The Swedish Spinal Cord Injury Study on Cardiopulmonary and Autonomic Impairment

Life expectancy for people with spinal cord injury (SCI) has increased during the 20th century as a result of improvements in health care systems and the environment. The incidence of SCI is stable and as a consequence the prevalence of SCI has increased globally leading to a growing population of persons aging with SCI. Therefore, SCI research need to focus on the physiology of aging to prevent premature cardiovascular and pulmonary diseases, which are the leading causes of death. The disruption of sensory-, motor- and autonomic pathways causes major neurological deficits which alter the physiologic conditions. Among people with SCI above the mid-thoracic level dysfunction in pulmonary, autonomic cardiovascular regulation and emerging metabolic cardiovascular risk factors are well-known. In addition, paralysis of the abdominal and thoracic musculature causes restrictive pulmonary dysfunction, weak cough and atelectasis contributing to the mortality in SCI. Cardiovascular disease (CVD) is more prevalent and occurs earlier in life among people with SCI compared to the general population. The increased prevalence of traditional risk factors cannot, however, fully explain these findings. Cardiovascular autonomic dysfunction has been hypothesized to contribute to the increased risk. The need for advances in risk management is therefore important as the first symptoms of coronary atherosclerosis are commonly sudden death or acute coronary syndrome. This is further complicated by the sensory loss and reduced ability to perform strenuous activities leading to asymptomatic disease as typical symptoms of exertional angina pectoris does not manifest. Risk assessment tools, such as Framingham risk score or Systematic Coronary Risk Evaluation (SCORE), are available but lack the precision in people with SCI as these tools are calibrated on the general population. The Swedish Spinal Cord Injury Study on Cardiopulmonary and Autonomic Impairment - SPICA - was initiated to assess the effects of aging with SCI on the cardiovascular, pulmonary and autonomic systems in a cohort of middle-aged persons with long-term SCI. SPICA combines advanced imaging techniques, likely to play an important role in risk stratification of CVD and pulmonary disease in the future, with functional analyses, and generic and SCI-specific assessment tools. The overarching aim of SPICA is to assess and extensively characterize the cardiopulmonary and autonomic health status in middle-aged persons with a severe and high-level SCI. The study will elucidate the cardiopulmonary health consequences specific to persons living with a SCI through comparison of results to matched controls. The results of SPICA will advance the investigator's knowledge in this field and thereby improve prevention strategies and risk prediction of CVD and pulmonary disorders in people with SCI.