Including hemoglobin levels and female sex provide the additional predictive value of the APPLE score for atrial fibrillation recurrence post-catheter ablation

Abstract

ObjectiveWe probed whether the addition of hemoglobin (HGB) or the female sex (SEX) as variables would provide additional prognostic value to the APPLE score. MethodsAn optimized APPLE score was used to evaluate the AF recurrence risk in the consecutive populations with AF post-catheter ablation including the development (n = 562) and validation (n = 239) cohorts. ResultsIn the populations of AF recurrence, most patients were female sex (103/164, 62.8%), and had the lower HGB levels. After adjusting for the APPLE score, HGB level (Odds Ratio [OR], 0.828; 95% Confidence Interval [CI], 0.749–0.915; P < 0.001) and female sex (OR, 1.596; 95% CI, 1.140-2.235; P = 0.006) independently predicted AF recurrence. Adjusting the APPLE score by HGB variable improved its predictive ability for AF recurrence (C-statistic value from 0.675 to 0.711, P = 0.010), which also increased the C-indexes in the external validation (from 0.653 to 0.725, p = 0.023). The female sex variable also enhanced the C-statistic value of the APPLE score for AF recurrence at both development and external validation (C-indices from 0.675 to 0.691, P = 0.004; C-indices from 0.653 to 0.704, p = 0.037, respectively). Decision curve analysis showed that the HGB plus APPLE score was better than the SEX plus APPLE score in predicting AF recurrence in two following AF populations. ConclusionThe inclusion of HGB level and female sex variables improved the predictability and clinical usefulness of adjusted APPLE score. Adjustment of the APPLE score by HGB levels may provide better predictive value than inclusion of the female sex variable.