College of Physicians and Surgeons of Canada) 09/2001; 34(5):292-6.
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Stroke 04/2001; 32(3):803-8. · 5.73 Impact Factor
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ABSTRACT: To characterize the rates of recurrent intracranial hemorrhage (ICH), ischemic stroke, and death in survivors of primary ICH.
Systematic review of studies reporting recurrent stroke in survivors of primary ICH, identified at index ICH and followed forward. Studies were identified by computerized search of the literature and review of reference lists.
Ten studies published between 1982 and 2000 reporting 1,880 survivors of ICH, followed for a total of 6,326 patient-years (mean follow-up, 3.4 patient-years), were included. The aggregate rate of all stroke from five studies was 4.3% per patient-year (95% CI, 3.5% to 5.4%). The rate in the three population-based studies was higher than in the two hospital-based studies, 6.2% versus 4.0% per patient-year (p = 0.04). About three fourths of recurrent strokes were ICH. Considering all 10 studies, a total of 147 patients had a recurrent ICH, an aggregate rate of 2.3% per patient-year (95% CI, 1.9% to 2.7%). Based on data from four studies, patients with a primary lobar ICH had a higher rate of recurrent ICH than those with a deep, hemispheric ICH (4.4% versus 2.1% per patient-year; p = 0.002). The aggregate rates of subsequent ischemic stroke and mortality were 1.1% per patient-year (95% CI, 0.8% to 1.7%) and 8.8% per patient-year (95% CI, 5.2% to 11.0%).
Recurrent stroke among survivors of primary ICH occurs at a rate of about 4% per patient-year, and most are recurrent ICH. Survivors of ICH have a higher risk of recurrent ICH than of ischemic stroke, and this has implications for the use of antithrombotic agents in these patients.
Neurology 04/2001; 56(6):773-7. · 8.31 Impact Factor
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ABSTRACT: 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.
Journal of General Internal Medicine 11/2000; 15(10):723-30. · 2.83 Impact Factor
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ABSTRACT: The risk of ischemic stroke varies widely among patients with nonvalvular atrial fibrillation, influencing the choice of prophylactic antithrombotic therapy. We assessed three schemes for stroke risk stratification in these patients who were treated with aspirin and who did not have prior cerebral ischemia.
Criteria from three schemes of risk stratification were applied to a longitudinally observed cohort of patients with atrial fibrillation who did not have prior cerebral ischemia and who were treated with aspirin alone or aspirin combined with low, ineffective doses of warfarin in a multicenter clinical trial. The ability of the schemes to identify patients at high (>/=6%), low (</=2%), and intermediate annual risks of ischemic stroke was assessed.
During a mean follow-up of 1.8 years, 48 ischemic strokes occurred among 1,073 patients with atrial fibrillation who were taking aspirin (rate = 2.5 per 100 person-years). Each of the three schemes predicted stroke and disabling stroke, and successfully identified patients at low risk (observed stroke rates of 0.3 to 1.1 per 100 person-years), although the fractions of the cohort that were categorized as low risk varied from 14% to 45%. The observed rates of ischemic stroke among patients categorized as high risk ranged from 3.5 to 7.2 per 100 person-years among the stratification schemes. Two schemes considered all patients >75 years old as high risk (observed stroke rate 4.2 per 100 person-years), while the remaining scheme classified one third of patients in this age group as low risk (observed stroke rate 0.6 per 100 person-years).
When tested in a large cohort of patients with atrial fibrillation who were treated with aspirin, available risk-stratification schemes successfully identified patients with low rates of ischemic stroke, but less consistently identified high-risk patients.
The American Journal of Medicine 07/2000; 109(1):45-51. · 5.43 Impact Factor
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ABSTRACT: Aspirin therapy reduces stroke by about 25% for persons with atherosclerotic vascular disease, but the effect in those without clinically apparent vascular disease is distinctly different.
To define the effect of aspirin use on stroke and other major vascular events when given for primary prevention to persons without clinically recognized vascular disease.
Systematic review of randomized clinical trials and large prospective observational cohort studies examining the relation between aspirin use and stroke in persons at low intrinsic risk. Studies were identified by a computerized search of the English-language literature.
Five randomized trials of primary prevention included 52 251 participants randomized to aspirin doses ranging from 75 to 650 mg/d; the mean overall stroke rate was 0.3% per year during an average follow-up of 4.6 years. Meta-analysis revealed no significant effect on stroke (relative risk = 1.08; 95% confidence interval, 0.95-1.24) contrasting with a decrease in myocardial infarction (relative risk = 0.74; 95% confidence interval, 0.68-0.82). The lack of reduction of stroke by aspirin for primary prevention was incompatible with its protective effect against stroke in patients with manifest vascular disease (P = .001). Intracranial hemorrhage was increased by the regular use of aspirin (relative risk = 1.35; P = .03), similarly for both primary and secondary prevention. In 4 large observational studies, self-selected use of aspirin was consistently associated with higher rates of stroke.
