PubMed Health⌕ Search

Biomedical subjects

Peter Sleight

Publications and source records attributed to Peter Sleight.

33 records · Page 2Linked to original sources
PubMed2003

Effects of unilateral and bilateral carotid baroreflex stimulation on cardiac and neural sympathetic discharge oscillatory patterns.

BACKGROUND: Left and right carotid baroreflex afferents participate in generating the spontaneous variability of heart rate (HR), arterial pressure (AP), and muscle sympathetic nerve activity (MSNA), but the relative contribution of each side is unclear. Pathophysiological conditions unilaterally affecting carotid baroreceptor function might result in abnormal changes of HR, AP, and MSNA variability, thus markedly affecting prognosis. We tested the hypothesis that unilateral carotid baroreceptor perturbation might differentially affect HR, AP, and MSNA variability compared with stimulation of the opposite side. METHODS AND RESULTS: In 12 healthy volunteers, 4 sinusoidal neck suction procedures (0.1 Hz, from 0 to -50 mm Hg) were applied at the right, left, and combined right and left sides of the neck, in concordance or with phase opposition. Respiration was controlled at 0.25 Hz. Power spectrum analysis assessed the changes in the 0.1-Hz oscillatory component of the R-R interval, systolic AP (SAP), and MSNA variability induced by rhythmic baroreceptor stimulation. Mean R-R interval, SAP, and MSNA were unchanged during all procedures. The increase of the 0.1-Hz component of R-R and SAP variability during right and combined right and left carotid baroreceptor stimulation was greater than the changes induced by left-sided stimulation. The increase in the 0.1-Hz oscillatory component of MSNA variability was similar during all neck suction procedures. CONCLUSIONS: Right carotid baroreflex loading was as efficient as bilateral stimulation and more effective than left carotid suction in modulating R-R and SAP variability. There was no asymmetry in neural sympathetic discharge responses after single-sided carotid baroreceptor stimulation.

Adult↗
PubMed2003

New evidence on the importance of the renin-angiotensin system in the treatment of higher-risk patients with hypertension.

We reviewed the drug treatment of hypertension in the light of recent trials. beta-Blockers and diuretics clearly reduce mortality, strokes, and coronary heart disease (CHD) in hypertension. Recent trials assessed whether newer agents that block the renin-angiotensin-aldosterone system, or calcium blockers, offer any additional advantage, or have benefits in high-risk individuals with conventionally 'normal' blood pressure. The recent ALLHAT study claimed no differences in CHD or mortality when chlorthalidone, amlodipine, and lisinopril were compared. However, the decrease in blood pressure was not the same with the three agents, and a substantial proportion of patients enrolled did not have clinical disease. In contrast, the LIFE study (comparing losartan and a beta-blocker) and the ANBP-2 study [comparing angiotensin-converting enzyme (ACE) inhibition and a diuretic] reduced blood pressure similarly, yet demonstrated benefits in favour of angiotensin II type 1 receptor blockers (ARBs) and ACE inhibitors. Other trials indicated similar advantages of ACE inhibitors or ARBs in patients with diabetic nephropathy. Among high-risk patients with initial blood pressure in the 'normal' range, ACE inhibitors significantly reduce clinical events (mortality, strokes, and myocardial infarction), despite modest decreases in blood pressure, suggesting that additional mechanisms are responsible. Recent results of the Prospective Studies Collaboration show lower risk, even in the normal blood pressure range; high-risk patients will benefit further from ACE inhibitors and ARBs (and beta-blockers after myocardial infarction). Data for other blood pressure decreasing agents are unavailable in such populations. We conclude that blood pressure decreasing per se is of clinical benefit, but drugs that block the renin-angiotensin system offer additional advantages. Drug choice is best determined by the patient's clinical condition.

Antihypertensive Agents↗
PubMed2003

Relationship of electrocardiographic left ventricular hypertrophy to mortality and cardiovascular morbidity in high-risk patients.

