Because so many deaths were due to respiratory failure, many colleagues I talked with expected to find progressive pneumonia with lung destruction as the cause. However, researchers discovered something entirely different: blood clots in the lungs (also referred to as pulmonary emboli). Furthermore, they found countless additional smaller clots in many other organs as well. (Note that experts distinguish between clot and thrombus and embolus but for simplicity, we’ll call them all clots.)
Importantly, they looked at overall health not just in the immediate aftermath of the infection, but an entire year after Covid-19. (The researchers estimated the “post-Covid year” timeframe among those not actually infected using statistical methods.) Investigators included Covid-19 survivors who were never hospitalized (131,612 people), in addition to those who recovered after staying in the intensive care unit (5,388 people) or regular hospital ward (16,760 people).
The results are clear and very significant: Compared with similar people who had not been infected with SARS-CoV-2, those who recovered from infection had many more blood clots, heart problems and strokes. The extent of the differences across the 20 different cardiovascular conditions is among the greatest of any clinical study I have read. It is jaw-dropping.
The VA study has important limitations. It involves people infected in 2020 who are at least a year post-infection; these people likely had the initial “wild” strain of SARS-CoV-2 or perhaps the Alpha variant, which dominated in late 2020. Not enough time has passed to know if similar long-term dysfunctions of the blood vessels and heart also will occur among survivors of Delta or Omicron variant infections. And the study cannot predict the health impact of Covid-19 two and three and 10 years after recovery.
Indeed, this last issue may be the most pressing. No one knows how long the cardiovascular abnormalities will persist or if they will resolve at all. Advising this very large group of people who recovered from Covid-19 and may have lingering health issues is therefore a murky business. Should each find a cardiologist? A blood clotting specialist? Will long-term Covid-19 management become a new subspecialty similar to the not-so-long-ago emergence of the AIDS specialist?
It would be nice to think that this sort of information would be powerful to convince people still unwilling to receive the Covid-19 vaccine or the booster shot by providing simple and horrifying truths about the aftermath of the disease. Up till now, the core of the hesitancy has not been influenced by facts and figures.
This new welter of facts, though, may be different (hope springs eternal). The suddenness of the pandemic and the suddenness of so many deaths were unspeakably tragic. Yet, for those patients and families who have managed to stay Covid-free over the last two years, the fear of Covid and the urgent desire to protect oneself may have been dulled by time and the relatively mild symptoms that were widely reported with the last variant of concern.
But now, with an elevated risk of heart disease, stroke and blood clots as a possible long-term effect of Covid-19 — conditions that can be chronic and slowly debilitating — perhaps the VA researchers will do something that almost a million American deaths has not: frighten a broad swath of the vaccine-hesitant into rolling up their sleeves and taking the shots.