The effect of aspirin therapy on stroke differs between individuals based on the presence or absence of overt vascular disease, in contrast with the consistent reduction in myocardial infarction by aspirin therapy observed in all populations. We hypothesize that the effect of aspirin therapy on stroke for persons with major risk factors for vascular disease may be intermediate between a substantial decrease for those with manifest vascular disease and a possible small increase for healthy persons due to accentuated intracranial hemorrhage. When aspirin is given for primary prevention of vascular events, available data support using 75 to 81 mg/d.
Archives of Neurology 04/2000; 57(3):326-32. · 7.58 Impact Factor
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R G Hart
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ABSTRACT: Nonvalvular atrial fibrillation (AF) is an independent risk factor for stroke. The overall risk of ischemic stroke in patients experiencing AF without prior stroke averages about 5% per year, but varies depending on the presence of coexistent thromboembolic risk factors. Patients with AF with low (about 1% per year), moderate (2%-4% per year) and high (> or = 6% per year) stroke risks have been identified, but the generalizability of available risk stratification schemes to clinical practice has not been defined. Adjusted-dose warfarin (target International Normalized Ratio 2-3) is highly efficacious for prevention of stroke in patients with AF (about 60% reduction) and is relatively safe for selected patients, if carefully monitored. Aspirin has a modest effect on reducing stroke (about 20% reduction). The role of transesophageal echocardiography is routine management of AF remains unsettled. Warfarin therapy should be considered for patients with AF predicted to have a high risk of stroke and who can safely receive it. Aspirin may be indicated for patients with AF at low risk for stroke and for those who cannot safely receive adjusted-dose warfarin. For those with moderate stroke risk, individual bleeding risks during anticoagulation and patient preferences should guide antithrombotic therapy.
Current Cardiology Reports 02/2000; 2(1):51-5.
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ABSTRACT: This study was performed to characterize the risk of stroke in elderly patients with recurrent intermittent atrial fibrillation (AF).
Although intermittent AF is common, relatively little is known about the attendant risk of stroke.
A longitudinal cohort study was performed comparing 460 participants with intermittent AF with 1,552 with sustained AF treated with aspirin in the Stroke Prevention in Atrial Fibrillation studies and followed for a mean of two years. Independent risk factors for ischemic stroke were identified by multivariate analysis.
Patients with intermittent AF were, on average, younger (66 vs. 70 years, p < 0.001), were more often women (37% vs. 26% p < 0.001) and less often had heart failure (11% vs. 21%, p < 0.001) than those with sustained AF. The annualized rate of ischemic stroke was similar for those with intermittent (3.2%) and sustained AF (3.3%). In patients with intermittent AF, independent predictors of ischemic stroke were advancing age (relative risk [RR] = 2.1 per decade, p < 0.001), hypertension (RR = 3.4, p = 0.003) and prior stroke (RR = 4.1, p = 0.01). Of those with intermittent AF predicted to be high risk (24%), the observed stroke rate was 7.8% per year (95% confidence interval 4.5 to 14).
In this large cohort of AF patients given aspirin, those with intermittent AF had stroke rates similar to patients with sustained AF and similar stroke risk factors. Many elderly patients with recurrent intermittent AF have substantial rates of stroke and likely benefit from anticoagulation. High-risk patients with intermittent AF can be identified using the same clinical criteria that apply to patients with sustained AF.
