The role of psychological factors in chest pain with normal coronary arteries: a controlled study

One hundred and twenty three patients who were awaiting angiography for the investigation of chest pain were contacted by post and invited to participate in the study. Subjects were required to keep a chest pain diary for 14 days, and complete 5 self-report questionnaires examining physical and psychological aspects of their pain. Ofthe total sample of 123 patients who proceeded to angiogram, 72 (58.5%) were subsequently found to have Coronary Artery Disease (CAD) and 51 (41.5%) were found to have Normal Coronary Arteries (NCA). Seventy-two patients agreed to take part, 48 with CAD and 24 with NCA. This represents a return rate of 66.7% for CAD patients and 47% for NCA patients.Comparison ofthe NCA and CAD cohorts using chi-squared and t-tests for independent samples revealed the main factors found to be significantly associated with a finding ofNCA were : age (young), sex (female), non-elevated cholesterol, pain at rest, pain provoked by stress, wakening pain, relief by GTN after more than 5 minutes, and high levels of bodily awareness. Using these factors, a logistic regression was run. From this, factors which were found to be useful in discriminating between CAD and NCA patients were age, sex, somatic awareness and wakening pain. There was also found to be a lesser but consistent association with rest pain, anxiety and depression. These variables were found to correctly classify 85 % of cases. The classification of cases differed between groups with 64% ofNCA cases correctly classified, and 91.5% of CAD cases correctly classified.When the discriminatory power of this predictive equation was tested prospectively on a new sample of 74 patients (phase two) it was found to correctly predict 97.8% ofthe CAD cases and 58.3% of the NCA cases for an overall success rate of 89.5%. The implications of the results for the management of patients with chest pain and Normal Coronary Arteries are discussed. By inquiring routinely about psychological factors when taking a history, cardiologists would stand a better chance of anticipating which patients have an increased likelihood of having NCA. In addition to minimising unnecessary investigations, this could better prepare the patient psychologically for this finding from an early stage and allow more appropriate interventions to be more readily integrated