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.

Diuretics and risk of arrhythmic death in patients with left ventricular dysfunction.

Background-Treatment with diuretics has been reported to increase the risk of arrhythmic death in patients with hypertension. The effect of diuretic therapy on arrhythmic death in patients with left ventricular dysfunction is unknown. Methods and Results-We conducted a retrospective analysis of 6797 patients with an ejection fraction <0.36 enrolled in the Studies Of Left Ventricular Dysfunction (SOLVD) to assess the relation between diuretic use at baseline and the subsequent risk of arrhythmic death. Participants receiving a diuretic at baseline were more likely to have an arrhythmic death than those not receiving a diuretic (3.1 vs 1.7 arrhythmic deaths per 100 person-years, P=0.001). On univariate analysis, diuretic use was associated with an increased risk of arrhythmic death (relative risk [RR] 1.85, P=0.0001). After controlling for important covariates, diuretic use remained significantly associated with an increased risk of arrhythmic death (RR 1.37, P=0.009). Only non-potassium-sparing diuretic use was independently associated with arrhythmic death (RR 1.33, P=0.02). Use of a potassium-sparing diuretic, alone or in combination with a non-potassium-sparing diuretic, was not independently associated with an increased risk of arrhythmic death (RR 0.90, P=0.6). Conclusions-In SOLVD, baseline use of a non-potassium-sparing diuretic was associated with an increased risk of arrhythmic death, whereas baseline use of a potassium-sparing diuretic was not. These data suggest that diuretic-induced electrolyte disturbances may result in fatal arrhythmias in patients with systolic left ventricular dysfunction.

Effect of baseline or changes in adrenergic activity on clinical outcomes in the beta-blocker evaluation of survival trial.

BACKGROUND: Adrenergic activation is thought to be an important determinant of outcome in subjects with chronic heart failure (CHF), but baseline or serial changes in adrenergic activity have not been previously investigated in a large patient sample treated with a powerful antiadrenergic agent. METHODS AND RESULTS: Systemic venous norepinephrine was measured at baseline, 3 months, and 12 months in the beta-Blocker Evaluation of Survival Trial (BEST), which compared placebo treatment with the beta-blocker/sympatholytic agent bucindolol. Baseline norepinephrine level was associated with a progressive increase in rates of death or death plus CHF hospitalization that was independent of treatment group. On multivariate analysis, baseline norepinephrine was also a highly significant (P<0.001) independent predictor of death. In contrast, the relation of the change in norepinephrine at 3 months to subsequent clinical outcomes was complex and treatment group-dependent. In the placebo-treated group but not in the bucindolol-treated group, marked norepinephrine increase at 3 months was associated with increased subsequent risks of death or death plus CHF hospitalization. In the bucindolol-treated group but not in the placebo-treated group, the 1st quartile of marked norepinephrine reduction was associated with an increased mortality risk. A likelihood-based method indicated that 18% of the bucindolol group but only 1% of the placebo group were at an increased risk for death related to marked reduction in norepinephrine at 3 months. CONCLUSIONS: In BEST, a subset of patients treated with bucindolol had an increased risk of death as the result of sympatholysis, which compromised the efficacy of this third-generation beta-blocker.

Late effects in long-term survivors of high-grade non-Hodgkin's lymphomas.

