Marion E. Barnes

Secular Trends in Incidence of Atrial Fibrillation in Olmsted County, Minnesota, 1980 to 2000, and Implications on the Projections for Future Prevalence

Background— Limited data exist on trends in incidence of atrial fibrillation (AF). We assessed the community-based trends in AF incidence for 1980 to 2000 and provided prevalence projections to 2050. Methods and Results— The adult residents of Olmsted County, Minnesota, who had ECG-confirmed first AF in the period 1980 to 2000 (n=4618) were identified. Trends in age-adjusted incidence were determined and used to construct model-based prevalence estimates. The age- and sex-adjusted incidence of AF per 1000 person-years was 3.04 (95% CI, 2.78 to 3.31) in 1980 and 3.68 (95% CI, 3.42 to 3.95) in 2000. According to Poisson regression with adjustment for age and sex, incidence of AF increased significantly (P=0.014), with a relative increase of 12.6% (95% CI, 2.1 to 23.1) over 21 years. The increase in age-adjusted AF incidence did not differ between men and women (P=0.84). According to the US population projections by the US Census Bureau, the number of persons with AF is projected to be 12.1 million by 2050, assuming no further increase in age-adjusted incidence of AF, but 15.9 million if the increase in incidence continues. Conclusions— The age-adjusted incidence of AF increased significantly in Olmsted County during 1980 to 2000. Whether or not this rate of increase continues, the projected number of persons with AF for the United States will exceed 10 million by 2050, underscoring the urgent need for primary prevention strategies against AF development.

Outcome of 622 Adults With Asymptomatic, Hemodynamically Significant Aortic Stenosis During Prolonged Follow-Up

Background—This study assessed the long-term outcome of a large, asymptomatic population with hemodynamically significant aortic stenosis (AS). Methods and Results—We identified 622 patients with isolated, asymptomatic AS and peak systolic velocity ≥4 m/s by Doppler echocardiography who did not undergo surgery at the initial evaluation and obtained follow-up (5.4±4.0 years) in all. Mean age (±SD) was 72±11 years; there were 384 (62%) men. The probability of remaining free of cardiac symptoms while unoperated was 82%, 67%, and 33% at 1, 2, and 5 years, respectively. Aortic valve area and left ventricular hypertrophy predicted symptom development. During follow-up, 352 (57%) patients were referred for aortic valve surgery and 265 (43%) patients died, including cardiac death in 117 (19%). The 1-, 2-, and 5-year probabilities of remaining free of surgery or cardiac death were 80%, 63%, and 25%, respectively. Multivariate predictors of all-cause mortality were age (hazard ratio [HR], 1.05; P<0.0001), chronic renal failure (HR, 2.41; P=0.004), inactivity (HR, 2.00; P=0.001), and aortic valve velocity (HR, 1.46; P=0.03). Sudden death without preceding symptoms occurred in 11 (4.1%) of 270 unoperated patients. Patients with peak velocity ≥4.5 m/s had a higher likelihood of developing symptoms (relative risk, 1.34) or having surgery or cardiac death (relative risk, 1.48). Conclusions—Most patients with asymptomatic, hemodynamically significant AS will develop symptoms within 5 years. Sudden death occurs in ≈1%/y. Age, chronic renal failure, inactivity, and aortic valve velocity are independently predictive of all-cause mortality.

Left ventricular diastolic dysfunction as a predictor of the first diagnosed nonvalvular atrial fibrillation in 840 elderly men and women

OBJECTIVES The objective of this study was to determine whether diastolic dysfunction is associated with increased risk of nonvalvular atrial fibrillation (NVAF) in older adults with no history of atrial arrhythmia. BACKGROUND Few data exist regarding the relationship between diastolic function and NVAF. METHODS The clinical and echocardiographic characteristics of patients age > or =65 years who had an echocardiogram performed between 1990 and 1998 were reviewed. Exclusion criteria were history of atrial arrhythmia, stroke, valvular or congenital heart disease, or pacemaker implantation. Patients were followed up in their medical records to the last clinical visit or death for documentation of first AF. RESULTS Of 840 patients (39% men; mean [+/- SD] age, 75 +/- 7 years), 80 (9.5%) developed NVAF over a mean (+/- SD) follow-up of 4.1 +/- 2.7 years. Abnormal relaxation, pseudonormal, and restrictive left ventricular diastolic filling were associated with hazard ratios of 3.33 (95% confidence interval [CI], 1.5 to 7.4; p = 0.003), 4.84 (95% CI, 2.05 to 11.4; p < 0.001), and 5.26 (95% CI, 2.3 to 12.03; p < 0.001), respectively, when compared with normal diastolic function. After a number of adjustments, diastolic function profile remained incremental to history of congestive heart failure and previous myocardial infarction for prediction of NVAF. Age-adjusted Kaplan-Meier five-year risks of NVAF were 1%, 12%, 14%, and 21% for normal, abnormal relaxation, pseudonormal, and restrictive diastolic filling, respectively. CONCLUSIONS; The presence and severity of diastolic dysfunction are independently predictive of first documented NVAF in the elderly.

