Study finds no correlation between Covid vaccines and increased risk of heart attacks

New Delhi: An observational study, done on admitted patients at the GB Pant hospital in New Delhi, has shown that there is no correlation between Covid-19 vaccines used in India and increased risk of heart attacks. Rather, it was found that the jabs are protective and reduce the chances of mortality in patients suffering heart attacks.

The research, published recently in the journal ‘PLOS One,’ showed the impact of Covid-19 vaccination on mortality following acute myocardial infarction (AMI) or heart attack.

During the pandemic, the two made-in-India vaccines – Covishield and Covaxin – were developed and millions of people took the shots. Ever since, there have been rumours making rounds associating heart attacks with the vaccines.

The adverse effects (AEs) of Covid-19 vaccines have mostly been mild, transient and self-limiting such as mild fever, headache and body aches and people recovered on their own. However, concerns have been raised regarding the cardiovascular adverse effects of these vaccines.

The study

Eliminating bogus rumours that associated vaccination with heart attacks, a retrospective (on admitted, enrolled in the past), observational study was undertaken by GB Pant Hospital using the data from 1,578 people admitted to the hospital between August 2021 and August 2022.

Of the total, as many as 1,086 (68.8 per cent) were vaccinated against Covid-19 while 492 (31.2 per cent) were unvaccinated. Among the vaccinated group, 1,047 (96 per cent) had received two doses of the vaccine while 39 (4 per cent) had received only a single dose.

Any side effect can have catastrophic effects, especially in large densely populated countries such as India, the authors stated. In all the enrolled patients, data regarding the patient’s vaccination status including details on the type of vaccine, date of vaccination and adverse effects were obtained.

Mortality lower in vaccinated groups

On a 30-day follow-up, all-cause mortality occurred in 201 (12.7 per cent) patients with the odds of mortality being significantly lower in the vaccinated group.

Similarly, at six months of follow-up, the vaccinated AMI group had lower odds of mortality as compared to the non-vaccinated group. Covid-19 vaccines showed a decrease in all-cause mortality at 30 days and six months following AMI, according to the study. However, increasing age, diabetics and smokers had a higher risk of 30-day mortality, the researchers said.

The researchers found that the analysis did not show a specific clustering of AMI (rapid or frequent occurrence of several cases of heart attacks) at any particular time post-vaccination, suggesting there was no significant association between Covid-19 jabs and heart attacks.

“Our study found that vaccines used in India are safe. There was no association between vaccination in India with heart attack. In fact, the study found that there were less chances of death after heart attack in vaccinated individuals,” said Mohit Gupta, who led the study, from GB Pant Hospital, speaking to the media.

This study is the first to be conducted among a larger population of AMI patients, which has shown Covid-19 vaccine to be not only safe but also have a protective effect in terms of reduction of all-cause mortality both on short term as well as at six months of follow-up.

Limitations

However, the authors of the study noted some limitations. They said it was a single-centre retrospective study (based on data collected from one hospital), and so the findings need to be validated in further elaborate studies done on different ethnic groups.

Referring to the study at GB Pant Hospital, Dr Rajeev Jayadevan, physician and past president of IMA Cochin said, “Covid vaccination leading to heart attacks and deaths is a commonly circulating social media hoax. In fact, there is no correlation between the two. Two observations in this study help dispel that myth.”

“Firstly, there had been no cluster of events in the days following Covid vaccination in these patients. It means there have been no immediate deaths or complications in rapid frequency reported among those who took the vaccines during that time frame. Secondly, it was observed that six-month mortality among the vaccinated patients was substantially less compared to non-vaccinated patients,” he said.

“If vaccines were actually causing deaths, then there would be a spurt of heart-attack related or other complication-related deaths immediately or within a few days of taking the vaccine shots. The study shows this has not occurred in reality,” explained Dr Rajeev.