PURPOSE: To evaluate long-term survivors of high-grade non-Hodgkin's lymphomas (NHLs) for late effects and to attempt to assess the relative contributions of the primary treatment modalities to these late effects. PATIENTS AND METHODS: Of 103 young survivors followed up for 1 to 20 years, 74 patients were interviewed and underwent various investigations, and an additional 12 patients were interviewed only. Of the 86 patients, 65 had previously suffered from small non-cleaved-cell lymphoma, 16 from lymphoblastic lymphoma, and five from large-cell lymphoma. RESULTS: Left ventricular dysfunction was identified in eight of 57 (14.0%) patients who had received doxorubicin (DOX) in doses greater than 200 mg/m2, of whom four were symptomatic and four were asymptomatic. A ninth patient required a pacemaker. Of the 86 patients, 23 (26.7%) reported pregnancies, 18 of whom had 30 children. Two of the 86 (2.3%) patients developed second cancers. Other major late effects included posttransfusion viral hepatitis, eight patients; CNS toxicity, two patients; endocrine impairment, 14 patients; vitamin B12 deficiency, two patients; esophageal stricture, one patient; urinary tract problems, two patients; and musculoskeletal defects, three patients. Major late effects occurred in 11 of 21 (52.4%) patients who had received radiation as well as chemotherapy, eight of 22 (36.4%) patients who had surgical resections as well as chemotherapy, and 17 of 74 (23.0%) patients who had received chemotherapy alone. CONCLUSION: The predominant major late effects observed were late cardiac toxicity related to DOX therapy and hepatitis C virus infection that presumably resulted from blood product transfusions administered before the introduction of screening for the hepatitis C virus. Fertility was not greatly impaired, and second malignancies were uncommon. No patient had clinically significant impairment of growth. Radiation appeared to increase the likelihood of late effects.

Ejection fraction and risk of thromboembolic events in patients with systolic dysfunction and sinus rhythm: evidence for gender differences in the studies of left ventricular dysfunction trials.

OBJECTIVES: The aims of this study were to describe the incidence and spectrum of thromboembolic events experienced by patients with moderate to severe left ventricular systolic dysfunction in normal sinus rhythm and to study the association between ejection fraction and thromboembolic risk. BACKGROUND: The annual incidence of thromboembolic events in patients with heart failure is estimated to range from 0.9% to 5.5%. Previous studies demonstrating a relation between worsening left ventricular systolic function and thromboembolic risk are difficult to interpret because of the prevalence of atrial fibrillation, an independent risk factor for thromboembolism, in the patients with a lower ejection fraction. METHODS: This is a retrospective analysis of the Studies of Left Ventricular Dysfunction prevention and treatment trials data base. Patients with atrial fibrillation were excluded, resulting in 6,378 participants in sinus rhythm at the time of randomization. Thromboembolic events include strokes, pulmonary emboli and peripheral emboli. Separate analyses were conducted in each gender because there was evidence of a significant interaction between ejection fraction and gender on the risk of thromboembolic events (p = 0.04). RESULTS: The overall annual incidence of thromboembolic events was 2.4% in women and 1.8% in men. On univariate analysis, a decline in ejection fraction was [corrected] associated with thromboembolic risk in women (relative risk [RR] per 10% decrease in ejection fraction 1.58, 95% confidence interval [CI] 1.10 to 2.26, p = 0.01), but not in men. On multivariate analysis, a decline in ejection fraction remained independently associated with thromboembolic risk in women (RR per 10% decrease 1.53, 95% CI 1.06 to 2.20, p = 0.02), but no relation was demonstrated in men. CONCLUSIONS: In patients with left ventricular systolic dysfunction and sinus rhythm, the annual incidence of thromboembolic events is low. Ejection fraction appears to be independently associated with thromboembolic risk in women, but not in men.

Light-to-moderate alcohol consumption and prognosis in patients with left ventricular systolic dysfunction.

OBJECTIVES: The study evaluated the relationship between light-to-moderate alcohol consumption and prognosis in patients with left ventricular (LV) systolic dysfunction. BACKGROUND: Although chronic consumption of large amounts of alcohol can lead to cardiomyopathy, the effects of light-to-moderate alcohol consumption in patients with LV dysfunction are unknown. METHODS: The relationship between light-to-moderate alcohol consumption and prognosis was assessed in participants in the Studies of Left Ventricular Dysfunction (SOLVD), all of whom had ejection fraction values < or = 0.35. Baseline characteristics and event rates of patients who consumed 1 to 14 drinks per week (light-to-moderate drinkers, n = 2,594) were compared with those of patients who reported no alcohol consumption (nondrinkers, n = 3,719). The association between light-to-moderate alcohol consumption and prognosis was evaluated using Cox proportional hazards analysis, controlling for baseline differences and important covariates. RESULTS: Mortality rates were lower among light-to-moderate drinkers than among nondrinkers (7.2 vs. 9.4 deaths/100 person-years, p < 0.001). Among patients with ischemic LV dysfunction, light-to-moderate alcohol consumption was independently associated with a reduced risk of all-cause mortality (RR [relative risk] 0.85, p = 0.01), particularly for death from myocardial infarction (RR 0.55, p < 0.001). The risks of cardiovascular death, death from progressive heart failure, arrhythmic death, and hospitalization for heart failure were similar for light-to-moderate drinkers and nondrinkers in this group. Among patients with nonischemic LV dysfunction, light-to-moderate alcohol consumption had no significant effect on mortality (RR 0.93, p = 0.5). CONCLUSIONS: Light-to-moderate alcohol consumption is not associated with an adverse prognosis in patients with LV systolic dysfunction, and it may reduce the risk of fatal myocardial infarction in patients with ischemic LV dysfunction.