Left atrial volume: important risk marker of incident atrial fibrillation in 1655 older men and women

OBJECTIVE To evaluate the contribution of left atrial (LA) volume in predicting atrial fibrillation (AF). PATIENTS AND METHODS In this retrospective cohort study, a random sample of 2200 adults was identified from all Olmsted County, Minnesota, residents who had undergone transthoracic echocardiographic assessment between 1990 and 1998 and were 65 years of age or older at the time of examination, were in sinus rhythm, and had no history of AF or other atrial arrhythmias, stroke, pacemaker, congenital heart disease, or valve surgery. The LA volume was measured off-line by using a biplane area-length method. Clinical characteristics and the outcome event of incident AF were determined by retrospective review of medical records. Echocardiographic data were retrieved from the laboratory database. From this cohort, 1655 patients in whom LA size data were available were followed from baseline echocardiogram until development of AF or death. The clinical and echocardiographic associations of AF, especially with respect to the role of LA volume in predicting AF, were determined. RESULTS A total of 666 men and 989 women, mean +/- SD age of 75.2 +/- 7.3 years (range, 65-105 years), were followed for a mean +/- SD of 3.97 +/- 2.75 years (range, < 1.00-10.78 years); 189 (11.4%) developed AF. Cox model 5-year cumulative risks of AF by quartiles of LA volume were 3%, 12%, 15%, and 26%, respectively. With Cox proportional hazards multivariate models, logarithmic LA volume was an independent predictor of AF, incremental to clinical risk factors. After adjusting for age, sex, valvular heart disease, and hypertension, a 30% larger LA volume was associated with a 43% greater risk of AF, incremental to history of congestive heart failure (hazard ratio [HR], 1.887; 95% confidence interval [CI], 1.230-2.895; P = .004), myocardial infarction (HR, 1.751; 95% CI, 1.189-2.577; P = .004), and diabetes (HR, 1.734; 95% CI, 1.066-2.819; P = .03). Left atrial volume remained incremental to combined clinical risk factors and M-mode LA dimension for prediction of AF (P < .001). CONCLUSION This study showed that a larger LA volume was associated with a higher risk of AF in older patients. The predictive value of LA volume was incremental to that of clinical risk profile and conventional M-mode LA dimension.

Consecutive 1127 Therapeutic Echocardiographically Guided Pericardiocenteses: Clinical Profile, Practice Patterns, and Outcomes Spanning 21 Years

OBJECTIVES To evaluate consecutive therapeutic echocardiographically (echo)-guided pericardiocenteses performed at Mayo Clinic, Rochester, Minn, from 1979 to 2000 and to determine whether patient profiles, practice patterns, and outcomes have changed over time. PATIENTS AND METHODS Consecutive echo-guided pericardiocenteses performed between February 1, 1979, and January 31, 2000, for treatment of clinically significant pericardial effusions were identified in the Mayo Clinic Echocardiographic-guided Pericardiocentesis Registry. The medical records of these patients were examined, and a follow-up survey was conducted. Clinical profiles, echocardiographic findings, procedural details, and outcomes were determined for 3 periods: February 1, 1979, through January 31, 1986; February 1, 1986, through January 31, 1993; and February 1, 1993, through January 31, 2000. RESULTS During the 21-year study period, 1127 therapeutic echo-guided pericardiocenteses were performed in 977 patients. The mean +/- SD age at pericardiocentesis increased from 49+/-14 years in period 1 to 57+/-14 years in period 3. In recent years, cardiothoracic surgery replaced malignancy as the leading cause of an effusion requiring pericardiocentesis and together with malignancy and perforation from catheter-based procedures accounted for nearly 70% of all pericardiocenteses performed. The procedural success rate was 97% overall, with a total complication rate of 4.7% (major, 1.2%; minor, 3.5%). These rates did not change significantly over time. The use of a pericardial catheter for extended drainage increased from 23% in period 1 to 75% in period 3 (P<.001), whereas rates of effusion recurrence and pericardial surgery decreased significantly (P<.001). CONCLUSIONS The profile of patients presenting with clinically significant pericardial effusion has changed over time. Increasing numbers of older patients and those who have undergone cardiothoracic surgery or catheter-based procedures develop effusions that can be rapidly, safely, and effectively managed with echo-guided pericardiocentesis. Extended drainage with use of a pericardial catheter has become standard practice, and concomitantly, recurrence rates and need for surgical management have decreased considerably.

