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Biomedical subjects

K K Teo

Publications and source records attributed to K K Teo.

At least 55 records · Page 3Linked to original sources
PubMed1998

Changing practice patterns in the management of acute myocardial infarction complicated by cardiogenic shock: elderly compared with younger patients.

BACKGROUND: Cardiogenic shock continues to be an ominous complication of acute myocardial infarction (AMI). Evidence from retrospective analyses, registries and observational studies suggests that aggressive management using emergent revascularization strategies can bring about significant improvement in survival in this setting. Several studies have identified age as an independent predictor of survival. OBJECTIVE: To study retrospectively the possible changes in practice patterns in the management of patients with AMI complicated by cardiogenic shock in a tertiary care referral centre, and to determine what effect these changes may have had on survival of the patients, stratified by age. METHODS: From 1989 to 1995, 115 patients fulfilled the study criteria of cardiogenic shock based on pump failure and of presenting within 48 h of onset of shock. Prespecified data were extracted from medical records. All available coronary angiograms (n = 72) were analyzed by two experienced angiographers and consensus of findings was obtained. RESULTS: The study revealed a significant increase in the use of cardiac catheterization, interventional procedures and intra-aortic balloon pump (IABP) support in patients in the age groups 65 years or less, 66 to 75 years, and older than 75 years in 1989 to 1990, through 1991 to 1992, to 1993 to 1995. Significantly fewer patients aged older than 75 years received cardiac catheterization, coronary intervention and IABP support throughout the study period and even in the final period analyzed. In-hospital survival improved from 4% in 1989-90 to 33% in 1991-92, and 44% in 1993-95 (P = 0.001). Patients aged 65 years or less improved from 10% in 1989-90 to 59% in 1993-95 (P = 0.032). Only 20% of patients aged older than 75 years survived in the 1993-95 period. By univariate analysis, use of coronary angiography (catheterization 46% versus no catheterization 5%; P < 0.0001), coronary intervention procedures (percutaneous transluminal coronary angioplasty or coronary artery bypass grafting) (intervention 48% versus no intervention 9%; P < 0.0001) and IABP support (IABP 41% versus no IABP 18%; P = 0.0096) were all associated with improved in-hospital survival. Use of thrombolytic therapy showed possible survival benefit only in patients aged older than 75 years (thrombolysis 33% versus no thrombolysis 5%; P = 0.10). Patients who underwent coronary intervention were younger (P = 0.002), had a lower incidence of previous myocardial infarction (P = 0.0002), lower heart rate (P = 0.04), higher peak creatine phosphokinase (P = 0.04) and fewer vessels with at least 70% stenosis (P < 0.0001). On multivariate analysis only lower age, lower heart rate and presence of coronary intervention procedures were found to have an independent effect on survival. CONCLUSIONS: Use of invasive treatment strategies has increased significantly since 1989-90 in the management of patients with AMI complicated by cardiogenic shock. This increase has been associated with improved in-hospital survival in all age groups except possibly the very elderly. Patients undergoing coronary interventional procedures are significantly different in baseline clinical characteristics from patients not undergoing these procedures. These observations underscore the need for randomized trials to define the optimal treatment strategies in these patients. Efficacy of invasive treatment strategies in elderly patients aged older than 75 years-deserves special attention.

Age Factors↗
PubMed1998

Possible adverse skin reaction to carvedilol.

As experience with beta-blocker use in patients with congestive heart failure is increasing, enthusiasm for carvedilol use in these patients is also increasing. Dermatological reactions to carvedilol are rare and have not been well described in the literature. A patient who developed an acute dermatological reaction after one dose of 3.125 mg carvedilol is presented. Given the rapid onset of symptoms experienced by the patient after a single, small dose of carvedilol, clinicians should be aware of the potential adverse effects of the drug.

Adrenergic beta-Antagonists↗
PubMed1998

The Study of Health Assessment and Risk in Ethnic groups (SHARE): rationale and design. The SHARE Investigators.

