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Biomedical subjects

L W Stevenson

Publications and source records attributed to L W Stevenson.

At least 19 recordsLinked to original sources
PubMed2001

Prognostic importance of elevated jugular venous pressure and a third heart sound in patients with heart failure.

BACKGROUND: The independent prognostic value of elevated jugular venous pressure or a third heart sound in patients with heart failure is not well established. METHODS: We performed a retrospective analysis of the Studies of Left Ventricular Dysfunction treatment trial, in which 2569 patients with symptomatic heart failure or a history of it were randomly assigned to receive enalapril or placebo. The mean (+/-SD) follow-up was 32+/-15 months. The presence of elevated jugular venous pressure or a third heart sound was ascertained by physical examination on entry into the trial. The risks of hospitalization for heart failure and progression of heart failure as defined by death from pump failure and the composite end point of death or hospitalization for heart failure were compared in patients with these findings on physical examination and patients without these findings. RESULTS: Data on 2479 patients were complete and analyzed. In multivariate analyses that were adjusted for other markers of the severity of heart failure, elevated jugular venous pressure was associated with an increased risk of hospitalization for heart failure (relative risk, 1.32; 95 percent confidence interval, 1.08 to 1.62; P<0.01), death or hospitalization for heart failure (relative risk, 1.30; 95 percent confidence interval, 1.11 to 1.53; P<0.005), and death from pump failure (relative risk, 1.37; 95 percent confidence interval, 1.07 to 1.75; P<0.05). The presence of a third heart sound was associated with similarly increased risks of these outcomes. CONCLUSIONS: In patients with heart failure, elevated jugular venous pressure and a third heart sound are each independently associated with adverse outcomes, including progression of heart failure. Clinical assessment for these findings is currently feasible and clinically meaningful.

Aged↗
PubMed2001

Spinal cord stimulation for chronic intractable angina pectoris: a unified theory on its mechanism.

The use of spinal cord stimulation (SCS) for chronic intractable anginal pain was first described in 1987. Numerous studies have demonstrated its efficacy in improving exercise tolerance, decreasing frequency of anginal episodes, and prolonging time to electrocardiographic signs of ischemia. This review will examine the potential mechanisms of this antianginal effect and propose a unified hypothesis explaining it. The effect of SCS involves a mutual interaction of decreased pain, decreased sympathetic tone, and a likely redistribution of myocardial blood flow to ischemic regions. Spinal cord stimulation reduces the transmission of nociceptive impulse via the spinothalamic tract due to an enhanced release of gamma aminobutyric acid (GABA) from dorsal horn interneurons. Improvement of myocardial blood flow at the microvascular level has been demonstrated by positron emission tomography (PET). A decreased sympathetic tone has been shown by norepinephrine kinetics, tests of sympathetic reflexes, and the use of ganglionic blockers. We hypothesize that SCS exerts its beneficial effects by decreasing pain and decreasing sympathetic tone, the result of which is decreased myocardial oxygen consumption along with an improved myocardial microcirculatory blood flow.

Angina Pectoris↗
PubMed2001

Prognostic impact of diabetes mellitus in patients with heart failure according to the etiology of left ventricular systolic dysfunction.

OBJECTIVES: We sought to determine the relative impact of diabetes mellitus on prognosis in ischemic compared with nonischemic cardiomyopathy. BACKGROUND: Ischemic myocardium is characterized by increased reliance on aerobic and anaerobic glycolysis. Because glucose utilization by cardiomyocytes is an insulin-mediated process, we hypothesized that diabetes would have a more adverse impact on mortality and progression of heart failure in ischemic compared with nonischemic cardiomyopathy. METHODS: We performed a retrospective analysis of the Studies Of Left Ventricular Dysfunction (SOLVD) Prevention and Treatment trials. RESULTS: In adjusted analyses, diabetes mellitus was strongly associated with an increased risk for all-cause mortality in patients with ischemic cardiomyopathy, (relative risk [RR] 1.37, 95% confidence interval [CI] 1.21 to 1.55; p < 0.0001), but not in those with nonischemic cardiomyopathy (RR 0.98, 95% CI 0.76 to 1.32; p = 0.98). The increased mortality in patients with ischemic cardiomyopathy compared with nonischemic cardiomyopathy was limited to those with ischemic cardiomyopathy and diabetes mellitus (RR 1.37, 95% CI 1.21 to 1.56; p < 0.0001). When patients with ischemic cardiomyopathy and diabetes mellitus were excluded, there was no significant difference in mortality risk between the ischemic and nonischemic cardiomyopathy groups after adjusted analysis (RR 0.99, 95% CI 0.86 to 1.15; p = 0.99). Previous surgical revascularization identified patients within the cohort with ischemic cardiomyopathy and diabetes mellitus, with improved prognosis. CONCLUSIONS: The differential impact of diabetes on mortality and heart failure progression according to the etiology of heart failure suggests that diabetes and ischemic heart disease interact to accelerate the progression of myocardial dysfunction. Evaluation of the potential for revascularization may be particularly important in patients with ischemic cardiomyopathy and diabetes mellitus.

