PubMed Health⌕ Search

Biomedical subjects

Peter Bogaty

Publications and source records attributed to Peter Bogaty.

At least 19 recordsLinked to original sources
PubMed2006

Acute ischemic heart disease and interventional cardiology: a time for pause.

BACKGROUND: A major change has occurred in the last few years in the therapeutic approach to patients presenting with all forms of acute coronary syndromes. Whether or not these patients present initially to tertiary cardiac care centers, they are now routinely referred for early coronary angiography and increasingly undergo percutaneous revascularization. This practice is driven primarily by the angiographic image and technical feasibility. Concomitantly, there has been a decline in expectant or ischemia-guided medical management based on specific clinical presentation, response to initial treatment, and results of noninvasive stratification. This 'tertiarization' of acute coronary care has been fueled by the increasing sophistication of the cardiac armamentarium, the peer-reviewed publication of clinical studies purporting to show the superiority of invasive cardiac interventions, and predominantly supporting (non-peer-reviewed) editorials, newsletters, and opinion pieces. DISCUSSION: This review presents another perspective, based on a critical reexamination of the evidence. The topics addressed are: reperfusion treatment of ST-elevation myocardial infarction; the indications for invasive intervention following thrombolysis; the role of invasive management in non-ST-elevation myocardial infarction and unstable angina; and cost-effectiveness and real world considerations. A few cases encountered in recent practice in community and tertiary hospitals are presented for illustrative purposes The numerous and far-reaching scientific, economic, and philosophical implications that are a consequence of this marked change in clinical practice as well as healthcare, decisional and conflict of interest issues are explored. SUMMARY: The weight of evidence does not support the contemporary unfocused broad use of invasive interventional procedures across the spectrum of acute coronary clinical presentations. Excessive and unselective recourse to these procedures has deleterious implications for the organization of cardiac health care and undesirable economic, scientific and intellectual consequences. It is suggested that there is need for a new equilibrium based on more refined clinical risk stratification in the treatment of patients who present with acute coronary syndromes.

Acute Disease↗
PubMed2006

Influence of glycemic control on pulmonary function and heart rate in response to exercise in subjects with type 2 diabetes mellitus.

Conflicting results exist regarding the impact of glycemic control on peak oxygen uptake (VO2peak) in subjects with type 2 diabetes mellitus. The influence of glycemic control on submaximal oxygen uptake (VO2) in these subjects is unknown. The aim of this study was to evaluate the impact of fasting blood glucose (FBG) (short-term glycemic control) and glycated hemoglobin (HbA1c) (long-term glycemic control) on submaximal VO2 and VO2peak during exercise in subjects with type 2 diabetes mellitus without cardiovascular disease. FBG and HbA1c levels and exercise tolerance in 30 sedentary men with type 2 diabetes mellitus treated with oral hypoglycemic agents and/or diet were evaluated. VO2, carbon dioxide production (VCO2), heart rate, pulmonary ventilation (VE), and the respiratory exchange ratio (RER) were measured throughout the exercise protocol. Subjects were separated into 2 groups of the same age, weight, and body mass index according to median FBG and HbA1c levels (6.5 mmol/L and 6.1%, respectively). Per protocol design, there was a significant difference in FBG and HbA1c levels (P < .001), but not for age, weight, or body mass index. There was no significant difference in peak exercise parameters between the 2 groups according to median FBG or median HbA1c levels. However, the subjects with elevated HbA1c level had lower submaximal V e throughout the exercise protocol (P < .03), and the subjects with elevated FBG concentration had a blunted heart rate pattern during submaximal exercise (P < .03). Although relatively small abnormalities in the control of glycemia do not affect VO2peak in subjects with type 2 diabetes mellitus without cardiovascular disease, they may influence pulmonary function and the chronotropic response during submaximal exercise in these subjects.

Blood Glucose↗
PubMed2006

A most unusual acute coronary syndrome.

