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, while 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

Chest pain is a leading reason for emergency department visits, the trial paper notes, 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, the medical term for a heart attack or a closely related sudden loss of blood supply to the heart muscle.

In the United States, chest pain accounts for more than 8 million emergency department visits a year, which makes it the second leading cause of such visits, according to figures the researchers cite in coverage of the trial by News-Medical, a medical news site. Nearly 80% of those patients are found not to have a heart or lung emergency.

Anxiety is common in this group and usually missed. News-Medical puts it at up to 55% of these patients, yet it remains undiagnosed in nearly 90% of cases. The trial’s published protocol made the broader point that in any setting, anxiety is often undiagnosed and undertreated.

“Anxiety is a common fellow traveler with low-risk chest pain,” said Kurt Kroenke, of the Indiana University School of Medicine and the Regenstrief Institute and a co-author of the trial, speaking last year when the team published its starting data. A clear heart test does not end the job, in the view of Paul Musey, of the same two institutions and the trial’s first author. “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 referring them for anxiety or depression management, since this might affect how much healthcare they use and how often they come back.

How the chest pain anxiety trial worked

The study, known as PACER, short for Patient-Centered Treatment of Anxiety After Low-Risk Chest Pain in the Emergency Room, was a randomized, 3-group comparative effectiveness trial: chance decided which treatment each person received, and three treatments already in use were set against each other, with no placebo.

Between April 2021 and July 2024 the team recruited adults from six Indiana University Health emergency departments who had been sent home after low-risk chest pain and who scored as at least moderately anxious on a questionnaire or screened positive for panic. That questionnaire, called the GAD-7, asks how often seven anxiety symptoms have bothered a person in the past two weeks. Scores range from 0 to 21, with higher scores meaning worse anxiety, and in the bands the trial used, scores from 8 to 14 are considered moderate anxiety and 15 or more severe, according to an earlier paper from the trial.

A total of 375 patients were enrolled, with an average age of 39.9. Of these, 265 (70.7%) were female and 109 (29.1%) male; 226 (60.3%) were White, 125 (33.3%) Black and 28 (7.5%) Hispanic. Their average GAD-7 score at the start was 13.1, in the moderate band, but the trial’s baseline analysis found that 42% of participants had severe anxiety and three in four screened positive for panic disorder.

All 3 groups received psychoeducation, an explanation of the link between anxiety and chest pain, which study staff gave every participant before assignment as a 15- to 30-minute brief intervention. After that the three groups parted, on a ladder the trial’s registration describes as graduated in the level of resource intensity, with the first taking the least staff time and the third the most.

The first group got an enhanced referral to primary care, along with their diagnostic results and educational materials, an arm the registry calls enhanced primary care coordination. The second used an online program of cognitive behavioral therapy (CBT), a talking treatment that teaches people to notice and change the thoughts and habits that keep anxiety going. The registry lists it as the medium-intensity arm, with support from a certified peer recovery specialist, a trained supporter who draws on personal experience of recovery and is not a clinician. The third group had eight telehealth CBT sessions with a trained therapist, held by video or phone, which the registry sets out as one-hour sessions spread over 8 to 10 weeks.

The main result the trial was designed to answer was the change in GAD-7 anxiety score over 12 months, with outcomes 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, so 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, a measure that sets a difference against how much people’s scores vary, and 0.25 is conventionally read as small.

The gap was widest among patients with severe anxiety, at 2.8 points. In that subgroup the online program also did better than the therapist sessions, News-Medical reported, with scores improving 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, a difference that 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, although 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, with most of the gains arriving within three months and generally holding through 12 months, according to News-Medical.

What else changed in the chest pain trial

Other symptoms improved too, in every group. Depression, disability and somatization, which the Regenstrief Institute describes as the experience of psychological distress through physical symptoms, all improved moderately within groups, with nothing to separate the three.

Participants’ own verdicts favored therapy more strongly than the scores did. Asked for their overall judgment of whether their anxiety was better, people in the 2 CBT groups had 3 times the odds of reporting improvement compared with primary care referral, odds being the chance of something happening set against the chance of it not happening.

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

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

The trial also tracked the heart, since the worry with any low-risk label is that something was missed. Over the year there were seven major adverse cardiovascular events among six participants, a rate of 1.6%, and only one came 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 and found a modest to moderate benefit, particularly for treatments built on CBT, though one largely restricted to the first three months. The reviewers called for further trials that follow people for at least 12 months, which is the length of follow-up PACER supplies.

The closest earlier comparison, a Swedish trial published in 2024, came out cooler. Its researchers assigned 109 patients with chest pain not caused by the heart 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 the internet program was not more effective than psychoeducation, although reports of how often chest pain occurred did shift in favor of the internet group.

Read together, the two trials show a similar pattern: 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 which options work best for patients at different levels of anxiety severity, and 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 trial lacked a usual-care group receiving no active intervention, News-Medical’s report says, part of the improvement in all three groups could reflect changes over time or regression to the mean, 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 notes that engagement was inconsistent, with about a third of participants completing no treatment sessions, so the results describe what happens when these treatments are offered, not what happens when they are completed.

Missing follow-up. About one in five participants supplied no later scores, since around 80% completed at least one follow-up assessment.

Medicines were not tracked. News-Medical’s report notes a lack of tracking for medication types, so 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, and the results, the report says, may not apply beyond the single health care system that ran it.

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, so 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.