Vascular Disease Prevention (Discontinued) - Volume 2, Issue 4, 2005

Cardiovascular disease (CVD) is a leading cause of death in women and is responsible for more deaths among women than men. Although traditional risk factors are similar between the two sexes, some factors are specific to women. There are also gender differences in CVD presentation, clinical characteristics and outcome. The poor outcome in women may be due to lack of understanding of CVD epidemiology, and gender-related differences in pathophysiology, presentation and efficacy of therapeutic interventions. Although female reproductive events including pregnancy complications such as pre-eclampsia and gestational diabetes may indicate cardiovascular risk, few women have access to long-term follow up and advice about life style modification to reduce these risks. Furthermore, current cardiovascular risk stratification strategies do not include pregnancy-related risk factors such as pre-eclampsia. Primary prevention to reduce the burden of CVD in women would depend on more robust risk stratification methods that incorporate reproductive history, particularly pregnancy-related complications. This review addresses gender-specific cardiovascular risk factors that may be present during intrauterine development, adolescence, reproductive years and the menopause. It also highlights the effects of pregnancy complications on long-term female cardiovascular risk.

Coronary artery bypass grafting (CABG) is usually performed with cardiopulmonary bypass (CPB). The offpump CABG technique is an alternative to the standard on-pump technique. The purpose of this study was to evaluate myocardial cell damage and antioxidant status in off-pump and on-pump CABG. Patients (30 men and 15 women) undergoing CABG were included. The off-pump technique was used in 25 patients (mean age 59 ± 10 years). The on-pump technique was used in 20 patients (mean age of 57 ± 11 years). Tissue injury markers [e.g. creatine kinase (CK), CK-MB isoenzyme and cardiac troponin-I (cTnI)] and antioxidant markers [e.g. glutathione peroxidase (GPx), superoxide dismutase (SOD) and malondialdehyde (MDA)] were measured before and 1, 6, 24, 48 and 72h postoperatively. The levels of CK, CK-MB after the on-pump technique were significantly higher when compared to after off-pump CABG (p<0.001). cTnI levels followed the same pattern (p<0.001). MDA levels after on-pump CABG were higher than after off-pump CABG (p<0.001). These findings suggest that off-pump CABG causes less myocardial injury than the on-pump technique.

We investigated the effects of the strict adherence to ACC/AHA guidelines in decision making for coronary angiography in patients who survived after a Q wave myocardial infarction (MI). This prospective observational study included 280 consecutive patients (≤ 75 years) in the Northwestern Region of Greece who survived a Q wave MI. Followup ranged from 22 to 29 months (mean: 26 months). Coronary angiography and revascularization rates in the early post- MI period (2 months after the index event) and mortality and morbidity during the follow-up period were the main outcome measures. In the early post-MI period, coronary angiography, percutaneous coronary intervention and coronary artery bypass surgery were performed in 48%, 16% and 14% of the patients, respectively. During the follow-up period 24 (8.2%) patients died (cardiac death: 21; 87.5%), and 15 (5.1%) suffered a re-infarction. Diabetes (OR 4.63, 95% CI 1.44 to 14.48, p=0.010), anterior MI (OR 4.54, 95% CI 1.51 to 15.15, p=0.007) and no prescription of beta-blockers (OR 9.86, 95% CI 2.69 to 18.61, p=0.001) were predictors of death at follow-up. Advanced age (OR 1.07, 95% CI 1.00 to 1.14, p=0.045) was the only predictor of re-infarction. We conclude that a) Implementation of published AHA/ACA guidelines in a Greek population resulted in coronary angiography and revascularisation procedures in the early phase of Q wave MI with rates of 48% and 30%, respectively. b) The two-year post discharge mortality was 8.2% and re-infarction rate 5.1%. c) Diabetes, anterior MI and lack of prescription of beta-blockers were strong predictors of mortality; advanced age being the only predictor of re-infarction.

Hyperthyroidism is due to exaggerated thyroid hormone bioactivity. We reviewed the vasculopathy in hyperthyroid rats through the following ways: 1) the voltage-gated calcium channels in vascular smooth muscle (VSM); 2) the receptor-operated calcium channels in VSM; 3) the different responses to catecholamines in VSM; 4) endothelium dependent/ independent relaxation; 5) the KATP channels; and 6) the altered allergic vascular responses. In the hyperthyroid state, the elevated intracellular calcium release and the impaired nitric oxide bioavailability resulted in abnormalities in vascular activities, which may be secondary to oxidative stress. The compromised vascular function consequent on the endothelial impairment observed in hyperthyroidism was also found in other diseases, such as neuro-degenerative disorders and diabetes. The study on these vascular alterations may throw a light on the understanding of mechanisms underlying vascular diseases.

