Daria Frestad

This study investigated whether digital reactive hyperemia index (RHI) measured by digital pulse amplitude tonometry is a sensitive indicator of coronary microvascular dysfunction (CMD). CMD is an early marker of cardiovascular disease. However, CMD is a complex diagnosis and consists of multiple abnormalities of the coronary circulation. Impaired RHI is a noninvasive measure of peripheral vascular dysfunction that can identify individuals with acetylcholine induced coronary vascular dysfunction. It is largely unknown whether there is also an association between RHI and the endothelial-independent aspect of CMD assessed as a coronary flow velocity reserve (CFVR). We included 339 women with chest pain suggestive of angina pectoris and a diagnostic invasive coronary angiogram without significant coronary artery stenosis (<50%). CFVR was measured by transthoracic pulsed wave Doppler echocardiography during dipyridamole infusion (0.84 mg/kg). RHI was assessed by digital pulse amplitude tonometry. Participants were categorized in 3 RHI and 3 CFVR groups. We examined the association between CFVR and RHI and the distribution of cardiovascular risk factors between the CFVR and RHI groups. CFVR and RHI were successfully measured in 322 participants. Median CFVR was 2.3 (interquartile range: 2.0 to 2.8) and median RHI was 2.1 (interquartile range: 1.6 to 2.6). No correlation was found between CFVR and RHI (Spearman's rho = -0.067, p = 0.23), and mean RHI did not differ between CFVR categories (p = 0.39). Participants with low CFVR were significantly older and had a significantly greater burden of hypertension, whereas participants with an impaired RHI had a higher body mass index and were more likely to have diabetes and be current smokers. RHI does not identify individuals with CMD assessed as impaired CFVR by dipyridamole stress echocardiography in women with no obstructive coronary artery disease. The two methods are likely to identify different aspects of vascular pathology, as indicated by the different association with cardiovascular risk factors.

Cardiovascular disease has been the leading cause of death in both sexes in developed countries for decades. In general, men and women share the same cardiovascular risk factors. However, in recent trials including both men and women sex-specific analyses have raised awareness of sex differences in cardiovascular risk factors due to both biological and cultural differences. Women experience their first myocardial infarction (MI) 6-10 years later than men and a protective effect of their natural estrogen status prior to menopause has been suggested. Female sex hormones have been associated with a less atherogenic lipid profile and a more healthy fat distribution. These differences are attenuated following menopause. Regarding life style the prevalence of smoking is highest in men but female smokers have a relatively higher cardiovascular risk than male smokers. Men are more physically active than women while women have healthier dietary habits. Genetic factors also affect cardiovascular risk but no sex differences have been seen. Increased cardiovascular risk attributed to psychosocial distress is similar in men and women, but since women are more prone to psychosocial distress their burden of disease is greater. Compared with a healthy population the relative risk of MI in a diabetic population is higher in women than in men. No sex difference exists in the prevalence of hypertension but it has an earlier onset in men. Sex differences in cardiovascular risk are becoming more apparent and paying attention to this is pivotal when addressing risk factors in preventive efforts.

Cardiovascular disease is the leading cause of death in the western countries. Conventional risk evaluation of asymptomatic individuals is unfortunately inaccurate. There is a need for better diagnostic tools to identify persons, who will benefit from intensified preventive treatment. Coronary artery calcium score (CACS) measured by multi-slice CT scan contributes significantly to risk stratification especially in persons with intermediate risk assessed by conventional risk analysis. A CACS-guided preventive intervention strategy seems appealing to reduce mortality due to cardiovascular disease.

RESUME Hjerte-kar-sygdom er den hyppigste dødsårsag i de vestlige lande. Konventionel risikoevaluering af asymptomatiske indivi-der er desvaerre upraecis, hvorfor der er behov for bedre redska-ber til at opspore personer, der vil have gavn af en intensiveret forebyggende indsats. Koronararteriecalciumscore (CACS) målt med multi-slice computertomografi bidrager vaesentligt til risiko-stratificering specielt hos personer, der bedømt med konventio-nel risikoanalyse vurderes at have intermediaer risiko. En CACS-guidet praeventiv interventionsstrategi synes at vaere attraktiv med henblik på at reducere dødelighed som følge af koronar-sygdom. I 2008 døde ca. 15.500 danskere som følge af hjerte-kar-sygdom (CVD), heraf hovedparten ca. 5.500 af iskaemisk hjertesygdom (IHD). Hovedårsagen til CVD er åreforkalkning, der rammer ca. to tredjedele af de ca. 320.000 danskere med CVD. De klassiske risiko-faktorer for udvikling af åreforkalkning er velkendte: arvelig disposition, forhøjet kolesteroln...