Introduction-
The world witnessed a catastrophe in the form of the COVID-19 pandemic. As per statistical data, more than 702 million active Covid positive cases are present worldwide. Moreover, the world lost around 7 million to the deadly virus. The COVID-19 is characterised by severe respiratory distress syndrome caused by novel SARS-CoV-2.
At the beginning of COVID-19, evidence of the acute symptoms of the pandemic was pretty straightforward. However, several studies are being carried out to analyse the long-term sequelae of COVID-19. Reports of the trials suggest a strong link between COVID-19 and Cardiovascular Diseases.
According to the World Health Organization, Cardiovascular Diseases are the leading cause of mortality worldwide. Heart attack and stroke are significant CVDs that have high mortality prevalence. The data put forward by a report, COVID-19 and Cardiovascular Diseases, published in 2020, stated a high occurrence of CVDs in COVID-19-positive patients, with more than 7% of patients experiencing myocardial injury due to the virus.
Therefore, the identification of risk factors and prevention of cardiovascular diseases in patients with a COVID-19 history is a challenge for the medical fraternity. Risk factors associated with cardiovascular diseases are well known, such as lifestyle and genetics. However, the role of these two factors in precipitating CVDs in patients affected by SARS-CoV-2 is still unknown.
COVID-19 and CVDs
One of the long-term consequences of the pandemic manifested in the form of an increased global cardiovascular burden. Recent statistical data presents a rise in mortality and morbidity related to Cardiovascular diseases owing to the direct and indirect effects of COVID-19.
Moreover, research has found an interlink between genetic factors and poor lifestyle with cardiovascular disorders in COVID-19 patients.
The genetic association is determined using the Polygenic Risk Score. High values show a high risk of developing coronary artery disease, atrial fibrillation and venous thromboembolism in people with SARS-CoV-2 infection. Similarly, poor living habits such as smoking habit, increased alcohol consumption, and sedentary living put individuals at a higher risk for developing cardiac complications.
Although the exact pathophysiology behind the risk of CVD in COVID-19 patients is not yet understood, researchers have attempted to explain a couple of mechanisms. Some of them are:
Direct cardiotoxicity- The SARS-CoV-2 virus directly infects the cardiac cells leading to myocarditis.
Post-disease hyper-inflammation- Post-COVID-19 cases have shown uncontrolled release of cytokines leading to plaque formation and vascular inflammation. It ultimately precipitates Myocardial Infarction, cardiomyopathy and Heart Failure.
Systemic manifestations- COVID-19 also causes systemic complications such as Disseminated Intravascular Coagulation(DIC), sepsis etc which result in cardiovascular diseases.
Genetics and Lifestyle- Potent Risk Factors for CVD
Genetics and lifestyle influence the occurrence of cardiovascular diseases. A family history of CVD raises the chances of acquiring the disease. The proportion of risk will also be influenced by the age of the affected relative. CVDs such as congenital diseases, high cholesterol levels, and high blood pressure can be inherited. Alteration even in the single gene code can lead to heritable cardiac disorders.
Similarly, lifestyle also influences the prevalence of CVD in an individual. Poor diet, high alcohol consumption, a history of smoking, and less physical activity are culprits of cardiac diseases.
But, how do these two potential risk factors augment the chances of CVDs in people who have a history of COVID-19?
What does Research Show?
A study was conducted between March 2020 and September 2021 on 25,335 COVID-19-positive patients to evaluate the role of genes and lifestyle. The study aimed to correlate the link between PRS(Polygenic Risk Score), lifestyle factors and cardiovascular disorders in selected patients within 90 days after diagnosis of COVID-19.
A polygenic Risk Score is an accumulation of genetic risk factors for a particular trait. It is an authentic tool to predict precision medicine and cardiovascular disease occurrence rates. In the study, the PRS was determined for cardiac diseases such as venous thromboembolism, coronary artery disease, atrial fibrillation and ischemic strokes. Moreover, the prospective cohort research also used a lifestyle index comprising 9 variables to determine its role in the precipitation of cardiovascular diseases.
The study used the Cox proportional hazard model to calculate the hazard ratio and confidence interval for studying the link between genes and CVD. In contrast, the multivariable Cox regression model was applied to determine the lifestyle factors.
The result of the study confirmed a linear association between gene mutations and a higher incidence of cardiovascular disorders post-COVID-19 infection. The participants with the top 20 per cent Polygenic Risk Score have a high risk of developing atrial fibrillation(3-fold increase), coronary artery disease(3.5-fold increase) and venous thromboembolism (2-fold rise). However, no apparent association is observed between ischemic strokes and genetic factors. Another interesting finding is the positive existence of risk factors even in fully vaccinated individuals.
A positive correlation exists between a healthy lifestyle and a lower incidence of CVDs in COVID-19 patients. It is also noteworthy that COVID-positive cases with unhealthy lifestyles, when switched to healthy living diminished their risk of developing CVDs. Cardiac complications such as CAD and AF also demonstrate an additive rise in patients with high scores of PRS and an unhealthy lifestyle.
The Conclusion
Although the fatal wave of the pandemic is over. The world lost more than a million lives. But, the threat persists. The long-term consequences of COVID-19 in patients with a positive history are still a medical mystery. Several research groups and pharmaceutical companies like Globela Pharma are trying to do evidence-based studies to deal with chronic complications.
