After low-risk chest pain, peer-supported online therapy eased anxiety a little more than a doctor referral

Most people who go to an emergency department with chest pain are told, after tests, that it was not a heart attack. Many of them are anxious, and few get help for it. A trial in the United States has now compared three ways of treating that anxiety in the year after the visit.

Anxiety eased in all three groups. An online therapy program backed by a trained peer supporter did slightly better than a simple referral to primary care, by 1.22 points on a 21-point scale. Sessions with a therapist by video or phone did not clearly beat the referral. The trial, published on September 28 in JAMA Internal Medicine, had no group that went untreated, so it cannot show how much of the improvement would have happened anyway.

Why anxiety after low-risk chest pain matters

The paper opens with the scale of the problem. Chest pain is a leading reason for emergency department (ED) visits, and in most cases tests find no heart emergency. Doctors call these cases low-risk chest pain, a label given after excluding acute coronary syndrome. Acute coronary syndrome is the medical term for a heart attack or a closely related sudden loss of blood supply to the heart muscle.

News-Medical, a medical news site that reported the trial, set out the figures the researchers cite. Chest pain is the second leading cause of emergency department visits in the United States, with more than 8 million cases annually. Of those people, nearly 80% of patients are found not to have cardiac or cardiopulmonary emergencies. Cardiopulmonary means involving the heart and lungs.

Anxiety is common in this group and usually missed. In News-Medical’s account, it affects up to 55% of them, yet remains undiagnosed in nearly 90% of cases. The trial’s published protocol made the same point more broadly, saying anxiety is often undiagnosed and undertreated in any setting.

Kurt Kroenke, of the Indiana University School of Medicine and the Regenstrief Institute and a co-author of the trial, described the overlap last year, when the team published its starting data. “Anxiety is a common fellow traveler with low-risk chest pain,” Kroenke said. Paul Musey, of the same two institutions and the trial’s first author, spoke then about what a clear heart test leaves undone. “Emergency physicians often reassure patients that their chest pain isn’t caused by the heart, but reassurance alone is not enough,” Musey said.

A US emergency medicine guideline had already pointed the same way. In 2021 a panel convened by the Society for Academic Emergency Medicine, with Musey as first author, issued advice on adult patients with recurrent, low-risk chest pain. One of its eight statements suggested referral for anxiety or depression management, as this might have an impact on healthcare use and on return visits.

How the chest pain anxiety trial worked

The study is known as PACER, short for Patient-Centered Treatment of Anxiety After Low-Risk Chest Pain in the Emergency Room. The paper describes it as a randomized, 3-group comparative effectiveness trial. Randomized means that chance decided which treatment each person received. A comparative effectiveness trial is one that sets treatments already in use against each other, without a placebo.

Participants were recruited from six Indiana University Health emergency departments between April 2021 and July 2024. To join, adults had to have been sent home after low-risk chest pain and to score as at least moderately anxious on a questionnaire, or to screen positive for panic.

The questionnaire, called the GAD-7, asks how often seven anxiety symptoms have bothered a person in the past two weeks. An earlier paper from the trial explains that scores range from 0 to 21, with higher scores representing more severe anxiety symptoms. By the bands the trial used, scores from 8 to 14 are considered moderate anxiety, and scores of 15 or more severe.

A total of 375 patients were enrolled. Of these, 265 (70.7%) were female and 109 (29.1%) male. There were 226 White participants (60.3%), 125 Black participants (33.3%) and 28 Hispanic participants (7.5%). The average age was 39.9.

The trial’s baseline analysis put their average GAD-7 score at 13.1, in the moderate band. In that analysis, 42% of participants had severe anxiety, and three in four screened positive for panic disorder.

All 3 groups received psychoeducation. Psychoeducation means explaining a condition to a patient, in this case the link between anxiety and chest pain. Before being assigned, all participants received a 15- to 30-minute brief intervention of this kind from study staff.

After that the three groups parted. The trial’s registration describes them as pragmatic, graduated in the level of resource intensity, meaning the first takes the least staff time and the third the most.

The first group received an enhanced primary care referral, diagnostic results, and educational materials. The registry calls this arm enhanced primary care coordination.

The second group used an internet program of cognitive behavioral therapy (CBT). CBT is a talking treatment that teaches people to notice and change the thoughts and habits that keep anxiety going. The registry lists this arm as online CBT with support from a certified peer recovery specialist (medium intensity). A peer recovery specialist is a trained supporter who draws on personal experience of recovery and is not a clinician.

The third group participated in eight telehealth CBT sessions with a trained therapist. Telehealth means care given by video or phone. The registry sets these out as 8 one-hour sessions over the course of 8 to 10 weeks.

The primary outcome was change over 12 months in the GAD-7 anxiety score. A primary outcome is the one result a trial is designed to answer. Outcomes were assessed at 3, 6, 9, and 12 months.

What the trial found for anxiety

Everyone improved. After adjustment, GAD-7 scores fell over 12 months by 4.32 points in the referral group, 5.54 points in the peer-supported online group and 5.13 points in the therapist group.

