Intraventricular synchronism assessment by gated-SPECT myocardial perfusion imaging in cardiac resynchronization
Amalia Peix1, Kenia Padrón2, Lázaro O Cabrera2
1Nuclear Medicine Department, Institute of Cardiology and Cardiovascular Surgery, 17 #702, Vedado, 10 400, La Habana, Cuba. atpeix@gmail.com.
Insights
Cardiac resynchronization therapy (CRT) significantly improves left ventricular non-compaction (LVNC) cardiomyopathy, especially in non-ischemic patients. Gated-SPECT myocardial perfusion imaging effectively assesses CRT response, showing marked dyssynchrony reduction in LVNC patients.
Area of Science:
- Cardiology
- Nuclear Medicine
- Cardiomyopathy Research
Background:
- Left ventricular non-compaction (LVNC) is a rare cardiomyopathy with significant morbidity.
- Cardiac resynchronization therapy (CRT) is a treatment for heart failure patients with reduced ejection fraction and dyssynchrony.
- The response to CRT in LVNC patients compared to other cardiomyopathies is not well-defined.
Purpose of the Study:
- To analyze the clinical and functional evolution of left ventricular non-compaction (LVNC) cardiomyopathy patients post-cardiac resynchronization therapy (CRT).
- To compare CRT outcomes in LVNC patients with those suffering from ischemic and non-ischemic cardiomyopathies.
- To evaluate the utility of gated-SPECT myocardial perfusion imaging (MPI) in assessing CRT response.
Main Methods:
- Ninety-three patients were divided into three groups: non-ischemic CM with LVNC (11), ischemic CM (28), and non-ischemic CM (53).
- Gated-SPECT MPI with 99mTc-MIBI was performed pre- and 6 months post-CRT, including phase analysis for intraventricular dyssynchrony.
- Quality of life was assessed using the Minnesota Living with Heart Failure Questionnaire (MLHFQ).
Main Results:
- LVNC patients exhibited significantly higher baseline intraventricular dyssynchrony (higher phase standard deviation) compared to other groups.
- All groups showed improved quality of life post-CRT, with non-ischemic patients (including LVNC) demonstrating greater left ventricular ejection fraction increase and volume reduction.
- LVNC patients, despite higher baseline dyssynchrony, showed the most significant improvement in synchronism post-CRT, with 100% responders and no adverse events.
Conclusions:
- Cardiac resynchronization therapy (CRT) significantly benefits patients with non-compaction cardiomyopathy, particularly in the non-ischemic subgroup.
- Phase analysis in gated-SPECT MPI is a valuable tool for assessing CRT effectiveness and predicting response.
- LVNC patients demonstrate a robust positive response to CRT, highlighting its therapeutic potential in this specific cardiomyopathy.
Purpose:
To analyze the evolution post-cardiac resynchronization therapy (CRT) in left ventricular non-compaction (LVNC) cardiomyopathy (CM) patients compared to other types of CM, according to clinical and functional variables, by using gated-SPECT myocardial perfusion imaging (MPI).
Methods:
Ninety-three patients (60 ± 11 years, 28% women) referred for pre-CRT assessment were studied and divided into three groups: 1 (non-ischemic CM with LVNC, 11 patients), 2 (ischemic CM, 28 patients), and 3 (non-ischemic CM, 53 patients). All were studied by a 99mTc-MIBI gated-SPECT MPI at rest pre-CRT implantation and 6 ± 1 months after, including intraventricular dyssynchrony assessment by phase analysis. Quality of life was measured by the Minnesota Living with Heart Failure Questionnaire (MLHFQ).
Results:
No differences in sex, atherosclerotic risk factors other than smoking habit, and MLHFQ results were found among groups. LVNC CM patients were younger, with greater QRS width and lower left ventricular ejection fraction (LVEF) at baseline, but the differences were not significant. No significant differences were found at baseline regarding ventricular function, although end-systolic volume was slightly higher in LVNC CM patients. Mean SRS was significantly higher (p < 0.0001) in ischemic patients (14.9) versus non-ischemic ones (8.7 in group 1 and 9 in group 2). At baseline, LVNC CM patients were significantly more dyssynchronous: Their phase standard deviation (PSD) was higher (89.5° ± 14.2°) versus groups 2 (65.2° ± 23.3°) and 3 (69.7° ± 21.7°), p = 0.007. Although the quality of life significantly improved in all groups, non-ischemic patients (with or without LVNC) showed a higher LVEF increase and volumes reduction at 6 months post-CRT. Dyssynchrony reduced post-CRT in all groups. Nevertheless, those more dyssynchronous at baseline (LVNC CM) exhibited the most significant intraventricular synchronism improvement: PSD was reduced from 89.5° ± 14.2° at baseline to 63.7° ± 20.5° post-CRT (p = 0.028). Six months post-CRT, 89% of patients were responders: 11 (100%) of those with LVNC CM, 25 (86%) of those with ischemic CM, and 47 (89%) of patients with non-ischemic CM. No patient with LVNC CM had adverse events during the follow-up.
Conclusion:
CRT contributes to a marked improvement in non-ischemic CM patients with non-compaction myocardium. Phase analysis in gated-SPECT MPI is a valuable tool to assess the response to CRT.