BACKGROUND: The prognostic significance of left ventricular hypertrophy (LVH) identified by simple electrocardiographic (ECG) criteria in high-risk patients with established cardiovascular (CV) diseases is not clearly understood. DESIGN AND METHODS: The Heart Outcomes Prevention Evaluation (HOPE) trial was a randomized trial, which evaluated the effects of ramipril and of vitamin E on major CV outcomes in 9541 men and women aged 55 years or older with a history of coronary artery disease, stroke, peripheral vascular disease or diabetes mellitus with at least one additional CV risk factor. Patients were followed for an average of 4.5 years. We evaluated the association between simple ECG criteria for LVH and the risk for major vascular events, for CV and all-cause mortality and for heart failure. RESULTS: Electrocardiographic LVH was present in 793 (8.3%) HOPE study participants. Of these, 19.0% sustained a major CV event (MI, stroke or CV death), 15.6% died and 6.1% developed heart failure compared with 15.6%, 10.8% and 2.9% respectively of those without ECG-LVH (P = 0.0023; P < 0.0001 and P < 0.0001). In multivariate analysis ECG-LVH was an independent predictor of CV and all-cause death and of heart failure. CONCLUSIONS: In patients with CV disease simple, easily applicable ECG criteria for LVH identify a subset of individuals at particularly high risk for death and for heart failure.

Aged↗
PubMed2003

Hypertrophy at ECG and its regression during treatment survey (HEART survey). Rationale, design and baseline characteristics of patients.

BACKGROUND: Left ventricular hypertrophy (LVH) detected at electrocardiography (ECG) is a predictor of an increased cardiovascular risk in essential hypertension. However, uncertainty remains concerning the reproducibility of ECG LVH and the prognostic relevance of its regression over time in hypertension. The aim of this study was to determine the prognostic value of baseline ECG LVH and its serial changes in a large cohort of hypertensive patients. METHODS: The Hypertrophy at ECG and its Regression during Treatment Survey (HEART Survey) is a prospective observational study conducted in 66 Italian centers. Inclusion criteria are essential hypertension with ECG LVH defined by the Perugia score (Cornell voltage criteria and/or a typical left ventricular "strain" pattern and/or a Romhilt-Estes score > or = 5 points) in subjects aged 45-84 years. The treatment of hypertension and other risk factors accords with current guidelines and is individually tailored. ECG is recorded twice at entry and periodically repeated over a 4-year follow-up period. Expert readers (unaware of the clinical findings) classify ECG. The incidence of major cardiovascular events in relation to baseline ECG and its changes over time are assessed, together with the reproducibility in the two baseline recordings. Overall, 708 patients aged 64 +/- 9 years have been enrolled in centers from northern (27%), central (32%) and southern (41%) Italy. Their baseline characteristics are presented. Follow-up is ongoing. CONCLUSIONS: The HEART Survey will examine the prognostic value of baseline ECG LVH and of its regression over time in a wide population of hypertensive patients.

Aged↗
PubMed2002

Who is fooling us?

Explore the source record for details and available documents.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed2002

Effect of long-term therapy with ramipril in high-risk women.