The Study of Health Assessment and Risk in Ethnic groups (SHARE) is a study to determine the risk factors for atherosclerosis among three ethnic populations in Canada. Three hundred and thirty South Asian Canadian, 320 Chinese Canadian and 320 European Canadian men and women between 35 and 75 years of age are being randomly sampled from communities in Hamilton and Toronto, Ontario and Edmonton, Alberta for assessment of conventional (i.e., smoking, dyslipidemia, diabetes and hypertension) and emerging (i.e., candidate genes for atherosclerosis, homocysteine, fibrinolytic parameters, neurohormones, glucose intolerance, markers of infection, socioeconomic status, psychosocial status and diet) cardiovascular disease risk factors. Subclinical atherosclerosis is measured by quantitative B-mode ultrasonography of the carotid arteries, and other objective measures of vascular disease are a 12-lead electrocardiogram, a two-dimensional echocardiogram, ankle to arm blood pressure ratio and urine microalbumin concentration. The relationship between the conventional and emerging risk factors, and atherosclerosis, vascular disease and markers of end-organ damage will be evaluated between and within ethnic groups.

Adult↗
PubMed1997

Contemporary practice patterns in the management of newly diagnosed hypertension.

OBJECTIVE: To determine what proportion of patients with hypertension are managed in accordance with guidelines established by the Canadian Hypertension Society. DESIGN: Retrospective medical record review. SETTING: Outpatients seen in primary care offices and internal medicine referral clinics in Edmonton. PATIENTS: All 969 adults who presented with a new diagnosis of essential hypertension from Sept. 1, 1993, to Dec. 31, 1995. OUTCOME MEASURES: Initial laboratory tests performed, advice concerning nonpharmacologic treatment given, antihypertensive drugs prescribed and any contraindications to thiazide diuretics or beta-adrenergic blocking agents documented. RESULTS: The mean age of the 969 patients in the sample was 52.5 years; 129 (13%) of the patients were older than 70 years of age; and 500 (52%) were women. Most of the patients (704, 73%) had mild or moderate diastolic hypertension. In the 617 patients who underwent laboratory tests related to hypertension, the creatinine level was determined in 466 (76%), the cholesterol level in 372 (60%), a urinalysis was conducted in 378 (61%), the serum potassium level was checked in 343 (56%), the sodium level in 323 (52%) and an electrocardiogram was performed in 303 (49%). Liver function tests, which are not recommended in the guidelines, were performed in 338 patients (55%). Although there were differences in prescribing among physicians in the 711 patients given first-line therapy, most (238, 34%) were prescribed angiotensin-converting-enzyme (ACE) inhibitors. Lifestyle modification, without drug therapy, was suggested for 180 (25%) of the patients. Although the guidelines recommend their use for first-line drug therapy, only 82 patients (12%) were given beta-adrenergic blocking agents and only 75 (11%) were given thiazide diuretics. Of the patients who were prescribed an antihypertensive other than a thiazide or beta-adrenergic blocking agent as first-line drug therapy, only 161 (43%) had a documented contraindication to thiazides or beta-adrenergic blocking agents. CONCLUSIONS: There is variation in the contemporary care of patients with hypertension. Further studies are required to determine the reasons underlying physicians' noncompliance with the evidence-based guidelines established by the Canadian Hypertension Society.

Adult↗
PubMed1997

A survey of clinician attitudes and management practices in hypertension.