The prognostic implications of renal insufficiency in asymptomatic and symptomatic patients with left ventricular systolic dysfunction.

OBJECTIVES: The present analysis examines the prognostic implications of moderate renal insufficiency in patients with asymptomatic and symptomatic left ventricular systolic dysfunction. BACKGROUND: Chronic elevations in intracardiac filling pressures may lead to progressive ventricular dilation and heart failure progression. The ability to maintain fluid balance and prevent increased intracardiac filling pressures is critically dependent on the adequacy of renal function. METHODS: This is a retrospective analysis of the Studies of Left Ventricular Dysfunction (SOLVD) Trials, in which moderate renal insufficiency is defined as a baseline creatinine clearance <60 ml/min, as estimated from the Cockroft-Gault equation. RESULTS: In the SOLVD Prevention Trial, multivariate analyses demonstrated moderate renal insufficiency to be associated with an increased risk for all-cause mortality (Relative Risk [RR] 1.41; p = 0.001), largely explained by an increased risk for pump-failure death (RR 1.68; p = 0.007) and the combined end point death or hospitalization for heart failure (RR 1.33; p = 0.001). Likewise, in the Treatment Trial, multivariate analyses demonstrated moderate renal insufficiency to be associated with an increased risk for all-cause mortality (RR 1.41; p = 0.001), also largely explained by an increased risk for pump-failure death (RR 1.49; p = 0.007) and the combined end point death or hospitalization for heart failure (RR 1.45; p = 0.001). CONCLUSIONS: Even moderate degrees of renal insufficiency are independently associated with an increased risk for all-cause mortality in patients with heart failure, largely explained by an increased risk of heart failure progression. These data suggest that, rather than simply being a marker of the severity of underlying disease, the adequacy of renal function may be a primary determinant of compensation in patients with heart failure, and therapy capable of improving renal function may delay disease progression.

Effect of angiotensin converting enzyme inhibition on sudden cardiac death in patients following acute myocardial infarction. A meta-analysis of randomized clinical trials.

UNLABELLED: Estimate the effect of angiotensin converting enzyme (ACE) inhibitors on the risk of sudden cardiac death (SCD) following myocardial infarction (MI). BACKGROUND: Trials in post-MI patients have shown that ACE inhibitor therapy reduces mortality. However, the effect on SCD as a mechanism has not been clarified. METHODS: Trials of ACE inhibitor therapy following MI reported between January, 1978 and August, 1997 were identified. Studies were included if they met the following criteria: 1) randomized comparison of ACE inhibitor to placebo within 14 days of MI; 2) study duration/blinded follow-up of > or =6 weeks; 3) the number of deaths and modes of death were reported or could be obtained from the investigators. RESULTS: We identified 374 candidate articles, of which 15 met the inclusion criteria. The 15 trials included 15,104 patients, 2,356 of whom died. Most (87%) fatalities were cardiovascular and 900 were SCDs. A significant reduction in SCD risk or a trend towards this was observed in all of the larger (N > 500) trials. Overall, ACE inhibitor therapy resulted in significant reductions in risk of death (random effects odds ratio [OR] = 0.83; 95% confidence interval [CI] 0.71-0.97), cardiovascular death (OR = 0.82; 95% CI 0.69-0.97) and SCD (OR = 0.80; 95% CI 0.70-0.92). CONCLUSIONS: This analysis is consistent with prior reports showing that ACE inhibitors decrease the risk of death following a recent MI by reducing cardiovascular mortality. Moreover, this analysis suggests that a reduction in SCD risk with ACE inhibitors is an important component of this survival benefit.

