A comparison of rate control and rhythm control in patients with atrial fibrillation.

BACKGROUND: There are two approaches to the treatment of atrial fibrillation: one is cardioversion and treatment with antiarrhythmic drugs to maintain sinus rhythm, and the other is the use of rate-controlling drugs, allowing atrial fibrillation to persist. In both approaches, the use of anticoagulant drugs is recommended. METHODS: We conducted a randomized, multicenter comparison of these two treatment strategies in patients with atrial fibrillation and a high risk of stroke or death. The primary end point was overall mortality. RESULTS: A total of 4060 patients (mean [+/-SD] age, 69.7+/-9.0 years) were enrolled in the study; 70.8 percent had a history of hypertension, and 38.2 percent had coronary artery disease. Of the 3311 patients with echocardiograms, the left atrium was enlarged in 64.7 percent and left ventricular function was depressed in 26.0 percent. There were 356 deaths among the patients assigned to rhythm-control therapy and 310 deaths among those assigned to rate-control therapy (mortality at five years, 23.8 percent and 21.3 percent, respectively; hazard ratio, 1.15 [95 percent confidence interval, 0.99 to 1.34]; P=0.08). More patients in the rhythm-control group than in the rate-control group were hospitalized, and there were more adverse drug effects in the rhythm-control group as well. In both groups, the majority of strokes occurred after warfarin had been stopped or when the international normalized ratio was subtherapeutic. CONCLUSIONS: Management of atrial fibrillation with the rhythm-control strategy offers no survival advantage over the rate-control strategy, and there are potential advantages, such as a lower risk of adverse drug effects, with the rate-control strategy. Anticoagulation should be continued in this group of high-risk patients.

Cardiac risk of noncardiac surgery: influence of coronary disease and type of surgery in 3368 operations. CASS Investigators and University of Michigan Heart Care Program. Coronary Artery Surgery Study.

BACKGROUND: The influence of prior coronary artery bypass surgery (CABG) versus medical therapy for reducing the risk of postoperative cardiac complications after noncardiac surgery continues to be debated. To further clarify this controversy we studied 24,959 participants in the Coronary Artery Surgery Study (CASS) database with suspected coronary disease by identifying those who required noncardiac surgery during more than 10 years of follow-up. METHODS AND RESULTS: CASS registry enrollees were either treated with CABG or medical therapy after initial entry. During follow-up, patients who required noncardiac operations were evaluated for hospital death or out-of-hospital death within 30 days of noncardiac surgery and nonfatal postoperative myocardial infarction (MI). At a mean follow-up of 4.1 years, 3368 patients underwent noncardiac surgery, with abdominal (36%), urologic (21%), orthopedic (15%), and vascular being most common. Abdominal, vascular, thoracic, and head and neck surgery each had a combined MI/death rate among patients with nonrevascularized coronary disease >4%. Among 1961 patients undergoing higher-risk surgery, prior CABG was associated with fewer postoperative deaths (1.7% versus 3.3%, P=.03) and MIs (0.8% versus 2.7%, P=.002) compared with medically managed coronary disease. Contrariwise, 1297 patients undergoing urologic, orthopedic, breast, and skin operations had mortality of <1% regardless of prior coronary treatment. Prior CABG was most protective in patients with advanced angina and/or multivessel coronary artery disease. CONCLUSIONS: In patients with known coronary artery disease, noncardiac surgeries involving the thorax, abdomen, vasculature, and head and neck are associated with the highest cardiac risk, which is reduced among patients with prior CABG.

Long-term survival of African Americans in the Coronary Artery Surgery Study (CASS).

OBJECTIVES: This study sought to determine the long-term (> 15 years) outcome of a clinically well characterized cohort of African Americans with known or suspected coronary artery disease (CAD). BACKGROUND: The mortality rate from CAD is higher in African Americans than in whites. An earlier analysis of data from the Coronary Artery Surgery Study (CASS) registry suggested that African American and white patients treated surgically had equal 5-year survival rates. METHODS: Survival data from the CASS registry were analyzed to determine whether 1) African American race is an independent predictor of mortality; and 2) initial therapy is predictive of mortality among African American patients. RESULTS: Overall, 60% of white and 52% of African American patients survived 16 years (p < 0.00001). Multivariate Cox models confirmed that African American race was independently associated with higher mortality in both the medical group (hazard ratio [HR] 1.34, 95% confidence interval [CI] 1.11 to 1.63) and the surgical group (HR 1.63, 95% CI 1.19 to 2.23). Initial therapy was not predictive of survival among African American patients (p = 0.81). However, smoking status significantly influenced survival: African Americans who did not smoke experienced significantly improved survival (60% vs. 48% for smokers), which equaled survival for white nonsmokers (61%, p = NS). CONCLUSIONS: In contrast to results from shorter term studies, African Americans experienced higher overall mortality rates than whites over the long term, regardless of the type of initial treatment. Survival among nonsmoking African Americans at 16 years equaled survival among nonsmoking whites.