In order to determine the compliance of Canadian physicians with evidence-based hypertension guidelines, a self-administered questionnaire survey was distributed to a stratified random sample of 473 physicians in Central Alberta, Canada in December 1995. Excluding non-deliverable questionnaires, a response rate of 67% was obtained. Twenty-five per cent of respondents routinely used the fourth Korotkoff sound to define diastolic blood pressure (DBP). Investigations recommended for the initial workup of a patient with mild hypertension included serum creatinine (90%), electrolytes (72%), glucose (50%), cholesterol (44%), electrocardiogram (65%), and urinalysis (76%). The non-pharmacologic treatment advice routinely advocated for patients with mild hypertension included salt restriction (87%), weight loss (100%), and regular aerobic exercise (92%). While 46% of respondents recommended antihypertensive therapy for an otherwise healthy patient with an average DBP of 95 mm Hg, 76% recommended therapy for patients with the same BP plus target organ damage or other cardiovascular risk factors. Medication choices varied, although angiotensin-converting enzyme inhibitors were chosen by 46% for patients with uncomplicated essential hypertension and 67% for patients with other cardiovascular risk factors, and beta-blockers were the most frequently chosen first-line agents (56%) for the patient with target organ damage. There was considerable variability in the self-reported practice patterns, and concordance was greater for those recommendations which were consistent across the currently available guidelines. Consistent with the principle underlying all of the current hypertension guidelines, respondents were more aggressive in their treatment of hypertensive patients with other cardiovascular risk factors or target organ damage.

Adult↗
PubMed1997

A survey of management practices for isolated systolic hypertension.

OBJECTIVE: To determine the management practices of clinicians for patients with isolated systolic hypertension, with particular attention to treatment thresholds, medication choices, and target blood pressures. DESIGN: Self-administered questionnaire. SETTING: Edmonton, Alberta, a large Canadian city. PARTICIPANTS: A random sample of 348 family physicians and 125 internists. MEASUREMENTS: Demographics of the respondents, first and second choice of antihypertensives, treatment thresholds, and target blood pressures for patients with isolated systolic hypertension. RESULTS: Excluding 54 nondeliverable questionnaires, a response rate of 67% (281 surveys) was obtained. The responding clinicians reported treatment thresholds and target blood pressures consistent with the evidence from randomized clinical trials and the recommendations of the Canadian Hypertension Society and the Fifth Report of the Joint National Committee on Detection, Evaluation, and Treatment of High Blood Pressure. Thiazide diuretics were recommended as first line therapy by 74% of internists and 58% of family physicians. Angiotensin converting enzyme inhibitors were the most frequently chosen second line drug (27% of internists and 45% of family physicians). CONCLUSIONS: The reported management practices of this group of clinicians are consistent with the evidence from randomized clinical trials and the recommendations of national consensus guidelines.

Adult↗
PubMed1997

The management of congestive heart failure.

Despite the remarkable advances in cardiovascular therapeutics over the past four decades, little impact has been made on either the incidence or mortality rate of congestive heart failure and it remains a major clinical and public health problem. Recent practice audits have suggested that proven efficacious therapies are not maximally applied in patients with this condition. An approach to the patient with congestive heart failure is presented, emphasizing the two distinct syndromes of systolic dysfunction and diastolic dysfunction. Treatment recommendations are derived from consideration of the underlying pathophysiology and the evidence from randomised clinical trials.

Adrenergic beta-Antagonists↗
PubMed1997

Antiarrhythmic therapies for the prevention of sudden cardiac death.

Despite remarkable advances in cardiovascular therapeutics, sudden cardiac death remains a significant problem. In this review, data from clinical trials and other studies on antiarrhythmic therapies have been evaluated in order to determine effective strategies for the prevention of sudden cardiac death in high risk patients. Overall, routine prophylactic use of class I antiarrhythmic agents in high risk patients, mostly survivors of acute myocardial infarction, is associated with increased risk of death [61 trials, 23,486 patients: odds ratio (OR) 1.13; 95% confidence interval (CI) 1.01 to 1.27, p < 0.05]. Conversely, beta-blockers are associated with highly significant reductions in risk of death in postinfarction patients (56 trials, 53,521 patients: OR 0.81; 95% CI 0.75 to 0.87, p < 0.00001). Overall data from the amiodarone trials on high risk patients, including postinfarction patients, patients with congestive heart failure or survivors of cardiac arrest, suggest that this agent is effective in reducing the risk of death (14 trials, 5713 patients: OR 0.83; 95% CI 0.72 to 0.95, p = 0.01) although further studies are needed to better define which types of patients will potentially benefit most from this agent. No benefits were seen with calcium channel blockers (26 trials, 21,644 patients: OR 1.03; 95% CI 0.94 to 1.13, p = NS). The implantable cardioverter-defibrillator is a promising option for high risk patients, but definition of its role awaits the completion of ongoing clinical trials. Since causes of sudden death are heterogeneous, the clinician should pursue a multifactorial approach to its prevention. Primary and secondary prevention of cardiac ischaemia, through the treatment of cardiovascular risk factors and maximising the use of aspirin, beta-blockers, lipid-lowering drugs, and angiotensin converting enzyme inhibitors after acute myocardial infarction, should lead to a future decrease in the incidence of sudden cardiac death.

