Cardiac Resynchronization Therapy (CRT) Optimization: A Way Out for Non-Responders - A Case Report
Abstract
Background
Non-responders account for 30% of patients receiving Cardiac Resynchronization Therapy (CRT). Optimization of CRT using Electrocardiographic (ECG) and Transthoracic Echocardiographic (TTE) guidance has been proposed as a strategy to enhance therapeutic efficacy in this subset. This case report presents a young female patient with advanced heart failure secondary to ischemic cardiomyopathy, highlighting the role of ECG- and TTE-guided CRT optimization in improving clinical and hemodynamic outcomes.
Case Illustration
A 37-year-old female presented with advanced heart failure. Her medical history was notable for recurrent episodes of acute coronary syndrome, multiple Percutaneous Coronary Interventions (PCIs), and Cardiac Resynchronization Therapy with Pacemaker (CRT-P) implantation, despite adherence to Guideline-Directed Medical Therapy (GDMT).
On admission, the ECG demonstrated atrial sensing with consistent biventricular pacing. Laboratory evaluation revealed an elevated N-terminal pro–B-type natriuretic peptide (NT-proBNP) level of 5.462 pg/mL. TTE showed a severely reduced Left Ventricular Ejection Fraction (LVEF) of 20% and an absent A wave on mitral inflow Doppler, indicating impaired diastolic filling. Additionally, the Left Ventricular Outflow Tract (LVOT) Velocity Time Integral (VTI) was reduced to 7.4 cm, consistent with low forward stroke volume.
Six months after the implantation, CRT optimization was performed using ECG and TTE guidance. Optimization resulted in a reduction of QRS duration to 129 ms, distinct separation of the mitral inflow E and A waves, an increase in LVOT VTI to 10.9 cm, and an improvement in functional capacity to New York Heart Association (NYHA) class III.
Conclusion
CRT optimization, guided by ECG or TTE, is critical in managing non-responders. In this case, it led to improved QRS duration, hemodynamics, and NYHA functional class. Routine reassessment should be considered in patients with persistent symptoms despite optimal GDMT to enhance clinical response.
Downloads
References
2. Katbeh A, Van Camp G, Barbato E, et al. Cardiac Resynchronization Therapy Optimization: A Comprehensive Approach. Cardiology (Switzerland). 2019;142(2):116-127. doi:10.1159/000499192
3. Yamin M. What Is the Cause of Non-responders in CRT and How to Identify It? Indonesian Journal of Cardiology. 2017;38(2):59-63. doi:10.30701/ijc.v38i2.728
4. Tomassoni G. How to Define Cardiac Resynchronization Therapy Response. Journal of Innovations in Cardiac Rhythm Management. 2016;7(00):S1-S7. doi:10.19102/icrm.2016.070003
5. Pujol-López M, San Antonio R, Mont L, et al. Electrocardiographic optimization techniques in resynchronization therapy. Europace. 2019;21(9):1286-1296. doi:10.1093/europace/euz126
6. Daubert C, Behar N, Martins RP, Mabo P, Leclercq C. Avoiding non-responders to cardiac resynchronization therapy: A practical guide. Eur Heart J. 2017;38(19):1463-1472. doi:10.1093/eurheartj/ehw270
7. Shanks M, Delgado V, Bax JJ. Cardiac Resynchronization Therapy in Non-Ischemic Cardiomyopathy. J Atr Fibrillation. 2016;8(5):1362. doi:10.4022/JAFIB.1362
8. Ypenburg C, Schalij MJ, Bleeker GB, et al. Impact of viability and scar tissue on response to cardiac resynchronization therapy in ischaemic heart failure patients. Eur Heart J. 2007;28(1):33-41. doi:10.1093/EURHEARTJ/EHL379,
9. Adelstein EC, Saba S. Scar burden by myocardial perfusion imaging predicts echocardiographic response to cardiac resynchronization therapy in ischemic cardiomyopathy. Am Heart J. 2007;153(1):105-112. doi:10.1016/J.AHJ.2006.10.015,
10. Sieniewicz BJ, Gould J, Porter B, et al. Understanding non-response to cardiac resynchronisation therapy: common problems and potential solutions. Heart Fail Rev. 2019;24(1):41-54. doi:10.1007/s10741-018-9734-8
11. Gorcsan J, Abraham T, Agler DA, et al. Echocardiography for Cardiac Resynchronization Therapy: Recommendations for Performance and Reporting-A Report from the American Society of Echocardiography Dyssynchrony Writing Group Endorsed by the Heart Rhythm Society. Journal of the American Society of Echocardiography. 2008;21(3):191-213. doi:10.1016/j.echo.2008.01.003
12. Brabham WW, Gold MR. The role of AV and VV optimization for CRT. J Arrhythm. 2013;29(3):153-161. doi:10.1016/j.joa.2013.02.001
13. Jastrzebski M, Baranchuk A, Fijorek K, et al. Cardiac resynchronization therapy-induced acute shortening of QRS duration predicts long-term mortality only in patients with left bundle branch block. Europace. 2019;21(2):281-289. doi:10.1093/europace/euy254
14. Borgquist R, Marinko S, Platonov PG, et al. Maximizing QRS duration reduction in contemporary cardiac resynchronization therapy is feasible and shorter QRS duration is associated with better clinical outcome. Journal of Interventional Cardiac Electrophysiology. 2023;66(8):1799-1806. doi:10.1007/S10840-022-01463-Y,
15. Sudesh S, Abraham WT, Cleland JGF, et al. Cardiac Resynchronization Therapy in Ischemic Versus Nonischemic Cardiomyopathy: Patient-Level Meta-Analysis of 7 Randomized Clinical Trials. JACC Heart Fail. 2024;12(11):1915-1924. doi:10.1016/j.jchf.2024.08.010
16. Leclercq C, Burri H, Calò L, et al. Multipoint pacing is associated with reduction of heart failure hospitalizations or death in patients who do not respond to cardiac resynchronization therapy: Results of the MORE-CRT MPP randomized trial. Europace. 2025;27(6). doi:10.1093/EUROPACE/EUAF070,
17. Tavolinejad H, Kazemian S, Bozorgi A, et al. Effectiveness of conduction system pacing for cardiac resynchronization therapy: A systematic review and network meta-analysis. J Cardiovasc Electrophysiol. 2023;34(11):2342-2359. doi:10.1111/JCE.16086,
18. Khan FZ, Virdee MS, Palmer CR, et al. Targeted left ventricular lead placement to guide cardiac resynchronization therapy: The TARGET study: A randomized, controlled trial. J Am Coll Cardiol. 2012;59(17):1509-1518. doi:10.1016/J.JACC.2011.12.030,
19. Kingma TJ, Albeyoumi H, Kolluri M, et al. Target doses of guideline-directed medical therapeutic agents predicts response to cardiac resynchronization therapy. Clinical Research in Cardiology. Published online 2025. doi:10.1007/S00392-025-02708-2
PDF downloads: 133
Copyright (c) 2026 Indonesian Journal of Cardiology
This work is licensed under a Creative Commons Attribution 4.0 International License.
Authors who publish with this journal agree to the following terms:
- Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.
- Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.
- Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work (See The Effect of Open Access).
