PubMed Health⌕ Search

Biomedical subjects

M R Cowie

Publications and source records attributed to M R Cowie.

At least 19 recordsLinked to original sources
PubMed2006

A high prevalence of sleep disordered breathing in men with mild symptomatic chronic heart failure due to left ventricular systolic dysfunction.

BACKGROUND: Sleep disordered breathing (SDB) is common in severe chronic heart failure (CHF) and is associated with increased morbidity and mortality. The prevalence of SDB in mild symptomatic CHF is unknown. AIM: The aim of this study was to determine the prevalence and characteristics of SDB in male patients with NYHA class II symptoms of CHF. METHODS AND RESULTS: 55 male patients with mild symptomatic CHF underwent assessment of quality of life, echocardiography, cardiopulmonary exercise, chemoreflex testing and polysomnography. 53% of the patients had SDB. 38% had central sleep apnoea (CSA) and 15% had obstructive sleep apnoea. SDB patients had steeper VE/VCO(2) slope [median (inter-quartile range) 31.1 (28-37) vs. 28.1 (27-30) respectively; p=0.04], enhanced chemoreflexes to carbon dioxide during wakefulness [mean+/-sd: 2.4+/-1.6 vs. 1.5+/-0.7 %VE Max/mmHg CO(2) respectively; p=0.03], and significantly higher levels of brain natriuretic peptide and endothelin-1 compared to patients without SDB. No differences in left ventricular ejection fraction, percent predicted peak oxygen uptake, or symptoms of SDB were observed. CONCLUSIONS: A high prevalence of SDB was found in men with mild symptomatic CHF. Patients with SDB could not be differentiated by symptoms or by routine cardiac assessment making clinical diagnosis of SDB in CHF difficult.

Aged↗
PubMed2006

Can heart rate variation rule out sleep-disordered breathing in heart failure?

In patients with obstructive sleep apnoea (OSA), the very low frequency power spectral density index (VLFI) derived from analysis of heart rate correlates with the severity of obstructive apnoeas. VLFI is also associated with Cheyne-Stokes respiration/central sleep apnoea (CSR/CSA) in congestive heart failure (CHF). The present authors have tested the hypothesis that per cent VLFI, derived from a standard Holter ECG recording, can be used to detect the presence of OSA and CSR/CSA in patients with mild-to-moderate CHF. In total, 60 CHF patients underwent polysomnography with monitoring of heart rate. Data from 33 patients were analysed for per cent VLFI. Of the 60 patients, 27 were excluded due to atrial fibrillation, extensive pacing or frequent ventricular extra systoles. Receiver operator characteristic curves were constructed to establish the per cent VLFI that would optimally identify the presence or absence of sleep-disordered breathing. Using an apnoea-hypopnoea index>20 events.h-1 and setting the per cent VLFI at 2.23% yielded a sensitivity of 85%, specificity of 65%, positive predictive value of 61% and a negative predictive value of 87%. The latter increased to 100% when using an apnoea-hypopnoea cut-off of 30 events.h-1. In conclusion, these results suggest that spectral analysis of heart rate may be useful as a "rule-out test" for sleep-disordered breathing in patients with mild-to-moderate congestive heart failure.

Female↗
PubMed2005

Simultaneous treatment of hypertension and dyslipidaemia may help to reduce overall cardiovascular risk: focus on amlodipine/atorvastatin single-pill therapy.

Single-pill amlodipine besylate/atorvastatin calcium (Caduet), Pfizer Inc, NY, USA) is the first therapy aimed at the simultaneous treatment of hypertension (HTN) and dyslipidaemia (DYS). The benefits of lowering blood pressure (BP) in patients with HTN and lowering cholesterol in patients with DYS are well known and well studied. However, worldwide, many patients with HTN have concomitant DYS, which places them at greater risk for cardiovascular disease compared with patients with just one of these risk factors. Clinical trials have demonstrated that amlodipine plus atorvastatin can be safely co-administered across the dose range. Single-pill amlodipine/atorvastatin reduces both BP and cholesterol and may help to improve the management of patients with concomitant HTN and DYS.

Amlodipine↗
PubMed2004

B type natriuretic peptide testing: where are we now?