The prevalence of atrial fibrillation in incident stroke cases and matched population controls in Rochester, Minnesota: Changes over three decades

OBJECTIVES We sought evidence of a change in the prevalence of atrial fibrillation (AF) over a 30-year period among residents of Rochester, Minnesota. BACKGROUND Atrial fibrillation is increasingly encountered in clinical practice, but there is limited data on secular trends of AF over time. METHODS Within a longitudinal case-control study of ischemic stroke, the prevalence of AF and of selected comorbid conditions among incident stroke cases and age- and gender-matched controls between 1960 and 1989 was determined. RESULTS The mean age +/- standard deviation for the 1,871 stroke cases (45% men) and matched controls was 75 +/- 11 years. For cases, age-adjusted estimates of AF prevalence for 1960 to 1969, 1970 to 1979, and 1980 to 1989 were 11%, 13%, and 16%, respectively, for men, and 13%, 16%, and 20% for women. For controls, the rates were 5%, 8%, and 12%, respectively, for men, and 4%, 6%, and 8% for women. Increasing AF prevalence was associated with increasing age (doubling of odds per decade of age in both cases and controls) and calendar time adjusted for age and gender (cases: odds ratio [OR] per 5 years 1.13, 95% confidence interval [CI], 1.05 to 1.22; controls: OR per 5 years 1.24, 95% CI 1.12 to 1.37). The rates of increase with calendar time were significant for cases (p = 0.001) and controls (p < 0.001) and comparable between the genders. CONCLUSIONS The prevalence of AF increased significantly in ischemic stroke patients and their controls from 1960 to 1989 in Rochester, Minnesota, independent of age and gender. The rate of increase did not differ significantly between men and women.

Left Atrial Volume in the Prediction of First Ischemic Stroke in an Elderly Cohort Without Atrial Fibrillation

OBJECTIVE To determine the clinical importance of left atrial (LA) volume in the prediction of first ischemic stroke. PATIENTS AND METHODS This retrospective cohort study included randomly selected residents of Olmsted County, Minnesota, aged 65 years or older, who had undergone transthoracic echocardiography at least once at the Mayo Clinic in Rochester, Minn, between January 1, 1990, and December 31, 1998, were in sinus rhythm, and had no history of stroke, transient ischemic attack, atrial fibrillation, or valvular heart disease. Patients were monitored through medical records for first ischemic stroke or death. RESULTS Of 1554 residents (59% women) aged 75+/-7 years, 92 (6%) had experienced at least 1 ischemic stroke over 4.3+/-2.7 years (incident stroke rate, 1.4 per 100 person-years). Left atrial volume of 32 mL/m2 or greater (hazard ratio [HR], 1.63; confidence interval [CI], 1.08-2.46) was independent of age (HR, 1.04; CI, 1.02-1.07), diabetes (HR, 1.91; CI, 1.07-3.41), myocardial infarction (HR, 1.64; CI, 1.01-2.64), and hyperlipidemia (HR, 1.55; CI, 1.01-2.37) for the prediction of first ischemic stroke. When quartiles of LA dimension were plotted against quartiles of indexed LA volume, a stepwise increase in risk with each quartile increment was evident only for indexed LA volume. Also, an LA volume of 32 mL/m2 or greater was associated with an increased mortality risk (HR, 1.30; CI, 1.09-1.56), independent of age, sex, and stroke status. CONCLUSIONS In our elderly cohort with no prior atrial fibrillation, LA volume was independently predictive of first ischemic stroke, incremental to age, diabetes, myocardial infarction, and hyperlipidemia. It was also an independent predictor of death.

