Association of extracranial carotid arterial disease and chronic atrial fibrillation with the incidence of new thromboembolic stroke in 1,846 older persons

Co-prevalence of carotid stenosis and coronary artery disease in Chinese patients with paroxysmal atrial fibrillation

OBJECTIVES

To investigate the co-prevalence of coronary artery disease (CAD) and carotid stenosis and to determine predictors related to CAD in Chinese patients with paroxysmal atrial fibrillation (PAF), presenting without previously diagnosed or excluded CAD.

METHODS

Consecutive patients with PAF were recruited. CAD was evaluated using multislice computed tomography. Intima-media thickness (IMT) of the carotid artery was evaluated via ultrasonography.

RESULTS

A total of 62/192 (32.3%) patients had CAD. Carotid stenosis was observed in 26/192 (13.5%) patients. The co-prevalence of carotid stenosis and CAD was 7.8% (15/192). The prevalence of carotid stenosis was 8.5%, 16.7%, 25.0%, and 41.7% in patients with zero-, one-, two-, and three-vessel CAD, respectively. Diabetes mellitus, maximal IMT and hyperhomocysteinaemia were independently related to the presence of CAD.

CONCLUSIONS

The prevalence of CAD was 32.3% in Chinese patients with PAF. Carotid stenosis and CAD co-occurred in 7.8% of patients, and the prevalence of carotid stenosis correlated with the severity of CAD. Screening of carotid stenosis is recommended, especially in patients with PAF and multivessel CAD.

Atrial Fibrillation: The New Epidemic of the Ageing World

The prevalence of atrial fibrillation (AF) increases with age. As the population ages, the burden of AF increases. AF is associated with an increased incidence of mortality, stroke, and coronary events compared to sinus rhythm. AF with a rapid ventricular rate may cause a tachycardia-related cardiomyopathy. Immediate direct-current (DC) cardioversion should be performed in patients with AF and acute myocardial infarction, chest pain due to myocardial ischemia, hypotension, severe heart failure, or syncope. Intravenous beta blockers, diltiazem, or verapamil may be administered to reduce immediately a very rapid ventricular rate in AF. An oral beta blocker, verapamil, or diltiazem should be used in persons with AF if a fast ventricular rate occurs at rest or during exercise despite digoxin. Amiodarone may be used in selected patients with symptomatic life-threatening AF refractory to other drugs. Digoxin should not be used to treat patients with paroxysmal AF. Nondrug therapies should be performed in patients with symptomatic AF in whom a rapid ventricular rate cannot be slowed by drugs. Paroxysmal AF associated with the tachycardia-bradycardia syndrome should be treated with a permanent pacemaker in combination with drugs. A permanent pacemaker should be implanted in patients with AF and symptoms such as dizziness or syncope associated with ventricular pauses greater than 3 seconds which are not drug-induced. Elective DC cardioversion has a higher success rate and a lower incidence of cardiac adverse effects than does medical cardioversion in converting AF to sinus rhythm. Unless transesophageal echocardiography has shown no thrombus in the left atrial appendage before cardioversion, oral warfarin should be given for 3 weeks before elective DC or drug cardioversion of AF and continued for at least 4 weeks after maintenance of sinus rhythm. Many cardiologists prefer, especially in elderly patients , ventricular rate control plus warfarin rather than maintaining sinus rhythm with antiarrhythmic drugs. Patients with chronic or paroxysmal AF at high risk for stroke should be treated with long-term warfarin to achieve an International Normalized Ratio of 2.0 to 3.0. Patients with AF at low risk for stroke or with contraindications to warfarin should be treated with aspirin 325 mg daily.

Etiology, pathophysiology, and treatment of atrial fibrillation: part 1

Atrial fibrillation (AF) is associated with a higher incidence of mortality, stroke, and coronary events than is sinus rhythm. AF with a rapid ventricular rate may cause a tachycardia-related cardiomyopathy. Immediate direct-current cardioversion should be performed in patients with AF and acute myocardial infarction, chest pain due to myocardial ischemia, hypotension, severe heart failure, or syncope. Intravenous beta blockers, verapamil, or diltiazem may be given to immediately slow a very rapid ventricular rate in AF. An oral beta blocker, verapamil, or diltiazem should be used in persons with AF if a fast ventricular rate occurs at rest or during exercise despite digoxin. Amiodarone may be used in selected patients with symptomatic life-threatening AF refractory to other drugs. Digoxin should not be used to treat patients with paroxysmal AF. Nonpharmacologic therapies should be used in patients with symptomatic AF in whom a rapid ventricular rate cannot be slowed by drugs. This is part 1 of a 2-part review of the etiology, pathophysiology, and treatment of atrial fibrillation. The second part will be published in the subsequent issue of Cardiology in Review.

