Since it was first reported in Wuhan, China in late December 2019, the respiratory infection caused by the SARS-CoV-2 virus (COVID-19) has spread rapidly around the world and become a global pandemic affecting over 200 countries. This pandemic has caused dramatic public health interventions and profound global socio-economic disruptions (which include the deepest recession in a hundred years). The dramatic increase in the number of patients with COVID-19 in the last 6 months has flooded health systems in many countries around the world. (1) The pandemic also created new significant challenges to the public health systems of developed countries, as they had been mostly focused on chronic non-communicable diseases. Given that there is currently no effective causal treatment or vaccine, many countries have opted for a certain degree of movement restriction and isolation of their residents, and there has often been a period of complete closure of most economic activities (lockdown). (2) The Republic of Croatia was not spared this fate: a pandemic was declared in mid-March and the maximum possible reduction of patients’ visits to outpatient clinics was recommended, with only urgent examinations and procedures being allowed during the epidemic. (3) Because of the aforementioned reasons and fear of infection, the number of examinations and diagnostic procedures in patients with cardiovascular (CV) diseases has also decreased. Comparison of the number of primary health care examinations in the Republic of Croatia in April 2019 and April 2020 (according to data published by the Croatian National Institute for Public Health (3)) shows a significant decline (P<0.001, Whitehead test for Poisson distribution) of activity, which always has negative consequences for CV diseases, in which prevention is key. Furthermore, according to a large questionnaire intended for clinical cardiologists conducted in 141 countries on 6 continents, 78.8% respondents answered that the number of patients hospitalized for ST-segment elevation myocardial infarction (STEMI) decreased since the outbreak of the pandemic and 65.2% indicated that it was a reduction greater than 40%. Approximately 60% of all subjects reported that patients with STEMI arrived to hospital later than usual, and 58.5% answered that more than 40% of patients with STEMI admitted to the hospital arrived outside the optimal timeframe for primary percutaneous intervention (PCI) or thrombolysis. (2)

According to available data, the number of examinations in primary health care as well as the number of procedures in secondary health care have been reduced. Let us now examine the repercussions of all of these factors on mortality. The European Group for Monitoring Excessive Mortality (EuroMOMO) published data on weekly mortality in 2020 in several European countries and compared them with the previous multi-year average (thus calculating “excessive” or higher-than-expected mortality each year). These data show a significant increase in mortality in the 15th week of 2020 in most of the observed countries in all age groups except the 0-14 years group. (4) A similar increase in total mortality during the pandemic has been recorded outside Europe, but is SARS-CoV-2 directly or indirectly responsible for this increase? Electronic national mortality registries could help us answer that question. According to a study conducted among patients with diabetes in the United Kingdom, an increase in the number of deaths in which COVID-19 was not the cause of death was recorded during the pandemic (Figure 1). (5) The same study also illustrates the increased risk of death from COVID-19 in people at higher cardiovascular risk (there are many common risk factors).

From all the above, it is evident that pandemic there has been a decrease in the availability of health care (both primary and secondary) during the COVID-19 and an increase in mortality not directly caused by COVID-19. This has created new challenges in the daily work of cardiologists and the lives of patients with CV diseases. How then to deal with this challenge and increase the availability and quality of health care for patients? It is certainly important to keep the focus on CV diseases (which still have a significant share in the morbidity and mortality of the general population) and not to allow delays or cancelations of timely diagnosis and treatment of CV diseases due to fear of infection. Given the common risk factors with COVID-19, and in order to protect against infection, telemedicine treatment options should be used as much as possible in patients with CVD, such as correction of pharmacological therapy via A5 referral or digital ECG interpretation. Telephone contact with patients is also important, through which they can be encouraged to self-monitor risk factors (e.g. blood pressure) and be encouraged to persevere in adhering to therapy.

Regular use of antihypertensive and hypolipemic therapy is important not only for the reduction of complications of these diseases (e.g. myocardial infarction) but has also been proven to reduce mortality. (6) It should be kept in mind that fixed (double and triple) combinations of drugs also contribute to therapy adherence, which is why they are recommended in the guidelines of the European Society of Cardiology. (7) Regarding hypertension treatment during the COVID 19 pandemic, it is important to point out the now well-known misconception about ACE inhibitors. Namely, at the beginning of the pandemic (the peak of the epidemic in China), an observational study was published linking the use of ACE inhibitors with a higher risk of mortality in COVID-19. (8) SARS-CoV-2 has a peplomer (glycoprotein spike) by which the virion binds to the enzymatic domain of the transmembrane protein ACE2 (angiotensin converting enzyme) which is most present on lung endothelial cells (type 2), enterocytes, endothelium, the heart, and the arterial smooth muscle. Patients under ACE inhibitor therapy were thought to be somehow more vulnerable to the virus. This resulted in a global fear and even aversion towards these drugs (there was a time when some believed that chloroquine was effective against SARS-CoV-2, which was temporarily approved for this indication in Croatia). The story has only recently received its scientifically-based epilogue (the yet unpublished randomized BRACE CORONA study), with large professional societies supporting the continuation of hypertension treatment with ACE inhibitors. (9) This is another fine example of why small observational studies should not be used to draw conclusions on causal links even if the paper was published in a journal with a high impact factor.

Finally, we can summarize that CV diseases have not disappeared with the onset of the COVID-19 pandemic, and we must in fact engage in additional efforts to preserve the pre-epidemic quality of treatment. Various telemedicine aids can help us with this, but it is equally important to maintain contact with the patients themselves. As much as possible, patients should be encouraged, supported, and educated in achieving self-control and adhering to therapy. If necessary, diagnostic processing and treatment should be carried out without delay, and it is the duty of all healthcare providers to organize work and adjust facilities so that healthcare can be carried out efficiently and safely for both patients and staff.