What does this research mean for the field?

Cardiac resynchronization therapy (CRT) upgrade is associated with long-term clinical and echocardiographic improvement, with pacemaker-induced cardiomyopathy identified as a predictor of left ventricular reverse remodelling. Novelty: ClaimNovelty.CONFIRMATORY. Consensus alignment: ConsensusAlignment.SUPPORTS_CONSENSUS.

March 13, 2026Open Access

Long Term Outcomes and Predictors of Reverse Remodelling After Cardiac Resynchronization Therapy Upgrade

Q: What question did this study set out to answer?

The study aims to assess long-term outcomes and identify predictors of left ventricular reverse remodelling after cardiac resynchronization therapy upgrades.

Key Result

Patients upgraded to CRT with pacemaker showed a greater improvement in left ventricular ejection fraction (15% vs. 9%, p < 0.003) compared to those upgraded to CRT with defibrillator.

Key Points

The study aims to assess long-term outcomes and identify predictors of left ventricular reverse remodelling after cardiac resynchronization therapy upgrades.
Evaluated 97 patients who underwent CRT upgrade at a tertiary referral centre.
Patients were split into two groups: 57 upgraded to CRT with pacemaker (CRT-P) and 40 to CRT with defibrillator (CRT-D).
Long-term clinical and echocardiographic outcomes were measured over a 5-year follow-up period.
47% of patients died from any cause during the follow-up.
CRT-D patients had a 63% composite endpoint occurrence of death or first appropriate shock, compared to 37% in CRT-P patients (p = 0.013).
CRT-P patients showed a greater improvement in left ventricular ejection fraction (LVEF) compared to CRT-D patients (15% vs. 9%, p < 0.003).
Non-ischemic cardiomyopathy patients experienced a more significant LVEF improvement than ischemic patients (17% vs. 10%, p < 0.01).
Pacemaker-induced cardiomyopathy was identified as a predictor of left ventricular reverse remodelling.

Structured PICO

Does cardiac resynchronization therapy (CRT) upgrade improve long-term clinical and echocardiographic outcomes, and what predicts left ventricular reverse remodelling?

Population

97 patients undergoing cardiac resynchronization therapy (CRT) upgrade at a single tertiary referral centre (57 upgraded to CRT-P, 40 to CRT-D).

Intervention

Cardiac resynchronization therapy (CRT) upgrade (CRT-P or CRT-D)

Comparator

CRT-P versus CRT-D (observational comparison, though not originally designed for direct comparison)

Outcome

Long-term clinical, echocardiographic (LVEF improvement), and device-related outcomes (including a composite endpoint of death or time to first appropriate shock) over a 5-year follow-up periodcomposite

CRT upgrade is associated with long-term clinical and echocardiographic improvements, with pacemaker-induced cardiomyopathy serving as a strong independent predictor of left ventricular reverse remodelling.

Main Result

Absolute Event Rate: 0% vs 0%

Abstract

Background and Objectives: Upgrades to cardiac resynchronization therapy (CRT) account for approximately one quarter of all CRT indications. Although recent clinical trials have demonstrated significant clinical benefits of upgrade procedures, data on the long-term clinical effects of CRT upgrades remain limited. This study aimed to evaluate long-term clinical, echocardiographic, and device-related outcomes after CRT upgrade and to determine predictors of left ventricular reverse remodelling. Materials and Methods: A total of 97 patients underwent CRT upgrade at a tertiary referral centre, including 57 patients upgraded to CRT with pacemaker (CRT-P) and 40 to CRT with defibrillator (CRT-D). Results: During a 5-year follow-up period, 46 patients (47%) died from any cause. Appropriate device therapy was recorded in 13 (33%) CRT-D patients. The composite endpoint of death or time to first appropriate shock occurred in 25 (63%) CRT-D patients compared with 21 (37%) CRT-P patients (p = 0.013). Patients with CRT-P demonstrated a significantly greater improvement in left ventricular ejection fraction (LVEF) than those with CRT-D (15% vs. 9%, p < 0.003). Greater LVEF improvement was observed in patients with non-ischemic compared with ischemic cardiomyopathy (17% vs. 10%, p < 0.01). In multivariable analysis, pacemaker-induced cardiomyopathy (PICMP) was identified as a predictor of left ventricular (LV) reverse remodelling. Conclusions: In this prospective, non-randomized cohort, CRT upgrade was associated with long-term clinical and echocardiographic improvement. Differences observed between CRT-P and CRT-D groups should be interpreted cautiously, as the study was not designed for direct comparison. PICMP was independently associated with LV reverse remodelling.