OBJECTIVES: We evaluated the effects of long-term therapy with the angiotensin-converting enzyme (ACE) inhibitor ramipril on major cardiovascular (CV) outcomes in high-risk women. BACKGROUND: The effect of long-term ACE inhibitor therapy in high-risk women without heart failure and with preserved left ventricular (LV) systolic function has not been previously reported. METHODS: The Heart Outcomes Prevention Evaluation (HOPE) trial is a large, randomized clinical trial that evaluated ramipril and vitamin E in high-risk patients. We present the preplanned analysis of the effects of ramipril in women in the HOPE study. The study randomized 2,480 women aged >or=55 years with vascular disease or diabetes and at least one additional CV risk factor and without heart failure or a known low LV ejection fraction to ramipril (10 mg/day) or placebo. The primary outcome was the composite of myocardial infarction, stroke or CV death. Average follow-up was 4.5 years. RESULTS: Treatment with ramipril resulted in reduced primary end point rates (11.3% vs. 14.9% in the placebo arm; relative risk [RR] 0.77, 95% confidence interval [CI] 0.62 to 0.96; p = 0.019), fewer strokes (3.1% vs. 4.8%; RR 0.64, 95% CI 0.43 to 0.96; p = 0.029) and fewer CV deaths (4.2% vs. 6.9%; RR 0.62, 95% CI 0.44 to 0.88; p = 0.0068). There were trends toward reduced rates of myocardial infarction, heart failure and all-cause death. The beneficial effect of ramipril was similar in women and men. CONCLUSIONS: Treatment with ramipril reduces the CV risk in high-risk women without heart failure and with preserved LV systolic function.

Aged↗
PubMed2002

Use of ramipril in preventing stroke: double blind randomised trial.

OBJECTIVE: To determine the effect of the angiotensin converting enzyme inhibitor ramipril on the secondary prevention of stroke. DESIGN: Randomised controlled trial with 2x2 factorial design. SETTING: 267 hospitals in 19 countries. PARTICIPANTS: 9297 patients with vascular disease or diabetes plus an additional risk factor, followed for 4.5 years as part of the HOPE study. OUTCOME MEASURES: Stroke (confirmed by computed tomography or magnetic resonance imaging when available), transient ischaemic attack, and cognitive function. Blood pressure was recorded at entry to the study, after 2 years, and at the end of the study. RESULTS: Reduction in blood pressure was modest (3.8 mm Hg systolic and 2.8 mm Hg diastolic). The relative risk of any stroke was reduced by 32% (156 v 226) in the ramipril group compared with the placebo group, and the relative risk of fatal stroke was reduced by 61% (17 v 44). Benefits were consistent across baseline blood pressures, drugs used, and subgroups defined by the presence or absence of previous stroke, coronary artery disease, peripheral arterial disease, diabetes, or hypertension. Significantly fewer patients on ramipril had cognitive or functional impairment. CONCLUSION: Ramipril reduces the incidence of stroke in patients at high risk, despite a modest reduction in blood pressure.

Aged↗
PubMed2002

Angiotensin II and trials of cardiovascular outcomes.

Proven cardiovascular benefit from angiotensin-converting enzyme (ACE) inhibition is a cornerstone of evidence-based medicine. The first study to show dramatic benefits from ACE inhibition was the Cooperative North Scandinavian Enalapril Survival Study (CONSENSUS-I), in which a 31% decrease in the rate of death was observed in patients with severe heart failure at the end of 1 year of enalapril treatment (p = 0.001). This result led to large long-term studies-including Survival and Ventricular Enlargement (SAVE), Acute Infarction Ramipril Efficacy (AIRE), Trandolapril Cardiac Evaluation (TRACE), and Study of Left Ventricular Dysfunction (SOLVD)-which verified that ACE inhibition decreases heart failure, myocardial infarction (MI), and mortality, and that striking benefit could be observed within 30 days. Short-term studies of patients in the acute phase of a heart attack verified that ACE inhibition provided rapid benefits. A meta-analysis of short-term (up to 8 weeks) studies of ACE inhibition (including CONSENSUS-II, Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto Miocardico [GISSI]-3, International Study of Infarct Survival [ISIS]-4, and the Chinese Captopril Study [CCS]-1) demonstrated that post-MI risk was reduced by 10% within the first day of treatment. The immediacy of the benefit suggested that ACE inhibition not only improved cardiovascular function in failing hearts but also affected important mechanisms in patients without overt heart failure. Effects on more general mechanisms of heart disease suggested that patients with problems other than hypertension or heart failure might benefit from ACE inhibitors. The Heart Outcomes Prevention Evaluation (HOPE) study investigated the hypothesis that ACE inhibition would confer benefits to patients who were at high risk for cardiovascular events, but who were without left ventricular dysfunction or heart failure. Long-term reductions in MI, stroke, cardiac arrest, and heart failure, as well as improvements in mortality, were observed in this population after treatment with ACE inhibitors. Substudies of the HOPE study revealed that ACE inhibition reduced progression of atherosclerosis and improved myocardial remodeling. Taken together, these studies provide evidence that supports treatment of a broad population of patients at risk for cardiovascular events with ACE inhibitors. The next step is to combine ACE inhibition with other treatments to maximize patient benefit. The Ongoing Telmisartan Alone and in combination with Ramipril Global Endpoint Trial (ONTARGET) will compare the efficacy of an ACE inhibitor (ramipril) with an angiotensin receptor blocker (telmisartan), and determine whether these treatments in combination will further reduce morbidity and mortality from cardiovascular disease.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed2001

