Association of age-adjusted Charlson comorbidity index with adverse outcomes in patients undergoing transcatheter aortic valve replacement: A retrospective cohort study

Abstract

Patients undergoing transcatheter aortic valve replacement (TAVR) have a high comorbid burden. Our objective was to assess the association between the age-adjusted Charlson comorbidity index (Age-CCI) and mortality and readmission rates within 1-year post-TAVR. Data were extracted from the Medical Information Mart for Intensive Care IV database (MIMIC-IV version 2.0). The primary endpoint was a composite outcome of all-cause mortality or readmission within 1-year after TAVR. To examine the associations of Age-CCI with outcomes, we used multivariable Cox proportional hazards regression, restricted cubic spline (RCS), and Kaplan-Meier curves. A total of 785 patients (52.9% male) with a median age of 84.0 years were assessed. More than half of our patients had an Age-CCI ≥ 7. After adjustment for potential confounders, we found that a 1 unit increase in Age-CCI was associated with a 10% increase in mortality and readmission rates after TAVR (HR = 1.10, 95% CI: 1.04-1.17, P < .001). High Age-CCI (Age-CCI ≥ 7) compared with the low Age-CCI (Age-CCI < 7) showed a 36% increase of mortality and readmission rates (HR = 1.36, 95% CI: 1.07-1.73, P = .013). The RCS curve analysis showed a continuous linear relationship between Age-CCI and the composite outcome risk (P for non-linearity = .671). The Kaplan-Meier survival analysis showed that patients with Age-CCI ≥ 7 had a poorer prognosis than those with Age-CCI < 7 (log-rank P < .001). Subgroup analyses showed the results remained stable. Age-CCI is independently associated with all-cause mortality and readmission in patients treated with TAVR, which may help clinicians risk-stratify patients and offer an opportunity to improve patient outcomes.