Psychological Distress After Sudden Cardiac Arrest and Its Impact On Recovery

Abstract

Purpose of review.

To summarize the prevalence, correlates, and health consequences of poor mental health in the increasingly sizable population of survivors of cardiac arrest (CA) and to describe current intervention research in this area.

Recent findings.

After CA many patients report high psychological distress, including depression, generalized anxiety, and posttraumatic stress. Emerging evidence suggests that distressed patients’ attention may narrow such that anxious awareness of afferent cardiac signals e.g., changes in heart rate or blood pressure, becomes predominant and a cause for concerned, constant monitoring. This cardiac-specific anxiety followed by behavioral avoidance and physiological hyperreactivity may increase patients’ already high risk of secondary cardiovascular disease and undermine their health-related quality of life (HRQoL).

Summary.

Unlike other cardiovascular diseases, no clinical practice guidelines exist for assessing or treating psychological sequelae of CA. Future research should identify modifiable psychological targets to reduce secondary cardiovascular disease risk and improve HRQoL.

Introduction

Cardiac arrest (CA) survivorship is a relatively new phenomenon. Increasingly, more patients now survive CA to hospital discharge due to expanding adoption of cardiopulmonary resuscitation, public-access defibrillators, and standardized hospital protocols.¹ Specifically, about 1 in 10 patients who are treated by emergency medical services (EMS) survive out-of-hospital CA (~20,000 individuals per year in the US) and about 1 in 4 patients survive an in-hospital CA (~50,000 patients per year in the US). ² While out of hospital CA patients are less likely to survive than those with in-hospital cardiac arrest, out of hospital CA survivors often have fewer and less severe cognitive and physical impairments. Yet, regardless of the type of CA or its physical impact, the psychological consequences of CA are profound.

Survivors of CA experience a markedly different life after these events than survivors of other acute cardiovascular and cerebrovascular events. The experience of CA is unique. Unlike heart attack or stroke, sudden CA results in near-immediate loss of consciousness, as blood flow to the brain stops when the heart stops beating.³ For patients who wake up, they often do so in an intensive care unit, usually after many days in a medically induced coma, and they typically remain hospitalized for approximately three weeks.⁴ The psychological experience of CA is traumatic and life-altering.⁵ In one of the first in-depth qualitative studies of the subjective experience of CA, survivors felt ill-prepared for the psychological and emotional consequences of CA.⁶ One survivor stated, “That anxiety doesn’t just go away…just because you’re happy you survived.” While many respondents were young (60% were between the ages of 41 and 60 years) and able to return to work or school, mental health remained their biggest challenge after discharge. They endorsed frustration over psychosocial issues not being addressed before discharge, and follow-up appointments being centered solely on cardiac recovery. In other in-depth interview studies, CA survivors most commonly reported existential insecurity, distress, and vulnerability.^5,7,8

The Prevalence of Post-CA Psychological Distress

Generalized anxiety and depression are commonly found among CA survivors spanning from 10%–11%^9,10 to as high as 51%–52%.^11–13 Despite lack of consistency in measurement, small sample sizes, non-uniform time intervals, and limited long-term follow-up,^10,14 anxiety and depression seem to be most prevalent while the patient is still in hospital,⁹ with an increased risk for long-term distress unless measures are in place to support the survivor.

PTSD symptoms are also common after CA. The prevalence of elevated PTSD symptoms at one month is 2.5 to 3 times greater in CA survivors compared to patients with other acute cardiovascular diseases (CVD) events (28-32% after CA vs 11-15% after an acute coronary syndrome (ACS) or stroke).^4,14–19 We have shown that CA-induced PTSD symptoms at discharge are represented by a 4-factor numbing model with predominant symptoms of avoidance, numbing, and hyperarousal symptoms.²⁰ PTSD also has a profound on patients’ perceptions of recovery. We recently found that more than two-thirds of CA survivors felt that they had not recovered from the CA six months after, even though their CA was effectively managed and they were discharged home.²¹ Regardless of patients’ age, sex, and cognitive or physical status, the most important determinant of patients’ perceptions of whether they had recovered was a positive screen for CA-induced PTSD symptoms at discharge.²¹ Indeed, every survivor that screened positive for PTSD (31% of the sample) reported non-recovery, even at six months post-CA.²² Given the memory impairments implicated in cardiac arrest, it is unclear how certain hallmark re-experiencing symptoms, such as flashbacks and intrusive memories, manifest in these patients. Instead, there is the possibility that the PTSD symptoms are not anchored towards a discrete traumatic event per se, but rather through daily somatic reminders of patients’ near-death experience and mortality (e.g., increased heart rate, chest pain, restricted mobility) and chronic maladaptive fear of recurrence.

