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Novel Non-Invasive Index for Prediction of Responders in Cardiac Resynchronization Therapy Using High-Resolution
Takahiro Nakashima1, Shunsuke Usami1, Takeshi Aiba1
1Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Center.
Insights
Magnetocardiography (MCG) can predict cardiac resynchronization therapy (CRT) response in heart failure patients. Unidirectional conduction patterns on MCG indicate a higher likelihood of CRT success and better long-term outcomes.
Area of Science:
- Cardiology
- Biomedical Engineering
- Medical Imaging
Background:
- Cardiac resynchronization therapy (CRT) is a treatment for advanced heart failure (HF).
- Approximately one-third of HF patients do not respond to CRT.
- Predicting CRT response is crucial for optimizing patient outcomes.
Purpose of the Study:
- To investigate if left ventricular (LV) conduction patterns on magnetocardiography (MCG) can predict CRT response.
- To assess the long-term prognostic value of MCG-derived conduction patterns after CRT.
Main Methods:
- Retrospective study of 56 advanced HF patients undergoing CRT.
- Magnetocardiography (MCG) recorded pre-CRT to classify LV conduction as multidirectional (MDC) or unidirectional (UDC).
- Assessed CRT response at 6 months and adverse cardiac events over 5 years.
Main Results:
- Unidirectional conduction (UDC) on MCG was associated with significantly higher CRT response rates (89% vs. 14% for MDC).
- Patients with UDC showed fewer adverse cardiac events over 5 years (P=0.027).
- UDC was the strongest independent predictor of CRT response (OR 69.8, P<0.001).
Conclusions:
- Preoperative non-invasive MCG can predict CRT response in heart failure patients.
- MCG-based LV conduction patterns offer valuable prognostic information for long-term outcomes after CRT.
Background:
Approximately one-third of patients with advanced heart failure (HF) do not respond to cardiac resynchronization therapy (CRT). We investigated whether the left ventricular (LV) conduction pattern on magnetocardiography (MCG) can predict CRT responders.
Methods And Results:
This retrospective study enrolled 56 patients with advanced HF (mean [±SD] LV ejection fraction [LVEF] 23±8%; QRS duration 145±19 ms) and MCG recorded before CRT. MCG-QRS current arrow maps were classified as multidirectional (MDC; n=28) or unidirectional (UDC; n=28) conduction based on a change of either ≥35° or <35°, respectively, in the direction of the maximal current arrow after the QRS peak. Baseline New York Heart Association functional class and LVEF were comparable between the 2 groups, but QRS duration was longer and the presence of complete left bundle branch block and LV dyssynchrony was higher in the UDC than MDC group. Six months after CRT, 30 patients were defined as responders, with significantly more in the UDC than MDC group (89% vs. 14%, respectively; P<0.001). Over a 5-year follow-up, Kaplan-Meyer analysis showed that adverse cardiac events (death or implantation of an LV assist device) were less frequently observed in the UDC than MDC group (6/28 vs. 15/28, respectively; P=0.027). Multivariate analysis revealed that UDC on MCG was the most significant predictor of CRT response (odds ratio 69.8; 95% confidence interval 13.14-669.32; P<0.001).
Conclusions:
Preoperative non-invasive MCG may predict the CRT response and long-term outcome after CRT.
