Thromboembolic Complications in Patients with COVID-19
As the number of coronavirus disease 2019 (COVID-19) cases in the United States crosses the million mark, more than 60,000 patients have succumbed to this disease in a short span of nearly three months since the first case. COVID-19 is produced by the single-stranded RNA virus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) characterized by its high affinity binding to the angiotensin-converting enzyme 2 (ACE2) receptor in humans. The clinical spectrum of this disease ranges from asymptomatic to mild upper respiratory illness to severe viral pneumonia with respiratory failure and death.
New emerging complication of COVID-19
Though acute respiratory distress syndrome (ARDS) remains the predominant cause of COVID-19-related mortality, data in patients with COVID-19 in China indicate that this virus affects clotting and can also cause cardiac injury. Another recent study in patients from a Dutch medical facility demonstrates a similarly high incidence (31%) of thrombotic complications in patients with COVID-19. Symptoms associated with COVID-19 include, without limitation, severe illness, hypoxia, associated inflammation, platelet activation, endothelial dysfunction, and stasis which may predispose patients to thrombotic events. Clearly, COVID-19 has a number of important cardiovascular implications. Specifically, the foregoing data suggests that in addition to respiratory complications, patients with COVID-19 are susceptible to venous and arterial thrombotic disease.
Stroke in patients with COVID-19
In line with these previous data, a new rapid communication to the New England Journal of Medicine(NEJM) published on April 29, 2020, describes five cases of middle-aged COVID-19 patients (under 50 years of age), presenting as strokes. Surprisingly and alarmingly, these five patients had either no symptoms or mild symptoms of COVID-19. Significantly, all of these patients had enlarged blood vessels. Large arteries such as the middle cerebral artery or the anterior cerebral artery supply large areas of the brain; hence blockage of these vessels can cause extensive damage. Such associated damages undoubtedly leads to higher morbidity and mortality. The study published in NEJM, led by Dr. Thomas Oxley at Mount Sinai Health System in New York City, albeit a small population, shows a disease incidence that was approximately seven-fold higher than that in the pre-COVID era in the same hospital setting!
Similarly, another study currently under review for publication is led by Dr. Pascal Jabbour. This study presents data from patients hospitalized with COVID-19 at Thomas Jefferson University Hospitals in Philadelphia, and NYU Langone Health in New York City. Their data demonstrate that 12 patients presented with a cerebrovascular incident and were treated for large artery blockages in their brains. Importantly, forty percent of the patients were under 50, with few other risk factors.
It is speculated that infection with SARS-CoV-2 predisposes patients to thromboembolic disease due to excessive inflammation and hypoxia, in addition to disease-related immobilization and diffuse intravascular coagulation (DIC). Whether this predisposition is due to the infection or secondary to the cytokine storm remains to be determined. However, surgical intervention to remove the blood clot, followed by antiplatelet and anticoagulant therapies is beneficial for these patients. Furthermore, extended treatment with an anticoagulant is recommended as thromboprophylaxis is one of the most effective means of reducing morbidity and mortality in these patients. In addition to the commonly observed medical complications of COVID-19, the treating physician needs to be cognizant of the cerebro/cardiovascular implications of COVID-19 and preempt such life threatening thromboembolic events particularly cerebrovascular with prophylaxis.