Cardiac anxiety – fear about cardiac-related sensations due to concerns about negative health consequences - has been identified in patients after CA and other life-threatening cardiac events, such as acute coronary syndrome and stroke. A hallmark consequence of cardiac anxiety is excessive cardiac symptom monitoring. Similarly, in a national registry study, most CA survivors reported “often” or “always” paying attention to their heartbeat (53%), and a substantial subset reported being frightened by sensations in their chest (20%), avoiding activities that increase heart rate (15%), and worrying about their heart even when tests were normal (18%).²³ The association between generalized anxiety and cardiac anxiety was only weak to moderate in strength, suggesting that the two constructs are distinct.²³ Patients with cardiac anxiety are more likely to seek medical reassurance for normal alterations in cardiac function, resulting in medically unnecessary emergency department visits, costly diagnostics and procedures, and provider burden.²⁴ Cardiac anxiety is also associated with higher rates of CVD-related distress, excessive cardiac symptom monitoring, avoidance of physical activity as it could trigger worrisome cardiac sensations, patient-reported disability, and poorly perceived health.^24–28An ongoing study funded by the National Heart, Lung, and Blood Institute²⁹ is testing the association of CA-induced cardiac anxiety with one-year CVD/mortality risk and health-related quality of life (HRQoL). If the associations hold true, cardiac anxiety may be a trans-diagnostic intervention target for reducing psychological distress, improving adherence to health behaviors, and reducing CVD risk in CA survivors.

Associations of Psychological Distress with Recovery and Survivorship after Cardiac Arrest

CA survivors are at high risk of major adverse cardiovascular events (MACE) and mortality due to the same chronic CVD risk factors that set the stage for the index CA, including diabetes mellitus, hypertension, and dyslipidemia.^1,30,31 Among CA survivors, 32% will have a CVD event or die in the first three years after CA,³² and half of all CA patients are rehospitalized within two years.^33,34 In the Nationwide Readmissions Database, a study of CA survivors with shockable rhythms found that 40% of hospital readmissions within 30 days were due to cardiac causes.³⁵ Current recommendations for CA survivors include placement of an implantable cardioverter-defibrillator (ICD) and/or the initiation of anti-arrhythmic medication to prevent recurrent CA,³⁶ but no guidelines or recommendations address other significant, modifiable dimensions of CA survivorship that may contribute to CVD risk or poor HRQoL, such as psychological distress. To date, in the largest, prospective, observational study of CA survivors in a racially and ethnically diverse patient population in the United States (N=114), 32% screened positive for CA-induced PTSD, and during the one year follow-up period, 9% died and 25% of survivors had a MACE.⁴ CA-induced PTSD was associated with a tripling of risk for the combined MACE/mortality outcome even after adjusting for age, sex, prior psychiatric condition, comorbidities, and initial cardiac rhythm. Further, in a follow-up analysis, of the 4 dimensions of PTSD symptoms, only hyperarousal symptoms were significantly associated with CVD prognosis.³⁷ The hyperarousal symptom dimension arising from interoceptive hypersensitivity and catastrophic interpretations has shown to be associated with dysregulated sympathetic responses, heightened cardiovascular reactivity, and disordered sleep quality.³⁸ Similar associations between other types of acute medical event-induced PTSD and adverse prognosis have been reported. Specifically, in our meta-analytic review of the acute coronary syndrome (ACS)-induced PTSD,³⁹ ACS-induced PTSD was associated with a doubling of risk for recurrent ACS and mortality in the one to three years after ACS. This finding is crucial because the pathophysiology of CA differs from ACS and stroke, and neither acute care management nor secondary prevention after CA can be adopted from ACS/stroke research. Unlike ACS, where multiple studies have revealed that anxiety⁴⁰ and depression⁴¹ increase the risk for death and recurrent cardiac events, and guidelines recommend screening and treatment for depression,⁴² there are few studies assessing the impact of psychological distress on post-CA outcomes, and there are no evidence-based psychological treatment recommendations in CA samples.