Beta-adrenergic blocking agent use and mortality in patients with asymptomatic and symptomatic left ventricular systolic dysfunction: a post hoc analysis of the Studies of Left Ventricular Dysfunction.

OBJECTIVES: This analysis was performed to assess whether beta-adrenergic blocking agent use is associated with reduced mortality in the Studies of Left Ventricular Dysfunction (SOLVD) and to determine if this relationship is altered by angiotensin-converting enzyme (ACE) inhibitor use. BACKGROUND: The ability of beta-blockers to alter mortality in patients with asymptomatic left ventricular dysfunction is not well defined. Furthermore, the effect of beta-blocker use, in addition to an ACE inhibitor, on these patients has not been fully addressed. METHODS: This retrospective analysis evaluated the association of baseline beta-blocker use with mortality in 4,223 mostly asymptomatic Prevention trial patients, and 2,567 symptomatic Treatment trial patients. RESULTS: The 1,015 (24%) Prevention trial patients and 197 (8%) Treatment trial patients receiving beta-blockers had fewer symptoms, higher ejection fractions and different use of medications than patients not receiving beta-blockers. On univariate analysis, beta-blocker use was associated with significantly lower mortality than nonuse in both trials. Moreover, a synergistic reduction in mortality with use of both a beta-blocker and enalapril was suggested in the Prevention trial. After adjusting for important prognostic variables with Cox multivariate analysis, the association of beta-adrenergic blocking agent use with reduced mortality remained significant for Prevention trial patients receiving enalapril. Lower rates of arrhythmic and pump failure death and risk of death or hospitalization for heart failure were observed. CONCLUSIONS: The combination of a beta-blocker and enalapril was associated with a synergistic reduction in the risk of death in the SOLVD Prevention trial.

Independent prognostic information provided by sphygmomanometrically determined pulse pressure and mean arterial pressure in patients with left ventricular dysfunction.

OBJECTIVES: The purpose of this study was to evaluate the relationship of baseline pulse pressure and mean arterial pressure to mortality in patients with left ventricular dysfunction. BACKGROUND: Increased conduit vessel stiffness increases pulse pressure and pulsatile load, potentially contributing to adverse outcomes in patients with left ventricular dysfunction. METHODS: Pulse and mean arterial pressure were analyzed for their effect on mortality, adjusting for other modifiers of risk, using Cox proportional hazards regression analysis of data collected from 6,781 patients randomized into the Studies of Left Ventricular Dysfunction trials. RESULTS: Pulse and mean arterial pressure were related positively to each other, age, ejection fraction and prevalence of diabetes and hypertension and inversely to prior myocardial infarction and beta-adrenergic blocking agent use. Higher pulse pressure was associated with increased prevalence of female gender, greater calcium channel blocking agent, digoxin and diuretic use, lower heart rate and a higher rate of reported smoking history. Higher mean arterial pressure was associated with higher heart rate, lower calcium channel blocker and digoxin use and lower New York Heart Association functional class. Over a 61-month follow-up 1,582 deaths (1,397 cardiovascular) occurred. In a multivariate analysis adjusting for the above covariates and treatment assignment, higher pulse pressure remained an independent predictor of total and cardiovascular mortality (total mortality relative risk, 1.05 per 10 mm Hg increment; 95% confidence interval, 1.01 to 1.10; p = 0.02). Mean arterial pressure was inversely related to total and cardiovascular mortality (total mortality relative risk, 0.89; 95% confidence interval, 0.85 to 0.94; p <0.0001). CONCLUSIONS: One noninvasive blood pressure measurement provides two independent prognostic factors for survival. Increased conduit vessel stiffness, as assessed by pulse pressure, may contribute to increased mortality in patients with left ventricular dysfunction, independent of mean arterial pressure.

Prognostic factors for atherosclerosis progression in saphenous vein grafts: the postcoronary artery bypass graft (Post-CABG) trial. Post-CABG Trial Investigators.

