DYNAMICS OF MECHANICAL DYSSYNCHRONY IN PATIENTS WITH SUPERRESPONSE TO CARDIAC RESYNCHRONISATION THERAPY WITH A LONG-TERM FOLLOW-UP

Abstract

Aim. The aim is to assess clinical features of organism and morpho-functional properties of heart and to study the dynamics of mechanical dyssynchrony in patients with congestive heart failure and superresponse to cardiac resynchronization therapy.Material and Methods. 72 patients were examined (mean age 54.3±8.9 years) at baseline and during follow-up visits: 10.5±3.7 months, 52.0±21.4 months. Patients were divided into groups: I group (n=31) with decrease of left ventricle endsystolic volume ≥30% (superresponders) and II group (n=41) — decrease of left ventricle endsystolic volume <30% (nonsuperresponders).Results. At baseline there were differences in the presence of myocardial infarction (22.5% in I group vs 46.3% in II group; p=0.038), the groups were comparable in severity of electrical and mechanical dyssynchrony. Left ventricle pre-ejection period in I group was statistically significantly decreased at both control visits, in group II there was no significant change. Right ventricular pre-ejection period significantly increased only in I group at the second control visit compared to baseline values. The mechanical interventricular delay significantly decreased in I group at both control visits compared to baseline values, in II group only at first control visit. The Intraventricular dyssynchrony assessed by tissue doppler imaging significantly decreased in both groups compared to baseline values. The survival rate in I group was 87.1%, in group II was 65.9% (Log-Rank test p=0.038).Discussion. Based on the results of the subanalysis of the Echo-CRT study, it was shown that a decrease in mechanical dyssynchrony in patients with cardiac resynchronization therapy is associated with a lower incidence of hospitalization due to heart failure or death. Persistent or worsening dyssynchrony according to echocardiography may be a marker of a severity of the disease in patients with congestive heart failure and has a prognostic value. It is important to note that in our study the described facts confirm the preservation of cardiac resynchronization therapy effect with long follow-up in superresponders and limited cardiac resynchronization therapy effect with short follow-up in nonsuperresponders.Conclusion. Superresponse is associated with a decrease of mechanical dyssynchrony with a long-term follow-up also with a higher survival rate.