Background
Several studies suggested that diastolic strain rate
measures may be superior to E/E' ratio for estimating left ventricular
end-diastolic pressure and outcome in cardiovascular disease. However, different
measures of diastolic strain rate have been proposed in literature.
Comprehensive evidence for the predictive value in chronic heart failure (HF)
under consideration of the clinical profile and established measures of cardiac
function is currently not available.
Methods
Individuals with chronic HF from the prospective
MyoVasc study (NCT04064450) were investigated in a highly standardized clinical
setting. Echocardiography was performed and diastolic strain measures (i.e., early
diastolic strain rate (E/DSr ratio), E/DSrTDI-E ratio and E/DSrPW-E
ratio) were read offline in the three standard apical views using QLab 9.0.1
(Philips, Germany) in individuals in sinus rhythm during echocardiography. Worsening
of HF (i.e., composite of transition from asymptomatic to symptomatic HF, HF
hospitalization, and cardiac death) was assessed during a structured follow-up
with subsequent validation and adjudication of endpoints. HF phenotypes
including HF with preserved left ventricular ejection fraction (LVEF) (HFpEF),
HFpEFborderline and HF with reduced LVEF (HFrEF) were defined
according to current American Heart Association (AHA) guidelines.
Results
Out of 3,289 participants, diastolic strain rate
measures were available in 2,177 individuals classified as AHA stage A to D for
the present analysis (mean age 65.1±10.5years, 35.0% female). Median E/DSr,
E/DSrTDI-E and E/DSrPW-E ratio were 80.0 (64.7/102.2),
128.1 (92.2/196.2) and 169.3 (110.3/294.8), respectively. After a median
follow-up of 2.28 years (interquartile range: 1.14 to 3.97 years), worsening of
HF was observed in 157 participants. E/DSr ratio (hazard ratio (HR) per standard
deviation (SD): 1.25; 95%CI [1.01/1.56], p=0.04), E/DSrTDI-E ratio (HR[per
SD] 1.56 [1.40/1.74], p<0.0001 and E/DSrPW-E ratio (HR[per
SD] 1.39 [1.23/1.56], p<0.0001) indicated an increased risk for
worsening of HF in multivariable Cox analysis adjusted for age, sex and image
quality. After additional adjustment for cardiovascular risk factors (CVRF) and
comorbidities, E/DSr ratio (HR 1.62 [1.39/1.89], p<0.0001), E/DSrTDI-E
ratio (HR[per SD] 1.41 [1.23/1.60], p<0.0001) and E/DSrPW-E
ratio (HR[per SD] 1.23 [1.07/1.41], p=0.0043) remained independent
predictors of worsening of HF. However, after subsequent incorporation of
echocardiographic measures of systolic (i.e. LVEF and global longitudinal
strain (GLS) and diastolic (i.e. E/E’-ratio) function into the model, only
E/DSr ratio (HR 1.25 [1.01/1.56], p=0.04) independently predicted worsening of
HF. Interestingly, further introduction of HF medication into the model, did
not relevantly attenuate the results (HRE/DSr [per SD] 1.25 [1.01/1.54],
p=0.044). Finally, E/DSr ratio per SD was predictive of worsening of HF in all
HF phenotypes independent of age, sex, image quality and CVRF (HFpEF: HR 1.45 [1.05/2.01],
p=0.026; HFpEFborderline: (HR 1.86 [1.29/2.70], p=0.00099; HFrEF: HR
1.45 [1.14/1.83], p=0.0023).
Conclusion
Early diastolic strain rate was a robust predictor of
HF outcome independent of clinical status, medication and other
echocardiographic functional measures. Since its predictive value was observed
in all HF phenotypes, early diastolic strain rate might be a promising biomarker
for risk stratification in chronic HF.