OBJECTIVES: The study was done to assess patients in the Post-Coronary Artery Bypass Graft (Post-CABG) trial to determine prognostic factors for atherosclerosis progression. BACKGROUND: Saphenous vein grafts (SVGs) are effective in relieving angina and, in certain patient subsets, in prolonging life. However, the progression of atherosclerosis in many of these grafts limits their usefulness. METHODS: The Post-CABG trial studied moderate versus aggressive lipid-lowering and low-dose warfarin versus placebo in patients with a history of coronary artery bypass surgery and found that more aggressive lipid lowering was effective in preventing progression of atherosclerosis in SVGs, but warfarin had no effect. Using variables measured at baseline, we sought the independent prognostic factors for atherosclerosis progression in SVGs, employing the statistical method of generalized estimating equations with a logit-link function. RESULTS: Twelve independent prognostic factors for atherosclerosis progression were found. In the order of their importance they were: maximum stenosis of the graft at baseline angiography, years post-SVG placement; the moderate low-density lipoprotein-cholesterol (LDL-C) lowering strategy; prior myocardial infarction; high triglyceride level; small minimum graft diameter; low high-density lipoprotein-cholesterol (HDL-C); high LDL-C; high mean arterial pressure; low ejection fraction; male gender; and current smoking. CONCLUSIONS: This study identified Post-CABG patient and SVG characteristics associated with saphenous vein graft atherosclerosis progression. These data provide a basis for rational risk factor management to prevent progression of SVG atherosclerosis.

Safety and efficacy of elective carotid artery stenting in high-risk patients.

OBJECTIVES: We sought to evaluate the safety and efficacy of carotid artery stenting (CAS) in high risk patients. BACKGROUND: Carotid endarterectomy (CE) has been shown to be more effective than medical therapy, but it has limitations. Carotid artery stenting may be a reasonable alternative, particularly in high-risk patients. METHODS: We prospectively evaluated the safety and efficacy of CAS in 170 consecutive patients who underwent the procedure in 192 carotid arteries. Of the patients enrolled, 129 (76%) would have been excluded from the major trials of CE and 54 (32%) were referred by vascular surgeons. This series represents a very high-risk group that included patients with unstable angina, previous ipsilateral CE, contralateral carotid artery occlusion and other severe comorbid illnesses. Only 25 (24%) of 104 symptomatic patients would have met the North American Symptomatic Carotid Endarterectomy Trial (NASCET) entry criteria. The patients' mean age was 73 +/- 8 years (95 confidence interval [CI] 57 to 89), and 42 patients (25%) were > or = 80 years old. Patients had an independent neurologic examination before and after the procedure. RESULTS: The procedural success rate was 99%, including 73 patients who had a coronary intervention. Mean carotid artery stenosis was 78 +/- 10% before (95 CI 58 to 98) and 2 +/- 3% after the procedure (95 CI -4 to 8). During the initial hospital period and 30 days after CAS, there was one major and two category 2 minor strokes, as well as two category 1 minor strokes (total 30-day stroke rate was 2.9% for treated patients or 2.6% for treated arteries). There were no myocardial infarctions or deaths during or within 30 days of CAS. None of the NASCET-eligible patients had a stroke. At a mean follow-up of 19 +/- 11 months, three patients (2%) had asymptomatic restenosis. No other major strokes or neurologic deaths occurred. CONCLUSIONS: Carotid artery stenting is feasible, can be performed even in high-risk patients and is associated with a low restenosis rate.

Atrial fibrillation is associated with an increased risk for mortality and heart failure progression in patients with asymptomatic and symptomatic left ventricular systolic dysfunction: a retrospective analysis of the SOLVD trials. Studies of Left Ventricular Dysfunction.