Cohort Studies↗
PubMed2001

Preferences for quality of life or survival expressed by patients with heart failure.

BACKGROUND: As many patients with heart failure develop symptoms limiting daily life, newer therapies may be found to improve functional status without concomitant survival benefit. As some of these therapies may actually increase mortality, it is increasingly relevant to assess patients' preferences for survival vs improvement in symptoms. METHODS: We enrolled 99 patients with advanced heart failure (ejection fraction 24 +/- 10, duration 6 +/- 5 years). Each patient completed time trade-off and standard gamble instruments, Minnesota Living with Heart Failure questionnaires and visual analog scales for dyspnea and overall health. Jugular venous pressure was assessed in all patients and peak oxygen consumption was measured during bicycle exercise in 60 patients. RESULTS: Strong polarity of preference toward either survival or quality of life was expressed by 60% of patients. There was good correlation between time trade-off and standard gamble utility scores (r = 0.64), and between preference and functional class (r = 0.60). Higher jugular venous pressure and lower peak oxygen consumption were associated with poorer utility scores (p <.05). Higher dyspnea scores and worse Living with Heart Failure scores were also associated with preference to trade time or take risks for better health. CONCLUSIONS: These findings suggest that heart failure patients express meaningful preferences about quality vs length of life. High jugular venous pressure, low peak oxygen consumption and poor Living with Heart Failure scores were related to low utility scores. These cannot be assumed, however, to predict the intensity of individual preference to trade nothing or virtually everything for better health.

Adult↗
PubMed2001

Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness (ESCAPE): design and rationale.

BACKGROUND: There is little information about how to adjust pharmacologic agents in the treatment of patients with advanced congestive heart failure (CHF). Some studies have suggested that use of pulmonary artery catheterization to guide reductions in filling pressures may improve outcomes for patients with heart failure who are hospitalized with evidence of elevated filling pressures. However, there is no consensus regarding the true utility of this strategy. A randomized clinical trial is needed to test the safety, efficacy, and treatment benefit of pulmonary artery catheterization in patients with advanced CHF. STUDY DESIGN: The Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness (ESCAPE) trial is a multicenter, randomized trial designed to test the long-term safety and efficacy of treatment guided by hemodynamic monitoring and clinical assessment versus that guided by clinical assessment alone in patients hospitalized with New York Heart Association class IV CHF. Five hundred patients will be randomly assigned to receive either medical therapy guided by a combination of clinical assessment and hemodynamic monitoring (PAC arm) or medical therapy guided by clinical assessment alone (CLIN arm). The primary end point of ESCAPE will be the number of days that patients are hospitalized or die during the 6-month period after randomization. Secondary end points will include changes in mitral regurgitation, peak oxygen consumption, and natriuretic peptide levels. Other secondary end points will be pulmonary artery catheter-associated complications, resource utilization, quality of life measures, and patient preferences regarding survival. IMPLICATIONS: The primary goal of ESCAPE will be to provide information about the utility of the pulmonary artery catheter in patients with advanced heart failure, independent of various treatment approaches used by individual physicians. In addition, this study will define current outcomes for this severely compromised population.

Catheterization, Swan-Ganz↗
PubMed2000

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.

