Poor validity of GPs' heart failure diagnoses?

A new systematic review of pooled data of 196,105 patients with heart failure (HF) has confirmed a phenotype of older women with hypertension rather than ischaemic heart disease as the predominant HF population in general practice. Interestingly, the review found five main approaches to identifying patients with HF in general practice.

"The majority of studies (70 percent) did not incorporate echocardiography and included patients with HF based on GP judgment or GP chart review; however, several studies have shown a poor validity of GP's HF diagnoses," according to the review published in the International Journal of Cardiology.

HF is a prevalent disease associated with high morbidity and mortality and has a strong impact on quality of life. Unfortunately, identifying patients with HF in general practice is challenging. First, the symptoms and signs are nondiscriminating and therefore of minimal diagnostic value. This is particularly relevant for older people, who often have multiple comorbidities and may present with many other possible causes of dyspnoea, fatigue or peripheral oedema. Additionally, natriuretic peptide biomarkers and echocardiography are underused, leading to under- and over-diagnosis of HF.

This systematic review aimed to provide an overview of the methods used to identify patients with HF in general practice and to assess the impact of these different identification methods on the characteristics of the included patients. MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials (CENTRAL) were searched from 01/01/2001 to 31/12/2015. In all, 105 studies on HF in general practice were included, totalling 196,105 patients.

Five main identification methods for HF were distinguished, including 1) echocardiographic assessments, 2) results of echocardiography in general practitioner (GP) charts, 3) GP judgment after chart review, 4) GP judgment of consecutive patients and 5) only chart review. Only 30% of studies used the results of echocardiography. Despite a large heterogeneity between studies, researchers say the pooled data revealed a predominant phenotype of older women with hypertension rather than ischaemic heart disease.

In addition, linear regression analysis showed that the impact of the identification method on patient characteristics was limited. However, study design had a greater impact, with RCTs including younger, male patients with ischaemic heart disease and higher HF drug prescription rates at baseline.

The classic definition of HF as a clinical syndrome is of limited use in the elderly, in whom HF symptoms and signs are common in both patients with or without objective cardiac abnormalities, says the review team. Moreover, HF symptoms and signs and measures of cardiac dysfunction can evolve over time in response to treatment and contextual factors.

"Accordingly, the poor validity of GPs' diagnoses can be questioned because the confirmation of their diagnoses depends on the reference standard used at one moment in time.  Furthermore, it has been shown that patients with HF according to GPs had similar mortality rates as 'objectified' patients with HF," the review team writes. "Moreover, this systematic review did not show large differences in patient characteristics between studies using echocardiography as an inclusion criterion and studies that did not. Therefore, covering real-world community-based patients with HF seems more important than the identification method or definition of HF used."

Source: International Journal of Cardiology
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