The device, which is used to temporarily support a patient's heart, remains on the market in the US.

The US Food and Drug Administration (FDA) has issued its highest-level alert about a heart pump that has been linked to 49 deaths and 129 injuries.

The Impella left sided pumps are used to temporarily support a patient’s heart during high-risk procedures or after a severe heart attack.

But the regulator warned it could puncture a wall in the heart’s left ventricle if used incorrectly. The device’s manufacturer, Abiomed, has issued new instructions for the pump.

A summary posted on the FDA’s website on 21 March classified the move as “most serious type of recall” because of the risk of serious injuries or death if the device is used incorrectly.

The agency warned that the use of affected pumps may also cause serious adverse health consequences, including “hypertension, lack of blood flow, and death”.