[Age, an independent risk factor for thrombosis. Epidemiologic data]

The incidence of thrombosis--arterial and venous--increases with age. This is the case for atheromatous diseases, atrial fibrillation and even venous thromboembolic disease. Ischemic heart disease is the most common cause of death in the elderly. Atrial fibrillation, an independent risk factor for cerebral vascular accidents, affects around 10% of persons older than 80 years. The incidence of venous thromboembolic disease increases with age, reaching 12.5 per 1000 people older than 75 years, compared with 5 per 1000 aged 60-75 and 2.5 per 1000 aged 40-59. Elderly persons often have two or more cardiovascular or venous thromboembolic risk factors and thus a still higher risk of thrombotic events. Their risk of thrombosis justifies the systematic search for acquired risk factors to assess the level of risk and take appropriate prevention measures.

Is cardiovascular reactivity associated with atherosclerosis among hypertensives?

Exaggerated cardiovascular reactivity to behavioral challenges among otherwise healthy individuals has been associated with carotid atherosclerosis. We evaluated whether a similar relationship exists among hypertensives, who are at a heightened atherosclerotic risk. Untreated, hypertensive men (n=251; age range, 40 to 70 years; 197 white, 54 black) completed a standardized battery of behavioral challenges while their blood pressure responses to the battery were measured. Mean and maximum carotid intima-media thickness and the occurrence of carotid plaques were subsequently determined using B-mode ultrasonography. Although greater systolic and diastolic responses to the battery were associated with greater mean and maximum intima-media thickness in univariate analyses (P<0.01), only diastolic reactivity showed a unique association with mean and maximum carotid intima-media thickness after multivariate adjustment for age, race, socioeconomic status, smoking and alcohol use, body mass index, lipid profile, glucose and insulin concentrations, and resting blood pressure (P<0.05). Carotid plaque occurrence was associated with greater systolic reactivity (P=0.05) and was marginally associated with greater diastolic reactivity (P=0.07) in univariate analyses, but neither systolic nor diastolic reactivity was uniquely associated with the presence of carotid plaques after multivariate risk-factor adjustment. Among hypertensives, exaggerated behaviorally evoked cardiovascular reactivity appears to be uniquely associated with greater carotid intima-media thickness but not with carotid plaque occurrence.

Greater intima-media thickness in the carotid bulb is associated with reduced baroreflex sensitivity

The aim of this study was to evaluate the association between resting baroreflex sensitivity (BRS) and carotid intima-media thickness (IMT), a putative marker of subclinical atherosclerosis. Participants were 64 men and 18 women (median age, 57 years; range, 40 to 70 years), who did not have a previous history of coronary artery disease or treatment for hypertension. Resting BRS was measured during a 9-min baseline period using the noninvasive sequence technique; carotid IMT was subsequently determined using ultrasonography. Hierarchical multiple regression analyses showed that greater IMT in the carotid bulb (an area with a high density of baroreceptors) was associated with reduced BRS. These findings remained after adjusting BRS for resting mean arterial pressure, age, body mass index, gender, and smoking history, R2 = 0.06, P = .03. In contrast, IMT in the common and internal carotid regions (areas with presumably lower baroreceptor densities) did not account for a significant proportion of the variance in BRS. These results suggest that subclinical atherosclerosis, specifically in a region with high baroreceptor density, is associated with a reduced sensitivity of the baroreflex.

Management of the older person with atrial fibrillation

Atrial fibrillation (AF) is associated with a higher incidence of mortality, stroke, and coronary events than is sinus rhythm. AF with a rapid ventricular rate may cause a tachycardia-related cardiomyopathy. Immediate direct-current (DC) cardioversion should be performed in patients with AF and acute myocardial infarction, chest pain due to myocardial ischemia, hypotension, severe heart failure, or syncope. Intravenous beta blockers, verapamil, or diltiazem may be given to slow immediately a very rapid ventricular rate in AF. An oral beta blocker, verapamil, or diltiazem should be used in persons with AF if a fast ventricular rate occurs at rest or during exercise despite digoxin. Amiodarone may be used in selected patients with symptomatic life-threatening AF refractory to other drugs. Nondrug therapies should be performed in patients with symptomatic AF in whom a rapid ventricular rate cannot be slowed by drugs. Paroxysmal AF associated with the tachycardia-bradycardia syndrome should be treated with a permanent pacemaker in combination with drugs. A permanent pacemaker should be implanted in patients with AF and with symptoms such as dizziness or syncope associated with ventricular pauses greater than 3 seconds that are not drug-induced. Elective DC cardioversion has a higher success rate and a lower incidence of cardiac adverse effects than does medical cardioversion in converting AF to sinus rhythm. Unless transesophageal echocardiography has shown no thrombus in the left atrial appendage before cardioversion, oral warfarin should be given for 3 weeks before elective DC or drug cardioversion of AF and should be continued for at least 4 weeks after maintenance of sinus rhythm. Many cardiologists prefer, especially in older persons, ventricular rate control plus warfarin rather than maintaining sinus rhythm with antiarrhythmic drugs. Digoxin should not be used to treat patients with paroxysmal AF. Patients with chronic or paroxysmal AF at high risk for stroke should be treated with long-term warfarin to achieve an International Normalized Ratio of 2.0 to 3.0. Patients with AF at low risk for stroke or with contraindications to warfarin should receive 325 mg of aspirin daily.