OBJECTIVE: This study undertook to determine if the presence of atrial fibrillation in patients with asymptomatic and symptomatic left ventricular dysfunction was associated with increased mortality and, if so, whether the increase could be attributed to progressive heart failure or arrhythmic death. BACKGROUND: Atrial fibrillation is a common condition in heart failure with the potential to impact hemodynamics and progression of left ventricular systolic dysfunction as well as the electrophysiologic substrate for arrhythmias. The available data do not conclusively define the effect of atrial fibrillation on prognosis in heart failure. METHODS: A retrospective analysis of the Studies of Left Ventricular Dysfunction Prevention and Treatment Trials was conducted that compared patients with atrial fibrillation to those in sinus rhythm at baseline for the risk of all-cause mortality, progressive pump-failure death and arrhythmic death. RESULTS: The patients with atrial fibrillation at baseline, compared to those in sinus rhythm, had greater all-cause mortality (34% vs. 23%, p < 0.001), death attributed to pump-failure (16.7% vs. 9.4%, p < 0.001) and were more likely to reach the composite end point of death or hospitalization for heart failure (45% vs. 33%, p < 0.001), but there was no significant difference between the groups in arrhythmic deaths. After multivariate analysis, atrial fibrillation remained significantly associated with all-cause mortality (relative risk [RR] 1.34, 95% confidence interval [CI] 1.12 to 1.62, p=0.002), progressive pump-failure death (RR 1.42, 95% CI 1.09 to 1.85, p=0.01), the composite end point of death or hospitalization for heart failure (RR 1.26, 95% CI 1.03 to 1.42, p=0.02), but not arrhythmic death (RR 1.13; 95% CI 0.75 to 1.71; p=0.55). CONCLUSIONS: The presence of atrial fibrillation in patients with asymptomatic and symptomatic left ventricular systolic dysfunction is associated with an increased risk for all-cause mortality, largely explained by an increased risk for pump-failure death. These data suggest that atrial fibrillation is associated with progression of left ventricular systolic dysfunction.

Relative effectiveness of the implantable cardioverter-defibrillator and antiarrhythmic drugs in patients with varying degrees of left ventricular dysfunction who have survived malignant ventricular arrhythmias. AVID Investigators. Antiarrhythmics Versus Implantable Defibrillators.

OBJECTIVES: We sought to assess the effect of baseline ejection fraction on survival difference between patients with life-threatening ventricular arrhythmias who were treated with an antiarrhythmic drug (AAD) or implantable cardioverter-defibrillator (ICD). BACKGROUND: The Antiarrhythmics Versus Implantable Defibrillators (AVID) study demonstrated improved survival in patients with ventricular fibrillation or ventricular tachycardia with a left ventricular ejection fraction (LVEF) < or =0.40 or hemodynamic compromise. METHODS: Survival differences between AAD-treated and ICD-treated patients entered into the AVID study (patients presenting with sustained ventricular arrhythmia associated with an LVEF < or =0.40 or hemodynamic compromise) were compared at different levels of ejection fraction. RESULTS: In patients with an LVEF > or =0.35, there was no difference in survival between AAD-treated and ICD-treated patients. A test for interaction was not significant, but had low power to detect an interaction. For patients with an LVEF 0.20 to 0.34, there was a significantly improved survival with ICD as compared with AAD therapy. In the smaller subgroup with an LVEF <0.20, the same magnitude of survival difference was seen as that in the 0.20 to 0.34 LVEF subgroup, but the difference did not reach statistical significance. CONCLUSIONS: These data suggest that patients with relatively well-preserved LVEF (> or =0.35) may not have better survival when treated with the ICD as compared with AADs. At a lower LVEF, the ICD appears to offer improved survival as compared with AADs. Prospective studies with larger patient numbers are needed to assess the effect of relatively well-preserved ejection fraction (> or =0.35) on the relative treatment effect of AADs and the ICDs.

Clinical investigation of antiarrhythmic devices. A statement for healthcare professionals from a joint task force of the North American Society of Pacing and Electrophysiology, the American College of Cardiology, the American Heart Association, and the Working Groups on Arrhythmias and Cardiac Pacing of the European Society of Cardiology.

The goal of radiofrequency catheter ablation and the criterion for efficacy is the elimination of arrhythmogenic myocardium. The application of radiofrequency current in the heart clearly results in lower morbidity and mortality rates than thoracic and cardiac surgical procedures in general, and comparisons of therapy with radiofrequency catheter ablation and therapy with thoracic and cardiac surgical procedures in randomized clinical trials is unwarranted. Trials of radiofrequency catheter ablation versus medical or implantable cardioverter-defibrillator therapy may be indicated in certain conditions, such as ventricular tachycardia associated with coronary artery disease. Randomized trials are recommended for new and radical departures in technology that aim to accomplish the same goals as radiofrequency catheter ablation. Surveillance using registries and/or databases is necessary in the assessment of long-term safety and efficacy.