Gender differences in left ventricle geometry and function in patients undergoing balloon dilatation of the aortic valve for isolated aortic stenosis. NHLBI Balloon Valvuloplasty Registry.

BACKGROUND: Gender differences in cardiac size have been described in normal humans and animals and in response to pressure overload. To examine the influence of gender on the left ventricular response to pressure overload, clinical, haemodynamic, and echocardiographic data were analysed in the 232 adults with isolated aortic stenosis enrolled in the Balloon Valvuloplasty Registry. METHODS AND RESULTS: There were 92 men (mean (SD) age 75 (11) years) and 140 women (79 (9) years; P = 0.002). Women had similar symptoms (New York Heart Association class) but lower overall functional status than men (P = 0.008). Catheterisation data showed similar valve area indices (mean (SD) (0.30 (0.09) in men and 0.31 (0.13) cm/m2 in women) but higher peak and mean gradients in women (peak 74 (30) v 63 (22) mm Hg; mean 61 (21) v 54 (18) mm Hg; both P < or = 0.01). On M mode echocardiography women had greater septal and posterior wall thickness but similar cavity diameter, after normalising dimensions to body surface area, resulting in higher relative wall thickness (0.60 (0.20) v 0.50 (0.15); P = 0.0002). Left ventricular mass index was similar in women and men (166 (59) v 159 (50) gm/m2 respectively), however, the prevalence of left ventricular hypertrophy according to sex specific criteria was 54% in men and 81% in women (P = 0.0001). Multiple logistic regression models that adjusted for age, functional status, fractional shortening, and left ventricular systolic pressure found the presence or absence of hypertrophy to be independently associated with gender (P < or = 0.002). Left ventricular systolic function tended to be better in women, who had a higher cardiac index (2.5 (0.8) v 2.3 (0.6) 1/min/m2; P = 0.01), left ventricular peak systolic pressure (211 (36) v 192 (35) mm Hg; P = 0.0001), and echo fractional shortening (32 (13) v 28 (12)%; P = 0.05); however, these differences were reduced when patients with regional wall motion abnormalities were excluded. CONCLUSIONS: In this population of elderly patients undergoing balloon dilatation of isolated aortic stenosis, left ventricular chamber geometry was different in men and women. Because this was a selected population, gender should be further evaluated as a possible determinant of the cardiac adaptation to chronic pressure overload.

Surgical therapy for coronary artery disease among patients with combined coronary artery and peripheral vascular disease.

BACKGROUND: Among patients with combined coronary artery and peripheral vascular disease, long-term benefits of surgical therapy compared with medical therapy for coronary artery disease are unknown. METHODS AND RESULTS: Using prospectively collected data from the Coronary Artery Surgery Study registry, we performed a retrospective cohort analysis of 1834 patients (mean age, 56 years; 20% women) with both coronary artery and peripheral vascular disease and evaluated their long-term outcomes. Of these patients, 986 received (nonrandomly) coronary artery bypass graft surgery, and 848 were treated medically. Perioperative mortality was 4.2% (2.9% in the absence of peripheral vascular disease; P = .02). In a mean follow-up period of 10.4 years, 1100 deaths occurred (80% due to cardiovascular causes). For the surgical group, 4-, 8-, 12-, and 16-year estimated probabilities of survival were 88%, 72%, 55%, and 41%, respectively, and 73%, 57%, 44%, and 34%, respectively, for the medical group (P < .0001). Multivariate analysis demonstrated that type of therapy was independently associated with survival (P = .0001; chi 2 = 15.34). Subgroup analysis suggested that benefits of surgical treatment on survival were limited to patients with three-vessel coronary artery disease and were inversely related to ejection fraction. Survival free of death or myocardial infarction was also significantly better among the surgical group. Type of therapy was significantly associated with occurrence of late events (P = .01; chi 2 = 6.55). Subgroup analysis again demonstrated that beneficial effects of surgery were limited to patients with three-vessel coronary artery disease and were inversely related to ejection fraction. CONCLUSIONS: Surgical treatment provides long-term benefit for certain subgroups of patients with combined coronary artery and peripheral arterial vascular disease.