It is possible that plasma BNP measurement might be to heart failure what glycated haemoglobin measurement is to diabetes mellitus. Indeed, within 12-24 months, BNP testing might become a routine addition to the monitoring of patients with heart failure. In the meantime its main role is in helping to rule out heart failure in patients with new symptoms

Biomarkers↗
PubMed2003

The use of hospital admission data as a measure of outcome in clinical studies of heart failure.

AIM: To describe and evaluate the methods currently used to summarize, depict, and analyse hospitalization data in clinical studies of patients with heart failure. METHODS AND RESULTS: Studies published during 1999 and 2000 were reviewed if they reported hospitalization data collected during the follow-up of a defined group of adults who had been diagnosed as having heart failure. Of 130 studies identified, the majority considered only the first of any hospital admissions for each individual. When presented, statistical analyses in 70% of papers, and graphics in 75% of papers, were based purely on the first hospitalization. A minority of papers based analyses on the number of admissions (23%), or the amount of time spent in hospital by patients (14%) during the follow-up period. CONCLUSIONS: Data on the hospitalizations undergone by patients with heart failure are potentially informative about the disease burden to individuals and health services. The widespread practice of focussing a statistical analysis on the first admission a patient undergoes discards those aspects of hospitalization that are informative about disease burden: multiple admissions and length of stay. Statistical methods that incorporate these aspects appeared in a handful of papers, and the more widespread adoption of these is desirable.

Data Collection↗
PubMed2003

Clinical applications of B-type natriuretic peptide (BNP) testing.

Many claims have been made in recent years regarding the utility of plasma B-type natriuretic peptide (BNP) concentration measurements in the diagnosis, risk stratification and monitoring of patients with heart failure. This paper summarizes the current evidence and provides guidance for practising clinicians. Overall, plasma BNP testing appears to be of most value in the diagnostic arena, where it is likely to improve the performance of non-specialist physicians in diagnosing heart failure. In clinical practice, BNP testing is best used as a 'rule out' test for suspected cases of new heart failure in breathless patients presenting to either the outpatient or emergency care settings; it is not a replacement for echocardiography and full cardiological assessment, which will be required for patients with an elevated BNP concentration. Although work is ongoing in establishing the 'normal' values of BNP, heart failure appears to be highly unlikely below a plasma concentration of 100 pg/ml. However, as BNP levels rise with age and are affected by gender, comorbidity and drug therapy, the plasma BNP measurement should not be used in isolation from the clinical context.

Ambulatory Care↗
PubMed2002

Hospitalization of patients with heart failure: a population-based study.

AIMS: To describe the clinical course of heart failure in a population-based sample of incident cases, and to identify factors predicting hospitalization and mortality. METHODS AND RESULTS: Three hundred and thirty-two incident cases were identified over 15 months; 208 inpatients and 124 outpatients. Thirty-eight inpatients died during the first hospital admission (case fatality 18%) leaving 294 at risk of subsequent hospitalization. Over an average follow-up of 19 months, 173 cases were hospitalized on 311 occasions. Two hundred and twenty-four (72%) of these admissions were unplanned, with 51% due to worsening heart failure. One hundred and ten cases died over the same period. Cases diagnosed as an inpatient had 26 more admissions for worsening heart failure per 100 cases during follow-up (95% CI 9 to 44) compared to cases diagnosed as an outpatient, and also a higher mortality (hazard ratio 3.1 (95% CI 1.9 to 5.1)). Age was the only factor associated with an increased risk of hospitalization for worsening heart failure, but age, functional class and serum creatinine were predictive of mortality. CONCLUSIONS: New cases of heart failure are at high risk of subsequent hospitalization, especially during the first months after diagnosis. Whilst predicting which patients will be hospitalized is difficult, interventions designed to reduce hospitalizations for worsening heart failure should be targeted at elderly inpatients with a new diagnosis.

Age Factors↗
PubMed2001

Coronary artery disease as the cause of incident heart failure in the population.

