Global longitudinal strain: the best biomarker for predicting prognosis in heart failure?

The desire to predict who will develop heart failure (HF) has inspired researchers for a long time. Numerous so-called predictive biomarkers have been developed, studied, published, and forgotten. Various suggestions of biomarkers have been deemed to add little to clinical practice.1–3 However, a few have reached current clinical practice, including NT-proBNP, troponins, and creatinine, which can be used as biomarkers for an unfavourable cardiac prognosis. In this issue of the journal, echocardiographic biomarkers for HF development are presented.4 Marwick and co-workers present a community-based study on 419 asymptomatic subjects with risk factors for HF who were screened with echocardiography. At baseline there was a considerable prevalence of stage B HF measured by LV hypertrophy, diastolic measures, global longitudinal strain (GLS), and left atrial enlargement. During 14 months of follow-up, new HF symptoms or death occurred in ∼13% of the study population. The echocardiographic markers were tested for predictive value of outcome by a variety of statistical methods. The authors reported convincing evidence that echocardiographic markers, in particular GLS and LV mass, were useful for screening of incident HF. The study adds to an increasing number of studies demonstrating the superiority of GLS compared with EF,5–8 and the usefulness of GLS in asymptomatic subjects.9 While the EF is one of the most well established markers for cardiac prognosis, GLS obviously has advantages by a discriminative value for both death and occurrence of ventricular arrhythmias when systolic function is still relatively preserved.5–7 In fact, the Australian research team was one of the first to demonstrate the usefulness and the predictive value of GLS as a biomarker of cardiac prognosis.7 Since the introduction of strain echocardiography almost two decades ago, the technique has struggled to become a clinical tool, which can partly be explained by scepticism in the cardiology community, time-consuming analyses,