Isolated systolic hypertension : prognostic information provided by pulse pressure.

Increased arterial stiffness results in increased characteristic impedance of the aorta and increased pulse wave velocity, which increases systolic and pulse pressures. An association between increased pulse pressure and adverse cardiovascular events has been found in normotensive and hypertensive patient populations. Increased pulse pressure has also been associated with thickening of the carotid intima and media. However, the relationship between pulse pressure and stroke has not previously been evaluated. In this study, we examined the hypothesis that pulse pressure is an independent predictor of stroke in elderly patients with systolic hypertension entered in the Systolic Hypertension in the Elderly Program. Differences in baseline characteristics were examined by tertiles of pulse pressure. The independent prognostic value of pulse pressure and mean arterial pressure for predicting either stroke or total mortality was assessed with Cox proportional hazards models that included pulse pressure, mean arterial pressure, and other variables that were significant on univariate analysis. This analysis demonstrated an 11% increase in stroke risk and a 16% increase in risk of all-cause mortality for each 10-mm Hg increase in pulse pressure. Each 10-mm Hg increase in mean arterial pressure was independently associated with a 20% increase in the risk of stroke and a 14% increase in the risk of all-cause mortality. These data provide strong evidence of an association of increased conduit vessel stiffness, as indicated by increased pulse pressure, with stroke and total mortality, independent of the effects of mean arterial pressure, in elderly patients with isolated systolic hypertension.

Percutaneous cardiopulmonary bypass support in high-risk patients undergoing percutaneous transluminal coronary angioplasty.

Fifty-one consecutive patients in whom percutaneous cardiopulmonary bypass support was instituted to enhance the safety of high-risk elective coronary angioplasty were studied. All patients had a low ejection fraction, a large amount of viable myocardium perfused by the target artery(s) or both. Thirty-five men and 16 women, mean age 63 years, with Canadian Cardiovascular Society class III angina (23 patients) or class IV (28 patients) were studied. There was a history of myocardial infarction in 45 (88%), bypass surgery in 14 (27%) and congestive heart failure in 17 (33%). Forty-six (90%) had impaired left ventricular function. Twenty (39%) had an ejection fraction of less than or equal to 25%. Left main stenosis was present in 9 (18%), 3-vessel disease in 48 (94%) and 2-vessel disease in 2 (4%). Twenty (39%) were considered at a prohibitive risk for bypass surgery (14 were turned down for surgery). Bypass was instituted percutaneously with flows ranging from 2 to 5 liters/min (mean 3.6). Angioplasty was successful in 115 of the 117 lesions attempted with the culprit vessel dilated in all. Dilatation of the only remaining vessel was performed in 14 (27%). Inflation times up to 10 minutes were well tolerated. Bypass was discontinued after a mean bypass time of 37 minutes. Hemostasis was achieved by external clamp compression in 50. There were 3 hospital deaths unrelated to bypass. Patient follow-up at 2 to 8 months (mean 4.9) disclosed 1 late death, 31 (66%) asymptomatic patients, 12 (26%) patients in class I and 4 patients (9%) in class II. Thus, this study demonstrates the safety and efficacy of percutaneous bypass support in selected patients undergoing high-risk coronary angioplasty.

Emergency percutaneous cardiopulmonary bypass support in cardiogenic shock from acute myocardial infarction.

