Cardiac resynchronisation therapy optimisation of interventricular delay by the systolic dyssynchrony index: A
Jiri Vondrak1, Dan Marek2, Jan Vecera3
1Department of Cardiology, Pardubice Regional Hospital a.s., Pardubice, Czech Republic.
Insights
Optimizing cardiac resynchronization therapy (CRT) interventricular delay using systolic dyssynchrony index (SDI) showed no significant difference compared to QRS width for improving heart function. Both methods yielded similar volumetric and clinical outcomes at 12 months.
Area of Science:
- Cardiology
- Medical Imaging
- Heart Failure Management
Background:
- Cardiac resynchronization therapy (CRT) is used to treat heart failure patients with electrical dyssynchrony.
- Optimizing the interventricular (VV) delay in CRT is crucial for maximizing therapeutic benefits.
- Current methods for VV delay optimization include QRS width assessment and more advanced echocardiographic measures.
Purpose of the Study:
- To compare the effectiveness of VV delay optimization based on systolic dyssynchrony index (SDI) derived from 3D echocardiography (3DE) versus standard QRS width assessment.
- To evaluate the impact of these optimization strategies on left ventricle volume reduction at 12-month follow-up in CRT recipients.
Main Methods:
- A randomized, open-label trial included 63 patients recently implanted with CRT.
- Patients were assigned to either QRS width optimization (Group 1, n=31) or SDI optimization (Group 2, n=32).
- Left ventricular end-systolic volume (LVESv), ejection fraction (LVEF), and SDI were assessed using 3DE before implantation and at 12-month follow-up. Clinical outcomes were also evaluated.
Main Results:
- No significant difference was observed in the number of volumetric responders between the SDI group and the QRS width group (20 vs. 17, P=0.786).
- Both groups showed similar reductions in LVESv (-61 ± 51 mL vs. -41 ± 55 mL, P=0.111) and improvements in LVEF (+13.0 ± 9.9% vs. +10.1 ± 10.6%, P=0.213).
- Clinical outcomes, including New York Heart Association functional class, 6-minute walk test, quality of life, and NT-proBNP levels, were comparable between the two groups at 12 months.
Conclusions:
- Optimization of interventricular delay in CRT using SDI derived from 3DE did not demonstrate a significant advantage over QRS width assessment.
- Both methods resulted in similar volumetric and clinical responses at the 12-month follow-up.
- These findings suggest that standard QRS width assessment may be sufficient for VV delay optimization in CRT recipients.
Background:
The aim of our study was to compare the effect of interventricular (VV) delay optimisation in CRT recipients on the basis of systolic dyssynchrony index (SDI) derived from the three-dimensional echocardiography (3DE) versus QRS width assessment on left ventricle volume reduction at the 12-month follow-up.
Methods:
We included 63 patients with recently implanted CRT in this randomised, open-label trial. Patients were randomised to VV delay optimisation according to QRS complex width measurement in group 1 (n = 31) to obtain the narrowest QRS complex and SDI in group 2 (n = 32) to achieve its lowest possible value. We evaluated left ventricular end-systolic volume (LVESv), left ventricular ejection fraction (LVEF) and SDI by 3DE before CRT implantation and at a 12-month follow-up in all the patients. We also obtained the New York Heart Association functional class, the 6-minute walk test, the quality of life questionnaire and the level of NT-proBNP.
Results:
The number of volumetric responders was similar in both groups (17 vs. 20, P = 0.786). There were also no significant differences in the reduction of LVESv (-41 ± 55 mL vs. - 61 ± 51 mL, P = 0.111), improvement in LVEF (+10.1 ± 10.6% vs. + 13.0 ± 9.9%, P = 0.213) or differences in clinical outcomes between both groups at the 12-month follow-up.
Conclusion:
CRT optimisation of interventricular delay using SDI compared with QRS width assessment did not reveal any significant difference in terms of volumetric and clinical response at the 12-month follow-up.
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