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ABSTRACT: To evaluate whether body mass index (BMI) and other anthropometric indices of visceral obesity vary by ethnic group in their distribution and their relationship to metabolic abnormalities.
Cross-sectional study.
Canadian men and women, aged 35-75 years, of South Asian (n=342), Chinese (n=317), European (n=326) and Aboriginal (n=301) descent were recruited using stratified random sampling.
Anthropometric indices (BMI, waist to hip ratio (WHR) and waist circumference (WC)), metabolic markers (fasting glucose, HbA1c, the ratio of total cholesterol/HDL) and clinical markers (systolic blood pressure) were assessed.
In subjects with BMI<30 kg/m2, the mean marker levels in people with elevated WC (>88 cm in women, >102 cm in men) vs people with normal WC were 6.16 vs 5.34 mmol/l for fasting glucose, 6.05 vs 5.66% for HbA1c and 5.46 vs 4.68 for the ratio of total cholesterol to HDL (P<0.001 in each case). At nearly every given level of BMI, non-European ethnic groups displayed significantly higher marker levels than Europeans. For example, for a given BMI, age and sex, the difference between European and non-European groups in HbA1c levels was 0.53% (95% confidence interval (CI): 0.37-0.69) for South Asians, 0.37% (95% CI: 0.2-0.54) for Chinese and 0.95% (95% CI: 0.78-1.12) for Aboriginal People.
Uniform cut-points for the classification of obesity using BMI, WHR or WC result in marked variation in the levels of glucose-metabolic abnormalities between ethnic groups. Existing action thresholds for these anthropometric indices do not apply to non-European ethnic groups and warrant revision.
International Journal of Obesity 06/2005; 29(6):656-67. · 4.69 Impact Factor
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ABSTRACT: To determine whether multidisciplinary disease management programmes for patients with coronary heart disease improve processes of care and reduce morbidity and mortality.
Randomised clinical trials of disease management programmes in patients with coronary heart disease were identified by searching Medline 1966-2000, Embase 1980-99, CINAHL 1982-99, SIGLE 1980-99, the Cochrane controlled trial register, the Cochrane effective practice and organisation of care study register, and bibliographies of published studies.
Studies were selected and data were extracted independently by two investigators, and summary risk ratios were calculated by using both the random effects model and the fixed effects model.
A total of 12 trials (9803 patients with coronary heart disease) were identified. Disease management programmes had positive impacts on processes of care. Patients randomised to these programmes were more likely to be prescribed efficacious drugs (risk ratio 2.14 (95% confidence interval 1.92 to 2.38) for lipid lowering drugs, 1.19 (1.07 to 1.32) for beta blockers, and 1.07 (1.03 to 1.11) for antiplatelet agents). Five out of seven trials evaluating risk factor profiles showed significantly greater improvements with these programmes in comparison with usual care (with effect sizes in the moderate range). Summary risk ratios were 0.91 (0.79 to 1.04) for all cause mortality, 0.94 (0.80 to 1.10) for recurrent myocardial infarction, and 0.84 (0.76 to 0.94) for admission to hospital. Five of the eight trials evaluating quality of life or functional status reported better outcomes in the intervention arms. Only three of these trials reported the costs of the intervention-the interventions were cost saving in two cases.
Disease management programmes improve processes of care, reduce admissions to hospital, and enhance quality of life or functional status in patients with coronary heart disease. The programmes' impact on survival and recurrent infarctions, their cost effectiveness, and the optimal mix of components remain uncertain.
BMJ 11/2001; 323(7319):957-62. · 14.09 Impact Factor
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R T Tsuyuki,
R S McKelvie,
J M Arnold,
Avezum A,
A C Barretto,
A C Carvalho,
D L Isaac,
A D Kitching,
L S Piegas, K K Teo,
S Yusuf
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ABSTRACT: Few studies have prospectively and systematically explored the factors that acutely precipitate exacerbation of congestive heart failure (CHF) in patients with left ventricular dysfunction. Knowledge of such factors is important in designing measures to prevent deterioration of clinical status. The objective of this study was to prospectively describe the precipitants associated with exacerbation of CHF status in patients enrolled in the Randomized Evaluation of Strategies for Left Ventricular Dysfunction Pilot Study.