Health Behaviors after CA

Low physical activity (PA) is one of the strongest predictors of future CVD events and death in patients with CVD.^43–46 We have reported that cardiac anxiety and PTSD symptoms are associated with avoidance of PA in ACS patients.⁴⁷ This is an important behavioral pathway by which psychological distress may influence CVD risk, but no study has objectively measured PA or tested its association with CVD risk in CA survivors. Cardiac anxiety has also been shown to interfere with cardiac rehabilitation programs if not addressed before hospital discharge.^48,49 Ongoing mechanism-driven interventions that help patients identify and overcome fearful thoughts relevant to PA, also known as exercise sensitivity, are currently being tested.⁵⁰ If effective, such approaches are likely to be applicable to improving PA after CA.

Sleep is likely to be another important health behavior in patients who have experienced CA. Sleep duration is linked to a greater risk of developing or dying of coronary heart disease, stroke, and CVD in patients with cardiac conditions,^51–55 but no study has objectively measured sleep or tested these associations in CA survivors. A small study of 43 survivors of CA assessed sleep using a modified version of the Pittsburgh Sleep Quality Index at a mean 7.2-month follow-up and found that 22% of CA patients experience frequent insomnia symptoms and/or poor-quality sleep.⁵⁶ Adherence to anti-arrhythmic, antithrombotic, and other types of cardiovascular medications is a key component of the prevention of adverse outcomes after CA. Despite psychological distress being associated with poor medication adherence after other types of cardiac events⁵⁷, to our knowledge, no studies have rigorously assessed medication adherence after CA.

Health-Related Quality of Life

Optimizing mental and physical HRQoL are key considerations in evaluating CA treatments and is increasingly a focus for CA survivors.^2,58 Recently, the Core Outcome Set for Cardiac Arrest (COSCA) group⁵⁸ identified HRQoL as one of the primary outcomes for all future CA-related effectiveness trials, based on a high-level consensus achieved between patients, partners, clinicians, research scientists, and guidelines committees. Quantitative estimates find that survivors’ scores on standardized QoL assessment tools are 0.5-1 SD below the norms for their age. The largest published study of HRQoL after CA is based on an Australian registry, in which more than half of the respondents (55%) reported a decline in HRQoL a year after CA.⁵⁹ Contributors to the HRQoL decline were poorly understood. Subgroup analyses identified age- and sex-based differences: younger patients (18-44 years) had 0.4 SD lower HRQoL than older patients, and women reported significantly lower physical and mental component summary scores based on the Medical Outcomes Survey Short Form-12 item (SF-12) scale (0.35 SD lower than men).^59,60 There is some evidence that post-CA event amnesia, anxiety, depression, or PTSD following CA can contribute to increased dependency on others for activities of daily living (ADL), thereby decreasing HRQoL.^61,62 Two ongoing studies will determine the associations of psychological factors with key health behaviors (PA, sleep) and HRQoL after CA.^29,63

Return to work, society participation, and relationships

Psychological distress plays a large role in post-arrest societal reintegration for CA survivors.² Those demonstrating high instances of intrusive thoughts and avoidance behavior in regards to their CA have been shown to experience demoralization, lack of confidence, and narrowing of social activities, thus, negatively impacting their HRQoL.⁶⁴ Data suggest that survivors of CA achieve lower societal participation than the general population.^2,65 Some changing behaviors include moving homes to avoid memories of the arrest, purchasing an automatic defibrillator for their home, distancing from personal relationships, and cessation of sexual relations. Loved ones often helped survivors return to their normal activities by monitoring them during the activity to provide a sense of comfort and safety, or by actually participating in the activity with them. Some survivors (between 13% and 76%) are also unable to return to work post-arrest, depending on their level of cognitive and psychological impairment.²

