Influence of body mass index on extent of coronary atherosclerosis and cardiac events in a cohort of patients at risk of coronary artery disease.

BACKGROUND AND AIM: To estimate if a meaningful relationship exists between body mass index (BMI) and the entity of coronary atherosclerosis, coronary events and mortality in a cohort of consecutive patients with suspected coronary artery disease (CAD). METHODS AND RESULTS: In this prospective study, we enrolled 1299 consecutive patients (905 [69.7%] males) who had undergone coronary angiography. Our sample consisted of 477 patients (36.8%) of normal weight; 567 (43.6%) overweight and 255 (19.6%) obese, according to the WHO classification. Conventional cardiovascular risk factors, BMI, endothelial function and subclinical inflammation were studied. Different angiographic CAD scores were used to quantify coronary atherosclerotic burden. In overweight and obese patients, respect to normal weight population, there is a higher prevalence of hypertension, hypercholesterolemia and diabetes mellitus, but BMI was not significantly associated with greater extent of coronary atherosclerosis. At follow-up (mean: 40; range: 24-82 months) obese and overweight patients showed a higher incidence of coronary events compared to the normal weight population (74.9% [obese] versus 62.7% [overweight] versus 53.2% [normal weight]; adjusted relative risk [obese versus overweight]: 1.08 [95% confidence interval: 1.02-1.23]; P<0.05; and adjusted RR [obese versus normal weight]: 1.17 [95% CI: 1.10-1.42], P<0.01). Mortality from cardiac events was not significant within the categories. The Cox regression model showed flow mediated dilation (P<0.0001), high-sensitive C reactive protein (P=0.022) and BMI (P=0.045) as independent predictors of acute coronary events. CONCLUSION: BMI is not associated with the extent of coronary atherosclerosis and mortality. The higher incidence of coronary events in obese subjects is only partly explained by conventional associated risk factors. Impaired endothelial function and sub-clinical inflammation could be involved in this association but BMI itself is related to cardiovascular events suggesting that other unknown (or not considered) pathways are involved.

Coronary calcification in cardiovascular risk stratification.

The correlation between coronary calcifications and subclinical atherosclerotic disease has been well known for some years now. Today we are able to quantify coronary calcium deposits, the calcium score, by means of new imaging techniques such as electron beam computed tomography and multislice spiral computed tomography. A large number of studies performed using these methods has confirmed the association between coronary calcifications and atherosclerotic disease and has opened up the possibility of early diagnosis of any subclinical atherosclerotic disease in various subpopulations such as diabetics and nephropatics. The etiopathogenesis of coronary calcium has not yet been made clear; it appears to be an active process similar to bone formation that involves cells similar to those involved in the reabsorption of bone matrix. The calcium score, therefore, provides physicians with a further diagnostic tool able to better determine cardiovascular risk patients and supplements the Framingham risk score. International guidelines have not yet illustrated with any precision in which ambits to apply screening for the quantification of coronary calcium and consequently, for the time being, the use of such methods must be restricted to cases in which the possibility of any benefit can be scientifically shown. This review represents the state of the art on coronary calcification and its role in clinical practice.