Quality of life as predictor for the development of cardiac ischemia in high-risk asymptomatic diabetic patients.

BACKGROUND: Ischemia induced by psychological stress and depression is a common phenomenon in stable coronary artery disease (CAD). We evaluated the quality of life (QoL) of diabetic patients screened for CAD and assessed the prognostic value of mental and physical QoL scores to predict the development of new cardiac ischemia.

METHODS: Prospective multicentre outcome study. The study comprised 400 asymptomatic diabetic patients without history or symptoms of CAD. They underwent myocardial perfusion single-photon emission computed tomography (MPS) and assessment of QoL by two questionnaires: Hospital Depression and Anxiety Scale (HADS-D and HADS-A) and Medical Outcomes Study Short Form 36 (SF-36) at baseline and after 2 years. Patients with normal MPS received usual care; those with abnormal MPS received medical or combined invasive and medical management.

RESULTS: Only mental QoL scores but not physical QoL scores or traditional cardiovascular risk factors were predictive of new ischemia (n = 11/306) during follow-up. The prognostic value for new ischemia as quantified by the area under the receiver operating characteristics curve (AUC) amounted to 0.784 (95% confidence interval (CI) 0.654-0.914, P = 0.002) for HADS-D and to 0.737 (95% CI 0.580-0.893, P = 0.011) for HADS-A. This finding was confirmed by SF-36 mental sum score (AUC 0.688, 95% CI 0.539-0.836, P = 0.036), but not SF-36 physical sum score. QoL scores did not change after 2 years in patients with ischemia at baseline.

CONCLUSIONS: QoL scores assessing mental health, particularly depression and anxiety, predicted the development of new cardiac ischemia in asymptomatic diabetic patients. The study is limited by a small number of events (new ischemia) and so the results should be considered hypothesis generating rather than conclusive.