Impact of CA on Caregivers and Partners

Due to the sudden, unexpected nature of the CA event, caregivers report stress-related responses, feelings of anxiety, and lower quality of life. Family members who witness the event, perform cardiopulmonary resuscitation or call for emergency services, and experience life and death related decisional conflicts during the hospitalization, all while the patient is comatose, estimate much higher clinical severe PTSD symptoms (45%–48%) compared to patients (26%–28%).^66–68 Higher acute traumatic stress severity is positively associated with higher PTSD symptom severity at three months and one-year post-resuscitation both in the patients and close family members, with the strongest association for women, compared with men.⁶⁶ After discharge, 17% of the close family members experience high caregiver strain which is associated with the patient’s level of physical and cognitive functioning.¹⁰ In a 2020 scientific statement,² the AHA acknowledged that families are integral to the patient’s survivorship journey.

An Urgent Need for Interventions Tailored to Recovery and Survivorship after CA

Interventions that reduce psychological distress, lower secondary CVD risk, and improve HRQoL could significantly improve long-term well-being and outcomes amongst survivors of CA. These interventions should aim to influence well-chosen upstream targets that serve as mechanisms for improving mental, physical, and social health (see Figure 1). Given its high prevalence and strong association with poor physical and mental health outcomes, our prior findings suggest that we should target PTSD symptoms. However, our systematic review found that none of the 17 PTSD prevention trials that used conventional intervention approaches were efficacious for PTSD prevention after life-threatening medical events.⁶⁹ Since that review, a large intensive care unit-based PTSD prevention trial failed to show a reduction in PTSD risk.⁷⁰ The researchers trained nurses in trauma-informed care, made changes to the ICU environment, and offered participants up to three sessions of psychoeducation and cognitive behavioral therapy focused on processing the experience. Together, these studies suggest that we may be selecting the wrong intervention targets.

Figure 1.

The impact of psychological distress on poor cardiovascular prognosis and low quality of life are potentially mediated by autonomic hyperactivity and poor health behaviors. Intervention studies targeting indicators of psychological distress and physiological hyperarousal phenomenon are underway in survivors of cardiac arrest and their family members.

There are several aspects of CA-induced PTSD that suggest a need for a distinct approach to intervention development. Interventions in patients with PTSD induced by other types of traumatic events often require patients to repeatedly recall the traumatic event to reduce psychological and physiological reactivity to reminders of the past trauma, but CA patients typically do not remember the event. PTSD symptoms in CA patients are typically identified using screening instruments as opposed to psychiatric interviews; the prevalence of PTSD diagnosis is likely to be much lower.⁷¹ Instead of pathological fear memory processing, scores on PTSD screens may reflect patients’ sensitization to frequent physiological signals that they associate with present and future CVD risk.⁷² Many patients report pathological somatic hyperawareness and maladaptive avoidance of CVD reminders, including key secondary prevention behaviors.⁷²

Brief interventions, such as interoceptive exposure interventions, which induce feared physiological sensations systematically to provide experiential learning that sensations are not harmful, have been shown to be highly effective.⁷³ These interventions may also reduce cardiac anxiety. A meta-analysis of 24 RCTs (N = 1,851) showed that interoceptive exposure and cognitive restructuring, as well as exercise interventions, resulted in large reductions in anxiety sensitivity in treatment seekers (Hedges’ g = 1.40), and moderate to large reductions for at-risk samples (Hedges’ g = 0.74).⁷⁴ Accordingly, interventions that more directly target cardiac anxiety, as opposed to conventional PTSD interventions may be more promising approaches to relieving psychological distress and improving health behaviors and health outcomes in CA survivors.