Left atrial function: physiology, assessment, and clinical implications

The interest in the left atrium (LA) has resurged over the recent years. In the early 1980s, multiple studies were conducted to determine the normal values of LA size. Over the past decade, LA size as an imaging biomarker has been consistently shown to be a powerful predictor of outcomes, including major public health problems such as atrial fibrillation, heart failure, stroke, and death. More recently, functional assessment of the LA has been shown to be, at least as, if not more robust, a marker of cardiovascular outcomes. Current available data suggest that the combined evaluation of LA size and LA function will augment prognostication. The aim of this review is to provide a critical appraisal of current echocardiographic techniques for the assessment of LA function and the implications of such assessment for prediction and disease prevention.

Left Atrial Reservoir Function as a Potent Marker for First Atrial Fibrillation or Flutter in Persons ≥ 65 Years of Age

The aim of this prospective study was to evaluate the incremental value of left atrial (LA) function for the prediction of risk for first atrial fibrillation (AF) or atrial flutter. Maximum and minimum LA volumes were quantitated by echocardiography in 574 adults (mean age 74 +/- 6 years, 52% men) without a history or evidence of atrial arrhythmia. During a mean follow-up period of 1.9 +/- 1.2 years, 30 subjects (5.2%) developed electrocardiographically confirmed AF or atrial flutter. Subjects with new AF or atrial flutter had lower LA reservoir function, as measured by total LA emptying fraction (38% vs 49%, p <0.0001) and higher maximum LA volumes (47 vs 40 ml/m(2), p = 0.005). An increase in age-adjusted risk for AF or atrial flutter was evident when the cohort was stratified according to medians of LA emptying fraction (< or =49%: hazard ratio 6.5, p = 0.001) and LA volume (> or =38 ml/m(2): hazard ratio 2.0, p = 0.07), with the risk being highest for subjects with concomitant LA emptying fractions < or =49% and LA volume > or =38 ml/m(2) (hazard ratio 9.3, p = 0.003). LA emptying fraction (p = 0.002) was associated with risk for first AF or atrial flutter after adjusting for baseline clinical risk factors for AF or atrial flutter, left ventricular ejection fraction, diastolic function grade, and LA volume. In conclusion, reduced LA reservoir function markedly increases the propensity for first AF or atrial flutter, independent of LA volume, left ventricular function, and clinical risk factors.

Outcomes of Primary and Secondary Treatment of Pericardial Effusion in Patients With Malignancy

OBJECTIVE To evaluate the treatment strategies for primary and secondary management of malignancy-related pericardial effusions. PATIENTS AND METHODS Retrospective review of Mayo Clinic Rochester charts and external records of patients with pericardial effusion associated with malignant disease who required treatment between February 1979 and June 1998 was performed. Telephone interviews with patients, their families, or their physicians were conducted to determine the outcomes of treatment. Recurrence of pericardial effusion and survival were the main outcome measures. RESULTS Of 1002 consecutive pericardiocenteses performed during the period under study, 341 were performed in 275 patients with confirmed malignant disease. Patients were followed up for a minimum of 190 days, unless death occurred first. Of 275 patients, recurrence of pericardial effusion or persistent drainage necessitated secondary management in 59 (43 of 118 simple pericardiocenteses, 16 of 139 pericardiocenteses with extended catheter drainage, and 0 of 18 pericardial surgery following temporizing pericardiocentesis). Recurrence was strongly and independently predicted by absence of pericardial catheter for extended drainage, large effusion size, and emergency procedures. Recurrence after secondary management occurred in 12 patients: 11 underwent successful pericardiocentesis with extended catheter drainage, and 1 had pericardial surgery. Median survival of the cohort was 135 days, and 26% survived the first year after diagnosis of pericardial effusion. Male sex, positive fluid cytology for malignant cells, lung cancer, and clinical presentation of tamponade or hemodynamic collapse were independently associated with poor survival. CONCLUSION Echocardiographically guided pericardiocentesis with extended catheter drainage appears to be safe and effective for both primary and secondary management of pericardial effusion in patients with malignancy.