The value of D-dimer in the prognosis of dilated cardiomyopathy: a retrospective cohort study

Abstract

D-dimer is a biomarker of coagulation and fibrinolytic system activation in response to the hypercoagulable state of the body. The research aimed to analyze the value of D-dimer in the prognosis of patients with dilated cardiomyopathy (DCM). Patients admitted to our center for the first time with DCM were enrolled consecutively. The clinical characteristics variables were obtained from the electronic medical record system, and the prognostic information was obtained using telephone return visits and a review of repeated hospitalization records. Univariate and multivariate Cox regression was used to explore the association of D-dimer with all-cause mortality. Smooth curve fitting, threshold saturation effect analysis, and subgroup analysis were performed. Ultimately, 534 patients were included. After a follow-up of the enrolled patients, 485 patients obtained prognostic information, of which 159 died from all causes, and the main cause of death was heart failure (89/159), the sudden death accounted for about 17%. The independent positive association between D-dimer and all-cause mortality remained unchanged in both unadjusted and adjusted Cox regression models. In the fully adjusted model, each standard deviation increase in D-dimer was associated with a 14% increase in all-cause mortality (HR = 1.14; 95% CI: 1.02 ~ 1.27; P < 0.05). Curve fitting and threshold effect analysis showed an inflection point in the relationship between D-dimer and all-cause mortality (non-linear test: P = 0.03). When D-dimer was equal to 362ng/ml, HR = 1; and as the value increased, the risk of all-cause mortality increased by 34.7% for every 2-fold increase in D-dimer gradually (HR = 1.347; 95% CI: 1.069 ~ 1.697; P = 0.012). In subgroup analysis, D-dimer and BMI had a significant interaction on all-cause mortality, with a significantly increased risk of all-cause mortality in subjects with BMI ≥ 25 kg/m² (HR = 1.99; 95% CI: 1.34 ~ 2.97; P < 0.01). The ROC curve showed that D-dimer was a good predictor of all-cause mortality, and the areas under the curve at 1-, 3-, and 5-year were 0.71, 0.64, and 0.59, respectively. In addition, D-dimer improved the predictive performance of the MAGGIC heart failure score in patients with DCM. D-dimer is not only independently associated with all-cause mortality in DCM patients, but also has good predictive value, suggesting that D-dimer may be an early and useful marker for improving the management of DCM patients.

Keywords: All-cause mortality; D-dimer; Dilated cardiomyopathy; Prognosis.

Fig. 1

Kaplan-Meier survival curve of T1, T2, and T3. Notes: Lines represent different groups of populations, and shading represents 95% confidence intervals.

Fig. 2

Smooth curve fitting of the relationship between log₂(D-dimer) and all-cause mortality. Notes: The blue solid and dashed lines represent estimates and their corresponding 95% confidence intervals. Only 95% of the data is displayed. Adjusted for all covariates of model e in the expanded model.

Fig. 3

Association of D-dimer with all-cause mortality in different subgroups. Notes: Each stratification adjusted for all covariates of model e in the expanded model except the stratification factor itself. HR, hazard ratio; CI, confidence interval.

Fig. 4

ROC analysis of D-dimer in predicting all-cause mortality. Notes: A represents the ROC curve at each time point, and B represents the changing trend of the area under the curve with time (the unit of time in months).

Fig. 5

Comparison of ROC curve and calibration curve before and after adding D-dimer to the MAGGIC score scale. Notes: Model 1 represents the MAGGIC score scale, and Model 2 represents the “MAGGIC score scale + D-dimer”. (A, B, and C) are the ROC curves of the two models corresponding to 1-year, 3-year, and 5-year, respectively; (D, E, and F) are the calibration curves of the two models corresponding to 1 year, 3-year, and 5-year, respectively.

Fig. 6

Comparison of IDI and NRI before and after adding D-dimer to MAGGIC score scale. Notes: Standard Model is the MAGGIC score scale model, New Model is the “MAGGIC score scale + D-dimer” model. (A, B, and C) are the IDI corresponding to 1-year, 3-year, and 5-year, respectively; (D, E, and F) are the NRIs corresponding to 1-year, 3-year, and 5-year, respectively.