In addition to testing interventions that target fear, PTSD, and other negative psychological consequences of CA, future work in this population should examine interventions that aim to increase positive psychological well-being.⁷⁵ In spite of their high rates of psychological distress, patients after CA often conceive of their post-CA lives as a “second chance” that could include newfound joy and purpose.⁷⁶ Optimism, positive affect, and purpose in life have each been shown to predict improved long-term recovery in non-CA populations (e.g., a faster rate of return to normal life, reduced mortality), independently of negative psychological factors, such as depressive symptoms.^77–79 These positive factors show evidence of being modifiable.^80,81 Despite optimism being conceptualized typically as a stable dispositional factor, interventions targeting this factor have increased it reliably with small-to-moderate effects (g = 0.41; 95% CI: 0.29 – 0.53; p < .001).⁸¹ Stronger effects in that meta-analysis were evident for the 10 studies that tested the Best Possible Self intervention to increase optimism (g = 0.64; 95% CI: 0.42 – 0.86; p < .001).⁸² This intervention involves the establishment of future goals for one’s self in personal, professional, and relational domains, explicit statements of future goal achievement, and an integration visualization in which goal achievement is vividly imagined across all three domains. This important intervention work that directly targets positive factors has not yet been applied to CA survivors in randomized controlled trials.

Current Psychological Interventions for CA Survivors

Although many CA survivors suffer from substantial psychological distress, only a limited number of studies have yet tested interventions aiming to improve their psychological well-being. To date, interventions relevant to improving CA patients’ long-term psychological outcomes exist in two broad domains: (1) traditional cardiac rehabilitation or nurse-led psychosocial rehabilitation programs and (2) interventions that target fear symptoms.

Traditional cardiac rehabilitation is now a recommended aspect of care for patients with varied forms of cardiovascular disease.⁸³ A growing body of evidence reveals that this multifaceted program improves not only physical functioning but also the mental component of HRQoL. For example, one trial showed that heart failure patients randomized to cardiac rehabilitation had improved emotional functioning.⁸⁴ A trial assessing the effectiveness of cardiac rehabilitation on psychological distress in CA survivors is much needed.

Cardiologists, psychologists, and cardiovascular prevention experts who care for CA survivors have recently come together to advocate for integrating enhanced treatment of psychological distress (e.g., anxiety, depression) into traditional cardiac rehabilitation programs.⁸⁵ Consistent with this perspective, newer rehabilitation interventions emphasize psychosocial and educational components. A recent meta-analysis⁸⁶ examined two randomized clinical trials of these kinds of rehabilitation interventions.^87,88 Collectively, the interventions did not reliably improve the mental component summary of HRQoL relative to standard care.⁸⁶ Notably, however, one of these two nurse-led psychosocial interventions showed promising signs of efficacy in adult CA survivors.⁸⁸ Specifically, the intervention improved three of the eight aspects of HRQoL (mental health, general health, and disruption in roles due to emotional problems) 12 months after the CA. This intervention involved 1 to 6 consultations between patients and specialized nurses who had expertise in rehabilitation medicine, cardiology, or neurology and who had completed a 12-hour training program for the intervention. The sessions consisted of nurse-led semi-structured interviews to identify patients’ cognitive and emotional problems as well as the provision of information about CA and its frequent consequences (e.g., common symptoms, potential cognitive and emotional problems), guidance on self-management (e.g., coping techniques, action plans), and referrals to relevant resources when needed (e.g., information about driving restrictions, neurological deficits, cardiac medications, and implantable cardiac defibrillators).⁸⁹

The second category of interventions targets CA survivors’ cardiac-related fear, posttraumatic stress symptoms, and other negative psychological symptoms. This wide-ranging group of interventions uses diverse strategies to lower fear. The rationale is that fear—and related constructs (e.g., PTSD, cardiac anxiety)—may maladaptively lead to avoidance of healthy behaviors, such as PA, sleep, and medication adherence. A suite of pilot feasibility studies is currently being conducted in this area with the support of the National Institute of Aging sponsored Roybal Center for Fearless Behaviour Change at Columbia University Irving Medical Center.⁹⁰

One such intervention involves remote administration of eight sessions of acceptance and mindfulness-based exposure therapy (ClinicalTrials.gov Identifier: NCT04596891). This therapy aims to undo patterns of fearful, interoceptive focused attention. The approach builds upon the traditional exposure therapy used to treat PTSD caused by non-cardiac traumatic events.⁹¹ In contrast to traditional exposure techniques, however, this therapy incorporates acceptance and mindfulness as key components to facilitate successful exposure, and it aims not only for symptom reduction but also for enhanced well-being.

