[The evaluation of the appropriateness of instrumental exams in cardiology. The case of echocardiography]. / La valutazione dell'appropriatezza degli esami strumentali in cardiologia. Il caso dell'ecocardiografia.

BACKGROUND: The aim of this study was to evaluate the appropriateness and utility rates of echocardiograms performed in 309 patients in an outpatient clinical setting. METHODS: Data were collected by means of a questionnaire filled in by the cardiologists who performed the examinations. Appropriateness was evaluated according to international guidelines and scored as class I: appropriate, class II: doubtful appropriateness, class III: inappropriate; the exam was deemed useful if it was able to influence the clinical decision-making; normalcy rate was also checked. The relationship between both the referring physicians and motivation of the exam and its appropriateness, and the relationship between appropriateness and both the normalcy rate and utility of the exam were assessed. RESULTS: An echocardiogram was requested by the cardiologist in 46% of patients; the more common reasons for the exam were arterial hypertension (26%), cardiac murmur (18%), palpitations (15%), and known coronary artery disease (10%). The echocardiogram was appropriate (class I) in 25% of patients, doubtfully appropriate (class II) in 39% of patients and inappropriate (class III) in 36% of patients. The appropriateness rate between the cardiologists was similar to that of other prescribing clinicians (p = NS). The highest class III rate was found in patients with hypertension, while the highest class I rate was found in patients with a cardiac murmur (p < 0.01). Normalcy rate was lower in class I than in class II and III exams (p < 0.001). The utility rate was higher in class I (76%) than in class II (13%) and III (< 1%) exams (p < 0.01). CONCLUSIONS: International guidelines can be used effectively and safely to identify (not to prescribe) the useless echocardiograms.

[Atherogenic dyslipidemia, metabolic syndrome and cardiovascular risk]. / Dislipidemia aterogena, sindrome metabolica e rischio cardiovascolare.

The combination of high serum triglyceride levels and small low density lipoprotein particles, with a reduction in high density lipoprotein cholesterol levels has been named atherogenic lipoprotein phenotype or, simply, lipid triad. These lipid factors are commonly associated with peripheral resistance to the action of insulin, hyperinsulinism, central and visceral obesity, hypertension, hyperuricemia, hypercoagulability. The clustering of these nonlipid factors along with the lipid factors has been called metabolic syndrome. Insulin resistance plays a central role in the development of the lipid triad increasing the production of triglyceride-rich lipoproteins and decreasing their catabolism. There is currently great interest about the origins of the metabolic syndrome. One question under considerable research is whether genetic or acquired factors predominate in causing this syndrome. There seems to be little doubt that the metabolic syndrome taken as a whole constitutes a major risk factor for coronary heart disease. What is less certain is that each component of the syndrome is an independent risk factor. People with lipid triad are at very high risk of developing coronary heart disease, and careful management is warranted. Nonetheless, appropriate therapeutic strategies that will modify the metabolic syndrome as a whole are needed. More investigations about key metabolic steps that simultaneously affect multiple pathways will be required to yield a satisfactory therapy for high risk patients exhibiting the metabolic syndrome.

Compound heterozygosity for a structural apolipoprotein A-I variant, apo A-I(L141R)Pisa, and an apolipoprotein A-I null allele in patients with absence of HDL cholesterol, corneal opacifications, and coronary heart disease.

BACKGROUND: The concentration of HDL cholesterol is inversely correlated with the risk of coronary heart disease (CHD). Some rare mutations in the apolipoprotein (apo) A-I gene are associated with low levels of HDL cholesterol. Their association with cardiovascular risk is controversial. METHODS AND RESULTS: We studied the molecular defects underlying corneal opacities and absence of HDL cholesterol in three brothers and a sister. In a family study, the importance of these defects for lipid metabolism and manifestation of coronary heart disease was investigated. The frequency of these apo A-I defects was assessed by genotype and phenotype analysis of 477 DNA- and plasma samples, respectively, from the population. The four patients were compound heterozygotes for a null allele and a missense mutation in the apo A-I gene that leads to a leucine-->arginine substitution at residue 141 [apo A-I(L141R)Pisa]. Heterozygotes for either the null allele or the structural variant had half-normal concentrations of HDL cholesterol and apo A-I compared with unaffected family members. Apo A-I(L141R)Pisa was detected in one more unrelated subject. Coronary angiography of the four compound heterozygotes revealed the presence of CHD in all male patients, whose ages ranged between 45 and 52 years. They presented with additional risk factors, including elevated LDL cholesterol levels, obesity, and arterial hypertension. Despite complete HDL deficiency and hypercholesterolemia, CHD was absent in the 51-year-old premenopausal sister. CONCLUSIONS: Apo A-I deficiency may lead to premature atherosclerosis if present in conjunction with additional cardiovascular risk factors.