Biomedical subjects

Chris Ellis

Publications and source records attributed to Chris Ellis.

11 recordsLinked to original sources

PubMed2006

PHARMAC and the statin debacle.

Statins are lipid-modifying drugs which dramatically lower the total and low-density lipoprotein cholesterol levels and have been shown in large clinical trials to reduce the rate of vascular events, including heart attacks, strokes, and death. For every 1% reduction in the LDL cholesterol level, the relative risk for major coronary heart disease events is reduced by approximately 1%. Since the landmark Scandinavian Simvastatin Survival Study (4S) was published in 1994, multiple further clinical trials have reinforced the benefits of treating large numbers of patients with statins with the emphasis on achieving low LDL cholesterol levels (currently 1.6 mmol/L) for the optimal management of patients at very high risk. However PHARMAC's actions since statins were first available have significantly impaired the optimal management of New Zealand patients. A review of the methods employed during the statin era is a useful exercise in understanding how PHARMAC functions and emphasises the point that rather than achieving low-cost prices for drugs, PHARMAC simply impedes the timely delivery of modern medicines to New Zealand patients.

Drug Evaluation↗

PubMed2006

High-resolution intravital NADH fluorescence microscopy allows measurements of tissue bioenergetics in rat ileal mucosa.

OBJECTIVES: NADH fluorescence microscopy has been used as an index of the metabolic state of tissue but is associated with various obstacles such as low spatial resolution and quenching effects of blood pigments that prevent reliable monitoring of tissue bioenergetics. The objective of this study was to develop a system to monitor tissue bioenergetics in vivo using NADH fluorescence microscopy in the rat ileal mucosa. MATERIALS AND METHODS: Using an inverted microscope with an epifluorescence unit and an intensified charge-coupled device camera, NADH fluorescence images were visualized. Fluorescence intensity was measured of beta-NADH solutions at varying concentration (n = 6) and pH (n = 3) and in ex vivo (n = 6) and in vivo (n = 6) preparations of ileal mucosa of Sprague-Dawley rats anesthetized with isoflurane. RESULTS: Intravital fluorescence microscopy reveals a map of the microcirculation that permits visualization of NADH fluorescence and intercapillary areas. The system was adjusted so a linear relationship between physiological concentrations of beta-NADH and fluorescence was achieved (r(2) = 0.98, p < .0001). Decreasing the pH of the solution had no effect on fluorescence intensity and fluorescence intensity in an anoxic ex vivo ileal segment was similar to that of the in vivo ileum after ischemia. Ischemia also resulted in spatial heterogeneity that was abolished by the addition of a 550-nm LP filter. CONCLUSIONS: With this system, intravital NADH fluorescence microscopy provides the high resolution necessary to reliably monitor tissue bioenergetics in the rat ileal mucosa.

Animals↗

PubMed2005

PHARMAC and lack of funding for clopidogrel.

Clopidogrel is an antiplatelet drug that has been shown in several trials to reduce clinical events such as cardiovascular death, stroke, and myocardial infarction when compared to aspirin in a broad range of patients with atherosclerotic vascular disease. Clopidogrel has also been shown to reduce the same events by 20% when added to aspirin in patients with unstable angina and also in patients undergoing coronary artery stenting. Despite this information being available for 5 to 10 years, guideline recommendations, and the knowledge that 5% of patients have major allergy to aspirin, New Zealand patients have only been able to receive funded clopidogrel for a short period, typically 3 weeks, after coronary artery stenting. We believe this is an example where New Zealanders have been denied treatments, despite a strong evidence-base, by PHARMAC's actions of delaying the funding of new drugs. We need to have a better process whereby New Zealanders can rapidly access new treatments.

Clopidogrel↗

PubMed2005

Symptom experiences, symptom attributions, and causal attributions in patients following first-time myocardial infarction.

We examined symptom experiences, symptom attributions, and causal attributions reported by patients hospitalized for a first-time myocardial infarction (MI). We also explored the roles of symptoms, negative affect, and risk factors in promoting stress and other causal attributions. Patients (N = 65) completed measures of symptom experiences and attributions, perceived causes of their MI, state and trait negative affect, and risk factors. Patients attributed most of their symptoms to the heart condition, although rates varied from 48% (headaches) to 97% (nausea). The most common causal attribution was stress, followed by high cholesterol, heredity, fat consumption, and hypertension. Stress attributions were positively associated with state anxiety and specific, stress-related symptoms (e.g., fatigue and breathlessness). Anxious mood and stress-related symptoms appear to enhance the plausibility of stress as a cause of MI. Risk factors were moderately correlated with associated causal attributions. For many patients, however, attributions to hypertension, cholesterol, and family history of heart disease were discordant with their clinical data. Causal attributions remained stable over the subsequent 6 months.