Amiodarone↗
PubMed1997

Quantitative relation of electrocardiographic and angiocardiographic measures of risk in patients with coronary atherosclerosis. Simvastatin/Enalapril Coronary Atherosclerosis Trial (SCAT) Investigators.

OBJECTIVE: To correlate angiocardiographic and electrocardiographic (ECG) measures of risk in coronary artery disease (CAD) patients. SETTING: Baseline substudy of the Simvastatin/Enalapril Coronary Atherosclerosis Trial (SCAT), a 2 x 2 factorial, randomized, controlled trial of CAD regression. PATIENTS: One hundred and twenty-three CAD patients, 113 males and 10 females; average age, 59 years. METHODS: Bivariate correlations of multiple quantitative measures of epicardial coronary angiographic luminal narrowing (quantitative coronary angiography [QCA]) and body surface ECG maps of the sum of the decrease in the potential time integral of the ST segment (SST decrease) between rest and symptom-limited exercise and between rest and 1 and 5 mins postexercise recovery. RESULTS: The average number of epicardial coronary segments analyzed per patient was 12. The mean diameter averaged 2.78 mm; the minimal diameter, 2.01 mm. The mean percentage coronary stenosis averaged 29.6% and the most severe averaged 62.9%. sigma ST decrease averaged -5323 microV.s between rest and peak exercise and recovered slowly, averaging -5117 microV.s at 1 min postexercise and -4562 microV.s at 5 mins. No QCA measure correlated with any ECG variable (range of r, 0.002 to -0.179; not significant). CONCLUSIONS: Among CAD patients there are no close, or causal, relations between angiographic measures of anatomic epicardial coronary atherosclerosis and ECG functional measures of exercise-induced myocardial ischemia. These data suggest that demonstrated values of stress ECG and coronary angiography for the prediction of clinical risk in CAD patients are largely independent of each other.

Coronary Angiography↗
PubMed1997

Rationale and design features of a clinical trial examining the effects of cholesterol lowering and angiotensin-converting enzyme inhibition on coronary atherosclerosis: Simvastatin/Enalapril Coronary Atherosclerosis Trial (SCAT). SCAT Investigators.

