Crack cocaine may rip apart artery walls, according to the first study reviewing a group of middle-aged adults with a condition called aortic dissection, researchers report today at the American Heart Association’s Scientific Sessions 2001 conference.

Aortic dissection occurs when the lining of the aorta -- the major blood vessel that carries blood from the heart -- tears, exposing the second layer. Cocaine use causes an extraordinary outpouring of stress hormones that can cause blood pressure to quickly rise. This may tear the lining of the vessel, called the intima.

"As the vessel pulses, the inner lining starts to peel away. This is a very dangerous process that can move rapidly once it is started," says researcher Ann F. Bolger, M.D., associate professor of medicine at the University of California at San Francisco. The dissection may block blood from reaching critical organs, or even cause the aorta to rupture.

"This is such a lethal condition that patients may die if they don’t make it to the emergency room quickly," she says. "Nurses and physicians must be suspicious and ask about cocaine use and exposure. Patients aren’t always anxious to mention drug use, but a history of cocaine use should raise a flag."

An early diagnosis is imperative. Within the first 24 hours of a dissection of the aorta close to the heart, 25 percent of patients die. By 48 hours, half die, Bolger says.

The symptoms of aortic dissection usually start with chest and back pain and often are mistaken for a heart attack. However, if the person is young and the tests for heart attack are negative, then the physician must go further to make the diagnosis, Bolger notes.

Aortic dissection usually occurs in older individuals who have high blood pressure and may also occur as a result of a congenital disorder called Marfan syndrome.

The study was undertaken when researchers noticed cases of aortic dissection in younger individuals who did not have the usual risk factors, but admitted to habitual crack cocaine use, says lead researcher, Priscilla Y. Hsue, M.D., a cardiology fellow. Cocaine use is not a commonly recognized risk factor for aortic dissection.

Hsue and other researchers reviewed hospital charts of individuals diagnosed with aortic dissection at San Francisco General Hospital from 1981 to 2001. Thirty-eight cases were noted and 14 (37 percent) patients had used cocaine. Crack cocaine was smoked in 13 cases and powdered cocaine was snorted in the other. Crack is a form of smokable cocaine derived from powdered cocaine. Smoking allows extremely high doses of cocaine to reach the brain very quickly and brings an intense and immediate high. Powdered cocaine is inhaled through the nose where it is absorbed into the bloodstream through the nasal tissues or injected directly into the bloodstream.

The cocaine users were a median age of 42, which is 18 years younger than non-cocaine users who had aortic dissection. The average time of onset of chest pain after cocaine use was 12 hours. In the group of cocaine users, there was a higher number of African Americans. There were no significant differences in the incidence of hypertension among users and non-users or whether they were taking medications for high blood pressure.

Twenty-nine percent of those who had used cocaine died as a result of aortic dissection, while 17 percent of individuals who had not used cocaine died of the condition, Hsue notes.

Type A dissections involve the ascending aorta and usually require surgery. Type B dissections are sometimes treated with blood pressure-lowering medication alone. Although the two groups did not differ with respect to type of dissection, cocaine users were more likely to undergo emergency surgery compared to aortic dissection patients without cocaine use. Other study co-authors are: Cynthia Salinas and David Waters, M.D.

Crack and Cocaine Drug Dangers

Cocaine - On May 16th, 1499 Amerigo Vespucci set sail for the New World. Three months later, having navigated his way along the coastline of Brazil, he washed up on an idyllic desert island fifteen leagues from the mainland. There he was appalled to discover a tribe of hideous Indians, their mouths stuffed full of leaves "like beasts." The leaves were coca, source of the drug cocaine.

Five hundred years later, the effects of the discovery are still felt. In 1999 South America produced 613,4000 tons of coca, with a potential yield of 765 tons of cocaine. Last year a United Nations report estimated that the global cocaine trade generated $92 billion per year - $20 billion more than the combined revenues of Microsoft, Kellogg's and McDonald's.

For millennia, South Americans had used coca to cure everything from stomach maladies to snow blindness. Four hundred and fifty years before the civilized world discovered local anesthesia, the Incas were performing brain surgery using the numbing coca. For centuries conquistadors fed the Indians the leaves while they mined silver - fuelling the Spanish Empire while simultaneously decimating South America's population.

And when cocaine hit Europe and North America it caught on there too. It was incorporated into drinks and tonics as a pick-me-up, including the most famous of all, Coca-Cola. The drug created waves of addicts around the world until it was banned in the early twentieth century. By the 1960s if was back, and has been creating all sorts of trouble ever since.

Dominic Streatfeild examines the story of cocaine from its first medical uses to the worldwide chaos it causes today. His research takes him from the arcane reaches of the British Library to crack houses in New York to the jungles of Peru and Colombia. Along the way he speaks to some of the thousands involved in the trade: economists, scientists, botanists, lawmen, historians and traffickers, creating what is by far the most definitive history of a white powder worth more than its weight in gold.