Emergency percutaneous cardiopulmonary bypass support was instituted in 8 consecutive patients, ages 42 to 80 years, in cardiogenic shock for 30 to 180 minutes (mean 106) due to acute myocardial infarction. The location of the infarction was inferior in 4, anterior in 3 and lateral in 1. Four patients had a history of prior myocardial infarction. Two patients were in cardiac arrest; the remaining 6 had a mean blood pressure of 43 to 55 mm Hg before the bypass. Five had pulmonary capillary Wedge pressure greater than or equal to 20 mm Hg. One patient, with a right ventricular infarction, had a pulmonary wedge pressure of 10 mm Hg. Percutaneous insertion of 20Fr cannulas was carried out. Flow rates of 3.2 to 5.2 liters/min were achieved. Two patients in cardiac arrest regained consciousness while still in ventricular fibrillation or asystole. Left ventricular ejection fraction ranged from 17 to 40% (mean 32). One patient had left main, 4 had multivessel, and 4 had 1-vessel coronary disease. Seven patients had successful angioplasty of 15 of 16 lesions attempted, with all infarct-related vessels successfully dilated. One patient had lesions unsuitable for either bypass or angioplasty and died. Need for blood transfusion was the most frequent complication. One patient required surgical repair of the femoral artery. All 7 patients are alive at a mean follow-up of 8.2 months. It is concluded that cardiopulmonary bypass can be safely instituted percutaneously, hemodynamically stabilize patients in cardiogenic shock and facilitate emergency complex coronary angioplasty, which may be life-saving.

Determinants and prognostic information provided by pulse pressure in patients with coronary artery disease undergoing revascularization. The Balloon Angioplasty Revascularization Investigation (BARI).

Arterial stiffness, as evidenced by increased pulse pressure (PP), is associated with adverse cardiovascular events. However, the prognostic importance of PP in patients who have undergone revascularization is unknown. We examined the prognostic importance of PP and predictors of increased PP in patients entered into the Balloon Angioplasty Revascularization Investigation (BARI). Estimated correlation and standardized regression coefficients were reported, indicating the relative magnitude of independent effects of baseline characteristics on PP. The independent association of PP and outcome over 5 years was determined. Baseline characteristics independently associated with PP were higher mean arterial pressure, older age, female sex, noncoronary vascular disease, history of diabetes mellitus, and history of hypertension (p <0.001 for all). Cox regression covariates significantly associated with time to death were age, smoking, male gender, diabetes history, congestive heart failure, and baseline use of angiotensin-converting enzyme inhibitors, diuretic, or digitalis. When PP was added to the model, it was found to be an independent predictor of time to death (p = 0.008). When PP and mean arterial pressure were added to the model, PP remained significantly associated with time to death (p = 0.033). When renal disease and noncoronary vascular disease were added to the model, the relative risk declined from 1.07 to 1.04 and the association was no longer statistically significant. Thus, increased PP is directly and independently associated with mean arterial pressure, hypertension, age > or =65 years, diabetes mellitus, and the presence of noncoronary vascular disease, and inversely associated with a history of myocardial infarction. After coronary revascularization, PP, reflecting arterial stiffness, is independently associated with total mortality.

Effect of antithrombotic therapy on risk of sudden coronary death in patients with congestive heart failure.

Data from epidemiologic, autopsy, Holter monitoring, and electrophysiologic studies support the hypothesis that acute myocardial ischemia, even in the absence of myocardial infarction, is a critical component of the pathophysiology of sudden coronary death. Acute myocardial ischemia superimposed upon ventricles damaged from previous infarctions has been demonstrated to enhance the generation of lethal ventricular arrhythmias. This is a retrospective analysis of 6,797 participants in the Studies of Left Ventricular Dysfunction prevention and treatment trials. Both univariate and multivariate Cox proportional-hazards modeling were used to study the association of anticoagulant and antiplatelet therapy with the risk for sudden cardiac death. The following covariates were adjusted for in the analysis: age, ejection fraction, gender, atrial fibrillation, diabetes, a history of angina, prior infarction, prior revascularization, and the regular use of beta blockers, diuretics, digoxin, antiarrhythmic agents, or enalapril. The overall incidence of sudden cardiac death per 100 patient-years of follow-up was 2.24%. In multivariate analysis, antiplatelet and anticoagulant monotherapy each remained independently associated with a reduction in the risk of sudden cardiac death: antiplatelet therapy with a 24% reduction (relative risk [RR] 0.76; 95% confidence interval [CI] 0.61-0.95) and antiplatelet monotherapy with a 32% reduction (RR 0.68; 95% CI 0.48-0.96). Thus, in patients with moderate to severe left ventricular systolic dysfunction resulting from coronary artery disease, antiplatelet and anticoagulant therapy are each associated with a reduction in the risk of sudden cardiac death.