Association of Impaired Relaxation Mitral Inflow Pattern (Grade 1 Diastolic Function) with Long-term Non-Cardiovascular and Cardiovascular Mortality.

Background: Abnormalities of left ventricular (LV) diastolic function are established independent predictors of heart failure (HF) and mortality.

Objectives: To determine whether the association of diastolic function with all-cause mortality is driven by cardiovascular or non-cardiovascular death and if impaired relaxation mitral inflow filling pattern is a risk marker.

Methods: Diastolic function was graded by the Mayo Clinic algorithm utilizing the well characterized prospective Olmsted County Heart Function Study. Those with reduced LV ejection fraction (EF), ≥moderate valve disease, clinical diagnosis of HF, or indeterminate diastolic function were excluded. Notably all patients with an impaired relaxation pattern (E/A <0.8) are classified as abnormal (grade 1) regardless of ejection fraction, clinical or other echocardiographic abnormalities. Individuals were followed for a median of 19.7 years (IQR 18.9 - 20.6) for mortality outcomes.

Results: In a community cohort of 1,005 subjects 63 (57-71) years of age, grade 1 diastolic function was common (26%) and associated with all-cause mortality (HR 4.05, 95% CI 3.22-5.09, p<0.0001). This association persisted in a subgroup of those with impaired myocardial relaxation and no other clinical or echocardiographic abnormalities (HR 2.71, 95% CI 1.89-3.88, p<0.0001). The association of diastolic function with non-cardiovascular death was not significant after adjustment for age, sex, and comorbidities, though there was an association with grade 1 diastolic function and risk of death from dementia (age and sex-adjusted HR 2.30, 95% CI 1.54-3.45, p<0.001). The association of diastolic function and cardiovascular mortality persisted in multivariable model, including for grade 1 diastolic function (HR 2.43, 95% CI 1.16-5.05, p=0.02).

Conclusions: Impaired relaxation mitral inflow pattern (Grade 1) is common in older adults in the community and found to be associated with cause-specific death, highlighting this simple echo finding as a potential biomarker of cardiovascular and cognitive risk, and not necessarily a benign finding that is normal with age.