What explains a six-fold rise in heart attacks in Mumbai ? Reasons given not convincing

A report last month in The Indian Express claimed that there had been a six-fold increase in heart attacks in Mumbai in 2021 compared to previous years. The report was based on an RTI response received from the Brihanmumbai Municipal Corporation. The report discussed the numbers, possible causes for the rise in heart attacks and called for a deeper probe.

There were 5,633 heart attacks in 2020 (full year) and 17,880 heart attacks in just the first six months of 2021. So, the number of deaths caused by heart attack was at least 12,000 more in 2021. To put the number in perspective, the same table put Covid-19 deaths in 2020 at 11,105.

In other words, the increase in heart attack deaths in the first six months of 2021 was more than the total deaths due to Covid-19 in 2020. One would have expected such increase in heart attacks to attract as much attention as Covid deaths, but such attention has been missing.

This points to two unmistakable aspects. First, the disproportionately low attention the nonCovid health conditions are getting in media, among administrators and also among doctors and scientists. And the related second aspect: the disproportionately high attention Covid has been getting in the same circles.

Possible causes offered do not add up: In attributing possible causes for the increased heart attacks, Express report quotes a doctor as offering three possibilities: (1) Thrombosis due to Covid19, (2) Delay in diagnosis, and (3) Better recording of data.

A quick look at the data (see graph) tells us that all three possibilities speculated do not hold water, because otherwise there should have been an increase in heart attacks in 2020 as well.

This pattern is however noticeable not just in Mumbai, but also in other parts of the world. A recent publication in April 2022 in the journal Scientific Reports shows that Israel saw an increase in heart attacks, coinciding with its jab rollout as well as its third Covid wave, with no such signal in the first two Covid waves. Likewise, Germany’s official data shows an increase in cardiac events starting about April 2021, but neither its first Covid wave in April 2020 nor its much steeper second wave in January 2021 showed such an increase in cardiac events.

A recent methodical cohort study published in April 2022 in the Journal of Clinical Medicine, involving nearly 200,000 participants however has not shown any increased myocarditis (inflammation of the heart muscle) events in patients after Covid-19 infection. So, the question begging to be asked is: why is there an increase in heart attacks in 2021, not seen in 2020 anywhere in the world?

Need to probe link with Covid-19 vaccines: Cardiac issues as a side-effect of Covid-19 vaccines is known, and was also reported in the media as early as March 2021. Another recent media report in Mid Day acknowledged the link between heart attacks and the Covid jabs, but suggested that this risk is only with the mRNA jabs.

This is untrue. The risk is documented in scientific publications for the mRNA jabs AstraZeneca (Covishield) as well as Covaxin. Indeed, as early as April 2021, several European countries such as Spain, Italy, Belgium, stopped using AstraZeneca for younger age groups citing increased safety concerns.

One thing which is common with the timing of increase in heart attacks in several parts of the world is the rollout of the Covid-19 vaccines. Such time correlation is worrying, but time correlation by itself is considered weak evidence scientifically.

While there is no need to implicate the jabs without sufficient evidence, there is no need to exonerate them either. When it comes to medicines, especially new ones still under trial, they must be assumed guilty unless proven innocent (safe) beyond doubt. A deeper analysis of the data is therefore warranted.

There is an urgent need for a dispassionate look at the data involving heart-attacks along various dimensions: Covid status, vaccination status, age, gender, etc -- data which must be available with BMC already.

(The writer is a professor at IIT Bombay. Views are personal)

(This was first published in National Herald on Sunday)