Prognostic importance of distressed (Type D) personality and shocks in patients with an implantable cardioverter defibrillator

BACKGROUND: Clinical trials have shown the benefit of implantable cardioverter defibrillator (ICD) treatment. In this study, we examined the importance of chronic psychological distress and device shocks among ICD patients seen in clinical practice.

METHODS: This prospective follow-up study included 589 patients with an ICD (mean age=62.6 ± 10.1 years; 81% men). At baseline, vulnerability for chronic psychological distress was measured by the 14-item Type D (distressed) personality scale. Cox regression models of all-cause and cardiac death were used to examine the importance of risk markers.

RESULTS: After a median follow-up of 3.2 years, 94 patients (16%) had died (67 cardiac death), 61 patients (10%) had experienced an appropriate shock and 28 (5%) an inappropriate shock. Inappropriate shocks were not associated with all-cause (p=0.52) or cardiac (p=0.99) death. However, appropriate shocks (HR=2.60, 95% CI 1.47-5.58, p=0.001) and Type D personality (HR=1.85, 95% CI 1.12-3.05, p=0.015) were independent predictors of all-cause mortality, adjusting for age, sex, left ventricular ejection fraction, cardiac resynchronization therapy (CRT), secondary indication, history of coronary artery disease, medication and diabetes. Type D personality and appropriate shocks also independently predicted an increased risk of cardiac death. Other independent predictors of poor prognosis were older age, treatment with CRT and diabetes.

CONCLUSION: Vulnerability to chronic psychological distress, as defined by the Type D construct, had incremental prognostic value above and beyond clinical characteristics and ICD shocks. Physicians should be aware of chronic psychological distress and device shocks as markers of an increased mortality risk in ICD patients seen in daily clinical practice.