Why Are There So Many Heart Attacks?

The Health Advisory and Recovery Team (HART) reports this week on the unusually high number of heart attacks experienced in England since the end of May 2021 (see above). The data come from a weekly report from the ten ambulance trusts in England and show the number of emergency calls for cardiac or respiratory arrests. (The two are grouped together, HART explains, because it is not always clear whether a cardiac arrest was precipitated by a respiratory arrest.)

The two most significant points, HART says, are the dramatic rise in arrest calls since spring 2021 and the significant increase in the baseline (the dotted line) in the same period.

The baseline, of course, is crucial for establishing what is ‘normal’ and ‘excess’, yet the reports give no explanation as to why the baseline has risen so dramatically. As HART points out: “The expected number of daily arrest calls rose suddenly in March by about 50 per day – around 30% higher than before.” Why did the ‘normal’ or ‘expected’ number of arrest calls suddenly rise so dramatically in spring 2021? We should be told. It doesn’t appear that it would be explained simply by the inclusion of the 2020 data in the baseline.

It is doubly odd, HART notes, because there is no change in the baseline for other conditions such as overdoses, falls or injuries. The only other condition whose baseline has shifted significantly is the related category of “chest pain”, which, HART says, “has risen from a steady 1,600 per day to 2,000”. Nonetheless, the actual number of calls for chest pain has stayed around the previous baseline of 1,600, meaning the increased baseline makes it look like the figures are now running below average.

HART notes that prior to 2021 the peak daily calls were around 400 arrest calls in a day. However, during winter 2021-22 the peak surged beyond an unprecedented 500 in a single day (this isn’t shown in the chart above because the figures are a seven-day rolling average).

Using the 2019-20 baseline the number of arrest calls since May 2021 has been a huge 30% above expected levels, amounting to around 27,800 additional arrest calls – over 500 extra every day on average. This is significant because an estimated 90-97% of these people will have died as a result. A further comparison is that 2021 figures are up 20% on 2019, while 2020 figures are only up 6% on 2019.

Looking at excess deaths, it appears that a step change occurs around the same time, in late May 2021 (see below).

This does not correspond with a rise in Covid deaths (the orange line), which didn’t come until July. Rather, these arrest calls and deaths are associated with the worrying rise in non-Covid deaths in the same time period (which has occurred not just in the U.K. but across Europe), which as yet remains unexplained.

There is perhaps a broad correspondence with reported infections during the Delta wave (below) – though the rise in infections during June seems to begin somewhat late to explain a sharp rise in arrests in late May.

May 17th was Step 3 of the ‘Road Map‘ out of lockdown in England, when most restrictions on outdoor gatherings were lifted. Is it possible that the step change in arrests in late May was triggered by the resumption of more energetic activity among people who had remained sedentary under restrictions?

More generally across Western Europe there was a steep rise in non-Covid mortality in April and May 2021, beginning somewhat earlier than in the U.K. (see below, blue line). Some of this rise will be the bounce-back after the dip caused by mortality displacement due to the large winter Covid wave. Unfortunately, this phenomenon makes it hard to unpick how much mortality is additional to that.

What role might the vaccines be playing? While serious heart injury is a known side-effect of the Covid vaccines, it’s hard to see the thousands of additional arrests since May as driven exclusively by immediate injuries from the vaccines, as the vaccines were being rolled out from December in the oldest and most vulnerable groups, who are also those most likely to suffer an arrest. It remains possible that the signal for this is hidden under the winter Covid wave and subsequent mortality displacement, but that does rather leave one arguing from silence. However, given that the vaccines are one of the big differences between 2021 and 2020, any connection they might have with the wave of cardiac arrests and non-Covid deaths ought to be thoroughly investigated. The other big difference in 2021 was the Delta variant. Could non-Covid cardiac deaths be a trick of Delta, possibly in combination with the vaccines? Nothing should be ruled out in getting to the bottom of this.