Predictive values of left ventricular mechanical dyssynchrony for CRT response in heart failure patients with
Insights
Cardiac resynchronization therapy (CRT) response varies by heart condition. Optimal LV lead placement improves outcomes in dilated cardiomyopathy (DCM) but not ischemic cardiomyopathy (ICM) patients.
Area of Science:
- Cardiology
- Medical Imaging
- Biomedical Engineering
Background:
- Cardiac resynchronization therapy (CRT) effectiveness can be influenced by underlying heart conditions.
- Different pathophysiologies may lead to varying degrees of mechanical dyssynchrony and impact CRT outcomes.
Purpose of the Study:
- To investigate the relationship between left ventricular (LV) lead placement concordance and CRT response in patients with dilated cardiomyopathy (DCM) and ischemic cardiomyopathy (ICM).
- To identify predictors of CRT response specific to DCM and ICM.
- To compare CRT response rates based on LV lead positioning in relation to mechanical dyssynchrony.
Main Methods:
- Retrospective study of 92 DCM and 50 ICM patients undergoing CRT.
- Gated single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) used to assess mechanical dyssynchrony.
- Patients classified into 'both match', 'one match', or 'neither group' based on LV lead position relative to latest contraction/relaxation.
- CRT response defined as improvement in LV ejection fraction at 6-month follow-up.
Main Results:
- CRT response rates were 58.7% for DCM and 54% for ICM.
- In DCM, QRS duration, systolic/diastolic phase bandwidth (PBW), diastolic phase histogram standard deviation (PSD), and LV mechanical dyssynchrony (LVMD) concordance predicted response.
- In ICM, diabetes mellitus and LV end-systolic volume were associated with response.
- The 'both match' group showed significantly higher CRT response in DCM (94%) compared to ICM (62%).
Conclusions:
- Systolic PBW, diastolic PBW, and PSD are better predictors of CRT response in DCM than ICM.
- Optimizing LV lead placement to match latest contraction and relaxation improves outcomes in DCM patients.
- This lead placement strategy does not show similar benefits for ICM patients.
Background:
Cardiac resynchronization therapy (CRT) patients with different pathophysiology may influence mechanical dyssynchrony and get different ventricular resynchronization and clinical outcomes.
Methods:
Ninety-two dilated cardiomyopathy (DCM) and fifty ischemic cardiomyopathy (ICM) patients with gated single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) were included in this retrospective study. Patients were classified based on the concordance between the left ventricular (LV) lead and the latest contraction or relaxation position. If the LV lead was located on or adjacent to both the latest contraction and relaxation position, the patient was categorized into the both match group; if the LV lead was located on or adjacent to the latest contraction or relaxation position, the patient was classified into the one match group; if the LV lead was located on or adjacent to neither the latest contraction nor relaxation position, the patient was categorized to the neither group. CRT response was defined as [Formula: see text] improvement of LV ejection fraction at the 6-month follow-up. Variables with P < .05 in the univariate analysis were included in the stepwise multivariate model.
Results:
During the follow-up period, 58.7% (54 of 92) for DCM patients and 54% (27 of 50) for ICM patients were CRT responders. The univariate analysis and stepwise multivariate analysis showed that QRS duration, systolic phase bandwidth (PBW), diastolic PBW, diastolic phase histogram standard deviation (PSD), and left ventricular mechanical dyssynchrony (LVMD) concordance were independent predictors of CRT response in DCM patients; diabetes mellitus and left ventricular end-systolic volume were significantly associated with CRT response in ICM patients. The intra-group comparison revealed that the CRT response rate was significantly different in the both match group of DCM (N = 18, 94%) and ICM (N = 24, 62%) patients (P = .016). However, there was no significant difference between DCM and ICM in the one match and neither group. For the inter-group comparison, Kruskal-Wallis H-test revealed that CRT response was significantly different in all the groups of DCM patients (P < .001), but not in ICM patients (P = .383).
Conclusions:
Compared with ICM patients, systolic PBW, diastolic PBW and PSD have better predictive and prognostic values for the CRT response in DCM patients. Placing the LV lead in or adjacent to the latest contraction and relaxation position can improve the clinical outcomes of DCM patients, but it does not apply to ICM patients.
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