The Eye of the Storm: Investigating the Long-Term Cardiovascular Effects of COVID-19 and Variants

Abstract

COVID-19 had stormed through the world in early March of 2019, and on 5 May 2023, SARS-CoV-2 was officially declared to no longer be a global health emergency. The rise of new COVID-19 variants XBB.1.5 and XBB.1.16, a product of recombinant variants and sub-strains, has fueled a need for continued surveillance of the pandemic as they have been deemed increasingly infectious. Regardless of the severity of the variant, this has caused an increase in hospitalizations, a strain in resources, and a rise of concern for public health. In addition, there is a growing population of patients experiencing cardiovascular complications as a result of post-acute sequelae of COVID-19. This review aims to focus on what was known about SARS-CoV-2 and its past variants (Alpha, Delta, Omicron) and how the knowledge has grown today with new emerging variants, with an emphasis on cardiovascular complexities. We focus on the possible mechanisms that cause the observations of chronic cardiac conditions seen even after patients have recovered from the infection. Further understanding of these mechanisms will help to close the gap in knowledge on post-acute sequelae of COVID-19 and the differences between the effects of variants.

Keywords: COVID-19; SARS-CoV-2; acute cardiac injury; cardiovascular disease; long COVID; variants.

Figure 2

Mechanisms of COVID-Induced Cardiac Complications. SARS-CoV-2 virus infection can affect endothelial cells and cause an increased risk for thrombotic disorders [24,29]. Impaired mitochondrial function has also been demonstrated post-COVID infection and contributes to thrombotic disorders, oxidative stress, and inflammation [33]. Through action on ACE2 receptors, the infection also impacts cardiomyocytes and cardiac tissue by various pathways [29,32]. ACE2 action also produces increased amounts of Ang II, which is a known pathway of ultimate hypertension, cardiac fibrosis, and heart failure [37].

Figure 1

Timeline for COVID-19 variants based on the Center for Disease Control and Protection (CDC). Throughout the pandemic, SARS-CoV-2 has produced multiple variants due to mutations and viral recombination. This timeline depicts when each variant was determined as a Variant of Interest (VOI—purple), a Variant of Concern (VOC—green), or a Variant to Be Monitored (VBM—orange). Additionally, it shows the rise and fall of a multitude of variants; as noted, Omicron remains a VOC.

Figure 3

Acute and chronic cardiovascular complications caused by COVID-19. Many times, when patients are presented with acute cardiac symptoms due to COVID-19 infection, it can develop into chronic conditions. The most common acute manifestations are myocardial injury, myocarditis, and acute coronary syndrome. As symptoms worsen and develop, chronic conditions may arise, such as heart failure readmission, sudden cardiac death, myocardial fibrosis, onset hypertension, and diabetes.