The Association Between the Immune System, Comorbidities and Cardiovascular Disease

As progress in medical science and societal living standards improve over the years, so does the approximate life expectancy globally1. However, these increasing survival trends, in both developed and developing countries, raise some important issues. The part of the population older than 65 consists of approximately 12% of the population, yet accounts for approximately 26% of physician office visits, 35% of hospital stays, 34% of all prescriptions and 90% of nursing home occupancy2. This is not only due to the accumulation of diseases during a person’s lifetime, but also due to the stacking effects of comorbidities a person might suffer from. The importance of healthy ageing thus becomes clear, both in the reduction of healthcare expenditures as well as the sustainable prolongation of life expectancy. 
Currently, cardiovascular disease (CVD) and cancer constitute the most frequent causes of death worldwide3. The immune system is known to play an important role in both diseases4,5, and particularly in the case of cancer, immune-based treatments such as immune checkpoint inhibition and chimeric antigen receptor T-cell therapies have revolutionized the therapeutic approach to these patients and have led to drastic improvements in prognosis6,7. A similar trend for CVD was initiated with the CANTOS study, which demonstrated the benefits of interleukin-1 blockade in patients with previous myocardial infarction8. Nevertheless, the exact interplay between the immune system and CVD, the importance of comorbidities in this interaction, and how these can be utilized for therapeutic purposes are currently unclear. 
Within the spectrum of CVD, the prognosis of patients with heart failure (HF) increased over the last decades.9 This positive effect is mainly due to the increased therapeutic options, which reduce mortality and rehospitalization rates. As a consequence of HF patients growing older, they develop more comorbidities. However, the link between HF, comorbidities and the impact on live-saving HF drugs is fairly unknown. The Lifelines cohort would provide us with unique long-term data of community dwelling individuals to identify patterns in CVD, comorbidities and medication use.