Although we read daily about the coronavirus (COVID-19) pandemic, this has been more properly defined as a syndemic. A syndemic is the synergistic aggregation of two or more concurrent categories of disease clustering in the population within social groups according to patterns of health disparity or inequality, exacerbating the prognosis and/or the burden of each separate disease. The pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has a strong biological, pathophysiological and social interaction with the cardiovascular system and cardiovascular disease (CVD). This means that preventive or therapeutic strategies based only on cutting viral transmission lines may not be totally effective to protect the health of every community .
The interactions between COVID-19 and the cardiovascular (CV) system are multiple : the role of the CV system on the COVID-19 pathophysiology is well known. SARS-CoV-2 uses the angiotensin-converting enzyme 2 (ACE 2) receptor, a critical player in the homeostasis of the cardiovascular system and in the pathophysiology of CVD, as the entry point to penetrate and infect human cells . The role of the cardiovascular system on the pathophysiology of COVID-19 is so important that it has been defined as an endothelial disease .
SARS-Cov2 infection and the associated inflammatory state has direct and indirect effects on the CV system, including acute myocarditis, heart failure decompensation, increased risk of arrhythmias and, notably, a prothrombotic state leading to venous and arterial thrombotic events, most often pulmonary embolism .
The higher vulnerability of patients with cardiovascular risk factors or with CVD to severe COVID-19 and to COVID-19 death was identified early and has been confirmed by several observational and epidemiological studies and meta-analyses .
As mentioned before, a key feature of a syndemic is the heterogeneity of the impact according to social or economic inequalities. We see this in the more severe impact of COVID-19 on the most deprived populations. Although the several waves of COVID-19 have spread the disease throughout all social strata, the evidence illustrates the disproportionate burden of COVID-19 deaths among racial and ethnic minority groups [7, 8], women , and the most deprived neighbourhoods of cities in developed countries as well as in the regions with the highest prevalence of chronic non-communicable diseases, most notably CVD [10, 11]. Moreover, COVID-19 mortality has been correlated to the levels of all sources or fossil fuel-dependent air pollution , and therefore calls to join actions to reduce air pollution and emissions and move to a zero-emission economy have been published .
However, COVID-19 has also had a major impact on the epidemiology of CVD. Several reports from around the world have communicated, during the major waves of COVID-19, decreases in hospitalisations for acute cardiovascular conditions, such as acute coronary syndromes or heart failure, drops in cardiac non-invasive and invasive/surgical procedures, delays in cardiovascular care times (i.e., reperfusion times for ST-segment elevation acute myocardial infarction, waiting times for scheduled interventions…), reduction in the attention of out-of-hospital cardiac arrest, and worsening in their short-term outcomes and, finally, increases in the rates of some types of cardiovascular death.
Unfortunately, the effective solutions developed to overcome this tragic situation are heavily conditioned by socioeconomic conditions, limiting their availability to the most threatened segments of the population. The major inequalities in the access to any of the effective COVID-19 vaccines, which have been able to improve the situation, are not reducing but rather increasing the gap between privileged and less privileged society groups or countries . There are still unmet needs that we need to overcome and solutions that need to be determined in such topics as the impact of COVID-19 on CV care and the social determinants of vaccination.
COVID-19 is not just a viral pandemic but a syndemic; the interaction between an epidemic and the presence of chronic, non-communicable diseases amplified by social, economic, and regional inequities of many kinds. Virus-centred interventions, although essential, will fall short of reducing the global impact of Covid-19. We need to take a wider approach and use this crisis as an opportunity to improve health globally.