Only one of the two therapy groups clearly beat the referral. The peer-supported online program improved scores by 1.22 points more than referral did, with a range from 0.01 to 2.43. The bottom of that range sits almost at zero, which means the true advantage could be close to nothing or could be about two and a half points.

The paper gives this as an effect size of 0.25. An effect size is a way of expressing a difference in relation to how much people’s scores vary, and 0.25 is conventionally read as small.

The gap was wider among the most anxious. The paper says this effect was strongest (2.8 points) among patients with severe anxiety. In that subgroup, News-Medical adds, the online program also did better than the therapist sessions: scores improved by 2.2 points more than with therapist-delivered CBT. Subgroup results rest on fewer people and are less secure than the main result.

Therapist-led sessions improved scores about 0.8 points more than referral. That difference did not pass the trial’s test for ruling out chance.

So the less costly of the two therapies did at least as well as the more costly one. The trial was set up to compare each therapy with referral, and its main result does not show that the online program was better than a therapist across all patients.

The improvement came early and lasted. News-Medical describes most of the gains emerging within three months and generally persisting through 12 months.

What else changed in the chest pain trial

Other symptoms improved too, in every group. Depression, somatization, and disability improved moderately within groups, with nothing to separate the three. Somatization is, in the Regenstrief Institute’s words, the experience of psychological distress through physical symptoms.

Participants’ own verdicts favored therapy more strongly than the scores did. Odds of patient-reported global anxiety improvement were 3 times higher in the 2 CBT groups compared with primary care referral. Global improvement here means a person’s overall judgment of whether their anxiety is better. Odds are the chance of something happening set against the chance of it not happening.

How much people used the treatment mattered. Higher engagement was associated with greater anxiety reduction. In the online group, News-Medical reports, those with moderate and high engagement showed 3.8- and 3.2-point greater improvements than people who did not engage at all. That comparison is not randomized. People who stick with a program may differ from those who do not in ways that also affect anxiety.

Both therapies were liked. Therapeutic alliance and program satisfaction were high in both CBT groups. Therapeutic alliance means the working bond between a patient and the person guiding their treatment.

The trial also tracked the heart, since the worry with any low-risk label is that something was missed. Seven major adverse cardiovascular events occurred among six participants over the year, a rate of 1.6%, and only one occurred within 30 days of the initial emergency department visit. One participant died, of a cause unrelated to the heart.

What earlier research on chest pain and anxiety showed

Psychological treatment for chest pain without heart disease has been tested before, mostly in small trials. A Cochrane review in 2015 pooled 17 randomized trials with 1,006 participants. Its authors found a modest to moderate benefit for psychological interventions, particularly those built on CBT. The benefit was largely restricted to the first three months after the intervention. The reviewers concluded that further trials with follow-up periods of at least 12 months are needed.

PACER supplies that length of follow-up.

A Swedish trial published in 2024 is the closest earlier comparison, and its result was cooler. Researchers in Sweden assigned 109 patients with non-cardiac chest pain to a nurse-led internet CBT program or to psychoeducation alone, and followed them for a year. Anxiety about the heart fell in both groups, and the authors concluded that iCBT was not more effective than psychoeducation. The lowercase “i” stands for internet. Reports of how often chest pain occurred did shift in favor of the internet group.

Read together, the two trials show a similar pattern. In both, people improved a good deal whichever group they were in, and the online course added a small amount or nothing measurable.

The PACER protocol had also set out to learn what options work best for patient subgroups based on anxiety severity. The larger gain among people with severe anxiety is the trial’s answer so far.

What the chest pain anxiety trial cannot show

No untreated group. Every participant got the short explanatory talk, and the comparison group got a referral. Because the study lacked a usual-care group receiving no active intervention, the report says, the improvements seen across all three groups could also partly reflect changes over time or regression to the mean. Regression to the mean is the tendency of people picked for an extreme score to score closer to average later, with or without treatment. People were enrolled on a day they had gone to an emergency department with chest pain.

A small gap with a wide range. The main difference was 1.22 points on a 21-point scale, and its range nearly reached zero.

Many people did not take up treatment. News-Medical lists inconsistent engagement among the limits, with about one-third of participants completing no treatment sessions. The results describe what happens when these treatments are offered, not what happens when they are completed.

Missing follow-up. Around 80% of participants completed at least one follow-up assessment, so about one in five supplied no later scores.

Medicines were not tracked. The report notes a lack of tracking for medication types. Some participants may have started or changed anxiety medicines during the year, and the trial cannot account for that. Do not stop or change a prescribed medicine without talking to your doctor.

One health system. All six emergency departments belonged to one organization in Indiana. The results, the report says, may not be generalizable beyond the single health care system in which the trial was conducted.

Self-reported scores. Anxiety was measured by questionnaire, and participants knew which treatment they had.

Who was studied. Everyone had already been assessed and had a heart emergency ruled out. The trial says nothing about chest pain that has not been checked.

Whether chest pain in a particular person is linked to anxiety, to the heart or to something else is assessed by their doctor.

A year after a chest pain scare, anxious patients in all three groups were less anxious, and the online program with a peer added a small margin over a referral.