Overdiagnosis of heart failure in primary care: a cross-sectional study

Background Access to echocardiography in primary care is limited, but is necessary to accurately diagnose heart failure (HF). Aim To determine the proportion of patients with a GP's diagnosis of HF who really have HF. Design and setting A cross-sectional study of patients in 30 general practices with a GP's diagnosis of heart failure, based on the International Classification of Primary Care (ICPC) code K77, between June and November 2011. Method Electronic medical records of the patients' GPs were scrutinised for information on the diagnosis. An expert panel consisting of two cardiologists and an experienced GP used all available diagnostic information, and established the presence or absence of HF according to the criteria of the European Society of Cardiology (ESC) HF guidelines. Results In total, 683 individuals had a GP's diagnosis of HF. The mean age was 77.9 (SD 11.4) years, and 42.2% were male. Of these 683, 79.6% received cooperative care from a cardiologist. In 73.5% of cases, echocardiography was available for panel re-evaluation. Based on consensus opinion of the panel, 434 patients (63.5%, 95% confidence interval [CI] = 59.9 to 67.1) had definite HF, of which 222 (32.5%, 95% CI = 30.9 to 34.1) had HF with a reduced ejection fraction (HFrEF), 207 (30.3%, 95% CI = 29.0 to 31.6) had HF with a preserved ejection fraction (HFpEF), and five (0.7%, 95% CI = 1.2 to 2.6) had isolated right-sided HF. In 17.3% of cases (95% CI = 14.4 to 20.0), the panel considered HF absent, and in 19.2% (95% CI = 16.3 to 22.2) the diagnosis remained uncertain. Conclusion More than one-third of primary care patients labelled with HF may not have HF, and such overdiagnosis may result in inadequate patient management.