BACKGROUND: In the treatment of coronary atherosclerotic artery disease (CAD), the mechanisms by which lipid lowering, a proven therapy, produces beneficial clinical effects remain unclear. Moreover, although potential mechanisms of benefit are well known and increasingly applied clinically, there are no conclusive data from clinical trials studying primarily the antiischemic effects of angiotensin-converting enzyme (ACE) inhibition in patients with normal heart function. The Simvastatin/Enalapril Coronary Atherosclerosis Trial (SCAT) is designed to clarify some of these issues in CAD patients with normal or mildly elevated cholesterol. DESIGN AND OBJECTIVES: SCAT is a three- to five-year, multicentre, randomized, double-blind, placebo controlled, 2 x 2 factorial trial evaluating the effects of cholesterol lowering therapy by simvastatin and/or ACE inhibition by enalapril on anatomic coronary atherosclerosis progression assessed by quantitative coronary angiography in CAD patients with preserved left ventricular function and total cholesterol levels between 4.1 and 6.2 mmol/L. PATIENTS: Of 460 patients (age 61 +/- 9 years; 409 males, 51 females) enrolled between June 1991 and July 1995, 230 were randomized to simvastatin and 230 to placebo, and 229 to enalapril and 231 to placebo. Average baseline total cholesterol level was 5.20 +/- 0.61 mmol/L, high density lipoprotein cholesterol was 0.99 +/- 0.25 mmol/L, low density lipoprotein cholesterol was 3.36 +/- 0.57 mmol/L and triglycerides were 1.82 +/- 0.75 mmol/L. The trial will be completed in June 1998. SIGNIFICANCE: Insights gained from this long term angiographic trial will lead to a better understanding of the mechanisms of benefits of these two treatments, both alone and in combination. Of particular interest is that this trial will be able to examine a suspected beneficial interaction, if present, between these two treatments.

Aged↗
PubMed1997

Combination neurohormonal blockade with ACE inhibitors, angiotensin II antagonists and beta-blockers in patients with congestive heart failure: design of the Randomized Evaluation of Strategies for Left Ventricular Dysfunction (RESOLVD) Pilot Study.

BACKGROUND: The Randomized Evaluation of Strategies for Left Ventricular Dysfunction (RESOLVD) Pilot Study is a trial of combination neurohormonal blockade using an angiotensin II antagonist (candesartan), an angiotensin-converting enzyme inhibitor (enalapril) and a beta-blocker (metoprolol) in patients with congestive heart failure (CHF). OBJECTIVES: Primary objectives of stage I are to determine the efficacy (via the 6 min walk test) and safety of candesartan alone, and in combination with enalapril, versus enalapril alone. Secondary objectives are to determine the effect of the above combinations on neurohormones, ventricular function, quality of life and symptoms. Stage II objectives are similar, evaluating the effect of the addition of metoprolol or placebo to the above medication(s). DESIGN: Randomized, two-stage trial consisting of a three-way comparison (stage I), followed by a 3 x 2 partial factorial design (stage II). SETTING: Sixty out-patient clinics in five countries. PATIENTS: Patients with symptoms of CHF (New York Heart Association functional classes II to IV), ejection fraction less than 40% and 6 min walk distance of 500 m or less. INTERVENTIONS: In stage I, 770 patients are randomized to receive candesartan alone, enalapril alone, or candesartan plus enalapril. After five months (end of stage I), patients are assessed for eligibility to be randomized in stage II. Those who are not candidates for randomization to beta-blocker or placebo are followed on their stage I medications until the end of the study. In stage II, patients are randomized to receive metoprolol or placebo for a further six months in addition to their stage I medications. Endpoints are measured at baseline, end of stage I (week 20) and end of stage II (week 46). STUDY STATUS: The study has recently completed follow-up in both stages. The findings from this study will be used to design a large scale mortality study that will help further define the role of neurohormonal blockade in patients with CHF.

Adrenergic beta-Antagonists↗
PubMed1996

Cause-specific noncardiac mortality in patients with congestive heart failure--a contemporary Canadian audit. Clinical Quality Improvement Network (CQIN) Investigators.

BACKGROUND: Noncardiac mortality in congestive heart failure (CHF) is substantial. OBJECTIVE: To define the specific causes of noncardiac mortality among hospitalized CHF patients. DESIGN: Retrospective medical record audit. SETTING: Three hospitals in British Columbia and Alberta, 1992-93. PATIENTS: A total of 2216 consecutive patients admitted with CHF. MAIN RESULTS: The overall mortality rate was 404 of 2216 (18%). Cause of death was cardiac in 290 of 404 (72%) patients, with an average age of 76 years. However, 114 of 404 (28%) deaths, in patients with an average age of 69 years, had noncardiac causes. Four causes accounted for almost 70%, of the noncardiac deaths: cancer (24%); pneumonia (16%); other pulmonary diseases, including embolism (15%); and cerebrovascular disease (11%). Renal disease (9%), gastrointestinal disorders (9%), non-pulmonic sepsis (7%), multiple system failure (5%) and trauma or surgical complications (4%) accounted for most of the remaining noncardiac deaths. CONCLUSIONS: Noncardiac causes produce a substantial proportion of deaths among elderly and sick CHF patients. As the survival of patients with CHF improves, the relative risk of noncardiac mortality in this population will likely increase. However, since hospitalized CHF patients so closely reflect their general population counterparts in terms of cause-specific mortality risk, the search for an ideal therapy might be viewed as a quixotic search for the cure of death.

