Predictors and Clinical Outcomes of Transient Responders to Cardiac Resynchronization Therapy
Hirotoshi Ichibori1, Koji Fukuzawa1,2, Kunihiko Kiuchi1,2
1Division of Cardiovascular Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe, Japan.
Insights
Nearly one-third of cardiac resynchronization therapy responders experienced transient left ventricular end-systolic volume reduction. These patients, particularly those with chronic atrial fibrillation, face poorer long-term outcomes and increased heart failure hospitalizations.
Area of Science:
- Cardiology
- Heart Failure Management
- Medical Device Therapy
Background:
- Cardiac resynchronization therapy (CRT) response is typically assessed by left ventricular end-systolic volume (LVESV) changes at 6 months.
- Long-term LVESV regression beyond 6 months after CRT is not well-described.
- Understanding sustained CRT response is crucial for patient prognosis.
Purpose of the Study:
- To determine the proportion of CRT responders with transient LVESV reduction.
- To identify predictors of transient LVESV response to CRT.
- To evaluate the long-term clinical outcomes of transient versus sustained CRT responders.
Main Methods:
- Retrospective analysis of 104 consecutive CRT patients.
- Responder definition: ≥15% relative reduction in LVESV at 6 months post-CRT.
- Transient responder definition: <15% LVESV reduction at 2 years or cardiac death within 24 months.
Main Results:
- 16 out of 56 (29%) responders were classified as transient responders.
- Chronic atrial fibrillation (OR=19.2) and amiodarone use (OR=60.9) independently predicted transient responses.
- Transient responders had significantly higher heart failure hospitalizations (P<0.001) and a trend towards higher all-cause mortality (P=0.093) over 7.6 years.
Conclusions:
- Approximately one-third of CRT responders exhibit transient LVESV reduction.
- Transient responders have significantly worse long-term clinical outcomes, including heart failure hospitalizations.
- Patients with chronic atrial fibrillation require close monitoring to maintain LVESV reduction post-CRT.
Background:
Left ventricular end-systolic volume (LVESV) changes at 6 months and clinical status are useful for assessing responses to cardiac resynchronization therapy (CRT). Regression of the LVESV following CRT has not been described beyond 6 months. This study aimed to assess the proportion, predictors, and clinical outcomes of responders whose LVESVs had regressed.
Methods:
We retrospectively analyzed 104 consecutive CRT patients. A responder was defined as a patient with a relative reduction in the LVESV ≥15% at 6 months after CRT. Fifty-six responders participated in this study. A transient responder was defined as a responder without a relative reduction in the LVESV ≥15% at 2 years after CRT or who died of cardiac events during the 24-month follow-up period.
Results:
Of the 56 responders, 16 (29%) were transient responders. Multivariable logistic regression analysis showed that chronic atrial fibrillation (odds ratio [OR] = 19.2, 95% confidence interval [CI] [1.93, 190], P = 0.012) and amiodarone usage (OR = 60.9, 95% CI [4.18, 886], P = 0.003) were independent predictors of transient responses. Hospitalizations for heart failure were significantly higher among the transient responders than among the lasting responders during a mean follow-up period of 7.6 years (log-rank P < 0.001), and all-cause mortality tended to be higher among the transient responders (log-rank P = 0.093).
Conclusions:
One-third of the responders were transient responders at 2 years after CRT, and their long-term prognoses were poor. Careful attention should be paid to maintain the reduction in LVESV especially in patients with chronic AF.
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