In heart failure with preserved ejection fraction (HFpEF), echocardiographic studies suggest that global longitudinal strain (GLS) has an impact on survival. Feature-tracking cardiovascular MRI also allows for strain analysis; however, to the knowledge of the authors, little is known about its prognostic value and whether it reflects severity of diffuse fibrosis, as assessed by cardiovascular MRI T1 mapping.
To investigate the association between myocardial strain at cardiovascular MRI with extracellular volume by T1 mapping and outcome in participants with HFpEF.
Materials and Methods
In this secondary analysis of a prospective study (NCT03405987), consecutive participants with HFpEF underwent cardiovascular MRI between July 2012 and March 2018, including T1 mapping and three-dimensional strain analysis. Extracellular volume and strain results were assessed to determine if there was a correlation between these two factors. Cox regression was performed to determine the prognostic relevance of MRI-derived myocardial strain for a combined end point (events) of heart failure hospitalizations and cardiovascular death.
In total, 206 consecutive participants with HFpEF (mean age, 71 years ± 8 [standard deviation]; 69% women) were included. Median myocardial global longitudinal strain (GLS) at MRI was -8.5% and showed low correlation with extracellular volume (r = 0.28; P = .003). A total of 109 events (53%) were recorded during a follow-up of 38 months ± 29. Participants with a GLS above the median had higher event rates (log-rank test, P < .001). By multivariable Cox regression analysis, GLS remained independently associated with outcome (hazard ratio, 1.06 per 1% strain increase; 95% confidence interval: 1.01, 1.11; P = .03) when corrected for risk factors including age, diabetes, renal function, N-terminal pro-b-type natriuretic peptide serum concentration, and right ventricular size and function.
In participants with heart failure with preserved ejection fraction, global longitudinal strain at cardiovascular MRI was correlated with extracellular volume by T1 mapping and was associated with cardiovascular events.