This study included 1263 patients from 24 European sites which were referred for elective ICA or CTA.
There were significant differences in pre-diagnostic HRQoL according to patients’ chest pain characteristics. Adjusting for age and gender, patients with typical and atypical angina pectoris had worse quality of life in comparison to patients with non-anginal chest pain and other chest discomfort. These differences were observed across the different functional and emotional aspects of HRQoL and also across the different measures we employed here, confirming their good discriminative validity for different presentations of chest pain.
In comparison to patients with atypical angina, typical angina patients had worse self-rated physical functioning and higher levels of anxiety, but no HRQoL differences between these two angina groups were observed on the other measures. Thus, the SF-12 physical functioning and the HADS anxiety score appear to have a somewhat greater discriminatory power compared to the EuroQol utility score, which is a multidimensional conglomerate of several physical and emotional states.
Minimal clinically important differences (MCID) in these measures have not been assessed for patients with chest discomfort. Conventionally, for the SF-12, a 2-point difference is often assumed a MCID, and differences between typical angina patients and the other chest pain groups exceeded this difference in both the mental and physical health component score of the SF-12.
Comparisons of the HRQoL scores in the present sample with other patient samples should be made with caution due to sample differences in age, gender and clinical characteristics.
Patients in our sample had similar (<= 1 point difference) pre-diagnostic physical functioning and mental health component scores on the SF-12 compared to a sample of 4146 patients with stable angina from the Scottish COmputed Tomography of the HEART (SCOT-HEART) trial, which compared standard care for angina patients with standard care plus CTA . However, SCOT-HEART did not differentiate between different chest pain presentations and also included angina patients with known CAD. In the Cresent trial,  which compared the effectiveness and safety of cardiac CTA and functional testing in 350 patients (> 50% with typical chest pain), overall health ratings with the EuroQol VAS were comparable to the ones in our sample. In the recent Prospective Multicenter Imaging Study for Evaluation of Chest Pain (PROMISE) trial,  which randomized patients to either standard functional testing or CTA, the pre-diagnostic EuroQol VAS scores were higher in comparison to our sample. However, only 11% of patients included in the PROMISE trial had typical angina pectoris.
In comparison to the HRQoL of 8745 stable coronary heart disease patients with clinical events > 6 months ago in the Euroaspire study,  the total sample of the DISCHARGE pilot study patients had similar EuroQol utility and VAS scores, similar HADS depression scores, but substantially lower SF-12 mental health scores (4 point difference) and higher anxiety (1.6 point difference). In all these comparisons, HRQoL scores for the subgroups of patients with typical angina pectoris in our study fall substantially below the HRQoL of the other samples, indicating a high burden associated with this type of chest pain.
Notably, almost half of our entire sample had a HADS anxiety score > =8, the suggested cut-off  for probable clinical anxiety. Heightened anxiety prior to a diagnostic procedure has been described before  and could be attributed to the uncertainty of the origin of the chest pain / discomfort and the fear associated with heart disease.
Patients with and those without obstructive CAD did not differ in their pre-diagnostic HRQoL, not even in patients with typical angina pectoris. Thus, underlying obstructive cardiac disease cannot explain the HRQoL differences between angina groups. This is in accordance with findings from a Canadian study with 1009 patients referred for elective coronary angiography . Compared with population norms, patients with and without CAD had high anxiety levels and lower HRQoL; the two groups did not differ on most HRQoL measures with the exception of lower self-rated physical functioning in patients with CAD. However, no information on the initial chest pain characteristics were given in the Canadian sample and the CAD outcomes included mild CAD which we did not assess in our study.
There were substantial gender differences in HRQoL: women had consistently worse quality of life on all measures. Gender differences in HRQoL are well documented across a variety of chronic diseases. Women are at greater risk for having clinical and subthreshold depression and anxiety and perceive greater physical and social limitations in their daily lives. In a study with 123 patients with stable CAD and angina pectoris, men and women described their chest pain in a similar manner, but women reported significantly higher physical limitations due to angina pain .
It should be noted that HRQoL is also a prognostic factor in cardiac disease. In CAD patients, perceived physical limitations in everyday life were associated with increased mortality and admission for acute coronary syndrome across one year . Depression and anxiety are also prognostic factors for adverse cardiac outcomes and mortality in patients with established CAD [25, 26] and also in patients with stable angina [27, 28]. Whether patients’ HRQoL prior to or after receiving a diagnosis of CAD has an impact on the subsequent treatment recommendations by physicians (e.g., conservative treatment vs. invasive procedures) remains to be studied.
Strengths and limitations
In this multisite, multinational study, the range of patients with different presentation of chest pain reflects the clinical reality of diagnostic referrals. The pre-intervention assessments ensured that the HRQoL assessment was not influenced by patients’ knowledge of their actual diagnosis. One limitation was that only obstructive CAD was diagnosed. There may well have been HRQoL differences between patients with no CAD, mild (non-obstructive) CAD and obstructive CAD. We did not assess severity and frequency of chest discomfort, which may account for some of the HRQoL differences between the chest pain groups. The EuroQol utility values, for example, have been shown to covary with clinically important differences in angina severity, angina frequency and exertion [29, 30]. We did not include healthy controls from each of the sites. However, the main focus was to analyse whether different presentations of chest pain were associated with HRQoL and all measures were able to discriminate between chest pain groups.