Are Russian Men with Intermittent Claudication and/or Angina Pectoris Have the Same Cardiovascular and All-Cause Mortality Risks? The Data of the Prospective Population-Based Study

Abstract

Aim. To investigate the distribution of the intermittent claudication(IC) and/or angina pectoris (AP) and to evaluate the risk of cardiovascular and allcause mortality in Russian male population with pain syndrome of varying severity during more than 30-year observation period.Material and methods. The data were obtained from representative samples observed in Moscow and Saint-Petersburg (former Leningrad) from 1975 to 1986 with 75% response. Men (n=10953) aged 35-71 years (mean age 48.8±6.6 years) were examined by the same protocol which includes standard questionnaire, blood biochemistry, blood pressure (BP) and heart rate measurements, anthropometry and electrocardiography (ECG) in 12 leads. The original Rose questionnaire to determine the IC and AP was used. There were defined five risk groups with different pain features. The first group – no pain; the second group – mixed pain in legs and/or in chest including the pain connected with the effort, but without typical IC and AP features; the third group – only IC without AP; the fourth group – only AP without IC; finally, the fifth group – both IC and AP. The median follow-up period was 21.9 years with interquartile range of 13.4-33.5 years. During the follow-up 7893 all-cause deaths including 4220 cardiovascular deaths were found. The Kaplan-Meier method was applied to find out the associations between risk groups and survival. Mortality risk, including cardiovascular mortality, was evaluated by the Cox proportional hazard model.Results. There were 38.7% men with any pain. The prevalence of IC without AP was 0.7% and the prevalence of AP without IC was 5.8%. Only 0.3% of the population had both IC and AP. The prevalence of both parameters increased with age. As expected, men with no pain live longer than others. Median of the survival time in this group, which means the point when half of the population dies, was 24.9 years. Only in this group the value when 75% of population dies was not reached. Compared to no pain group, loss of the life expectancy of only IC group was 10.9 years, only AP group – 9.2 years, IC and AP group – 17.9 years. Both IC and AP had statistically significant contribution to mortality adjusted for high blood pressure, smoking, presence of ECG disturbances, history of myocardial infarction. Survival curves of isolated IC and AP groups did not have statistically significant difference which means that both diseases have the same contribution to mortality. Similar results were obtained for cardiovascular mortality.Conclusion. The prevalence of IC without AP was 0.7% and the prevalence of AP without IC was 5.8%. IC and AP are independent factors of all-cause and cardiovascular mortality among the Russian male population aged 35-71 years. However, no statistically significant difference was found between groups only with IC and only with AP for cardiovascular and all-cause deaths. The presence of both conditions in combination reduces the median survival time by 17.9 years compared to the group with no pain.