A 60-year-old man, known for stable coronary artery disease, was admitted for suspected unstable angina. In the previous month, the patient presented with progressive dyspnea on light exertion. In the preceding four months, he had experience occasional episodes of flushing and diarrhea, and had inexplicably lost 22.7 kg. Night sweats and fever were absent. ST segment elevation in the inferior leads and ST segment depression in the precordial leads were documented during an episode of chest pain. The coronary angiogram showed diffuse disease with 70% stenosis of the left anterior descending coronary artery and 50% stenosis on the second diagonal (D(2)). An echocardiogram showed a patent foramen ovale. Balloon angioplasty and stenting were performed on the two lesions. Two days later, prolonged chest pain recurred. Cardiac catheterization was repeated and showed occlusive thrombus within the stent on the D(2). Angioplasty was repeated. Symptoms recurred 36 h later, with the electrocardiogram showing ST segment elevation. The first angiogram was reviewed and vasospasm was suspected on a branch of the D(2), on the second marginal and in the distal circumflex artery. The diagnosis of vasospastic angina was retained. Beta-blockers were replaced by high doses of a calcium channel blocker with an excellent clinical response. The case described is of a patient with an acute coronary syndrome, vasospastic angina, in-stent thrombosis and carcinoid disease. Coronary vasospasm was attributed to serotonin, which was secreted by the carcinoid tumour that reached an atherosclerotic coronary vasculature through a patent foramen ovale, thereby avoiding pulmonary inactivation.

Angina, Unstable↗
PubMed2005

ACE-DD genotype is associated with the occurrence of acute coronary syndrome in postmenopausal women.

The insertion/deletion (I/D) polymorphism of the angiotensin converting enzyme (ACE), the A1166C polymorphism in the angiotensin type 1 receptor (AT1R), and the M235T polymorphism of the angiotensinogen gene are associated with cardiovascular disease mostly in men. Few data are available on the effects of these genetic variations in postmenopausal women according to hormone replacement therapy (HRT) use. In this case-control study, we determine the frequency of mutant alleles in the ACE I/D, M235T and A1166C polymorphisms in postmenopausal Caucasian women with and without a diagnosis of acute coronary syndrome (ACS). Data from 198 women with ACS (63+/-10 years) and 149 controls (62+/-7 years) showed that ACE-DD genotype was more prevalent in women with ACS compared to controls (30% vs. 19%, P<0.05). There was no difference in genotype distributions for either the M235T or the A1166C polymorphisms between groups. The difference in ACE genotype distribution between ACS women and controls was driven by current HRT users with 30% of ACS and 15% of controls carrying the ACE-DD genotype (P<0.05). The oligenic combination of ACE-DD and M235T-TT genotypes was higher in ACS compared to controls. Among carriers of M235T-TT, 7% of ACS and 1% of controls also had the ACE-DD genotype, P<0.05. Thus, the ACE-DD genotype may be associated with ACS in postmenopausal women, particularly in HRT users.

Acute Disease↗
PubMed2005

Fluctuating inflammatory markers in patients with stable ischemic heart disease.

BACKGROUND: C-reactive protein (CRP), a marker of inflammation, is increasingly measured to stratify coronary artery disease risk and guide clinical management. However, little is known about how inflammatory markers fluctuate over time in patients with stable ischemic heart disease. METHODS: We examined serial serum CRP values in 159 patients with histories spanning the clinical spectrum of ischemic heart disease. Two to 8 CRP measurements were made at intervals varying from 15 days to 6 years. Successive interleukin (IL)-6 values were examined in 1 subgroup. Blood samples were always taken when patients were clinically stable, in the absence of any potentially confounding inflammatory condition. RESULTS: C-reactive protein values in individual patients fluctuated considerably when examined in the following ranges: less than 1 mg/L, 1 to 3 mg/L, and greater than 3 mg/L, proposed to indicate low, average, and high risk. Sixty-four patients (40.3%) changed risk category between the first and the second measurement. Within-patient variances of CRP and IL-6 levels were 1.79 mg/L (95% confidence interval, 1.60-2.00) and 2.69 pg/mL (95% confidence interval, 2.29-3.18), respectively. The variability of CRP was consistent over different times and across clinical groups, and independent of body mass index, smoking status, medication, and clinical events. CONCLUSIONS: Relatively important fluctuations in CRP levels in patients with stable ischemic heart disease may be problematic for risk stratification and treatment monitoring. A similar IL-6 variability suggests that these patients have a dynamic inflammatory status whose kinetics may modulate acute coronary risk.

