Scientists Gain Insight Into How COVID Harms the Heart
MONDAY, Oct. 2, 2023 (HealthDay News) -- New research shows the COVID-19 virus can directly infect coronary arteries, inflaming fatty plaque inside them, which can increase the risk of heart disease and stroke.
This may explain why some people who get COVID-19 have a greater chance of developing heart disease. It also may shed light on why those who already have heart trouble develop more heart-related complications.
“Since the early days of the pandemic, we have known that people who had COVID-19 have an increased risk for cardiovascular disease or stroke up to one year after infection,” said Michelle Olive, acting associate director of the Basic and Early Translational Research Program at the U.S. National Heart, Lung, and Blood Institute (NHLBI).
“We believe we have uncovered one of the reasons why,” said Olive, who was not involved with the study.
While the researchers focused on older people with fatty plaques in the arteries who died from COVID-19, the findings could have broader implications for anybody who gets the virus.
Previous research had shown that COVID-19 could directly infect tissues such as the brain and lungs.
Once the virus reaches the cells, researchers knew that the immune system sends in white blood cells known as macrophages to help clear the virus.
These macrophages also help remove cholesterol in the arteries. But when macrophages become overloaded with cholesterol, they morph into a specialized type of cell called foam cells, according to the study authors.
The investigators theorized that if SARS-CoV-2 could infect arterial cells, the macrophages might increase inflammation in the existing plaque, explained senior author Dr. Chiara Giannarelli. She is an associate professor of medicine and pathology at New York University’s Grossman School of Medicine, in New York City.
The researchers tested the theory with tissue from the coronary arteries and plaque of people who had died from COVID-19. They were able to confirm the virus was in those tissues.
After that, they took arterial and plaque cells, including these macrophages and foam cells, from healthy patients. When researchers infected those cells in a lab dish, they found that the virus had infected them, too.
The findings showed that the virus infects macrophages at a higher rate than other arterial cells. Foam cells filled with cholesterol were the most susceptible to infection.
These foam cells may act as a reservoir of virus in the atherosclerotic plaque, the team reported. COVID-19 infection could be more severe or persistent in those with more plaque build-up.
The researchers also documented the release of cytokines, known to increase inflammation and promote plaque. This may help explain why people who have underlying plaque buildup and then get COVID may have heart-related complications long after, they suggested.
“This study is incredibly important as it adds to the larger body of work to better understand COVID-19,” Olive said in an NHLBI news release. “This is just one more study that demonstrates how the virus both infects and causes inflammation in many cells and tissues throughout the body. Ultimately, this is information that will inform future research on both acute and long COVID.”
The study was conducted in a small group of older individuals and in the original virus strains that circulated between May 2020 and May 2021 in New York City. So, it can’t be generalized to other strains of the virus or to younger, healthy individuals, the researchers noted.
This work was funded by the U.S. National Institutes of Health. The report was published online Sept. 28 in Nature Cardiovascular Research.
The U.S. Centers for Disease Control and Prevention has more on COVID-19.