We conducted a 2-stage, multicenter, randomized trial in 768 patients with CHF who had an ejection fraction of less than 40%. Patients were randomly assigned to receive enalapril maleate, candesartan cilexetil, or both for 17 weeks, followed by randomization to receive metoprolol succinate or placebo for 26 weeks. Investigators systematically documented information on clinical presentation, management, and factors associated with the exacerbation for any episode of acute CHF during follow-up.
A total of 323 episodes of worsening of CHF occurred in 180 patients during 43 weeks of follow-up; 143 patients required hospitalization, and 5 died. Factors implicated in worsening of CHF status included noncompliance with salt restriction (22%); other noncardiac causes (20%), notably pulmonary infectious processes; study medications (15%); use of antiarrhythmic agents in the past 48 hours (15%); arrhythmias (13%); calcium channel blockers (13%); and inappropriate reductions in CHF therapy (10%).
A variety of factors, many of which are avoidable, are associated with exacerbation of CHF. Attention to these factors and patient education are important in the prevention of CHF deterioration.
Archives of Internal Medicine 11/2001; 161(19):2337-42. · 11.46 Impact Factor
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Canadian Medical Association Journal 09/2001; 165(3):301-2. · 8.22 Impact Factor
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V Dzavik,
R G Carere,
G B Mancini,
E A Cohen,
D Catellier,
T E Anderson,
G Barbeau,
C Lazzam,
L M Title,
P B Berger,
M Labinaz, K K Teo,
C E Buller
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ABSTRACT: The Total Occlusion Study of Canada (TOSCA) is a multicenter, randomized trial evaluating the effect of stenting with > =1 heparin-coated stent on long-term patency after percutaneous coronary intervention by balloon angioplasty of occluded coronary arteries. The purpose of the current study was to compare the effect of stenting and balloon angioplasty on global left ventricular ejection fraction (LVEF) and regional wall motion and to examine what clinical and angiographic factors may have an effect on left ventricular function in this setting.
Analysis at the core angiographic laboratory of paired baseline and follow-up left ventricular angiograms, as well as target vessel patency, was possible in 244 of 410 cases. An improvement in LVEF was observed in the entire group (59.4% +/- 11% to 61.0% +/- 11%, P =.003). The LVEF change was +1.84 +/- 7.54 in the stent group (P =.009) and 1.28 +/- 8.16 in the percutaneous transluminal coronary angioplasty group (P =.085). There was no significant intergroup difference. Patients with duration of occlusion < or =6 weeks had an improvement in LVEF (+2.98 +/- 8.68, P =.0006), whereas those with an occlusion duration of > 6 weeks had no improvement (+0.48 +/- 7.01, P not significant). Multivariate analysis revealed baseline LVEF <60%, duration of occlusion < or =6 weeks, and Canadian Cardiology Society angina class I or II to be independent predictors of improvement in LVEF.
The restoration of coronary patency of nonacute occluded coronary arteries is associated with a small but significant improvement in regional and global left ventricular function, especially in patients with recent occlusions and depressed left ventricular function. In spite of significant effect on long-term patency, stenting of nonacute coronary occlusions does not result in significantly better left ventricular function compared with balloon angioplasty in this setting.
American Heart Journal 09/2001; 142(2):301-8. · 4.65 Impact Factor
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Journal of the American College of Cardiology 09/2001; 38(2):460-3. · 14.16 Impact Factor
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ABSTRACT: Disease management programs are often advocated for the care of patients with chronic disease. This systematic review was conducted to determine whether these programs improve outcomes for patients with heart failure.
Randomized clinical trials of disease management programs in patients with heart failure were identified by searching Medline 1966 to 1999, Embase 1980 to 1998, Cinahl 1982 to 1999, Sigle 1980 to 1998, the Cochrane Controlled Trial Registry, the Cochrane Effective Practice and Organization of Care Study Registry, and the bibliographies of published studies. We also contacted experts in the field. Studies were selected and data extracted independently by two investigators, and summary risk ratios (RR) and 95% confidence intervals (CI) were calculated using both the random and fixed effects models.
