Left Ventricular Dyssynchrony in Patients With Heart Failure and Preserved Ejection Fraction
Does left ventricular (LV) dyssynchrony play a pathogenic role in heart failure with preserved ejection fraction (HFpEF)?
LV systolic dyssynchrony was quantified in 130 patients with HFpEF and New York Heart Association class II-IV symptoms, EF ≥45%, and N-terminal pro–B-type natriuretic peptide levels >400 pg/ml, who were enrolled in the PARAMOUNT trial (a cohort of 301 patients >40 years old with HFpEF and LVEF ≥45%). These patients were compared with 40 healthy controls of similar age and sex. Dyssynchrony was assessed by 2-D speckle tracking as standard deviation (SD) of the time-to-peak longitudinal systolic strain in 12 LV segments, and related to measures of systolic and diastolic function.
Patients with HFpEF (62% women, mean age 71 ± 9 years, body mass index 30.2 ± 5.9 kg/m2, systolic blood pressure 139 ± 15 mm Hg) had a significantly greater measure of dyssynchrony than did controls (SD of time-to-peak longitudinal strain 90.6 ± 50.9 vs. 56.4 ± 33.5 ms, p < 0.001); evidence of greater LV dyssynchrony also was present in the subset of HFpEF patients (n = 63) with LVEF ≥55% and narrow QRS (≤100 ms). Among HFpEF patients, dyssynchrony was related to wider QRS interval, greater LV mass, and lower early diastolic tissue Doppler myocardial velocity (E’). Greater dyssynchrony remained significantly associated with worse diastolic function even after restricting the analysis to patients with EF ≥55% and adjusting for age, gender, systolic blood pressure, LV mass index, and LVEF.
The authors concluded that HFpEF is associated with greater mechanical dyssynchrony compared with healthy controls of similar age and sex. Among patients with HFpEF, the severity of dyssynchrony is related to the width of the QRS complex, the degree of LV hypertrophy, and measures of LV diastolic dysfunction.
This study suggests that LV dyssynchrony exists among patients with HFpEF. It remains to be seen whether cardiac resynchronization therapy could provide clinical benefit among this cohort.
Keywords: Heart Diseases, Hypertrophy, Left Ventricular, Body Mass Index, Cardiac Pacing, Artificial, Heart Failure, Peptide Fragments, Blood Pressure, Ventricular Dysfunction, Left, Cardiac Resynchronization Therapy, Natriuretic Peptide, Brain
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