Aged↗
PubMed2004

Primary angioplasty and thrombolysis are both reasonable options in acute myocardial infarction.

Primary angioplasty is increasingly being advocated as the preferred approach for treating acute ST-segment elevation myocardial infarction regardless of whether interinstitutional transfer is required. This review critically analyzes the evidence comparing primary angioplasty with thrombolytic therapy and concludes that reasonable health care professionals may still find considerable uncertainty about the superiority of primary angioplasty for all situations. The magnitude of benefit for primary angioplasty over thrombolysis is probably less than 1 to 2 lives saved/100 patients treated and largely depends on the choice of thrombolytic agent, time to treatment, place of treatment, and adjunctive therapy. There is little evidence that systematically transferring patients for primary angioplasty in routine practice will provide any health benefits over thrombolysis. Consequently, it may be most useful to view these treatments as complementary rather than competitive. Thrombolysis remains a clinically and economically attractive option for the treatment of acute myocardial infarction that does not require the radical restructuring of our health care systems.

Angioplasty, Balloon, Coronary↗
PubMed2004

Impact of prolonged cyclooxygenase-2 inhibition on inflammatory markers and endothelial function in patients with ischemic heart disease and raised C-reactive protein: a randomized placebo-controlled study.

BACKGROUND: The impact of cyclooxygenase (COX)-2 antagonist treatment on acute coronary risk is controversial. We investigated the effect of prolonged COX-2 inhibition on inflammatory profile and endothelial function in patients with ischemic heart disease and high serum C-reactive protein (CRP) values. METHODS AND RESULTS: In a double-blind study, 35 stable subjects on low-dose aspirin with > or =2 previous acute coronary events and 2 of 2 screening CRP values >2.0 mg/L were randomized to the COX-2 inhibitor rofecoxib (25 mg) or placebo daily for 6 months. Serum CRP, interleukin-6 (IL-6), P-selectin, matrix metalloproteinase-9 (MMP-9), and brachial artery endothelial function were evaluated. In the placebo group, CRP (median) was 3.16 mg/L (25% and 75% quartiles, 1.90 and 5.78 mg/L) at baseline and 4.22 mg/L (25% and 75% quartiles, 2.04 and 6.25 mg/L) at 6 months; in the rofecoxib group, CRP was 3.45 mg/L (25% and 75% quartiles, 2.08 and 5.78 mg/L) at baseline and 1.41 mg/L (25% and 75% quartiles, 1.17 and 4.81 mg/L) at 6 months (P=0.03). Rofecoxib compared with placebo also lowered IL-6 at 6 months (P=0.0002). There was a significant off-drug effect on CRP and IL-6 levels in the rofecoxib group 3 months after treatment (P=0.005 and P=0.009, respectively). Rofecoxib did not significantly affect P-selectin, MMP-9, and brachial artery vasoreactivity. CONCLUSIONS: Prolonged COX-2 inhibition attenuates CRP and IL-6, does not modify P-selectin and MMP-9, and has no deleterious effect on endothelial function in stable patients with a history of recurrent acute coronary events and raised CRP. These results strengthen the rationale for evaluating the clinical benefit of COX-2 inhibition in patients with ischemic heart disease.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2004

Canadian Cardiovascular Society Consensus Conference 2002: Management of heart disease in the elderly patient.

Cardiovascular disease is a major health issue for the elderly patient. Many diagnostic, therapeutic and ethical issues are specific for the the older adult with heart disease. The Canadian Cardiovascular Society 2002 Consensus Conference provides recommendations for the most frequently encountered cardiac problems in the elderly patient. A common theme of the recommendations is the need to apply the best evidence based medicine together with an assessment of frailty, comorbidity and quality of life. A major goal of the conference was to identify treatments that are not optimally used in the older patient.

