Association between Rapid Dementia Screening Test score and clinical events in elderly patients with cardiovascular disease: a retrospective cohort study

Aims: Cognitive decline is prevalent among patients with cardiovascular disease (CVD). Cognitive measurement has been considered as a standard assessment for secondary prevention; however, standard cognitive tests are sometimes infeasible due to time constraints. This study aimed to examine the association between the Rapid Dementia Screening Test (RDST), a brief screening tool for cognitive function, and clinical events in elderly patients with CVD.

Methods and results: This retrospective cohort study included 140 hospitalized patients with CVD who participated in inpatient cardiac rehabilitation (median age, 75 years; male, 67%). Cognitive function for each patient was assessed using the RDST and Montreal Cognitive Assessment (MoCA), a standard test of mild cognitive impairment. The clinical events assessed as outcomes included all-cause mortality and unplanned rehospitalization. Receiver-operating characteristic (ROC) curve analysis showed similar predictive accuracy for the study outcome (P = 0.337) between the RDST [area under the curve, 0.651; 95% confidence interval (CI), 0.559-0.743] and MoCA (0.625; 0.530-0.720). The ROC analysis identified a cut-off value of 9 points for the RDST (sensitivity, 77.8%; specificity, 50.5%). Patients with RDST ≤9 showed a poor survival rate compared with those with ≥10 points (log-rank test, P = 0.002; hazard ratio, 2.94, 95% CI, 1.46-5.94). This result was consistent even after adjusting for potential confounders.

Conclusion: The RDST was associated with clinical events in elderly patients with CVD and its predictive capability was comparable with that of MoCA, a standard cognitive test. The RDST may be useful in CVD as an alternative screening tool for cognitive decline.