A total of 11 trials (involving 2,067 patients with heart failure) were identified. Disease management programs were cost saving in 7 of the 8 trials that reported cost data and also appeared to have beneficial effects on prescribing practices. Hospitalizations (RR = 0.87, 95% CI: 0.79 to 0.96) but not all-cause mortality (RR = 0.94, 95% CI: 0.75 to 1.19) were reduced by the programs. However, there were considerable differences in the effects of various interventions on hospitalization rates; specialized follow-up by a multidisciplinary team led to a substantial reduction in the risk of hospitalization (RR = 0.77, 95% CI 0.68 to 0.86, n = 1366), whereas trials employing telephone contact with improved coordination of primary care services failed to find any benefit (RR = 1.15, 95% CI 0.96 to 1.37, n = 646).
Disease management programs for the care of patients with heart failure that involve specialized follow-up by a multidisciplinary team reduce hospitalizations and appear to be cost saving. Data on mortality are inconclusive. Further studies are needed to establish the incremental benefits of the different elements of these programs.
The American Journal of Medicine 05/2001; 110(5):378-84. · 5.43 Impact Factor
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ABSTRACT: To examine the relations between demographic factors, specific psychosocial factors, and cardiac rehabilitation attendance.
Cohort, repeated measures design.
A large tertiary care centre in western Canada
304 consecutive consenting patients discharged following acute myocardial infarction and/or coronary artery bypass graft surgery.
The Jenkins self-efficacy expectation scales and activity checklists of behaviour performance for maintaining health and role resumption, modified version of the self-motivation inventory, and the shortened social support scale.
Those who had higher role resumption behaviour performance scores at two weeks after discharge were significantly less likely to attend cardiac rehabilitation programmes. At six months after discharge, those who attended cardiac rehabilitation demonstrated higher health maintenance self-efficacy expectation and behaviour performance scores. Health maintenance self-efficacy expectation and behaviour performance improved over time. Women reported less social support but showed greater improvement in health maintenance self-efficacy expectation. Changes in self-efficacy scores were unrelated to-but changes in health maintenance behaviour performance scores were strongly associated with-cardiac rehabilitation attendance.
Cardiac patients and practitioners may have misconceptions about the mandate and potential benefits of rehabilitation programmes. Patients who resumed role related activities early and more completely apparently did not see the need to "rehabilitate" while those who attended cardiac rehabilitation programmes enhanced their secondary prevention behaviours.
Heart (British Cardiac Society) 04/2001; 85(3):290-4. · 4.22 Impact Factor
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ABSTRACT: A variety of factors influence patients' health behaviour; these are patterns of practitioner practice, patient characteristics and availability of resources.
To examine patient-related factors (demographic, health, psychosocial characteristics) that may influence patients' attendance at cardiac rehabilitation programs and their subsequent behaviour change.
A prospective cohort design was used. Three hundred four acute myocardial infarction and/or coronary artery bypass graft surgery patients from a tertiary care centre in a Western Canadian city were enrolled to participate in telephone interviews at two weeks and again at approximately six months after their hospital discharge. Measures of self-efficacy and behaviour performance for cardiac health maintenance and role resumption, motivation and social support were used at both interview times. A survey focusing on factors influencing patients' choices to attend cardiac rehabilitation programs was also administered at the interview six months after discharge.
Attendance at cardiac rehabilitation programs is not associated with patients' risk factor status, and elderly and rural-living patients are at particular risk for nonattendance.
Systematic mechanisms to guide the appropriate referral of patients to this health care resource and administer secondary prevention initiatives to those with limited access to resources need to be a priority in cardiovascular health care.
The Canadian journal of cardiology 04/2001; 17(3):291-6. · 3.36 Impact Factor
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ABSTRACT: This long-term, multicenter, randomized, double-blind, placebo-controlled, 2 x 2 factorial, angiographic trial evaluated the effects of cholesterol lowering and angiotensin-converting enzyme inhibition on coronary atherosclerosis in normocholesterolemic patients.