Aged↗
PubMed2004

The 2004 ACC/AHA Guidelines: a perspective and adaptation for Canada by the Canadian Cardiovascular Society Working Group.

Major changes in acute ST elevation myocardial infarction (STEMI) management prompted a comprehensive rewriting of the American College of Cardiology/American Heart Association Guidelines. The Canadian Cardiovascular Society (CCS) participated in both the writing process and the external review. Subsequently, a Canadian Working Group (CWG), formed under the auspices of the CCS, developed a perspective and adaptation for Canada. Herein, accounting for specific realities of the Canadian cardiovascular health system, is a discussion of the implications for prehospital care and transport, optimal reperfusion therapy and an approach to decision making regarding reperfusion options and invasive therapy following fibrinolytic therapy. Major recent developments regarding indications for implantable cardioverter defibrillator(s) (ICDs) also prompted a review of indications for ICDs and the optimal timing of implantation given the potential for recovery of left ventricular function. At least a 40-day, preferably a 12-week, waiting period was judged to be optimal to evaluate left ventricular function post-STEMI. A recommended algorithm for the insertion of an ICD is provided. Implementation of the new STEMI guidelines has substantial implications for resources, organization and priorities of the Canadian health care system. While on the one hand, the necessary incremental funding to provide tertiary and quaternary care and to support revascularization and device implantation capability is desirable, it is equally or more important to develop enhanced prehospital care, including the capacity for early recognition, risk assessment, fibrinolytic therapy and/or triage to a tertiary care centre as part of an enlightened approach to improving cardiac care.

Canada↗
PubMed2003

Effect of atorvastatin on exercise-induced myocardial ischemia in patients with stable angina pectoris.

To investigate whether marked and sustained lipid-lowering in subjects with stable angina pectoris and dyslipidemia reduces exercise-induced myocardial ischemia, 17 subjects were treated with dose-adjusted atorvastatin over 1 year and underwent serial evaluation of exercise electrocardiographic ischemic parameters, serum biomarkers, and brachial artery endothelial function. Endothelial function improved progressively and C-reactive protein, P-selectin, and tissue plasminogen activator inhibitor levels decreased, but there was no decrease in exercise electrocardiographic ischemia.

Aged↗
PubMed2003

What induces the warm-up ischemia/angina phenomenon: exercise or myocardial ischemia?

BACKGROUND: The relation of the warm-up ischemia phenomenon to the presence and intensity of initial myocardial ischemia is unclear. We sought to determine whether the warm-up ischemia phenomenon requires initial myocardial ischemia or can be induced by exercise without ischemia and whether there is a relation between the intensity of initial ischemia and the attenuation of ischemia on reexercise. METHODS AND RESULTS: Twelve subjects with exertional myocardial ischemia performed 2 exercise ECG tests (1 and 2) at a +/-10-minute interval on 3 occasions (A, B, C) 1 month apart. A1 and A2 were symptom-limited. B1 was kept as long as A1, but its intensity was held under the ischemic threshold (heart ratexsystolic pressure at 1-mm ST depression [STD]) noted at A1. B2 was symptom-limited. C1 was also kept as long as A1 but with an intensity adjusted to maintain one-half maximum STD of A1. C2 was symptom-limited. Exercise duration of A2, B2, and C2 increased similarly compared with A1 (P=0.009). However, the ischemic threshold (x10-3) increased at A2 (23.5+/-6.0) compared with A1 (20.3+/-4.8; P<0.0001) but not at B2 (19.8+/-5.0) or C2 (21.5+/-5.8). Similarly, maximum STD adjusted to the highest heart rate-systolic pressure product common to A1, A2, B2, and C2 decreased at A2 (1.4+/-0.7 mm) compared with A1 (2.5+/-0.9 mm; P<0.0001) but not at B2 (2.7+/-0.9 mm) or C2 (2.3+/-0.9 mm). CONCLUSIONS: Exercises under the ischemic threshold and of intermediate ischemic intensity increase short-term exercise capacity, but myocardial ischemia of more than moderate intensity is needed to induce the warm-up ischemia phenomenon.

