Extended prediction rule to optimise early detection of heart failure in older persons with non-acute shortness of breath: a cross-sectional study

OBJECTIVES: There is a need for a practical tool to aid general practitioners in early detection of heart failure in the elderly with shortness of breath. In this study, such a screening rule was developed based on an existing rule for detecting heart failure in older persons with a diagnosis of chronic obstructive pulmonary disease. The original rule included a history of ischaemic heart disease, body mass index, laterally displaced apex beat, heart rate, elevated N-terminal pro B-type natriuretic peptide and an abnormal ECG. DESIGN: Cross-sectional data were used to validate, update and extend the original prediction rule according to a standardised state-of-the-art stepwise approach. SETTING: Primary care with 30 participating general practices. PARTICIPANTS: Community-dwelling people aged ≥65 years with shortness of breath on exertion. METHODS AND RESULTS: Validation of the existing screening rule in our population showed satisfying discrimination with a concordance statistic of 0.84 (range 0.80–0.85), but poor calibration. Performance measures were most improved by adding the predictors age >75 years, peripheral oedema and systolic murmur, resulting in a concordance statistic of 0.88 (range 0.85–0.90) and a net reclassification improvement of 31%. A risk score was computed, which showed high accuracy with a negative predictive value of 87% and a positive predictive value of 73%. Evaluating the improved rule in the derivation set and an independent set of patients with type 2 diabetes aged 60 years or older showed satisfying generalisability of the rule. CONCLUSIONS: Our rule resulted in excellent prediction of heart failure in the large domain of the elderly with shortness of breath, and would help general practitioners to select those needing echocardiography. TRIAL REGISTRATION NUMBER: NCT01202006.