Journal of the American College of Cardiology 02/2000; 35(1):183-7. · 14.16 Impact Factor
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ABSTRACT: Stroke associated with atrial fibrillation (AF) is mainly due to embolism of thrombus formed during stasis of blood in the left atrial appendage (LAA). Pathophysiologic correlates of appendage flow velocity as assessed by transesophageal echocardiography (TEE) in patients with AF have not been defined. To evaluate the hypothesis that reduced velocity is associated with spontaneous echocardiographic contrast and thrombus in the LAA and with clinical embolic events, we measured LAA flow velocity by TEE in 721 patients with nonvalvular AF entering the Stroke Prevention in Atrial Fibrillation (SPAF-III) study. Patient features, TEE findings, and subsequent cardioembolic events were correlated with velocity by multivariate analysis. Patients in AF during TEE displayed lower peak antegrade (emptying) flow velocity (Anu(p)) than those with intermittent AF in sinus rhythm during TEE (33 cm/s vs 61 cm/s, respectively, P <.0001). Anu(p) < 20 cm/s was associated with dense spontaneous echocardiographic contrast (P <.001), appendage thrombus (P <.01), and subsequent cardioembolic events (P <.01). Independent predictors of Anu(p) < 20 cm/s included age (P =.009), systolic blood pressure (P <.001), sustained AF (P =.01), ischemic heart disease (P =.01), and left atrial area (P =.04). Multivariate analysis found both Anu(p) <20 cm/s (relative risk 2.6, P =.02) and clinical risk factors (relative risk 3.3, P =.002) independently associated with LAA thrombus. LAA Anu(p) is reduced in AF and associated with spontaneous echocardiographic contrast, appendage thrombus, and cardioembolic stroke. Systolic hypertension and aortic atherosclerosis, independent clinical predictors of stroke in patients with AF, also correlated with LAA Anu(p). Our results support the role of reduced LAA Anu(p) in the generation of stasis, thrombus formation, and embolism in patients with AF, although other mechanisms also contribute to stroke.
Journal of the American Society of Echocardiography 01/2000; 12(12):1080-7. · 3.71 Impact Factor
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Stroke 12/1999; 30(11):2502-11. · 5.73 Impact Factor
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ABSTRACT: Markers of thrombin generation and platelet activation are often elevated in patients with nonvalvular atrial fibrillation, but it is unclear whether such markers usefully predict stroke. Therefore, we undertook the present study to assess the relationship between prothrombin fragment F1.2 (F1.2), beta-thromboglobulin (BTG), fibrinogen, and the factor V Leiden mutation with stroke in atrial fibrillation.
Specimens were obtained from 1531 participants in the Stroke Prevention in Atrial Fibrillation III study. The results were correlated with patient features, antithrombotic therapy, and subsequent thromboembolism (ischemic stroke and systemic embolism) by multivariate analysis.
Increased F1.2 levels were associated with age (P<0.001), female sex (P<0.001), systolic blood pressure (P=0.006), and heart failure (P=0.001). F1.2 were not affected by aspirin use and were not associated with thromboembolism after adjustment for age (P=0. 18). BTG levels were higher with advanced age (P=0.006), coronary artery disease (P=0.05), carotid disease (P=0.005), and heart failure (P<0.001), lower in regular alcohol users (P=0.05), and not significantly associated with thromboembolism. Fibrinogen levels were not significantly related to thromboembolism but were associated with elevated BTG levels (P<0.001). The factor V Leiden mutation was not associated with thromboembolism (relative risk 0.5, 95% CI 0.1 to 3.8).
Elevated F1.2 levels were associated with clinical risk factors for stroke in atrial fibrillation, whereas increased BTG levels were linked to manifestations of atherosclerosis. In this large cohort of patients with atrial fibrillation who were receiving aspirin, F1.2, BTG, fibrinogen, and factor V Leiden were not independent, clinically useful predictors of stroke.
Stroke 12/1999; 30(12):2547-53. · 5.73 Impact Factor
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ABSTRACT: Atrial fibrillation is associated with a sixfold increased risk for stroke. More than a dozen published randomized trials of anticoagulants or antiplatelet agents for stroke prevention provide solid evidence on which to base antithrombotic prophylaxis. Adjusted-dose warfarin reduces risk for stroke by about 60% compared with placebo, aspirin reduces this risk (primarily for nondisabling stroke) by about 20% compared with placebo, and warfarin reduces it by about 40% compared with aspirin. Warfarin provides maximal protection against stroke at international normalized ratios of 2.0 to 3.0. Risk stratification of patients with atrial fibrillation identifies those who potentially benefit most or least from anticoagulation; this is important because a substantial percentage of patients with atrial fibrillation have relatively low rates of stroke if they are given aspirin. Many elderly patients with recurrent intermittent atrial fibrillation experience high rates of stroke and benefit from anticoagulation. The value of precordial or transesophageal echocardiography in addition to clinical risk stratifiers for stratifying stroke risk is controversial. Altered hemostasis favoring thrombosis may contribute to formation of atrial appendage thrombus, but these conditions remain ill defined. The past decade has brought unprecedented progress toward understanding thromboembolism in patients with atrial fibrillation and has changed the clinical perspective of a prevalent cardiac arrhythmia into an important opportunity for stroke prevention. Making the most of this promise calls for appreciation of the epidemiology of atrial fibrillation and the concept of risk specificity in the face of diverse therapeutic options.