Baseline Characteristics and Early Blood Pressure Control in the CONVINCE Trial.

-Blood pressure (BP) control rates around the world are suboptimal. Part 2 of the National Health and Nutrition Educational Survey (NHANES) III indicates that only 27.4% of hypertensive Americans aged 18 to 74 years have a BP of <140/90 mm Hg. We wanted to assess BP control during the first 2 years and to describe the baseline characteristics of patients enrolled in the Controlled ONset Verapamil INvestigation of Cardiovascular Endpoints (CONVINCE) Study, an international clinical trial that compares outcomes in hypertensive patients randomized to initial treatment with either controlled-onset extended-release verapamil or the investigator's choice of atenolol or hydrochlorothiazide. At randomization, BP was <140/90 mm Hg in only 20.3% of the 16 602 subjects (average+/-SD age 65.6+/-7.4 years; 56% women, 84% white/7% black/7% Hispanic). The average BP at enrollment was 148/85 mm Hg for patients taking BP medications (n=13 879) and 161/94 mm Hg for previously untreated patients (n=2723). After medication titration, with a transtelephonic computer that recommended an increase in the dose or number of antihypertensive agents whenever the BP was 140/90 mm Hg, 84.8% of the subjects attained the goal BP. During 2 years of treatment, BP control was maintained in 67% to 69% of the subjects (69% to 71% for systolic BP of <140 mm Hg and 90% for diastolic BP of <90 mm Hg). These data suggest that the control of systolic BP is more difficult than the control of diastolic BP. The US national goal of having 50% of hypertensives with a BP of <140/90 mm Hg may be achievable if a forced titration strategy is used. Interested investigators, free care and medications, and well-educated subjects may make the attainment of such a goal easier in the CONVINCE study than in the general population.

Journal Article↗
PubMed2000

Debate: Subgroup analyses in clinical trials: fun to look at - but don't believe them!

Analysis of subgroup results in a clinical trial is surprisingly unreliable, even in a large trial. This is the result of a combination of reduced statistical power, increased variance and the play of chance. Reliance on such analyses is likely to be more erroneous, and hence harmful, than application of the overall proportional (or relative) result in the whole trial to the estimate of absolute risk in that subgroup. Plausible explanations can usually be found for effects that are, in reality, simply due to the play of chance. When clinicians believe such subgroup analyses, there is a real danger of harm to the individual patient.

Journal Article↗
PubMed1995

Streptokinase Is Still the Agent of Choice for Most Patients with Myocardial Infarction.