A second intervention takes a more “bottom-up,” physiological approach by using heart rate variability biofeedback training to reduce distress (ClinicalTrials.gov Identifier: NCT04589559). This technique works by training participants to learn to increase their own parasympathetic activity via remote training.⁹² Participants are trained to practice slow-paced diaphragmatic breathing at a frequency of 0.1 Hz while wearing a heart rate monitor that transmits data wirelessly to a smartphone app that displays real-time visual feedback of breath-related fluctuations in heart rate. This kind of intervention has been successful in treating anxious and depressive symptoms in non-cardiac samples.^93,94

A third intervention attempts to disrupt the activity of the sympathetic branch of the autonomic nervous system that may maintain patterns of psychological distress. It entails a safe, in-hospital, ultrasonically guided injection of a local anesthetic to block nerve fibers in the stellate ganglion in the cervical portion of the spinal cord (ClinicalTrials.gov Identifier: NCT04582396). It aims to reduce distress by temporarily inhibiting sympathetic activity in these cervical nerve fibers to disrupt maladaptive “fight-or-flight” patterns. This intervention has shown previous success in treating PTSD symptoms in active-duty military personnel.⁹⁵

Another group of interventions involves caregivers or partners of patients with CA. Compared to behavioral interventions that target the patient-only group, a social cognitive theory-based dyadic intervention (patient and partner) is more effective at reducing distress in patients and partners.⁹⁶ There are no dyadic trials in CA populations. A psychological intervention, the Recovering Together (RT),⁹⁷ is currently being tested to prevent emotional distress in stroke patients and their caregivers. The pilot study observed excellent feasibility as evidenced by the ability to recruit ICU survivors from a neurological unit quickly and randomize and retain them with low attrition rates. Patients reported high satisfaction with the six-session, seven-module program. This early resilience intervention program showed clinically significant improvement in depression, anxiety, and post-traumatic stress in both patients and caregivers.⁹⁸

Family members may play a critical role in creating and cementing fear-based memories and distress in patients experiencing a CA through processes such as emotional contagion or social transmission. Distress in family members may also have an adverse impact on patients by undermining the capacity of partners to provide effective social support that can buffer patient distress. A recent meta-analysis showed that ICU diaries can improve psychological outcomes among ICU patients and their relatives.⁹⁹ However, dyadic effects of family distress on patient outcomes are rarely tested, and never in CA survivors and co-survivors. An ongoing pilot study (ClinicalTrials.gov Identifier: NCT05144477) is testing the feasibility of a Family-Authored ICU-diary intervention to reduce a proximal, dyadic mechanism, i.e., fear of CA in patients’ family members. The findings will provide impetus to test whether a family-authored ICU diary can reduce the fear of CA in family members, and in turn, improve patients’ mental wellbeing, health behaviors, and, ultimately, health outcomes.

Conclusions

In line with the American Heart Association’s urgent call for survivorship research in their recently published CA guidelines,² we urge physicians and researchers to recognize the substantial challenges faced by survivors and family members of CA. In particular, growing evidence suggests that adverse psychological consequences of CA are strikingly common and may further debilitate patients who are already struggling to recover from this typically unexpected and often shocking medical event. We must consider ways to improve the health, recovery, and well-being of CA survivors in the weeks and months after they are discharged from the hospital. Patients’ high psychological distress may impact a variety of health behaviors. Dysregulation in autonomic physiology that occurs in conjunction with psychological distress may further increase their secondary cardiovascular risk. Intervention research should continue to test a range of methods by which distress may be reduced and positive psychological factors may be increased in survivors of CA and their supporting families, with the goals of reducing mental health burden and enhancing physical, mental, and social health outcomes after CA.