An Evaluation of the Prevalence and Severity of Pain and Other Symptoms in Acute Decompensated Heart Failure

Introduction

With a prevalence of over five and a half million and an annual incidence of approximately 670,000 patients in the United States alone, heart failure (HF) continues to be a major public health burden and is the most common reason for hospital admission for patients above 65 years of age. ¹ Despite significant improvements in morbidity and mortality, ² HF remains a fatal chronic disease characterized by recurrent decompensations, persistent symptoms, disease progression, and multiorgan involvement. HF is commonly associated with shortness of breath and fatigue;^3–6 however, the prevalence and severity of pain in HF patients is uncommonly reported. A better understanding of the occurrence, severity, characteristics, and location of pain can provide insight into heart failure as a syndrome and provide us with data necessary to improve quality of life in HF patients. We evaluated pain and other symptoms experienced by patients with HF during acute decompensations requiring hospitalization using the validated^7,8 Edmonton Symptom Assessment System (ESAS). ⁹

Methods

Results

One hundred seven patients were contacted after hospital admission; 7 patients refused to participate. Of the 100 patients recruited and analyzed, the mean age was 58±17 years range (22–87 years) with a mean EF of 37±18% (Table 1). Group 1 (EF>40%) consisted of 36 patients, 23 males, with a mean age of 58±15 years. Group 2 (EF ≤40%) consisted of 61 patients, 43 males, with a mean age of 58±17 years. The prevalence of diabetes mellitus, statin use, peripheral neuropathy, peripheral vascular disease, and patients on hemodialysis was similar between groups.

Discussion

The prevalence and severity of pain and other symptoms was evaluated using a standardized and validated questionnaire (ESAS) for symptom assessment in 100 hospitalized patients with acute-on-chronic decompensated HF. Pain was reported by 60% of patients and was more severe in patients with a reduced EF. Shortness of breath, tiredness, and decreased well-being were the most prevalent and severe symptoms in all patients, regardless of EF.

There is limited data on the prevalence and severity of pain in HF patients hospitalized with decompensated HF. Data from outpatient studies suggest that two-thirds of HF patients with an EF<40% experienced pain, and the severity worsened with higher NYHA classification. ¹⁴ A study of 96 veterans in the ambulatory setting reported that 55% of patients experienced pain and 37% had moderate to severe pain. Pain was reported more frequently than dyspnea. ¹⁵ In addition, a recent study using the visual analog scale on pain in patients with chronic heart failure found comparable results to our ESAS pain scores. ³

The etiology and pathogenesis of pain in HF is not well understood. ¹⁶ Pain experienced by HF patients is likely due to a combination of mechanisms, including nociceptive, neuropathic, psychogenic, idiopathic, and mixed. In addition, a more severe degree of fluid overload with pulmonary or generalized congestion might increase capillary and tissue pressure leading to mitochondrial dysfunction, ¹⁷ cellular swelling, lactate production, and ischemia. Likewise, increased production of free radicals may induce focal or generalized tissue damage with immune and inflammatory responses possibly contributing to pain syndromes. ¹⁸

Our results reinforce prior available data that pain is a prevalent symptom in patients with HF. Pain therapy, however, has not evolved as an established management tool for the treatment of patients with HF. Typical therapies including nonsteroidal antiinflammatory drugs for arthritis are generally avoided in HF, as they can impair renal function and worsen HF. ¹⁹ Opioids have been suggested for use as first-line agents for moderate to severe pain. ²⁰ Without knowledge of the mechanisms and etiology of pain in HF patients, optimal pain management will not be achieved. This might be one reason why pain in general is undertreated in HF patients.^{15, 21}

Patients followed by our palliative care service were excluded from the study, as they presumably had better symptom management on tailored therapy and as a result may have reported lower values on the ESAS questionnaire. We do not suspect for two reasons that this patient population is different from those not followed by the palliative care team. Firstly, this may reflect the fact that these patients were amenable to palliative care consultation, while others were offered and declined the consultation. Secondly, palliative care consultation may reflect the preferences of an individual cardiologist and not necessarily a specific subset of patients.

While it is common knowledge that HF patients experience shortness of breath and fatigue, we suggest that pain needs to be further assessed and characterized, as a significant portion of patients hospitalized with decompensated HF have pain.^15,16,21,22 Specifically, further assessment behind the mechanism and location of pain is needed to better characterize and understand HF as a syndrome. We propose that patients with chronic heart failure admitted with acute decompensated HF should be screened for pain upon hospital admission, as pain contributes to the decreased quality of life in these patients.^5,6,14 Pain can be treated by the primary team; however, if a palliative care service is available, patients may benefit from the symptom tailored therapy that a palliative care team provides.

Conclusions

Pain is a common, underrecognized symptom in patients with acute-on-chronic decompensated heart failure. The severity of pain seems to increase with a reduced EF. Decreased well-being, shortness of breath, and tiredness are the most common and severe symptoms, regardless of ejection fraction. Further studies need to be done to better understand the etiology, mechanism, and management of pain in HF patients.