A Risk Prediction Model for In-hospital Mortality in Patients with Suspected Myocarditis.

BACKGROUND: Myocarditis is an inflammatory disease of the myocardium that may lead to cardiac death in some patients. However, little is known about the predictors of in-hospital mortality in patients with suspected myocarditis. Thus, the aim of this study was to identify the independent risk factors for in-hospital mortality in patients with suspected myocarditis by establishing a risk prediction model. METHODS: A retrospective study was performed to analyze the clinical medical records of 403 consecutive patients with suspected myocarditis who were admitted to Ningbo First Hospital between January 2003 and December 2013. A total of 238 males (59%) and 165 females (41%) were enrolled in this study. We divided the above patients into two subgroups (survival and nonsurvival), according to their clinical in-hospital outcomes. To maximize the effectiveness of the prediction model, we first identified the potential risk factors for in-hospital mortality among patients with suspected myocarditis, based on data pertaining to previously established risk factors and basic patient characteristics. We subsequently established a regression model for predicting in-hospital mortality using univariate and multivariate logistic regression analyses. Finally, we identified the independent risk factors for in-hospital mortality using our risk prediction model. RESULTS: The following prediction model for in-hospital mortality in patients with suspected myocarditis, including creatinine clearance rate (Ccr), age, ventricular tachycardia (VT), New York Heart Association (NYHA) classification, gender and cardiac troponin T (cTnT), was established in the study: P = ea/(1 + ea) (where e is the exponential function, P is the probability of in-hospital death, and a = -7.34 + 2.99 × [Ccr <60 ml/min = 1, Ccr ≥60 ml/min = 0] + 2.01 × [age ≥50 years = 1, age <50 years = 0] + 1.93 × [VT = 1, no VT = 0] + 1.39 × [NYHA ≥3 = 1, NYHA <3 = 0] + 1.25 × [male = 1, female = 0] + 1.13 × [cTnT ≥50 µg/L = 1, cTnT <50 µg/L = 0]). The area under the receiver operating characteristic curve was 0.96 (standard error = 0.015, 95% confidence interval [CI]: 0.93-0.99). The model demonstrated that a Ccr <60 ml/min (odds ratio [OR] = 19.94, 95% CI: 5.66-70.26), an age ≥50 years (OR = 7.43, 95% CI: 2.18-25.34), VT (OR = 6.89, 95% CI: 1.86-25.44), a NYHA classification ≥3 (OR = 4.03, 95% CI: 1.13-14.32), male gender (OR = 3.48, 95% CI: 0.99-12.20), and a cTnT level ≥50 µg/L (OR = 3.10, 95% CI: 0.91-10.62) were the independent risk factors for in-hospital mortality. CONCLUSIONS: A Ccr <60 ml/min, an age ≥50 years, VT, an NYHA classification ≥3, male gender, and a cTnT level ≥50 µg/L were the independent risk factors resulting from the prediction model for in-hospital mortality in patients with suspected myocarditis. In addition, sufficient life support during the early stage of the disease might improve the prognoses of patients with suspected myocarditis with multiple risk factors for in-hospital mortality.

Imbalanced response of ATP-binding cassette transporter A1 and CD36 expression to increased oxidized low-density lipoprotein loading contributes to the development of THP-1 derived foam cells.

ATP-binding cassette transporter A1 (ABCA1) and CD36, type B scavenger receptor, function as the key mediators of macrophages cholesterol efflux and intake, respectively. However, their contribution to development of foam cells still remains uncertain. We here examined the effects of increased oxidized low-density lipoprotein (oxLDL) loading on the ABCA1 and CD36 expression, and lipid accumulation in THP-1 macrophages. The cultured THP-1 macrophages were treated with different copper-oxLDL concentrations. The intracellular lipid contents and cholesterol efflux were measured, and the ABCA1 and CD36 expression were assessed. We found that expression of ABCA1 and CD36 were coordinately induced upon low to moderate doses of oxLDL loading. However, higher doses of oxLDL stimulation resulted in the imbalanced expression of ABCA1 and CD36 proteins with more preferentially suppressed ABCA1 protein, attenuated cholesterol efflux and development of THP-1 derived foam cells. The PPAR-γ expression was remarkably induced, and PPAR-γ agonist, pioglitazone, significantly promoted the ABCA1 and CD36 expression. Additionally, ABCA1 and CD36 proteins were strong colocalized in THP-1 macrophages membrane. In conclusion, the more preferentially suppressed ABCA1 expression as compared with CD36 at higher doses of oxLDL stimulation may be the initiator for the formation of macrophage-derived foam cells.