There were a total of 460 patients: 230 received simvastatin and 230, a simvastatin placebo, and 229 received enalapril and 231, an enalapril placebo (some subjects received both drugs and some received a double placebo). Mean baseline measurements were as follows: cholesterol level, 5.20 mmol/L; triglyceride level, 1.82 mmol/L; HDL, 0.99 mmol/L; and LDL, 3.36 mmol/L. Average follow-up was 47.8 months. Changes in quantitative coronary angiographic measures between simvastatin and placebo, respectively, were as follows: mean diameters, -0.07 versus -0.14 mm (P:=0.004); minimum diameters, -0.09 versus -0.16 mm (P:=0. 0001); and percent diameter stenosis, 1.67% versus 3.83% (P:=0.0003). These benefits were not observed in patients on enalapril when compared with placebo. No additional benefits were seen in the group receiving both drugs. Simvastatin patients had less need for percutaneous transluminal coronary angioplasty (8 versus 21 events; P:=0.020), and fewer enalapril patients experienced the combined end point of death/myocardial infarction/stroke (16 versus 30; P:=0.043) than their respective placebo patients.
This trial extends the observation of the beneficial angiographic effects of lipid-lowering therapy to normocholesterolemic patients. The implications of the neutral angiographic effects of angiotensin-converting enzyme inhibition are uncertain, but they deserve further investigation in light of the positive clinical benefits suggested here and seen elsewhere.
Circulation 11/2000; 102(15):1748-54. · 14.74 Impact Factor
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ABSTRACT: Six-minute walk distance (6MWd) is related to activities of daily living and is also an independent predictor of prognosis in patients with congestive heart failure (CHF). Therefore, it is important to determine factors that contribute to the variability of this test.
We assessed the relationship between 6MWd and peak aerobic capacity (VO2) and dynamic muscle strength in 180 patients with CHF (age, 66+/-10 years; 146 men, 34 women; ejection fraction, .29+/-0.08). We also hypothesized that a measure of work performed during the walk test (6MWw) would be a better indicator of exercise capacity than 6MWd. The 6MWd had weak to moderate correlations with dynamic muscle strength (r = 0.33 to 0.41) and peak VO2 (r = 0.48). However, 6MWw was strongly related to dynamic muscle strength (r = 0.63 to 0.70) and peak VO2 (r = 0.77). Multivariate analysis indicated that a model combining dynamic muscle strength and peak VO2 explained 69% of the variance in 6MWw, more than with peak VO2 alone (R2 = 0.59).
Compared with 6MWd, 6MWw correlates significantly better with peak VO2 and dynamic muscle strength, suggesting that 6MWw may be a better reflection of a patient's exercise capacity. Furthermore, these results suggest that an exercise program combining both aerobic and strength training in patients with CHF may improve 6MWw and therefore 6MWd.
Journal of Cardiac Failure 10/2000; 6(3):214-9. · 3.66 Impact Factor
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ABSTRACT: Bridging the research-practice gap has been a focus of concern for nursing and other health care disciplines. The challenge in linking research and practice is for practitioners to use consistently the best available evidence in their clinical practice and for researchers to engage in clinically relevant research that provides practitioners with the evidence to do so. The authors of this article advocate that blending Clinical Quality Improvement (CQI) strategies with research methodology is a means of bridging the research-practice gap. The process of blending CQI strategies and nursing research is described in this article.
Western Journal of Nursing Research 09/2000; 22(5):596-608. · 1.19 Impact Factor
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S S Anand,
S Yusuf,
V Vuksan,
S Devanesen, K K Teo,
P A Montague,
L Kelemen,
C Yi,
E Lonn,
H Gerstein,
R A Hegele,
M McQueen
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ABSTRACT: Cardiovascular disease rates vary greatly between ethnic groups in Canada. To establish whether this variation can be explained by differences in disease risk factors and subclinical atherosclerosis, we undertook a population-based study of three ethnic groups in Canada: South Asians, Chinese, and Europeans.
985 participants were recruited from three cities (Hamilton, Toronto, and Edmonton) by stratified random sampling. Clinical cardiovascular disease was defined by history or electrocardiographic findings. Carotid atherosclerosis was measured with B-mode ultrasonography. Conventional (smoking, hypertension, diabetes, raised cholesterol) and novel risk factors (markers of a prothrombotic state) were measured.
