Every year, about 850,000 people in the U.S. suffer a heart attack; 650,000 of which are first heart attacks, and 200,000 recurrent attacks. Although more people are surviving their first heart attack these days, the rate of complications such as irregular heartbeat and heart failure has risen.

Heart attack survivors are also more likely to suffer a recurrent incident. One of the main reasons the death rate has declined is balloon angioplasty, a minimally invasive procedure that revolutionized heart attack treatment. Today, about 1 million angioplasties are performed annually.

A heart attack occurs when a clot in a coronary artery ruptures and cuts off blood flow to the heart. When the heart doesn’t get enough oxygenated blood, cells die and the heart muscle can become damaged, which can cause two types of complications: irregular heartbeats and heart failure. Both can be disabling.

The best way to prevent heart muscle damage is to restore the blood flow as quickly as possible — and balloon angioplasty is by far the best way to accomplish that. The procedure involves a catheter-tipped balloon that is placed in the blocked coronary artery and inflated to widen the vessel and restore blood flow.

Ideally, the window for treatment is 90 minutes — sometimes called the “door to balloon time” — which means that no more than 90 minutes should pass between when a patient arrives at the hospital and undergoes angioplasty.

Unfortunately, in practice that window often exceeds 120 minutes. And many people who experience heart attack symptoms do not get to the hospital immediately.