COVID-19 has a significant impact on the cardiovascular system with the infection leading to various cardiovascular syndromes such as acute coronary syndrome, cardiac arrhythmias, and myocardial damage. One other complication of the cardiovascular system that can lead to long-term morbidity and disability arises from COVID-19 causing hypercoagulability, that is, increasing the tendency of blood to thrombose or clot. This increased risk of forming blood clots in the circulatory system has also been seen earlier in the other coronavirus diseases – SARS and MERS.

While the fact that this can lead to venous thromboembolism and pulmonary embolism, with consequent right ventricular dysfunction or failure is known, the alarming rise in occurrence of clots in arteries of the limbs is something vascular surgeons are encountering with increasing regularity. These clots are not always fatal and are very much manageable and curable provided the patient comes in time. These are however not ordinary clots and it is necessary for both the doctor and the patient to understand this. The clots occur in the extremities and may form in the upper and lower limbs (arms and legs).

There is a particular mechanism why these clots form and the nature of the clot is way different. The cause of the hypercoagulability can be traced to hypoxia or low oxygen levels in COVID-19 making the blood thicker or more viscous and stimulating thrombosis or clotting in the circulatory system. Hypercoagulability can also result from abnormal functioning of the endothelial cells that line the interior surface of blood vessels. The virus attacking blood vessel cells causes inflammation, excess generation of thrombin and formation of clots, big and small.

Various studies have confirmed this increased risk of arterial thrombosis in COVID-19 patients. If left untreated, these clots can compromise the blood circulation to the limb leading to gangrene and amputation as the only choice.

It is important to take a different approach with counselling of the patient at an early stage. Treating clots in COVID positive patients might not be as linear as say an appendicitis operation. While like any surgical emergency, earlier done, the better are the treatment outcome and result, choice of options in therapy and exercising them appropriately and judiciously is paramount to outcomes.

At Kokilaben Dhirubhai Ambani Hospital, we have treated around 20 patients with clots in their peripheral arteries. These COVID-19 patients had co-morbidities but their co-existing chronic condition such as diabetes or hypertension was stable with regular treatment and a disciplined medication routine. In three of the cases, the patient’s RT-PCR was negative but their CT scans indicated COVID-19 infection. The false negative swab test, with CT scan showing a classic picture has now been documented in COVID literature, and is one of the limitations of the RT-PCR test. This is critical as the limitations of the RT-PCR should not lull the treating doctor and patient into a false sense of security and the delay action in treating the blood clots.

Media Contact
John Mathews
Journal Manager
Journal of Phlebology and Lymphology
Email: phlebology@eclinicalsci.com