SOURCE: U.S. National Heart, Lung, and Blood Institute, news release, Sept. 28, 2023
Utafiti mpya unaonyesha kwamba virusi vya COVID-19 vinaweza kuambukiza moja kwa moja mishipa ya damu, na kuchochea plaque ya mafuta ndani yao, ambayo inaweza kuongeza hatari ya ugonjwa wa moyo na kiharusi. Hii inaweza kuelezea kwa nini watu wengine ambao hupata COVID-19 wana nafasi kubwa ya kuendeleza ugonjwa wa moyo. Pia inaweza kutusaidia kuelewa kwa nini watu walio na matatizo ya moyo huwa na matatizo zaidi ya moyo. "Tangu siku za mwanzo za janga hilo, tumekuwa tukijua kuwa watu walio na COVID-19 wana hatari kubwa ya ugonjwa wa moyo au kiharusi hadi mwaka mmoja baada ya maambukizi,"" alisema Michelle Olive, mkurugenzi msaidizi wa Programu ya Utafiti wa Msingi na Mapema wa Utafiti wa Utafiti wa Msingi katika Taasisi ya Kitaifa ya Moyo, Mapafu na Damu (NHLBI)." "Tunaamini tumegundua moja ya sababu za nini", alisema Olive, ambaye hakuwa na ushiriki katika utafiti huo. Wakati watafiti walijishughulisha na watu wazima wenye plaques za mafuta katika mishipa ya damu waliokufa kutokana na COVID-19, matokeo yanaweza kuwa na athari kubwa kwa mtu yeyote anayepatikana na virusi. Utafiti wa awali ulionyesha kuwa COVID-19 inaweza kuambukiza moja kwa moja tishu kama vile ubongo na mapafu. "Kama virusi hivyo vimefika kwenye chembe za mwili, mfumo wa kinga hutuma chembe za damu nyeupe zinazoitwa ""macrophages"" ili kusaidia kuondoa virusi hivyo." Makrofagi hayo pia husaidia kuondoa kolesteroli katika mishipa ya damu. Makrofagi yanapokuwa na cholesterol nyingi, hujifanyiza kuwa seli za aina ya foam. "Wachunguzi walifikiria kwamba ikiwa SARS-CoV-2 ingeweza kuambukiza seli za mishipa, macrophages inaweza kuongeza uvimbe katika plaque iliyopo, ""mwandishi mwandamizi Dk Chiara Giannelli alielezea." Yeye ni profesa msaidizi wa dawa na pathology katika Chuo Kikuu cha New York Grossman Shule ya Tiba, katika New York City. Watafiti walichunguza nadharia hiyo kwa kutumia tishu kutoka kwa mishipa ya damu ya coronary na plaque ya watu waliokufa kutokana na COVID-19. Walikuwa na uwezo wa kuthibitisha kwamba virusi vilikuwa katika tishu hizo. Baada ya hapo, walichukua chembe za mishipa na chembe za plaque, ikiwa ni pamoja na macrophages na seli za povu, kutoka kwa wagonjwa wenye afya. Watafiti walipowaambukiza chembe hizo katika chombo cha maabara, waligundua kwamba virusi hivyo vilikuwa vimewaambukiza pia. Matokeo yalionyesha kwamba virusi hivyo huambukiza makrofagi kwa kiwango cha juu kuliko chembe nyingine za mishipa. Chembe za povu zilizojaa kolesteroli ndizo zilizokuwa dhaifu zaidi kwa maambukizo. Kikundi hicho kiliripoti kwamba chembe hizo za povu zaweza kuwa hifadhi ya virusi katika chembe za atherosclerotic. Ugonjwa wa COVID-19 unaweza kuwa mbaya zaidi au unaendelea kwa wale walio na mkusanyiko wa plaque. Watafiti pia walirekodi kutolewa kwa cytokines, inayojulikana kuongeza uvimbe na kukuza plaque. Hii inaweza kusaidia kuelezea kwa nini watu ambao wana mkusanyiko wa plaque ya msingi na kisha kupata COVID wanaweza kuwa na matatizo yanayohusiana na moyo muda mrefu baada ya hapo. "Utafiti huu ni muhimu sana kwani unaongeza kwa mwili mkubwa wa kazi kuelewa vizuri COVID-19,""Olive alisema katika taarifa ya habari ya NHLBI." Hii ni utafiti mwingine tu unaoonyesha jinsi virusi vinavyoambukiza na kusababisha uvimbe katika seli na tishu nyingi katika mwili wote. "Hii ni habari ambayo itaelekeza utafiti wa baadaye juu ya COVID kali na ndefu. ""Utafiti huo ulifanywa katika kikundi kidogo cha watu wazima na katika aina za virusi vya asili vilivyosambazwa kati ya Mei 2020 na Mei 2021 huko New York City." Kwa hivyo, haiwezi kuenea kwa aina zingine za virusi au kwa watu wadogo, wenye afya, watafiti walibainisha. Kazi hiyo ilifadhiliwa na Taasisi ya Kitaifa ya Afya ya Marekani. Utafiti huo ulichapishwa kwenye jarida la Nature Cardiovascular Research. Vituo vya Marekani vya Kudhibiti na Kuzuia Magonjwa vimechapisha ripoti ya COVID-19 "Kifungu cha kwanza cha utafiti huo kilitolewa na Taasisi ya Kitaifa ya Moyo, Mapafu, na Damu ya Marekani, Septemba 28, 2023."""