RESUMO
(1) Background: Immunoglobulin gamma subclass 4 (IgG4) is a serum protein belonging to the immunoglobulin superfamily. It has a central role in certain immune-mediated conditions defined as IgG4-related disease. There is a paucity of data regarding the potential association of IgG4 and cardiovascular diseases. Our aim is to study the serum levels of IgG4 in patients with ischemic and non-ischemic dilated cardiomyopathy (DCM). (2) Methods: patients with ischemic and non-ischemic DCM were included in this study. Non-ischemic DCM was defined as a left ventricular ejection fraction (LVEF) < 40% without coronary artery disease (CAD). Ischemic DCM was defined as a LVEF < 40% and proven CAD. The serum concentrations of IgG4 were measured by turbidimetry. (3) Results: Overall 98 patients with cardiomyopathy had significantly higher levels of IgG4 compared with the control group (77.4 ± 64.0 vs. 50.3 ± 28.8 mg/dL, p < 0.01). Although there was no difference in the total IgG levels in patients with ischemic DCM, the serum concentrations of IgG4 were significantly higher than the corresponding values in the control group (89.8 ± 67.3 vs. 50.3 ± 28.8 mg/dL; interquartile ranges: 40.4−126.5 vs. 31.8−66.8 mg/dL, p < 0.01). This was altered by gender and smoking. (4) Conclusions: The patients with ischemic DCM had increased serum concentrations of IgG4. Future studies are warranted to explore the potential role of an IgG4-mediated process in patients with heart failure with reduced LVEF.
RESUMO
INTRODUCTION: Takotsubo cardiomyopathy (TCM) is characterized by transient left ventricle dysfunction. HYPOTHESIS: A residual cardiac and endothelial dysfunction is present in patients who recovered from TCM. METHODS: In this single-center prospective study, patients with prior TCM were included and followed for 6.4 ± 1.6 years. All underwent comprehensive cardiac function assessment, including tissue Doppler imaging (TDI) and 2-dimensional strain (2DS) echocardiography at their first visit. The number of circulating endothelial progenitor cells and levels of proangiogenic vascular endothelial growth factor (VEGF) and its receptor (VEGF-R) were measured. All measurements were compared with healthy controls. RESULTS: Forty-two women (age 58. ±8.6 years, LVEF 58.1 ± 6.1%) comprised the TCM group. Patients post-TCM had significantly lower early velocities E' (6 (5.0-8.0) vs. 9 (7.0-11.0) cm/s, p = .001) by TDI and higher E/E' ratio (p = .002), lower LV global average longitudinal strain (LGS) (-18.9 ± 3.5% vs. -21.7 ± 2.3%, p = .002) and RV LGS (-20.1 ± 3.9% vs. -23.4 ± 2.8%, p = .003) were evident. There was a trend toward a higher VEGF-R (p = .09) along with decreased VEGF/VEGF-R ratio representing inadequate VEGF production. In-hospital mortality was not reported and only two non-cardiac deaths occurred at long-term follow-up. CONCLUSIONS: Altered TDI and 2DS indices suggest residual biventricular myocardial injury in post-TCM patients with the apparent LV function recovery. Inappropriate production of VEGF and VEGF-R were observed, suggesting a possible underlying endothelial dysfunction in these patients.