AIMS: New approaches in the treatment of ischaemic left ventricular dysfunction, including revascularization, make it increasingly important to identify heart failure cases resulting from coronary artery disease. Without angiography these cases may be missed. We investigated the frequency of coronary artery disease in incident cases of heart failure in the population. METHODS AND RESULTS: We identified all incident cases of heart failure in a population of 292 000 in South London, U.K. by monitoring patients admitted to hospital and through a rapid access heart failure clinic. The presence and severity of coronary artery disease was identified by coronary angiography in patients under 75 years. Myocardial perfusion scanning was used to elucidate the aetiological significance of the coronary artery disease and identify hibernating myocardium. Three hundred and thirty-two cases of new heart failure were identified over 15 months. One hundred and thirty-six cases were under 75 years and angiography was undertaken in 99/136 (73%). Coronary artery disease was the aetiology in 71/136 (52%). In 18 of these 71 cases (25%), the aetiology was not recognised to be due to coronary artery disease prior to angiography, including eight cases with hibernating myocardium. CONCLUSION: Coronary artery disease is the cause of 52% (95% CI 43-61%) of incident heart failure in the general population under 75 years. Clinical assessment without angiography under-estimates the proportion of patients with coronary artery disease, and fails to identify those patients who may benefit from revascularization.

Adult↗
PubMed2000

A Rapid Access Heart Failure Clinic provides a prompt diagnosis and appropriate management of new heart failure presenting in the community.

BACKGROUND AND AIMS: The diagnosis of heart failure is an important clinical problem and yet reported diagnostic accuracy in primary care is less than 50%. We established a Rapid Access Heart Failure Clinic (RAHFC) in a district general hospital serving a population of 292,000 in SE London, UK, to diagnose and manage new cases of heart failure presenting for the first time in the community. METHODS: Patients with suspected new onset heart failure were referred by their Primary Care Physician without appointment for clinical assessment on the same or next working day. Assessment by a specialist registrar in cardiology included history, examination, chest X-ray, electrocardiogram (ECG) and echocardiogram. When a diagnosis of heart failure was made appropriate treatment, including angiotensin converting enzyme inhibitors (ACEI), was started. RESULTS: Over 15 months 383 patients were seen (0.4 cases/100,000 population/weekday) 178/383 (46%) were considered to have definite or possible heart failure at the initial assessment in the RAHFC. A normal ECG (negative predictive value 94%) and chest X-ray virtually excluded the diagnosis of heart failure. After subsequent specialist investigations and follow-up, including a trial of therapy where appropriate, 101/383 (26%) were finally diagnosed as clinical heart failure. ACEI therapy was commenced in 56/57 (98%) of patients in whom it was considered appropriate. CONCLUSION: The RAHFC provided rapid assessment, prompt diagnosis and early introduction of life prolonging therapy for patients presenting with suspected heart failure in the community.

Aged↗
PubMed2000

Survival of patients with a new diagnosis of heart failure: a population based study.

OBJECTIVE: To describe the survival of a population based cohort of patients with incident (new) heart failure and the clinical features associated with mortality. DESIGN: A population based observational study. SETTING: Population of 151 000 served by 82 general practitioners in west London. PATIENTS: New cases of heart failure were identified by daily surveillance of acute hospital admissions to the local district general hospital, and by general practitioner referral of all suspected new cases of heart failure to a rapid access clinic. INTERVENTIONS: All patients with suspected heart failure underwent clinical assessment, and chest radiography, ECG, and echocardiogram were performed. A panel of three cardiologists reviewed all the data and determined whether the definition of heart failure had been met. Patients were subsequently managed by the general practitioner in consultation with the local cardiologist or admitting physician. MAIN OUTCOME MEASURES: Death, overall and from cardiovascular causes. RESULTS: There were 90 deaths (83 cardiovascular deaths) in the cohort of 220 patients with incident heart failure over a median follow up of 16 months. Survival was 81% at one month, 75% at three months, 70% at six months, 62% at 12 months, and 57% at 18 months. Lower systolic blood pressure, higher serum creatinine concentration, and greater extent of crackles on auscultation of the lungs were independently predictive of cardiovascular mortality (all p < 0.001). CONCLUSIONS: In patients with new heart failure, mortality is high in the first few weeks after diagnosis. Simple clinical features can identify a group of patients at especially high risk of death.

Adult↗