I believe streptokinase is still the trombolytic of choice for the majority of patients with acute myocardial infarction for the following reasons: 1. The superiority of alteplase over streptokinase rests on insecure grounds, statistically (when net clinical benefit is computed for the SK/subcutaneous heparin arm versus the accelerated t-PA arm, the P value is only 0.04). 2. The excess of cerebral haemorrhage with t-PA is statistically highly significant and consistent over all trials. 3. Patients at greater risk of cerebral hemorrhage are those with raised systolic arterial pressure above about 130 to 140 on admission and those aged over about 55 years. These comprise the majority of patients admitted to ordinary Coronary Care Units. If t-PA is given to patients at low risk of cerebral hemorrhage, the extra cost per life saved will be very high, since such patients are at relatively low risk in any case. 4. The open design of the GUSTO-2 trial (the only trial showing a small mortality benefit for accelerated t-PA versus SK) introduces the possibility of bias. For example, unfamiliarity with SK in North American centers may have given risk to premature stopping of treatment because of hypotension; this might have resulted in a more favorable experience for accelerated t-PA in North American centers compared with the rest of the world. (The mortality benefit for accelerated t-PA in the GUSTO trial was seen only in North American centers.)

Journal Article↗
PubMedDate not supplied

Principal results of the Controlled Onset Verapamil Investigation of Cardiovascular End Points (CONVINCE) trial.

CONTEXT: Hypertensive patients are often given a calcium antagonist to reduce cardiovascular disease risk, but the benefit compared with other drug classes is controversial. OBJECTIVE: To determine whether initial therapy with controlled-onset extended-release (COER) verapamil is equivalent to a physician's choice of atenolol or hydrochlorothiazide in preventing cardiovascular disease. DESIGN, SETTING, AND PARTICIPANTS: Double-blind, randomized clinical trial conducted at 661 centers in 15 countries. A total of 16 602 participants diagnosed as having hypertension and who had 1 or more additional risk factors for cardiovascular disease were enrolled between September 1996 and December 1998 and followed up until December 31, 2000. After a mean of 3 years of follow-up, the sponsor closed the study before unblinding the results. INTERVENTION: Initially, 8241 participants received 180 mg of COER verapamil and 8361 received either 50 mg of atenolol or 12.5 mg of hydrochlorothiazide. Other drugs (eg, diuretic, beta-blocker, or an angiotensin-converting enzyme inhibitor) could be added in specified sequence if needed. MAIN OUTCOME MEASURES: First occurrence of stroke, myocardial infarction, or cardiovascular disease-related death. RESULTS: Systolic and diastolic blood pressure were reduced by 13.6 mm Hg and 7.8 mm Hg for participants assigned to the COER verapamil group and by 13.5 and 7.1 mm Hg for partcipants assigned to the atenolol or hydrochlorothiazide group. There were 364 primary cardiovascular disease-related events that occurred in the COER verapamil group vs 365 in atenolol or hydrochlorothiazide group (hazard ratio [HR], 1.02; 95% confidence interval [CI], 0.88-1.18; P =.77). For fatal or nonfatal stroke, the HR was 1.15 (95% CI, 0.90-1.48); for fatal or nonfatal myocardial infarction, 0.82 (95% CI, 0.65-1.03); and for cardiovascular disease-related death, 1.09 (95% CI, 0.87-1.37). The HR was 1.05 (95% CI, 0.95-1.16) for any prespecified cardiovascular disease-related event and 1.08 (95% CI, 0.93-1.26) for all-cause mortality. Nonstroke hemorrhage was more common with participants in the COER-verapamil group (n = 118) compared with the atenolol or hydrochlorothiazide group (n = 79) (HR, 1.54 [95% CI, 1.16-2.04]; P =.003). More cardiovascular disease-related events occurred between 6 AM and noon in both the COER verapamil (99/277) and atenolol or hydrochlorothiazide (88/274) groups; HR, 1.15 (95% CI, 0.86-1.53). CONCLUSIONS: The CONVINCE trial did not demonstrate equivalence of a COER verapamil-based antihypertensive regimen compared with a regimen beginning with a diuretic or beta-blocker. When considered in the context of other trials of calcium antagonists, these data indicate that the effectiveness of calcium-channel therapy in reducing cardiovascular disease is similar but not better than diuretic or beta-blocker treatment.

Adrenergic beta-Antagonists↗