This article originally appeared in the November 2005 Harvard Heart Letter and is provided courtesy of Harvard Health Publications.

Can you hold that heart attack until office hours?

In the average hospital, artery-opening angioplasty gets started sooner if you have a heart attack during office hours. The delay is relatively small, though, so don’t wait until 7 a.m. to get to the hospital.

There’s no good time to have a heart attack. It happens when it happens, totally out of your control. If you’re lucky enough to have yours during regular hospital hours (7 a.m. to 5 p.m.), you might be treated a bit faster, according to one study.

A heart attack happens when something, usually a blood clot, blocks blood flow through one of the arteries that nourish the heart. Muscle cells that depend on blood from this artery for oxygen and nutrients begin to hibernate, and then die. The heart sends out a distress call in the form of symptoms such as pressure or pain in the chest or along the left arm, fatigue, sweating, or nausea. The longer the clot stays in place, the greater the damage to the heart.

Clot-busting drugs such as tPA can break open the logjam and restore blood flow. So can opening the artery with balloon angioplasty followed by placement of a metal-mesh stent. For both approaches, the sooner treatment starts, the better.

Neither can start the minute you get to the hospital. Doctors first have to figure out if you really are having a heart attack — most people with chest pain aren’t. That means measuring blood pressure, checking the heart’s electrical system with an electrocardiogram, testing a blood sample for substances that signal damage to heart muscle, and possibly looking inside the heart’s arteries with an angiogram. Then it’s time for treatment. Ideally, tPA should be given within 30 minutes of entering the emergency room, and angioplasty should start within 90 minutes.

Heart attacks across the day

Although more people have heart attacks during the daytime, more than 40% of heart attacks happen between 6 p.m. and 6 a.m. Across the week, fewer heart attacks happen on Saturdays and Sundays than on other days of the week (they are most common on Mondays).

Angioplasty delayed
A study published in the August 19, 2005, Circulation looked at treatment times among more than 100,000 people treated for a heart attack in hospitals across the country. Drug therapy was started, on average, just a shade over 30 minutes after arrival in the emergency room during both weekday and off hours. That makes sense, since clot-busting drugs are usually administered right in the emergency room. The injection doesn’t take a special team or a complex procedure.

In contrast, arrival time affected the start of angioplasty: an average of 95 minutes after getting to the hospital during regular hours and 116 minutes during off hours.

Why the difference? In almost all hospitals that are set up to do this procedure, one or more angioplasty teams are on the premises during regular hours. They are usually performing scheduled operations, but are available for emergencies. Relatively few hospitals have an angioplasty team ready to go around the clock. At night and on weekends, most hospitals call in the experts when they’re needed.

One point to note: In this study, even during regular hospital hours angioplasty wasn’t started within two hours more than 25% of the time. At night and on weekends, it took more than two hours 41% of the time.

Don't wait
Minutes matter when you’re having a heart attack. The sooner you get to the hospital, the sooner treatment can begin. The best thing you can do is get help right away. Dial 911 (the smartest choice) or get to the closest emergency room as fast as you can.

The biggest delay in getting treatment occurs at home, not in the emergency room. It takes the average person more than two hours to call for help after heart attack symptoms appear, and one in four people wait more than five hours. It’s not ignorance — it takes the average doctor who is having a heart attack two hours, too. Instead, most people wait because they aren’t sure if they really are having a heart attack and can’t decide whether to seek medical care.

Such at-home procrastination usually dwarfs the few-minute differences in treatment times due to delays at the hospital. So don’t worry about what time it is, or what day. Get to the hospital ASAP.

Once there, keep in mind that there is a lot to do, and everything takes a few minutes. Pain and fear can make short delays seem to stretch out forever. But don’t hesitate to ask what the plan is, especially if things seem to be moving slowly. Better yet, if someone accompanied you to the hospital, have him or her act as your advocate to keep things moving.