Experimental and clinical studies have clearly demonstrated significant sex differences in myocardial structure and function, both under physiological and pathological conditions. The best example are significant sex differences in the cardiac tolerance to ischemia/reperfusion injury: pre-menopausal adult female hearts are more resistant as compared to the male myocardium. The importance of these findings is supported by the fact that the number of studies dealing with this issue increased significantly in recent years. Detailed molecular and cellular mechanisms responsible for sex differences are yet to be elucidated; however, it has been stressed that the differences cannot be explained only by the effect of estrogens. In recent years, a promising new hypothesis has been developed, suggesting that mitochondria may play a significant role in the sex differences in cardiac tolerance to oxygen deprivation. However, one is clear already today: sex differences are so important that they should be taken into consideration in the clinical practice for the selection of the optimal diagnostic and therapeutic strategy in the treatment of ischemic heart disease. The present review attempts to summarize the progress in cardiovascular research on sex-related differences in cardiac tolerance to oxygen deprivation during the last 40 years, i.e. from the first experimental observation. Particular attention was paid to the sex-related differences of the normal heart, sex-dependent tolerance to ischemia-reperfusion injury, the role of hormones and, finally, to the possible role of cardiac mitochondria in the mechanism of sex-dependent differences in cardiac tolerance to ischemia/reperfusion injury. Key words: Female heart, Cardiac hypoxic tolerance, Ischemia-reperfusion injury, Sex differences.

• MeSH
• Oxygen metabolism   MeSH
• Humans MeSH
• Myocardium metabolism   pathology   MeSH
• Sex Characteristics * MeSH
• Myocardial Reperfusion Injury metabolism   physiopathology   MeSH
• Sex Factors MeSH
• Mitochondria, Heart metabolism   pathology   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Male MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Review MeSH
• Names of Substances
• Oxygen MeSH

Ischaemic heart disease (IHD) is the most frequent cause of mortality among men and women. Many epidemiological studies have demonstrated that premenopausal women have a reduced risk for IHD compared with their male counterparts. The incidence of IHD in women increases after menopause, suggesting that IHD is related to declining oestrogen levels. Experimental observations have confirmed the results of epidemiological studies investigating sex-specific differences in cardiac tolerance to ischaemia. Female sex appears also to favourably influence cardiac remodelling after ischaemia/reperfusion injury. Furthermore, sex-related differences in ischaemic tolerance of the adult myocardium can be influenced by interventions during the early phases of ontogenetic development. Detailed mechanisms of these sex-related differences remain unknown; however, they involve the genomic and non-genomic effects of sex steroid hormones, particularly the oestrogens, which have been the most extensively studied. Although the protective effects of oestrogen have many potential therapeutic implications, clinical trials have shown that oestrogen replacement in postmenopausal women may actually increase the incidence of IHD. The results of these trials have illustrated the complexity underlying the mechanisms involved in sex-related differences in cardiac tolerance to ischaemia. Sex-related differences in cardiac sensitivity to ischaemia/reperfusion injury may also influence therapeutic strategies in women with acute coronary syndrome. Women undergo coronary intervention less frequently and a lower proportion of women receive evidence-based therapy compared with men. Although our understanding of this important topic has increased in recent years, there is an urgent need for intensive experimental and clinical research to develop female-specific therapeutic strategies. Only then we will be able to offer patients better evidence-based treatment, a better quality of life and lower mortality.

• Keywords
• acute coronary syndrome, cardioprotection, heart, ischaemia/reperfusion injury, oestrogen, sex differences, therapeutic implications,
• MeSH
• Acute Coronary Syndrome drug therapy   metabolism   physiopathology   MeSH
• Androgens metabolism   MeSH
• Estrogens metabolism   MeSH
• Myocardial Ischemia drug therapy   metabolism   physiopathology   MeSH
• Cardiovascular Agents therapeutic use   MeSH
• Humans MeSH
• Evidence-Based Medicine * MeSH
• Myocardium metabolism   MeSH
• Disease Susceptibility MeSH
• Sex Characteristics MeSH
• Myocardial Reperfusion Injury prevention & control   MeSH
• Heart drug effects   physiopathology   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Male MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Review MeSH
• Names of Substances
• Androgens MeSH
• Estrogens MeSH
• Cardiovascular Agents MeSH