Gender-specific aspects in primary and secondary prevention of cardiovascular disease.

Gender differences in biological substrates of disease determine different clinical manifestations of CV disease with important implications for prevention, diagnosis and therapy in the two sexes. In women, the activity of sex hormones reduces the influence of CV risk factors during the reproductive age, and delays the onset of CHD of 2 decades compared to men. However, women as men suffer from CV events, and in women mortality from all CV causes and have greater than the sum of the others 7 causes of death together. Women are more likely than men to die of a first myocardial infarction a probability of developing heart failure or a second infarction than their male counterparts. The levels of lipid components vary in different ages of life and in the two genders. TC and LDL increase in men between 35 and 50 years of age. On the contrary LDL levels do not change significantly in fertile women in which they have a lower predictive value for CHD than in men, HDL levels are higher in premenopausal women than in men of the same age and their role in predicting CHD is considerably higher in women. High triglycerides and Lp(a) are more important as a risk factor in women than in men. Because of the greater incidence of cardiovascular diseases in men until the early 80s, the information about the importance of risk factors associated with an increased risk of cardiovascular events has been gathered mainly in men and transferred to women. Most studies on lipid-lowering therapy did not have the adequate statistical power to show significant reductions in CV events in women. Regarding the indications for use of statins in daily practice, current data suggest that in secondary prevention statins are equally effective in both genders while in primary prevention the CV benefits of lipid-lowering therapy in women are less clear than in men and therefore should be used according to the degree of risk calculated from the available score systems.

Cardiac function, physical exercise capacity, and quality of life during long-term thyrotropin-suppressive therapy with levothyroxine: effect of individual dose tailoring.

As recently claimed, TSH-suppressive therapy with L-T4 may have adverse effects on the heart, but these results have not been consistently confirmed. We assessed cardiac function by clinical, echocardiographic, and ergometabolic criteria in 19 patients (16 women and 3 men) receiving long term L-T4 at a fixed daily dose ranging from 1.8-4.0 microg/kg. The results showed significant alterations in several cardiac parameters suggestive of subclinical hyperthyroidism. In particular, intraventricular septum thickness (10.0+/-1.4 vs. 8.1+/-1.1 mm), left ventricular posterior wall thickness (9.4 1.5 vs. 8.1+/-1.1 mm), end-diastolic dimension (47+/-4 vs. 44+/-3 mm), and left ventricular mass index (102+/-15 vs. 75+/-15 g/m2) were significantly increased compared to values in age- and sex-matched euthyroid controls. Exercise tolerance (expressed as maximal tolerated workload; 102+/-14 vs. 117+/-12 watts), maximal VO2 achieved at peak exercise (maximum VO2, 17.3+/-3.3 vs. 21.9+/-2.5 mL/min x kg), and anaerobic threshold (expressed as a percentage of VO2max, 46.5+/-8.4 vs. 56.2+/-6.6) were significantly reduced in L-T4-treated patients. The L-T4 dose was then reduced to the minimal amount able to keep the serum TSH concentration at 0.1 mU/L or less in 7 patients who were reevaluated 6 months after the initial study. This individual tailoring of the TSH-suppressive L-T4 dose was in all cases associated with normalization of all echocardiographic and ergometabolic parameters. In conclusion, our findings show that abnormalities of heart morphology associated with impaired exercise performance occur as a consequence of long term therapy with fixed TSH-suppressive doses of L-T4, but that these abnormalities improve or disappear after careful tailoring of TSH-suppressive therapy.

New noninvasive method for coronary flow reserve assessment: contrast-enhanced transthoracic second harmonic echo Doppler.

BACKGROUND: We tested the hypothesis that blood flow velocity could be recorded in the left anterior descending coronary artery (LAD) during transthoracic echocardiography by use of second harmonic echo Doppler modality along with contrast enhancement (intravenous Levovist) at rest and after pharmacologically induced maximal vasodilation to assess coronary flow reserve (CFR) with a totally noninvasive approach. METHODS AND RESULTS: Fifty-six consecutive patients undergoing coronary angiography underwent transthoracic contrast-enhanced pulsed-wave Doppler recording of blood flow velocity in the LAD by use of harmonic color Doppler as a guide at rest and after maximal vasodilation by dipyridamole infusion. Contrast enhancement with the harmonic mode greatly improved the success rate of recording adequate pulsed-wave Doppler signal in the LAD. CFR was (mean+/-SD) 1.54+/-0.7 in patients with (group 1) and 2. 79+/-0.9 in patients without (group 2) significant LAD stenosis (lumen narrowing >70%) (P<0.001); sensitivity and specificity in detecting significant LAD stenosis were 86% and 90%, respectively. There was close agreement between CFRs determined by this new method and intracoronary Doppler flow wire. CONCLUSIONS: Contrast-enhanced transthoracic echo Doppler with the harmonic mode is a feasible and promising technique for assessing CFR in a totally noninvasive way.