Long-term survival in patients with coronary artery disease: importance of peripheral vascular disease. The Coronary Artery Surgery Study (CASS) Investigators.

OBJECTIVES: The purpose of this study was to determine the importance of peripheral arterial disease in predicting long-term survival in patients with clinically evident coronary artery disease. BACKGROUND: Patients in the Coronary Artery Surgery Study (CASS) Registry were followed up for > 10 years. METHODS: Survival in 2,296 patients with peripheral arterial disease was compared with that of 13,953 patients without peripheral arterial disease using Kaplan-Meier survival curves. All patients had known stable coronary artery disease. Clinical, electrocardiographic (ECG), chest X-ray film and catheterization variables of the two groups were compared using the chi-square statistic or the two-sample t test. The independent effect of peripheral arterial disease (as well as other variables) on mortality was determined utilizing a Cox proportional hazards model. RESULTS: Patients with peripheral vascular disease were more likely to have hypertension, diabetes, family history of coronary artery disease, previous angina or myocardial infarction, previous coronary bypass surgery or to have smoked. They also had a higher incidence of congestive heart failure, ECG abnormality and modestly increased frequency of three-vessel disease. Independent correlates of long-term mortality for the entire cohort included age, smoking, diabetes, number of diseased coronary vessels, left ventricular function, hypertension, pulmonary disease, anginal class, previous myocardial infarction and peripheral vascular disease (all p < 0.001). At any point in time, patients with peripheral vascular disease had a 25% greater likelihood of mortality than patients without peripheral vascular disease (multivariate chi-square 25.83, hazard ratio 1.25, 95% confidence interval 1.15 to 1.36, p < 0.001). CONCLUSIONS: Peripheral vascular disease is a strong, independent predictor of long-term mortality in patients with stable coronary artery disease. Aggressive attempts at secondary disease prevention are warranted in this high risk group.

Three-year outcome after balloon aortic valvuloplasty. Insights into prognosis of valvular aortic stenosis.

BACKGROUND: To identify predictors of long-term outcome after balloon aortic valvuloplasty, we analyzed data on 674 adults (mean age, 78 +/- 9 years; 56% were women) undergoing this procedure at 24 clinical centers who had a mean initial increase in aortic valve area of 0.3 cm2. METHODS AND RESULTS: Baseline data included clinical, echocardiographic, and catheterization variables. Follow-up data included mortality, cause of death, rehospitalization, 6-month echocardiography, and functional status. Kaplan-Meier curves and log-rank tests were used to evaluate survival in subgroups. Multivariate Cox regression models were used to identify independent predictors of survival. Overall survival was 55% at 1 year, 35% at 2 years, and 23% at 3 years, with the majority of deaths (70%) classified as cardiac by an independent review committee. Rehospitalization was common (64%), although 61% of survivors at 2 years reported improved symptoms. Echocardiography at 6 months (n = 115) showed restenosis from the postprocedural valve area of 0.78 +/- 0.31 cm2 to 0.65 +/- 0.25 cm2 (P < .0001). With stepwise multivariate analysis, sequentially adding clinical, echocardiographic, and catheterization variables, the overall model identified independent predictors of survival as baseline functional status, baseline cardiac output, renal function, cachexia, female gender, left ventricular systolic function, and mitral regurgitation. Baseline and postprocedural variables were examined to identify which subgroup of patients has the best outcome after aortic valvuloplasty. A "lower-risk" subgroup (28% of the study population), defined by normal left ventricular systolic function and mild clinical functional limitation, had a 3-year survival of 36% compared with 17% in the remainder of the study group. CONCLUSIONS: Long-term survival after balloon aortic valvuloplasty is poor with 1- and 3-year survival rates of 55% and 23%, respectively. Although survivors report fewer symptoms, early restenosis and recurrent hospitalization are common.