Introduction

Atrial fibrillation (AF) and Heart attack (myocardial infarction or MI) have a bidirectional relationship, where each one of the two is a risk factor for the other.

It can definitely increase the risk of a heart attack.

It is a well-known fact that AF is the most common rhythm abnormality that occurs in patients with a heart attack.

According to the European Society of Cardiology (ESC) 2020 guidelines for the management of AF, 2-23% of patients suffering from a heart attack develop AF and such patients have a 60-77% increased risk of developing new-onset AF.

But the opposite is true as well.

AF itself is an independent risk factor and increases the risk of a heart attack several folds.

The ESC 2020 Guidelines for AF suggest that it may raise the risk of both ST-elevation myocardial infarct (STEMI) and non-STEMI Acute Coronary Syndrome (ACS).

It also says that 10-15% of AF patients develop heart disease to such an extent that they require angioplasty.

Research-based evidence

The above-mentioned facts have been supported by a number of studies done in the past few years

Details of a few of them are as below.

#1

This study was published in the Circulation journal in the year 2015.

It included 14,462 participants and the median follow-up duration was 21.6 years.

Out of the total, 1374 participants suffered a heart attack & 829 out of them had NSTEMI.

The study concluded that AF increases the risk of non-STEMI, affecting women more than men.

#2

In the year 2014, this research paper was published in JAMA Internal Medicine Journal.

It included 23,928 participants from the United States and all had no coronary artery disease at baseline.

The follow-up period was 6.9 years.

Out of the total, 648 people suffered a heart attack

So the study concluded that AF doubles the risk of a heart attack.

Also, the female gender and black people were more affected.

#3

This study was published in the year 2014 in the Heart Rythm Journal.

The total number of participants was 12,114, out of this 7254 were women.

The mean follow-up duration was almost 6 years.

Only those patients were included who had a CHA2DS2-VASc score of 0 (for men) and 1 (for women).

Out of the total, 258(1.1%) patients suffered a heart attack & the annual incidence of heart attack was 0.29% in patients with AF as compared to 0.10% in patients without AF.

The study ended up with the same conclusion that AF is an independent risk factor for heart attack but the male gender was more affected which was contrary to the results of the two above-mentioned studies.

#4

The PLOS one Journal published this research paper in the year 2014.

It included 261 patients and a coronary angiogram was performed in all of them.

Out of the total, 80(34%) had an underlying coronary artery disease.

56 patients had a severe disease requiring either PCI or CABG.

Whereas, 34 patients had stable disease.

How AF increases the risk of Heart Attacks?

The exact mechanism responsible for making AF a risk factor for MI is not clear.

Studies however suggest that it is underlying atherosclerosis that is responsible for this relationship.

Atherosclerosis means accumulation of cholesterol within the blood vessels, thus causing narrowing and ultimately can lead to complete occlusion of the blood vessel.

In patients without hypertension, diabetes, ischemic heart disease, or any other risk factor for AF, carotid artery atherosclerosis has been found to be the sole cause of AF.

So atherosclerosis in carotid arteries means atherosclerosis in the rest of the blood vessels as well.

And when it involves the vessels of the heart, it can manifest as an MI.

This explains that atherosclerosis is a risk for both AF and MI, and hence the two of them are inter-related and are risk factors for each other.

Take-Home

In the light of the above-mentioned studies, patients with AF are more likely to get an MI and this demands extra caution in such patients to avoid a heart attack.

AF can have serious consequences and MI is one of them, increasing the burden on the healthcare system.

Therefore it must always be taken seriously and patients should be counseled regarding proper management & risks of the disease.

Advice for patients having AF

Maintain ideal body weight.

Monitor your lipid levels regularly.

Quit smoking.

Avoid processed foods.

Eat a healthy balanced diet.

Exercise regularly.

Regularly follow up with your doctor.

Be compliant with the medication.

And remember ‘Prevention is the best cure’