This Is Your Heart On Drugs: Study May Help ER Doctors Identify And Treat Chest Pain Caused By Cocaine

Such plans have been in place for traditional chest pain patients for years, and many hospitals set aside part of their ERs to hold them for observation. But doctors have lacked criteria to help them decide how long to hold patients whose chest pain was caused by cocaine - even as millions of Americans are using the drug.

By following the new study's standardized guidelines for testing and observation, doctors can determine after a few hours which patients can go home, and which ones have a high risk for complications that should keep them in the hospital.

The study's results, published in the Feb. 6 issue of the New England Journal of Medicine, are important because the number of cocaine-related heart complications has been increasing in recent years as cocaine use has become more widespread. But many patients whose cocaine use sends them to the ER with chest pain don't tell their doctors about their drug use, putting them at risk if they receive conventional emergency heart treatments that can actually worsen the effects caused by cocaine.

"We hope to help emergency physicians better care for chest-pain patients by providing validated guidelines for which patients require admission to the hospital and which can be safely discharged home," says lead author Dr. Jim Edward Weber, a University of Michigan emergency medicine physician who led the study of patients at Hurley Medical Center in Flint, MI.

Weber notes that the study was made possible by cooperation between Hurley and the U-M Department of Emergency Medicine, whose physicians and residents staff the Hurley ER. Hurley was selected for its ability to care for large numbers of acutely ill patients, and for the large number of drug-related illnesses it treats each year - a proportion similar to other hospitals in economically depressed urban areas.

Weber and his colleagues also hope their work will raise awareness among doctors and drug users of just how harmful cocaine can be to the heart, even in otherwise healthy young people. The risk of heart attack in the first hour after using cocaine is 24 times normal, and cocaine users have a seven-fold lifetime risk of heart attack. Nearly one-fourth of heart attacks in people ages 18 to 45 are cocaine related.

None of the 344 patients treated prospectively under the U-M/Hurley plan died of a heart-related cause in the month-long follow-up period after their ER visits. Only four patients of the 302 who went home after 9 hours or more in the chest-pain center had heart attacks in that first month - and all four had kept using cocaine.

With cocaine being used chronically by 3.6 million Americans, and occasionally by millions more - including 5 percent of 12th graders - the study's protocol could be applied nationwide.

"While these findings come from a population with high cocaine use, and thus a high incidence of cocaine-related heart effects, this standard of care could be used in any hospital," says senior author Dr. Judd Hollander, professor of emergency medicine at the University of Pennsylvania who has led other studies of cocaine-related heart disease. "But studying this population means we were able to get results from a large number of patients relatively quickly."

The new study should help doctors decide who needs the most intensive heart care, Weber adds. "This is a serious issue nationwide, with little consistency in treatment from hospital to hospital, and care for these patients costs $83 million just in hospitalization annually. We devised this care standard to try to optimize care while containing costs." Weber, an assistant professor of emergency medicine at the U-M, serves as director of research at Hurley.

The study participants were young - with a mean age of 37.6 years old - and predominantly male. Seventy percent were African American, and more than 80 percent smoked tobacco.

The protocol divides patients into high-risk and low-risk categories. High-risk patients were those who had signs of acute heart attack or ischemia on their electrocardiogram results, high levels of cardiac markers, or other serious symptoms. In the study, there were 42 high-risk patients. All were admitted to Hurley; 20 percent were diagnosed with a severe heart condition.

The other 302 patients in the study were classed as low-risk - but were held for observation in the chest pain center because of their risk for heart effects in the next hours and days.

Weber and his colleagues treated them under a protocol that had been based on their long experience with cocaine-using chest pain sufferers, and previous studies of which treatments work best and which can prove deadly in patients who have been using cocaine.

For instance, 301 of the patients had urine tests for cocaine, in addition to being asked if they had used the drug recently. Previous studies have shown that nearly a third of cocaine users in the ER lie about their drug use, even when told their answers will help their care. In the study, 282 patients tested positive for cocaine, but only 169 reported using it in the last 24 hours.

Knowing for certain if patients have cocaine in their systems is a critical piece of knowledge because of the way cocaine affects the heart and the blood vessels that supply it with oxygen. Cocaine causes the heart's blood vessels - coronary arteries and capillaries - to constrict, cutting blood flow to the heart muscle. But at the same time, cocaine's effect on the body's adrenaline system causes spikes in the heart rate and blood pressure, meaning the heart muscle needs more and more oxygen, and therefore more blood flowing to it.

This conflict between the heart's increased demand for blood, and the narrowing of the blood vessels needed to supply it, can be worsened if the patient has existing blockages in their arteries - cutting off blood supply to parts of the heart altogether. Cocaine also causes blood cells to stick together, forming clots that can lodge in narrowed blood vessels.

Both effects can cause a heart attack after the first dose of cocaine a person takes - or their hundredth. And if the cocaine user also smokes, the two drugs can have an additive effect.

Cocaine users can benefit from certain tests and treatments commonly used in all chest-pain sufferers, but can be harmed by others. For instance, beta-blocker drugs used by many heart patients can further constrict cocaine users' narrow blood vessels - a potentially lethal effect.

The team monitored the patients for at least nine hours, performing regular blood tests, using continuous heart-rhythm monitors, and keeping an eye on other indicators of heart health. All patients were assessed by a cardiologist after nine hours, and some had stress tests.

Before allowing the patients to leave the chest pain center, the medical team asked them for their addresses and phone numbers, and contact information for friends or relatives who might be in touch with them. Patients also got information about the danger of using cocaine again.

One month after the patients were discharged, the team attempted to contact them or their friends or relatives. The researchers wanted to see if the patients were still alive, and if possible whether they had had a heart attack or more chest pain, or had continued using cocaine.

All but two patients were contacted or learned about secondhand; the other two were presumed alive because they were not listed in the National Death Index. There were no deaths from heart-related causes; one patient died of a heroin overdose, and one of a gunshot wound.

Of the 256 patients for whom detailed follow-up was obtained, four patients - all of whom kept using cocaine - had had heart attacks. Sixty-three of the patients had had more chest pain.

The fact that 64 of the 256 follow-up patients admitted they had continued using cocaine is the crux of the next issue that Weber and his colleague are tackling: what factors affect a patient's decision to pursue drug treatment, and how accessible treatment programs are for patients.

Currently, they're studying these issues, and the lives of cocaine users in the first year after a chest pain ER visit, through a $2.1 million, four-year National Institutes of Health grant.

"We want to see if an emergency room visit can be a teachable moment, and interrupt a vicious cycle of drug use and medical problems," says Weber.

He and the project's principal investigator, Brenda M. Booth of the University of Arkansas for Medical Sciences, lead a team of researchers that's gathering data on a group of cocaine users for a year after their chest pain visits. After data on 250 patients has been gathered, the researchers will look for characteristics of their drug use, health status, demographics, interactions with the health care system and drug treatment system, and overall outcomes.

In addition to Weber and Hollander, the new paper's authors include Amit Kalaria, M.D., a former Michigan State University medical student now doing a residency in emergency medicine at Northwestern University; Greg Larkin, M.D., MSPH, of the University of Texas Southwestern Medical Center; and Francis Shofer, Ph.D., of the University of Pennsylvania.

In addition to Weber and Booth, the follow-up study research team includes Rebecca Cunningham, M.D. and Ronald Maio, M.D. of the U-M Department of Emergency Medicine; and others from the University of Arkansas for the Medical Sciences.