Annals of internal medicine 12/1999; 131(9):688-95. · 16.73 Impact Factor
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ABSTRACT: To characterize the efficacy and safety of anticoagulants and antiplatelet agents for prevention of stroke in patients with atrial fibrillation.
Randomized trials identified by using the search strategy developed by the Cochrane Collaboration Stroke Review Group.
All published randomized trials testing antithrombotic agents to prevent stroke in patients with atrial fibrillation.
Data on interventions, number of participants, duration of exposure and occurrence of all stroke (ischemic and hemorrhagic), major extracranial bleeding, and death were extracted independently by two investigators.
Sixteen trials included a total of 9874 participants (mean follow-up, 1.7 years). Adjusted-dose warfarin (six trials, 2900 participants) reduced stroke by 62% (95% CI, 48% to 72%); absolute risk reductions were 2.7% per year for primary prevention and 8.4% per year for secondary prevention. Major extracranial bleeding was increased by warfarin therapy (absolute risk increase, 0.3% per year). Aspirin (six trials, 3119 participants) reduced stroke by 22% (CI, 2% to 38%); absolute risk reductions were 1.5% per year for primary prevention and 2.5% per year for secondary prevention. Adjusted-dose warfarin (five trials, 2837 participants) was more efficacious than aspirin (relative risk reduction, 36% [CI, 14% to 52%]). Other randomized comparisons yielded inconclusive results.
Adjusted-dose warfarin and aspirin reduce stroke in patients with atrial fibrillation, and warfarin is substantially more efficacious than aspirin. The benefit of antithrombotic therapy was not offset by the occurrence of major hemorrhage among participants in randomized trials. Judicious use of antithrombotic therapy, tailored according to the inherent risk for stroke, importantly reduces stroke in patients with atrial fibrillation.
Annals of internal medicine 11/1999; 131(7):492-501. · 16.73 Impact Factor
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ABSTRACT: Decision aids are tools designed to help patients participate in the clinical decision-making process.
To determine whether use of an audiobooklet (AB) decision aid explaining the results of a clinical trial affected the decision-making process of study participants.
Randomized controlled trial conducted from May 1997 to April 1998.
Fourteen centers that participated in the Stroke Prevention in Atrial Fibrillation (SPAF) III trial.
A total of 287 patients from the SPAF III aspirin cohort study, in which patients with atrial fibrillation and a relatively low risk of stroke received 325 mg/d of aspirin and were followed up for a mean of 2 years.
At the end of SPAF III, participants were randomized to be informed of the study results with usual care plus use of an AB (AB group) vs usual care alone (control group). The AB included pertinent information to help patients decide whether to continue taking aspirin or switch to warfarin.
Patients' ability to make choices regarding antithrombotic therapy, and 6-month adherence to these decisions. Their knowledge, expectations, decisional conflict (the amount of uncertainty about the course of action to take), and satisfaction with the decision-making process were also measured.
More patients in the AB group made a choice about antithrombotic therapy than in the control group (99% vs 94%; P = .02). Patients in the AB group were more knowledgeable and had more realistic expectations about the risk of stroke and hemorrhage (in the AB group, 53%-80% correctly estimated different risks; in the control group, 16%-28% gave correct estimates). Decisional conflict and satisfaction were similar for the 2 groups. After 6 months, a similar percentage of patients were still taking their initial choice of antithrombotic therapy (95% vs 93%; P = .44).
For patients with atrial fibrillation who had participated in a major clinical trial, the use of an AB decision aid improved their understanding of the benefits and risks associated with different treatment options and helped them make definitive choices about which therapy to take. Further studies are necessary to evaluate the acceptability and impact of decision aids in other clinical settings.
JAMA The Journal of the American Medical Association 09/1999; 282(8):737-43. · 30.03 Impact Factor
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ABSTRACT: Nonvalvular atrial fibrillation (AF) is a strong, independent risk factor for stroke, but the absolute rate of stroke varies widely among AF patients, importantly influencing the potential benefit of antithrombotic prophylaxis. We explore factors associated with ischemic stroke in AF patients taking aspirin.
We performed multivariate logistic regression analysis of 2012 participants given aspirin alone or in combination with low, inefficacious doses of warfarin in the Stroke Prevention in Atrial Fibrillation I-III trials followed for a mean of 2.0 years, during which 130 ischemic strokes were observed.