Atrial fibrillation

The prevalence and incidence of atrial fibrillation increase with age. Atrial fibrillation is associated with a higher incidence of coronary events, stroke, and mortality than sinus rhythm. A fast ventricular rate associated with atrial fibrillation may cause tachycardia-related cardiomyopathy. Management of atrial fibrillation includes treatment of underlying causes and precipitating factors. Immediate direct-current cardioversion should be performed in persons with atrial fibrillation associated with acute myocardial infarction, chest pain due to myocardial ischemia, hypotension, severe heart failure, or syncope. Intravenous beta-blockers, verapamil, or diltiazem may be used to immediately slow a fast ventricular rate associated with atrial fibrillation. An oral beta-blocker, verapamil, or diltiazem should be given to persons with atrial fibrillation if a rapid ventricular rate occurs a rest or during exercise despite digoxin. Amiodarone may be used in selected persons with symptomatic life-threatening atrial fibrillation refractory to other drug therapy. Nondrug therapies should be performed in persons with symptomatic atrial fibrillation in whom a rapid ventricular rate cannot be slowed by drug therapy. Paroxysmal atrial fibrillation associated with the tachycardia-bradycardia syndrome should be managed with a permanent pacemaker in combination with drugs. A permanent pacemaker should be implanted in persons with atrial fibrillation in whom symptoms such as dizziness or syncope associated with non-drug-induced ventricular pauses longer than 3 seconds develop. Elective direct-current cardioversion has a higher success rate and a lower incidence of cardiac adverse effects than medical cardioversion in converting atrial fibrillation to sinus rhythm. Unless transesophageal echocardiography shows no thrombus in the left atrial appendage before cardioversion, oral warfarin should be given for 3 weeks before elective direct-current or drug cardioversion of atrial fibrillation and continued for at least 4 weeks after maintenance of sinus rhythm. Many cardiologists prefer the treatment strategy of ventricular rate control plus warfarin rather than to maintain sinus rhythm with antiarrhythmic drugs, especially in older patients. Digoxin should not be used in persons with paroxysmal atrial fibrillation. Patients with chronic or paroxysmal atrial fibrillation who are at high risk for stroke should be treated with long-term warfarin to achieve an International Normalized Ratio (INR) of 2.0 to 3.0. Persons with atrial fibrillation who are at low risk for stroke or who have contraindications to warfarin should receive 325 mg aspirin daily.

Management of the older person with atrial fibrillation

OBJECTIVE

To review the management of the older person with atrial fibrillation (AF).

DATA SOURCES

A computer-assisted search of the English language literature (MEDLINE) database followed by a manual search of the bibliographies of pertinent articles.

STUDY SELECTION

Studies on the management of persons with AF were screened for review. Studies of persons older than age 60 and recent studies were emphasized.

DATA EXTRACTION

Pertinent data were extracted from the reviewed articles. Emphasis was placed on studies involving older persons. Relevant articles were reviewed in depth.

DATA SYNTHESIS

Available data about the management of persons with paroxysmal or chronic AF were summarized

CONCLUSIONS

Management of AF includes treatment of the underlying disease and precipitating factors. Immediate direct-current cardioversion should be performed in persons with AF associated with an acute myocardial infarction, chest pain caused by myocardial ischemia, hypotension, severe heart failure, or syncope. Intravenous verapamil, diltiazem, or beta-blockers should be used to slow a very rapid ventricular rate associated with AF immediately. Oral verapamil, diltiazem, or a beta-blocker should be given if a rapid ventricular rate occurs at rest or during exercise despite digoxin. Amiodarone may be used in selected persons with symptomatic life-threatening AF refractory to other drug therapy. Nondrug therapies should be performed in persons with symptomatic AF in whom a rapid ventricular rate cannot be slowed by drug therapy. Paroxysmal AF associated with the tachycardia-bradycardia syndrome should be treated with a permanent pacemaker in combination with drugs. A permanent pacemaker should be implanted in persons with AF who develop cerebral symptoms such as dizziness or syncope associated with ventricular pauses greater than 3 seconds that are not drug-induced. Elective cardioversion of AF should not be performed in asymptomatic older persons with chronic AF. Unless transesophageal echocardiography has shown no thrombus in the left atrial appendage before cardioversion, oral warfarin should be given for 3 weeks before elective direct-current or drug cardioversion of AF and continued for at least 4 weeks after maintenance of sinus rhythm. Many cardiologists prefer the treatment strategy, especially in older persons, of ventricular rate control plus warfarin rather than maintaining sinus rhythm with antiarrhythmic drugs. Digoxin should be avoided in persons with sinus rhythm who have a history of paroxysmal AF. Older persons with chronic or paroxysmal AF who are at high risk for stroke or who have a history of hypertension and no contraindications to warfarin should receive long-term warfarin to achieve an International Normalized Ratio of 2.0 to 3.0. Older persons with AF who are at low risk for stroke or who have contraindications to warfarin should receive 325 mg of aspirin daily.