Introduction Following ST-elevation myocardial infarction (STEMI) and treatment with PPCI, some patients are readmitted with potential ischaemic heart disease (p-IHD) symptoms. Symptoms may be related to cardiac ischaemia, reduced psychological health or a comorbid condition, all sharing similar symptoms. The purpose of the study was to investigate the proportion of PPCI patients readmitted due to p-IHD symptoms within 6 months of STEMI, and to explore associated factors.

Methods A mixed methods prospective study, which included questionnaires: Seattle Angina Questionnaire (SAQ), the Hospital and Anxiety and Depression Scale (HADS) at 0 and 6 months; clinical data: Global Registry of Acute Coronary Events (GRACE) and Charleson Comorbidity Index (CCI) at baseline; readmission data collected using patient records and telephone interview at 6 months; qualitative data collected purposefully through semi-structured interviews at 6 months.

Results 202 PPCI patients returned baseline questionnaires [mean age 59.7 yrs (SD 13.9), 75.7% male]; 38 (18.8%; 95% CI 14.0% to 24.8%) participants were readmitted due to p-IHD symptoms at 6 months; 16 (42.1%) due to a cardiac event and 22 (57.9%) did not receive a diagnosis. At both baseline and 6 months, mean HADS anxiety scores were higher for the readmission group compared to the non-readmission group (baseline 9.5 vs 7.1, p = 0.006; 6 months 9.4 vs 6.0, p < 0.001). Angina symptoms were stable and infrequent throughout for the groups. Logistic regression modelling with the inclusion of predictors HADS anxiety, SAQ angina stability, SAQ angina frequency, GRACE and CCI, determined HADS anxiety as a predictor of readmission with an adjusted odds ratio of 1.12 (95% CI 1.03 to 1.22, p = 0.008). Qualitative interviews with 25 participants (14 men, 27–79 years) identified four themes: fear of experiencing a further STEMI, uncertainty and inability to determine cause of symptoms, insufficient opportunity to validate self-construction of illness and difficulty adapting to life after a STEMI.

Conclusion Elevated levels of anxiety at baseline were predictive of readmission with p-IHD symptoms at 6 months. Factors such as shock at experiencing a STEMI, hypervigilance of symptoms and difficulty with symptom attribution appeared to play a role in raised anxiety levels for the readmission group. Findings suggested that changes are needed to cardiac rehabilitation and post-STEMI follow-up to address educational needs and psychological issues.