Angina Pectoris↗
PubMed2003

Preclinical diabetic cardiomyopathy: relation of left ventricular diastolic dysfunction to cardiac autonomic neuropathy in men with uncomplicated well-controlled type 2 diabetes.

Diabetic cardiomyopathy is an ill-defined entity. This study was designed to explore the possible association between left ventricular diastolic dysfunction (LVDD) and cardiac autonomic neuropathy (CAN) independently from metabolic control. Three groups of 10 age-matched men each with well-controlled type 2 diabetes were studied: (1) subjects with normal diastolic function, (2) subjects with LVDD characterized by impaired LV relaxation, and (3) subjects with a more severe form of LVDD characterized by a pseudonormalized pattern of LV filling. No subject had evidence of clinical diabetic complications, coronary artery disease (CAD), hypertension, congestive heart failure, or thyroid or overt renal disease, and all had a negative maximal exercise test. LVDD was evaluated by Doppler echocardiographic and CAN was evaluated using spectral analysis of heart rate variability (HRV; time and frequency domains) from 24-hour Holter recordings. Findings showed that the high frequency power (HF: 0.15 to 0.4 Hz) tends to decrease with worsening diastolic function; 5.0 +/- 0.2 ms(2) (mean +/- SE) in group 1, 4.2 +/- 0.3 ms(2) in group 2, and 3.9 +/- 0.4 ms(2) (P =.03) in group 3, respectively, whereas the low frequency power (LF: 0.04 to 0.15 Hz) was similar between groups. In the time domain, the mean squared differences of the successive RR intervals (rMSDD) also showed the same pattern, ie, 31.0 +/- 2.8 ms, 23.8 +/- 1.6 ms, and 21.5 +/- 2.9 ms in groups 1, 2, and 3, respectively (P =.03). The E/A ratio correlated significantly with indices of parasympathetic modulation (HF; r = 0.448, P =.013; rMSDD: r = 0.457, P =.011; pNN50: r = 0.425, P =.019). LVDD and CAN are associated in patients with otherwise uncomplicated well-controlled type 2 diabetes. The parameters defining these 2 abnormalities may serve to better define diabetic cardiomyopathy as a distinct entity and could eventually become useful prognostic indicators as it has been shown in nondiabetic populations.

Autonomic Nervous System Diseases↗
PubMed2003

Increased occurrence of diabetes in people with ischemic cardiovascular disease and general and abdominal obesity.

BACKGROUND: Diabetes worsens the prognosis of patients with ischemic cardiovascular disease (ICVD). Increased body weight and abdominal obesity have been shown to increase the risk of diabetes in people without ICVD. Such a relationship has not been assessed in patients with ICVD who may have a different occurrence due to their disease and medications. OBJECTIVE: To examine the risk of developing diabetes among patients with ICVD according to body mass index (BMI), waist-to-hip ratio and waist circumference METHODS: Anthropometric measurements were done in 4699 men and 1187 women with ICVD (mean age 66 years) and without known diabetes at entry to the Heart Outcomes Prevention Evaluation (HOPE) study. During the median 4.5-year follow-up, a diagnosis of diabetes was reported in 261 (4.4%) participants. RESULTS: There was a positive and graded association between increased BMI, waist circumference and waist-to-hip ratio, and the risk of developing diabetes (P for trends <0.0001). After adjusting for all baseline characteristic differences including medications, the relative risk of developing diabetes after the first 40th percentile of each anthropometric measure increased by 12% (95% CI 9% to 15%) for every 1 kg/m2 increase in BMI; the relative risk increased by 5% (95% CI 4% to 6%) for every 1 cm increase in waist circumference and by 38% (95% CI 18% to 61%) for every 0.1 unit increase in waist-to-hip ratio. CONCLUSION: In patients with ICVD, increased BMI, waist-to-hip ratio and particularly waist circumference constitute independent risk factors for development of diabetes.

Abdomen↗