Age Factors↗
PubMed1996

Resistant hypertension: an overview.

OBJECTIVE: To review the factors contributing to treatment resistance in hypertensive patients and assess the evidence from therapeutic trials in these patients. DESIGN: A MEDLINE search using the words 'resistant hypertension', 'refractory hypertension' and 'treatment resistance, hypertension' was carried out to identify relevant articles. The bibliographies of articles were used to screen for other relevant articles. All available English-language articles on the epidemiology, prognosis and management of hypertension resistant to standard treatment were reviewed. RESULTS: Resistant hypertension is an important public health problem and a common reason for referral of patients to specialized hypertension clinics. Patients with uncontrolled hypertension are at increased risk of stroke, myocardial infarction, congestive heart failure and renal failure. Many factors may play a role in the development of resistant hypertension, including misdiagnosis (pseudoresistance), noncompliance, occult secondary causes for hypertension, volume overload, obesity, cigarette smoking, excess alcohol intake, sleep apnea, interfering medications and suboptimal combinations of antihypertensives. Only beta-blockers and thiazide diuretics have been demonstrated to reduce cardiovascular morbidity and mortality in hypertension. The trials evaluating third-line agents in patients with resistant hypertension have demonstrated additional blood pressure lowering with all classes of agents, and the randomized controlled trials have not demonstrated any statistically significant differences between the agents in either efficacy or tolerability. CONCLUSIONS: Evaluation of the patient with resistant hypertension should include 24 h ambulatory blood pressure monitoring and an extensive search for hypertensive end organ damage. Contributing factors should be sought and stepped care should still form the basis for treatment decisions. The choice of third-line agent should be dictated by the patient's renin profile, current medication and any concomitant diseases.

Adrenergic beta-Antagonists↗
PubMed1996

Pathophysiology and treatment of cocaine toxicity: implications for the heart and cardiovascular system.

OBJECTIVE: To review the data on pharmacology, pathophysiology and treatment of cocaine toxicity, with particular relevance to the heart and cardiovascular system. DATA SOURCE AND STUDY SELECTION: Published epidemiology, laboratory and clinical studies on the pharmacology, electrophysiology and pathophysiology of cocaine toxicity and its treatment. MAIN RESULTS: Cocaine toxicity-related morbidity and mortality are frequent due to the potent pharmacological effects of the drug as an indirect-acting sympathomimetic agent and its class I antiarrhythmic property paradoxically inducing pro-arrhythmia. The cardiac and cardiovascular toxic effects of cocaine include various degrees of myocardial ischemia, cardiac arrhythmias, cardiotoxicity, hypertensive effects, cerebrovascular effects and a hypercoagulable state. Treatment of cocaine toxicity must be based on the multiple factors leading to the toxicity. Sodium bicarbonate appears to have an important role in the acute setting with conduction abnormalities, seizures or acidosis. Unopposed alpha-stimulation provided by beta-blockade should be avoided. Central nervous system hyperexcitability should be treated with diazepam. The use of calcium antagonists appears logical. CONCLUSION: Cocaine is an alkaloid with widespread illicit use. The rationale for treating acute cocaine intoxication has become clearer and more logical with increased knowledge of its mechanisms of action.

Arrhythmias, Cardiac↗