Sex differences in plaque morphology may explain the higher male prevalence of myocardial infarction compared to angina pectoris. The Tromsø Study.
OBJECTIVE
To study whether the degree of carotid atherosclerosis and the male predominance of echolucent plaques could explain the sex difference in myocardial infarction (MI) compared to angina pectoris (AP).


METHODS
Ultrasound examination of the carotid artery was performed in 6727 persons. The presence of plaque, plaque thickness and number of segments with plaque were recorded. Plaque morphology in terms of echogenicity was scored as echolucent (soft plaque) or echogenic (hard plaque). A questionnaire was used to obtain information about coronary heart disease.


RESULTS
In men with the most advanced atherosclerosis, the risk (OR, 95% CI) of having MI compared to those with no carotid atherosclerosis was less than half as the corresponding risk in women (2.2, 1.4-3.3 vs 5.3, 2.6-10.6). For MI, the male-to-female ratio was highest in the group with no carotid plaque and declined by increasing burden of atherosclerosis. For AP, the sex ratio was independent of the degree of atherosclerosis.


CONCLUSIONS
The findings support the hypothesis that the sex difference in MI compared to AP is due to the higher male prevalence of echolucent plaque.
Johnsen
Stein Harald
SH
Institute of Community Medicine, University of Tromsø, Tromsø, Norway. Stein.Johnsen@ism.uit.no
Joakimsen
Oddmund
O
Fosse
Einar
E
Arnesen
Egil
E
D017677:Age Distribution; D000368:Aged; D000704:Analysis of Variance; D000787:Angina Pectoris / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000473:pathology*; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000473:pathology*; D003430:Cross-Sectional Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016015:Logistic Models; D008297:Male; D008403:Mass Screening / Q000379:methods; D008875:Middle Aged; D015999:Multivariate Analysis; D009203:Myocardial Infarction / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000473:pathology*; D009664:Norway / Q000453:epidemiology; D015995:Prevalence; D018570:Risk Assessment; D012720:Severity of Illness Index; D017678:Sex Distribution; D016019:Survival Analysis; D018608:Ultrasonography, Doppler