Hypersensitivity to material and environmental burden as a possible cause of late complications of cardiac implantable electronic devices.

Aims: To evaluate whether patients with late complications of pacemakers or implantable cardioverter-defibrillators have hypersensitivity reactions to some of the materials used in generators or in electrodes, or to environmental metal burden. Methods and results: The cohort consisted of 20 men and 4 women (mean age: 62.3 ± 17.2 years) who had a history of late complications of implanted devices. The control group involved 25 men and 8 women (mean age: 64.6 ± 14.0 years) who had comparable devices, but no history of late complications. Lymphocyte transformation test was used to evaluate hypersensitivity to eight metal pollutants (antimony, manganese, mercury, molybdenum, nickel, platinum, tin, and titanium) selected by results of questionnaires on environmental burden, and by material analysis of generators and electrode surfaces. Exposures to metal pollutants were approximately the same in patients and in controls. Titanium alloy used in generators contained at least 99.32% of titanium and trace levels of other metals; higher levels of tin and platinum were detected in electrode surfaces. Hypersensitivity reactions to mercury and tin were significantly more frequent in patients than in controls (patients and controls: mercury: 68.2 and 31.1%, respectively; P = 0.022; tin: 25.0 and 3.2%, respectively; P = 0.035). In contrast, hypersensitivity to manganese was significantly more frequent in controls than in patients (patients and controls: 13.6 and 50.0%, respectively; P = 0.008). Conclusion: Our findings suggest a possible relation between hypersensitivity to metals used in implantable devices or to environmental metal burden and the occurrence of their late complications.

Delayed-Type Hypersensitivity to Metals of Environmental Burden in Patients with Takotsubo Syndrome - Is There a Clinical Relevance?

OBJECTIVE: Takotsubo syndrome (TS) is a heart condition characterised by a sudden transient left ventricular dysfunction; its pathophysiology is probably associated with elevated levels of catecholamines but the exact mechanism is not known as yet. Literature and clinical experience suggest that TS affects persons with various comorbidities. This pilot work aims to evaluate the frequency of comorbidities with potential pathological immune reactivity, and to evaluate the potential association between TS and hypersensitivity to metals assessed by LTT-MELISA®. METHODOLOGY, RESULTS: A total of 24 patients (23 women, 1 man) with a history of TS attack and 27 healthy controls were evaluated. Hypersensitivity was evaluated by a lymphocyte transformation test (LTT-MELISA®); a questionnaire of environmental burden was used to select evaluated metals. A total of 19 patients (79%) had at least one condition that might potentially be associated with pathological immune reactivity (autoimmune thyroid disease, drug allergy, bronchial asthma, cancer, contact dermatitis, rheumatoid arthritis). Hypersensitivity to metals was identified significantly more frequently in TS patients than in healthy controls (positive reaction to at least one metal was identified in 95.8% of TS patients and in 59.3% of controls; p = 0.003); the difference was statistically significant for mercury (45.8% and 14.8%, respectively; p = 0.029). CONCLUSION: Our work shows that conditions with pathological immune reactivity occur frequently in TS patients, and our data suggest a possible association between TS and hypersensitivity to metals (mercury in particular) evaluated by LTT-MELISA®. We also suggest that apart from the triggering stress factor, potential existence of other serious conditions should be considered when taking medical history of TS patients.