Results
Demographic and clinical characteristics: The study groups included 27 patients with echocardiographically NDFx, 21 patients with DDFx and 19 patients with IndtDFx who met the inclusion/exclusion criteria and had strain (using speckle tracking echocardiography ) analyzable echo studies. The quality of 23 studies was insufficient for strain-analysis, mostly due to low frame rates.
Clinical characteristics are demonstrated in table 1. Patients with DDFx were nearly 2 decades older compared to patients with NDFx (69±11 vs. 50±15 years, p<0.05, respectively). Their body mass index was higher, and they were 5 time more likely to be referred for echocardiography for the evaluation of HF symptoms. Parameters included in the metabolic syndrome (diabetes, hyperlipidemia, hypertension) were also significantly more common in patients with DDFx. Patients with IndtDFx showed the same pattern of differences as patients with DDFx compared to patients with NDFx, showing an “in-between” pattern regarding HF symptoms and diabetes mellitus. Age, body mass index, hypertension and hyperlipidemia rates among patients IndtDFx were nearly identical to patients with DDFx..
Echocardiographic findings: LV dimensions and systolic function were similar and within the normal range in the 3 groups (table 2). Left ventricular mass indexed for body surface area was abnormal and significantly larger in patients with DDFx and IndtDFx compared to NDFx (114±16, 110±25 vs. 94±16 gr/m2, respectively, p<0.05 both compared to NDFx). LV global longitudinal strain was found to be reduced among DDFx patients compared to NDFx and IndtDFx patients.
As expected from the group allocation process, the parameters E’, E/E’ , pulmonary pressure, and LA volume index were abnormal and significantly different in the DDFx compared to NDFx group. IndtDFx demonstrated intermediate parameter abnormalities; overlapping with DDFx but significantly different regarding E/E’. The parameters E’, E/E’ and LA volume index in IndtDFx were significantly different compared to NDFx., Pulmonary pressure estimation followed the same pattern between groups, but the difference was statistically significant between DDFx vs. NDFx.