Lower limb ischemia in women

Abstract

Arteriosclerosis is a general disease affecting different parts of the arterial system. In coronary heart disease (CHD) women have different risk factors, symptoms, indication for treatment, interpretation of diagnostic data and outcome than men. The overall aim of this thesis was to test the hypothesis that similar gender differences exist in patients with symptomatic arteriosclerosis in the arteries of the lower limb (LLI) and to investigate the magnitude of the problem.

The Stockholm Study. The number of procedures performed, development over time, survival and amputation rates in women and men were investigated in a large epidemiological study of all patients treated with vascular interventions for lower limb ischemia (LLI) in the county of Stockholm in 1970-1994 (8660 patients, 12200 interventions).

An increase from 18 vascular interventions to 786 / million inhabitants and in the proportion of women from 34% in 1970 to 48% in 1994 was shown. Mean age increased from 63 to 71 years. Women were older than men (71 years vs 66, p<0.001). The localisation of lesions treated for chronic LLI was similarly distributed between women and men. Women had poorer survival than men. In a Cox regression model, increasing age, later calendar years and being a man were risk factors for poorer survival. In a multivariate analysis of the risk for amputation, age and calendar year were important risk factors, not gender.

Our results confirmed the clinical observation of an increasing proportion of women and elderly, possibly related to an increasing prevalence, better knowledge about LLI among referring doctors, improved technique and wider indication for treatment, especially in elderly. The similar or better results after intervention in women could be explained by the generally better survival in women in the population as well as a restrictive attitude towards treating women compared to men.

Women treated for critical ischemia. Specific gender differences in preoperative conditions, localisation of treated lesions, complications and long-term outcome was retrospectively investigated in patients treated for chronic critical limb ischemia at the Karolinska Hospital (KH) in 1993-1994 (n=234 patients). Women were older than men (74 vs 68 years), smoking and diabetes was less frequent among women (smokers: 63 % vs 82%, p=0.005; diabetes: 22% vs 43%, p=0.0004). Other preoperative conditions were not worse in women.

Women were more commonly treated with suprainguinal interventions than men (44% versus 19%). Outcome was similar for women and men. The greatest disadvantage for women is their high mean age. The later onset for women could depend on biological differences combined with a different distribution of risk factors than in men. The different localisation of treated lesions can be related to age and anatomical differences. The similarities in outcome despite different preoperative conditions indicate that diabetic women with severe LLI are less frequently treated, alternatively men with high risk are offered interventions more generously.

Reproductive History. In order to evaluate the reproductive history in women with LLI compared with women in the population, 173 women treated for LLI in 1994-1996 at KH and 348 women living in the hospital catchment area were sent a validated questionnaire. Age at menopause and menarche, pregnancies, hysterectomy and hormone replacement therapy were similar between women treated for LLI and women in the population. More references had used oral contraceptives than patients (53% vs 16%, p<0.001).

Women with LLI do not have a different reproductive history than women in the population, contradictory to women with CHD. The influence on the development of arteriosclerotic disease by other risk factors could be more important in LLI patients. Maybe oestrogen levels are less important for the progression of arteriosclerotic disease in other peripheral arteries compared to coronary and carotid arteries.

Conclusion. The number of vascular interventions, especially in women, have probably increased further after the observed period, and the increase can be expected to continue. Biological and anatomical differences can probably explain several of the found differences between the sexes, such as localisation of treated lesions and age. The similar outcome between women and men indicates that we should continue to focus on established risk factors in our preoperative evaluation, rather than gender or reproductive history in women.