Left ventricular global longitudinal strain adds incremental value for risk prediction in an all-comer low-risk real-world clinical patient population

Abstract Background Cardiovascular diseases (CVD) remain a major socio-economic burden. Deformation imaging has previously demonstrated incremental prognostic value compared to left ventricular ejection fraction (LV EF) in a vast array of cardiovascular diseases, however, it still remains widely underused. Consequently, we sought to investigate the significance of deformation imaging in an unselected all-comer population to evaluate its value in a day-to-day in- and outpatient setting. Methods Patients were prospectively recruited to the single-center cardiovascular magnetic resonance registry. Volumetric right and left ventricular (RV/LV) analyses were performed on short axis (SAX) stacks. RV and LV global longitudinal strain was evaluated on long axis views, LV global circumferential strain on SAX respectively. A follow-up was conducted by telephone and medical chart review for the primary (all-cause mortality and heart failure hospitalisation) as well as secondary endpoint (all-cause mortality as well as hospitalised angina, infarction and stroke). Results The final population consisted of n=1655 patients classified as normal (n=454), chronic coronary syndrome (n=314), ischaemic heart disease (n=279), dilated (n=236), hypertrophic (n=37) or other (n=22) cardiomyopathies, hypertensive heart disease (n=28), storage disorders (n=8), inflammation (n=103), acute myocardial injury (n=11), right heart failure (n=19) and others (n=144). In total n=68 primary and n=107 secondary endpoints were met during a median follow-up of 399 days. GLS (HR 1.12, 95% CI 1.04-1.21 p=0.002/HR 1.10, 95% CI 1.03-1.16 p=0.002) but not LVEF (p=0.406/0.209) was an independent predictor for the primary and secondary endpoint. Furthermore, GLS was an independent predictor for the primary endpoint after correction for commonly considered risk factors including age, NYHA class, tissue characterisation native T1 as well as biomarkers NTproBNP and glomerular filtration rate (HR 1.09, 95% CI 1.03-1.15, p=0.003). After dichotomisation at the median of -16.4%, GLS added incremental value for risk stratification for the primary endpoint on Kaplan Meier plots and associated log-rank testing in patients with EF above (p= 0.045) and below (p=0.017) the median of 55%. Conclusion In an unselected all-comer low-risk real-world patient population, GLS emerges as an independent risk predictor compared to LV EF with incremental prognostic value. This finding may underline clinical routine implementation of GLS for cardiac in-and outpatient clinics.