Cardiovascular risk assessment of South Asians in a religious setting: a feasibility study.

AIMS: South Asians in the UK have high cardiovascular disease (CVD) mortality. Therefore, this population is likely to benefit from screening programmes. To address this issue, an initiative was set up between the Royal Free Hampstead NHS Trust, H.E.A.R.T. UK and two Hindu temples in North London to provide screening for CVD risk factors in the community. METHODS: A total of 434 individuals of Gujarati Indian origin were screened. Measurements included anthropometry, blood pressure and lipid profiles. Three different scoring systems: Framingham, Joint British Societies' 2 and QRISK2 were used to estimate CVD risk. RESULTS: At least one modifiable CVD risk factor was present in 92% of the individuals screened; 52% were hypertensive, 40% were obese, 75% had central adiposity and 10% had total cholesterol/high density lipoprotein cholesterol ratio > 6. In addition, 37% of a subset of 104 individuals with a fasting sample fulfilled the diagnostic criteria for metabolic syndrome. Overall, 15% of participants screened had a 10-year CV risk score > 20% using QRISK2. The three risk score calculators showed moderate agreement: QRISK2 and JBS2 (kappa 0.61, 95% CI 0.54-0.67), QRISK2 and Framingham (kappa 0.63, 95% CI 0.57-0.70) and JBS2 and Framingham (kappa 0.70, 95% CI 0.64-0.75). CONCLUSIONS: A high prevalence of modifiable risk factors for CVD was detected in the population screened.

Myocardial perfusion scintigraphy in asymptomatic diabetic patients: a critical review.

The increasing prevalence of diabetes mellitus and the associated high cardiovascular risk has made the non-invasive identification of silent coronary heart disease in diabetic individuals an important issue. This strategy could identify higher risk asymptomatic patients with diabetes mellitus in whom coronary revascularization may improve the outcome beyond that achieved by currently recommended medical management. Stress myocardial perfusion imaging has been shown to be effective in detecting coronary heart disease and predicting adverse cardiac events in asymptomatic diabetic patients. However, the clinical utility of myocardial perfusion scintigraphy is debated intensively due to the paucity of prospective and outcome based evidence. The controversy stems from several observational studies, epidemiologic data and cost-effectiveness analyses. Thus, although several authors and professional organizations advocate the use of stress imaging for screening higher risk asymptomatic diabetic patients, others are cautious in recommending any kind of stress testing in that population. This review is based on a broad survey of the literature and discusses the potential role of stress myocardial perfusion scintigraphy in screening asymptomatic diabetic subjects for coronary heart disease in the current era and in relation with other non-invasive screening tools.

Endothelial dysfunction in metabolic syndrome: prevalence, pathogenesis and management.

The metabolic syndrome (MetS) is characterized by the presence of central obesity, impaired glucose metabolism, dyslipidemia and hypertension. Several studies showed that MetS is associated with increased risk for type 2 diabetes mellitus (T2DM) and vascular events. All components of MetS have adverse effects on the endothelium. Endothelial dysfunction plays a role in the pathogenesis of atherosclerosis and might also increase the risk for insulin resistance and T2DM. We review the prevalence and pathogenesis of endothelial dysfunction in MetS. We also discuss the potential effects of lifestyle measures and pharmacological interventions on endothelial function in these patients. It remains to be established whether improving endothelial function in MetS will reduce the risk for T2DM and vascular events.

A role for near infrared spectroscopy in the assessment of intermittent claudication.

BACKGROUND: Near infrared spectroscopy (NIRS) can be used to monitor muscle oxyhemoglobin (HbO2), deoxyhemoglobin (Hb) and cytochrome oxidase (CytOx) oxidation. We evaluated the changes in NIRS in patients with intermittent claudication (IC) pre- and postexercise. Microalbuminuria is an index of endothelial dysfunction. Therefore, we also assessed whether the urinary excretion of albumin increased postexercise in patients with IC. METHODS: Each participant (14 patients with IC and 10 controls) underwent a treadmill test; NIRS was continuously recorded. The urinary albumin:creatinine ratio (ACR) and ankle: brachial systolic pressure index (ABPI) were measured pre- and postexercise. RESULTS: The ABPI in the claudicants dropped significantly (p<0.001) postexercise. The pre-exercise ACR did not differ between claudicants and controls but postexercise, the ACR increased significantly (p<0.001) in the claudicants. There was a significant (p<0.001) difference in the degree of HbO2 deoxygenation between claudicants and controls; the rate of deoxygenation was significantly higher in claudicants than in controls (-8.4 vs. -3.4 mol/L.min, p=0.024). The period of recovery of HbO2 postexercise was also significantly slower in claudicants (192 vs 68 sec, p=0.003). There was a significant correlation between the increase in the ACR and time of recovery of HbO2 levels postexercise (r=0.86, p<0.001, n=24). A similar pattern was seen with CytOx. CONCLUSIONS: NIRS may provide a simple, non-invasive assessment of the severity of IC. Furthermore, because the ACR is a marker of endothelial damage, it is possible that NIRS changes also reflect endothelial integrity. These applications of NIRS technique should be assessed in a larger study.

Measurement of platelet volume using a channelyzer: assessment of the effect of agonists and antagonists.

Platelets undergo morphological changes prior to aggregating. This phenomenon is known as the platelet shape change (PSC) and is usually accompanied by at increase in median platelet volume (MePV). We evaluated MePV changes in human platelet rich plasma (PRP) using a high resolution pulse-height analyser ("channelyzer"). Increases in MePV were induced by the addition of low concentrations of known aggregating agents. These agonists showed different patterns in terms of potency, duration and reversibility.

Assessment of platelet function in patients with Raynaud's syndrome.

Platelet function was studied in 11 patients with Raynaud's syndrome and 11 healthy controls. Platelets obtained from patients with Raynaud's syndrome were significantly more responsive to adrenaline, produced more thromboxane A2, and were resistant to prostaglandin inhibitors (prostacyclin and prostaglandin E1) of platelet aggregation. Platelets from control subjects and patients with Raynaud's syndrome were more resistant to prostaglandin inhibitors when reactions were carried out at 27 degrees C rather than at 37 degrees C. Patients with Raynaud's syndrome also had significantly increased plasma concentrations of beta-thromboglobulin, fibrinogen, and circulating platelet aggregates. In an attempt to elicit local platelet responses, the forearms of control subjects and patients with Raynaud's syndrome were cooled in water tanks and platelet function tests performed before and after cooling. No significant difference in the results was observed. The potential role of platelets in the pathogenesis of Raynaud's syndrome is discussed.