Affect↗

PubMed2004

Management of patients admitted with an Acute Coronary Syndrome in New Zealand: results of a comprehensive nationwide audit.

AIMS: To audit all patients presenting to a New Zealand hospital with a myocardial infarction or unstable angina (an acute coronary syndrome [ACS]) over a 14-day period, to assess their number, presentation type and patient management during the hospital admission. METHODS: We formed a group of clinicians to lead the local audit process with one representative for each hospital (n=36) that admitted ACS patients. A comprehensive data form was used to record individual patient information for patients admitted between 0000 hours on 13 May 2002 to 2400 hours on 26 May 2002. RESULTS: 930 patients were admitted with a suspected or definite ACS: 11% with a ST-segment-elevation myocardial infarction (STEMI), 31% with a non-STEMI, 36% with unstable angina pectoris (UAP), and 22% with another cardiac or medical diagnosis. Cardiac investigations were limited: echocardiogram (20%), exercise treadmill test (20%), cardiac angiogram (21%). In-hospital revascularisation rates were low for those patients with a definite presentation with an ACS (STEMI, non-STEMI, UAP, n=721). Percutaneous coronary intervention (PCI) rates were 13%, 8%, and 4%--with coronary artery bypass grafting (CABG) rates being 4%, 3%, and 4% respectively. The use of discharge medications of proven benefit was also generally low (n=695): aspirin (82%), clopidogrel (8%), beta-adrenergic blockers (63%), angiotensin converting enzyme (ACE) inhibitors (43%), and statins (55%). CONCLUSIONS: A collaborative group of clinicians has performed a nationwide audit of acute coronary syndrome patients, which has demonstrated low levels of investigations, evidence-based treatments, and revascularisation. There is a need for a comprehensive national strategy--particularly for continuing audit of the treatment of patients presenting with a suspected or definite acute coronary syndrome to a New Zealand hospital.

Adult↗

PubMed2004

Acute Coronary Syndrome patients in New Zealand receive less invasive management when admitted to hospitals without invasive facilities.

AIM: To compare differences in the presentation and management of acute coronary syndrome (ACS) patients presenting to interventional versus non-interventional New Zealand hospitals. METHODS: We assessed the data collected by the New Zealand Cardiac Society ACS Audit Group over 14 days from each hospital in New Zealand (n=36) that admits ACS patients. Patient management at intervention centres (5 public, 3 private) was compared with non-intervention centres (28 public). Investigations and revascularisation procedures performed on transferred patients were attributed to the referring centre. RESULTS: From 0000 hours on 13 May 2002 to 2400 hours on 26 May 2002, 930 patients were admitted to a New Zealand hospital with a suspected or definite ACS: ST-segment-elevation myocardial infarction [STEMI] (11%), non-STEMI (31%), unstable angina pectoris [UAP] (36%), or another cardiac or medical diagnosis (22%). Patients admitted to a non-intervention centre (n=612) were the same age (median 70 years) with similar risk factors, but were more likely to be Maori (8.2% vs 3.8%, p=0.0063) and were less likely to have a history of prior cardiac angiography (26% vs 28%, p=0.02) or percutaneous coronary intervention [PCI] (9.6% vs 14%, p=0.03) than patients admitted to an intervention centre (n=318). Patients admitted to a non-intervention centre were more likely to have a chest X-ray (88% vs 81%, p<0.0024), as likely to have an exercise treadmill test (20% vs 22%, p=0.39), but less likely to receive an echocardiogram (17% vs 26%, p<0.0005), a cardiac angiogram (17% vs 30%, p<0.0001), or neither a treadmill nor a cardiac angiogram (68% vs 53%, p<0.0001) for cardiac risk assessment. For patients with a definite ACS presentation (STEMI, Non-STEMI, UAP, n=721), PCI was performed less often for patients admitted to non-intervention centres: 3% vs 14% (p<0.0001), although the rate of coronary artery bypass grafting was similar: 3% vs 5% (p=0.16). CONCLUSION: Patients admitted to a hospital without cardiac interventional facilities receive fewer investigations and less revascularisation than patients admitted to Intervention Centres. Hence patients admitted with an acute coronary syndrome in New Zealand receive inequitable management. A comprehensive National strategy is needed to improve access to optimal cardiac care.

Adult↗

PubMed2004