Age (relative risk [RR]=1.8 per decade, P<0.001), female sex (RR=1.6, P=0.01), history of hypertension (RR=2.0, P<0.001), systolic blood pressure >160 mm Hg (RR=2.3, P<0.001), and prior stroke or transient ischemic attack (RR=2.9, P<0.001) were independently associated with increased stroke risk. Regular consumption of >/=14 alcohol-containing drinks per week was associated with reduced stroke risk (adjusted RR=0.4, P=0.04). Among SPAF III participants, estrogen hormone replacement therapy was associated with a higher risk of ischemic stroke (adjusted RR=3.2, P=0.007). With the use of these variables, a risk stratification scheme for primary prevention separated participants into those with high (7.1%/y, 22% of the cohort), moderate (2.6%/y, 37% of the cohort), and low (0.9%/y, 41% of the cohort) rates of stroke. Ischemic strokes in low-risk participants were less often disabling (P<0.001).
Patients with AF who have high and low rates of stroke during treatment with aspirin can be identified. However, validation of our risk stratification scheme is necessary before it can be applied with confidence to clinical management. Postmenopausal estrogen replacement therapy and moderate alcohol consumption may additionally modify the risk of stroke in AF, but these findings require confirmation.
Stroke 07/1999; 30(6):1223-9. · 5.73 Impact Factor
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ABSTRACT: Optimal treatment of the patient who has sustained an acute ischemic stroke requires rapid assessment and early intervention. The leisurely approach to acute stroke management sometimes taken in the past should be replaced by an approach that treats stroke as a true medical emergency. Thrombolysis with tissue plasminogen activator has been labeled for the treatment of acute ischemic stroke, but it must be given within three hours of stroke onset. However, fibrinolytic therapy can be given safely to only a fraction of patients with acute stroke, and more broadly applicable therapies are needed. Recent evidence does not support the routine use of heparin in patients with acute stroke, and early use of aspirin offers only modest benefit. Neuroprotective therapies designed to interfere with cytotoxic events initiated by ischemia are undergoing clinical trials that should be completed within the next year. At present, only tissue plasminogen activator has been labeled for acute stroke treatment; however, other agents are on the horizon, and much can be done supportively to improve neurologic outcome. Because of the unique susceptibility of neurons to ischemia, minutes count. Thus, hospitals providing care for patients with acute stroke should organize clinical protocols and pathways for effective implementation of therapies.
American family physician 06/1999; 59(10):2828-34 concl. · 1.70 Impact Factor
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ABSTRACT: Clinical trials conducted during the past five years have yielded important results that have allowed us to refine our approach to stroke prevention. Treatment of isolated systolic hypertension prevents stroke and is generally well tolerated. New antiplatelet agents (clopidogrel and the combination of aspirin plus high-dose dipyridamole) have been shown to be effective in reducing vascular events in survivors of ischemic stroke, although aspirin remains the mainstay of antiplatelet therapy for stroke prevention. Several clinical trials support the benefit of lipid-lowering agents ("statins") in reducing stroke. Warfarin reduces stroke for high-risk patients with atrial fibrillation. Carotid endarterectomy is highly beneficial in reducing stroke for symptomatic patients with severe carotid stenosis (greater than 70 percent), but the benefit is less for symptomatic patients with a moderate degree of stenosis (50 to 69 percent) and for patients with asymptomatic carotid disease of any severity.
American family physician 06/1999; 59(9):2475-82, 2485. · 1.70 Impact Factor
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ABSTRACT: 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.
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.
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%).
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.
Stroke 04/1999; 30(4):834-40. · 5.73 Impact Factor
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H C Dittrich,
L A Pearce,
R W Asinger,
R McBride,
R Webel,
M Zabalgoitia,
G D Pennock,
R E Safford,
R M Rothbart,
J L Halperin, R G Hart
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ABSTRACT: The left atrium (LA) is usually enlarged in patients with nonvalvular atrial fibrillation (AF), but factors associated with LA diameter are incompletely defined.
This transthoracic echocardiographic cohort study includes 3465 participants with nonvalvular AF in 3 multicenter clinical trials. LA diameter determined by M-mode echocardiography was correlated with clinical and echocardiographic features by cross-sectional multivariate regression analyses. The mean LA diameter was 47 +/- 8 mm, on average 6 mm larger in those with AF at the time of echocardiography than in those with sinus rhythm (48 vs 42 mm, P <. 001). Patient age and body weight were independently predictive of LA diameter (P <.0001), but sex, body surface area, and body mass index were not. The estimated independent contribution of atrial rhythm to LA diameter was approximately 2.5 mm. Prolonged duration of AF, left ventricular dilatation and increased muscle mass, mitral regurgitation, annular calcification, and hypertension were additional independent predictors of LA diameter.
Multiple factors appear to contribute to LA enlargement in patients with nonvalvular AF, including the presence and persistence of the dysrhythmia.
American Heart Journal 03/1999; 137(3):494-9. · 4.65 Impact Factor