Within each ethnic group and overall, the degree of carotid atherosclerosis was associated with a higher prevalence of cardiovascular disease. South Asians had the highest prevalence of this condition compared with Europeans and Chinese (11%, 5%, and 2%, respectively, p=0.0004). Despite this finding, Europeans had more atherosclerosis (mean of the maximum intimal medial thickness 0.75 [0.16] mm) than South Asians (0.72 [0.15] mm), and Chinese (0.69 [0.16] mm). South Asians had an increased prevalence of glucose intolerance, higher total and LDL cholesterol, higher triglycerides, and lower HDL cholesterol, and much greater abnormalities in novel risk factors including higher concentrations of fibrinogen, homocysteine, lipoprotein (a), and plasminogen activator inhibitor-1.
Although there are differences in conventional and novel risk factors between ethnic groups, this variation and the degree of atherosclerosis only partly explains the higher rates of cardiovascular disease among South Asians compared with Europeans and Chinese. The increased risk of cardiovascular events could be due to factors affecting plaque rupture, the interaction between prothrombotic factors and atherosclerosis, or as yet undiscovered risk factors.
The Lancet 08/2000; 356(9226):279-84. · 38.28 Impact Factor
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ABSTRACT: We undertook an angiographic, dose-finding study of staphylokinase (SAK42D variant) to evaluate its efficacy and safety in patients with acute ST-segment myocardial infarction.
Patients were studied within 6 hours of symptom onset and received SAK42D as a 30-minute infusion with 20% of the total dose given as a bolus. Eighty-two patients with a median age of 60 years (interquartile range 52 to 69 years), 84% male and 43% with an anterior myocardial infarction, were studied at a median time from symptom onset of 2.7 hours. There was a high degree of Thrombolysis in Myocardial Infarction (TIMI) 3 flow achieved with 15 mg of SAK42D, that is, 62%. Therefore after 21 patients had been studied at this dose the next dose of 30 mg was used and 65% TIMI 3 patency was achieved. At the peak dose of 45 mg, TIMI 3 90-minute patency was 63%. There were no allergic reactions, and no patient had intracranial hemorrhage. Four patients had major and 9 moderate bleeding during the study; 2 of the major and 5 of the moderate bleeding events occurred within 48 hours of commencement of treatment. The majority (62%) of these were related to vascular instrumentation, and there was no relation between the extent of bleeding and dose of SAK42D used. Forty-five minutes after cessation of SAK42D, there were small percent decrements in plasma fibrinogen and plasminogen levels that did not reach statistical significance. However, there were dose-related changes in alpha(2) anti-plasmin that revealed a borderline significant reduction that was dose related (P =.053).
These data revealed similar fibrinolytic efficacy across a 3-fold increment in dose, indicating that this study operated on a flat portion of the dose-response curve. The favorable efficacy/safety profile achieved with staphylokinase is encouraging, and further investigation is warranted.
American Heart Journal 06/2000; 139(5):820-3. · 4.65 Impact Factor
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The Canadian journal of cardiology 02/2000; 16(1):99. · 3.36 Impact Factor
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ABSTRACT: Atrial fibrillation (AF) is a growing public health problem associated with significant morbidity and mortality. Numerous randomized controlled trials of warfarin have conclusively demonstrated that long-term anticoagulation therapy can reduce the risk for stroke by approximately 68% per year in patients with nonvalvular AF, and even more in patients with valvular AF. However, available data show that of those patients with AF and no contraindication to warfarin therapy, only 15% to 44% are prescribed warfarin. Our literature review has identified patient-, physician-, and health care system-related barriers to warfarin prescription. However, the relative importance of these specific barriers remains unknown. Further work is needed to understand the discrepancy between the randomized controlled trial evidence and clinical practice patterns.