We compared the role of vegetarian and non-vegetarian diet on vascular reactivity in response to mental stress. Vegetarian under-graduate medical students (n = 100) were compared with non-vegetarian students (n = 100) both at rest and after examination stress. The measured parameters included systolic blood pressure (SBP), diastolic blood pressure (DBP), pulse pressure (PP), mean blood pressure (MBP) and heart rate (HR). Both groups showed significant vascular reactivity to mental stress but the non-vegetarians had higher BP and HR values both at rest and after exposure to stress. Under resting conditions, the SBP, DBP, PP, MBP (mmHg), HR (bpm) in the vegetarians were 127.7 ± 6.4, 77.8 ± 4.4, 49.9 ± 5.9, 94.5 ± 4.3, 77.1 ± 2.1 and in the non-vegetarian group were 133.7 ± 7.7, 86.0 ± 5, 47.7 ± 6.8, 101.9 ± 5.1, 82.3 ± 2.7, respectively. All the values except PP in the non-vegetarian group were significantly higher when compared with the vegetarian group (p < 0.05). After exposure to stress, the SBP, DBP, PP, MBP (mmHg), HR in the vegetarian group were 132.2 ± 6.5, 80.3 ± 4.6, 51.8 ± 6.8, 97.6 ± 4.2, 82.3 ± 2.7 and in the non-vegetarian group were 141.9 ± 7.9, 91.8 ± 6.7, 50.0 ± 7.5, 108.5 ± 6.2, 86.4 ± 3.0, respectively. All the values except PP in the non-vegetarian group were significantly higher when compared with the vegetarians (p < 0.05). The post-stress values were significantly greater than those taken at rest (p<0.05). This study showed better coping to mental stress in vegetarians and suggests a greater risk to develop future hypertension in non-vegetarians according to the reactivity hypothesis. Prospective follow-up studies are needed to test this hypothesis.

Introduction: Venous thromboembolism (DVT) is a prevalent, potentially fatal complication following orthopedic joint replacement of the lower extremity. Diagnosis is difficult because DVT symptoms are similar to the post operative sequelae. Prophylaxis treatment often varies based upon surgeon's preference. We determined the prevalence and factors associated with DVT in a cohort of total joint arthroplasty (TJA) patients admitted for comprehensive inpatient rehabilitation (CIR). Methods: Patient's admitted for CIR following TJA from 1995-1999 were retrospectively reviewed. All patients were screened within 48 hours of admission to CIR. The prevalence of DVT during the study period was calculated. Data collected on the co morbid medical conditions, type of surgery, anesthesia, complications, DVT prophylaxis therapy, and demographic variables were entered into a multiple logistic regression analysis to evaluate their association with DVT. Results: One-hundred eighty-one patients were included in the study. DVT prevalence was 19.3% (35/181). Pulmonary embolus (PE) rate was low at 0.6% (1/181). None of the associated variables reached statistical significance. Discussion: Although type of DVT prophylaxis was not predictive of DVT risk, the small sample size may explain the negative finding. The low prevalence rate of PE was attributed to the study design of screening patients on admission leading to early discovery and treatment of DVT which effectively lowered the risk of PE. The prevalence of DVT emphasizes the need for appropriate DVT prophylaxis in this at risk population.

Deep vein thrombosis (DVT) poses a threat in patients undergoing major operations especially, abdominal surgery. Hence, it is a well established, to use thromboprophylaxis for these patients. We provide an overview of the current practices and the future advancement of DVT prophylaxis.

This review considers the evidence for screening patients for abdominal aortic aneurysms (AAA). It describes how there was initial scepticism about screening asymptomatic patients, as there was a lack of knowledge about the incidence and natural history of patients with AAAs. Similarly, there was no consensus as to who to screen and when to operate. Additionally, no effective long-term measure for cost-effectiveness for such a screening programme had been demonstrated. After a literature search, 22 articles were selected for further review. Relevant guidelines, review articles, and randomised controlled studies were included. Several studies assessed when and why to consider intervention for asymptomatic AAAs. Other studies have identified possible target groups within the general population with a higher incidence of AAAs for screening. Ultrasonography was the agreed modality routinely used for screening in all the studies. Most studies supported the benefits for screening male patients above the age of 64 years. And, there is now also growing evidence of the cost-effectiveness of screening programmes that take into account quality adjusted life years (QALYs) gained. This review presents experiences from different countries on implementing screening programmes for AAAs. There is currently sufficient evidence to demonstrate that a targeted and coordinated screening programme for AAAs can be both life-saving and cost-effective in the long-term.

Patients with end stage kidney disease are characterised by a high prevalence of atherosclerotic vascular disease, which contributes significantly to their morbidity and mortality. Accelerated atherosclerosis is evident at the initiation of dialysis, suggesting that the increase in vascular risk occurs at an early stage of chronic kidney disease (CKD). Recent data confirm that patients with moderate CKD are characterised by a high prevalence of vascular disease, and epidemiological data suggest that even mild degrees of CKD are associated with an increased vascular risk. The increased vascular risk reflects a complex interaction between traditional and novel vascular risk factors and metabolic abnormalities associated with renal impairment. The vascular risk profile of CKD changes from one where classical vascular risk factors predominate in mild CKD to one where vascular risk is compounded by non-traditional risk factors and metabolic abnormalities in severe CKD. Patients with mild to moderate CKD are characterised by a high prevalence of classical vascular risk factors such as hypertension and dyslipidaemia. Insulin resistance is also a feature of moderate CKD. Non-traditional risk factors such as hyperhomocystenaemia and abnormalities of divalent ion homeostasis become apparent as renal function declines. Moderate and severe CKD are also characterised by a strong association between malnutrition, chronic inflammation and atherosclerosis. Alterations in endothelial function and reduced arterial compliance precede the onset of clinically overt vascular disease. The relative contribution of these factors to total vascular risk in CKD remains to be determined.