Pain is one of the most common reasons people seek medical care; indeed, over half of adults in the United States experience chronic or recurrent pain, and a significant number have to make lifestyle changes to accommodate pain.1 Furthermore, almost half of the adults in the United States report inadequate pain relief and that chronic pain adversely affects their quality of life-both in terms of their day-to-day activities and their emotional well-being.1

These issues led the American Pain Society to formally recognize the importance of properly assessing and managing pain by designating pain as "The Fifth Vital Sign."2 In addition, the Joint Commission on Accreditation of Healthcare Organizations has introduced new pain management standards focused on the patient's right to effective assessment and treatment of pain from admission to discharge.3

Clearly, pain is a pervasive and important problem in the general population. Of note is that multiple studies have shown that pain and/or physical discomfort is also reported in 30% to 80% of advanced heart failure (HF) patients.4-9 Indeed, several studies suggest that persons with advanced HF have a similar prevalence of pain as do persons with cancer.6,7,10

The study of Godfrey et al on pain in HF patients at hospital discharge11 published in this issue of the journal makes several significant contributions to the literature in this area. First, their study is the first prospective trial to examine pain in patients with HF. Prior studies were cross-sectional or retrospective in nature. Second, their study includes patients with New York Heart Association Class I-IV HF (although most of the subjects were Class III/IV). Prior studies have included only patients with advanced HF; indeed, several studies included patients considered terminally ill. Thus, until now, we have had no data on pain in those HF patients whose illness is in an earlier stage. Third, the study of Godfrey et al investigates the relationship between pain and quality of life for patients with HF, and again, this aspect has not been documented in prior trials.

Finally, and probably most importantly, Godfrey et al, in their discussion, raise the critical issue of whether the presence of pain may affect how patients with HF manage their illness. Prior reviews of the topic of pain in HF patients as well as in the general population have mostly focused on the possible consequences of pain such as depression, anxiety, decreased socialization, sleep disturbances, impaired ambulation, and increased healthcare utilization and costs.12 Patients' self-management of HF is key to successful treatment and includes managing complex medication regimens, making difficult lifestyle changes, and recognizing changes in their symptom pattern. It is currently unknown whether having pain affects how patients perform these actions, and further, whether pain and its consequences affect HF exacerbations and potential hospitalizations.

Although the study of Godfrey et al enhances our knowledge of pain in HF patients, there are still significant gaps in the literature. A few of the studies to date have just noted a "cardiac" diagnosis, and this may or may not have included patients with HF (although HF is usually the common pathway for end-stage cardiac illness). No information on pain location or etiology has been reported, except for 1 study that noted pain as anginal pain.8 In addition to pain from comorbid conditions, do patients with HF have pain from issues related to the HF itself such as organ congestion, device implants, or edematous limbs? No data on interventions for pain have been collected. This is a key area of study because treatment of pain in patients with HF is complicated by the inability to use nonsteroidal anti-inflammatory drugs due to their adverse effects on renal function and their associated risk with increased hospitalizations.13-15 Finally, the influence of inflammatory markers and neurohormonal activation on the presence, sensation, and treatment of pain in HF patients is unknown.

A new trial underway will help to answer some of the important introductory questions about this topic. Pain Assessment Incidence and Nature in Heart Failure (PAIN-HF) is a multisite, nationwide study that includes advanced HF patients from outpatient clinics and home hospice settings. PAIN-HF is designed to (1) identify the prevalence of pain, its location, and possible causes; (2) identify the severity of pain, its interference with activities, and its impact on quality of life; (3) understand the correlates of other symptoms and issues in patients' lives on their perception of pain; and (4) identify current treatments for pain and their effectiveness in relieving pain. Studies such as PAIN-HF and Godfrey's will surely improve outcomes in patients with HF.

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