Archives of Internal Medicine 02/2000; 160(1):41-6. · 11.46 Impact Factor
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ABSTRACT: Despite the availability of angiotensin converting enzyme (ACE) inhibitors for patients with congestive heart failure (CHF), mortality and morbidity remains unacceptably high. CHF is thought to progress as a result of activation of endogenous neurohormonal systems which are activated by the initial myocardial injury. The 2 neurohormonal systems which seem to be important in CHF are the sympathetic nervous system (SNS), and the renin-angiotensin-aldosterone system (RAAS). While stimulation of the SNS has important circulatory support functions in the short term, long term activation appears to have deleterious effects on cardiac function and outcomes. The purpose of this article is to review the literature on the use of beta-blockers in patients with CHF. The published randomised clinical trials of beta-blockers in patients with CHF have shown very promising effects on mortality and morbidity. Several systematic overviews of these trials also suggest beneficial effects on mortality, hospitalisation for CHFE need for transplant, and ejection fraction. The effect of beta-blockers on exercise tolerance. New York Heart Association Function Class (NYHA-FC) and quality of life remain equivocal. The recent presentation of the results from several large-scale trials which were terminated early because of significant survival benefit, has removed any concern over the robustness of the mortality data. Available evidence suggests that a wide variety of patients with CHF, including the elderly, should be considered for beta-blocker therapy. Caution is warranted in the initiation and titration of therapy, as symptoms of CHF may transiently worsen. Whether all beta-blockers are equally efficacious remains unknown.
Drugs & Aging 02/2000; 16(1):1-7. · 2.67 Impact Factor
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ABSTRACT: To assess the effects of long term (mean +/- SD 10+/-5 years, range three to 25 years) resistance training on left ventricular (LV) dimensions and mass.
The study participants were 21 elite male power-lifters (age 33.4+/-5.9 years) and 10 sedentary male control subjects (age 30.9+/-4.2 years). Two-dimensionally guided transthoracic M-mode echocardiograms were obtained at rest to quantify LV diastolic cavity dimension, posterior wall thickness, ventricular septal wall thickness and LV mass. Long term resistance training was not associated with an alteration in LV diastolic cavity dimension (resistance trained 54. 4+/-4.3 mm versus control 51.8+/-5.6 mm), ventricular septal wall thickness (resistance trained 9.7+/-1.0 mm versus control 10.1+/-0.7 mm), posterior wall thickness (resistance trained 9.6+/-1.5 mm versus control 9.3+/-1.4 mm) or LV mass (resistance trained 200. 3+/-32.5 g versus control 186.5+/-39.6 g). In addition, no resistance-trained athlete was found to have an LV mean wall thickness above clinical normal limits (12 mm or less).
Contrary to common beliefs, long term resistance training as performed by elite male power-lifters does not alter LV morphology.
The Canadian journal of cardiology 02/2000; 16(1):35-8. · 3.36 Impact Factor
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ABSTRACT: To examine the influence of cardiac patients' demographic and health characteristics on physicians' cardiac rehabilitation (CR) referral practice and patients' attendance at such programs.
A retrospective, systematic review of consecutive health records.
A tertiary care centre and the two associated CR programs in a Western Canadian city.
One thousand, three hundred and twenty-eight adult patients (21 years of age or older) discharged following acute myocardial infarction, percutaneous transluminal coronary angioplasty (PTCA) and/or coronary artery bypass graft surgery between September 1, 1996 and August 31, 1997.
There were 1245 surviving patients. Evidence of attendance at a CR program was 28.4%, while auditable evidence of referral to a CR program was 23.9%. Stepwise logistic regression revealed that ability to speak English (OR 9.56) living in a city (OR 3.97) and current smoking (OR 1.51) were associated with an increased likelihood, whereas having a history of chronic obstructive pulmonary disease or asthma (OR 0.53), being 70 years of age or older (OR 0.42), having a current admission for PTCA (OR 0.32) and having a history of neurological or cognitive impairment (OR 0.26) were associated with a decreased likelihood of CR attendance. Sex, nature of coronary artery disease risk factors, incidence of postevent complications and pre-event cardiac status (including New York Heart Association status and number of previous events) were not associated with patients' CR attendance.
This study suggests that there is an inconsistent and poorly documented approach to referral of patients to CR programs for reasons that remain unclear. These findings provide a foundation for development and testing of enhanced referral mechanisms and of innovative means to provide rehabilitation services to patients who are at risk for not being referred to or attending CR programs.
The Canadian journal of cardiology 10/1999; 15(9):979-85. · 3.36 Impact Factor
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American Heart Journal 10/1999; 138(3 Pt 1):400-2. · 4.65 Impact Factor