Aged↗
PubMed2000

Randomized trial of candesartan cilexetil in the treatment of patients with congestive heart failure and a history of intolerance to angiotensin-converting enzyme inhibitors.

BACKGROUND: Many patients with congestive heart failure do not receive the benefits of angiotensin-converting enzyme (ACE) inhibitors because of intolerance. We sought to determine the tolerability of an angiotensin II receptor blocker, candesartan cilexetil, among patients considered intolerant of ACE inhibitors. METHODS: Patients with CHF, left ventricular ejection fraction less than 35%, and history of discontinuing an ACE inhibitor because of intolerance underwent double-blind randomization in a 2:1 ratio to receive candesartan (n = 179) or a placebo (n = 91). The initial dosage of candesartan was 4 mg/d; the dosage was increased to 16 mg/d if the drug was tolerated. A history of intolerance of ACE inhibitor was attributed to cough (67% of patients), hypotension (15%), or renal dysfunction (11%). RESULTS: The study drug was continued for 12 weeks by 82.7% of patients who received candesartan versus 86.8% of patients who received the placebo. This 4.1% greater discontinuation rate with active therapy was not significant; the 95% confidence interval ranged from 4.8% more discontinuation with placebo to 13% more with candesartan. Titration to the 16-mg target dose was possible for 69% of patients who received candesartan versus 84% of those who received the placebo. Frequencies of death and morbidity were not significantly different between the candesartan and placebo groups (death 3.4% and 3.3%, worsening heart failure 8.4% and 13.2%, myocardial infarction 2.8% and 5.5%, all-cause hospitalization 12.8% and 18.7%, and death or hospitalization for heart failure 11.7% and 14.3%). CONCLUSIONS: Candesartan was well tolerated by this population. The effect of candesartan on major clinical end points, including death, remains to be determined.

Aged↗
PubMed2000

Drug therapy of heart failure caused by systolic dysfunction in the elderly.

The presence of multiple medical illnesses often distinguishes elderly patients with heart failure and can make pharmacologic management of symptomatic heart failure challenging in this population. Physiologic changes that occur with normal aging may complicate clinical assessment. Limited data from large clinical trials of heart failure therapy are applicable to aged patients. Available data suggest that elderly patients should be treated with the same regimen as younger patients but that more careful attention should be paid to dosing, especially when initiating a new drug. History and physical examination techniques can be used to uncover evidence of congestion and inadequate perfusion and are critical adjuncts when making therapeutic decisions. The objectives of therapy for elderly patients with heart failure must be individualized within the larger context of patients' goals and stage of life.

Adrenergic Antagonists↗
PubMed2000

Early outcome of initiating amiodarone for atrial fibrillation in advanced heart failure.

BACKGROUND: Little information exists about the early outcomes of initiating amiodarone for atrial fibrillation in patients with advanced heart failure. This study assessed the initial rate of success and complications of amiodarone therapy initiated for patients with atrial fibrillation during hospitalization for heart failure. METHODS: We reviewed medical records for 37 consecutive patients with left ventricular ejection fractions </=40% who underwent initiation of amiodarone for atrial fibrillation during hospitalization on a heart failure service. RESULTS: Atrial fibrillation was present in 35 (95%) and atrial flutter in 2 (5%), with mean duration of 30 months. New York Heart Association class was 3.1 (+/-1.1). Left ventricular ejection fraction was 24% +/- 7%. All patients had received oral amiodarone with an initial dose of 1.2 +/- 0.2 g/day. Bradyarrhythmia led to discontinuation of digoxin in 12 (32%) patients and to permanent pacemaker placement in 7 (19%) patients. Conversion to sinus rhythm occurred spontaneously in 2 patients and after electrical cardioversion in 26 patients, for an initial success of 76%. After a median follow-up of 9.5 months, 21 of 37 (57%) patients remained in sinus or atrial-paced rhythm. Amiodarone complications occurred after discharge in 5 (14%) patients, 4 with hypothyroidism. CONCLUSIONS: Amiodarone with electrical cardioversion has a high initial success rate for treatment of atrial fibrillation in patients with heart failure with advanced systolic dysfunction. The major early side effect was bradyarrhythmia, frequently requiring discontinuation of digoxin or permanent pacemaker placement.

Administration, Oral↗