Long-term outcome of patients with and without super-response to CRT-D

Predictive value of frontal QRS-T angle after cardiac resynchronization therapy

OBJECTIVE

It is practical and useful to detect patients who benefit from cardiac resynchronization therapy (CRT) by electrocardiographic (ECG) methods. In this study, the predictive role of the frontal QRS-T angle and other ECG parameters was evaluated in CRT responder patients.

METHOD

Seventy-seven consecutive patients with left ventricular ejection fraction (LVEF) ≤ 35%, New York Heart Association (NYHA) classes II-III, ambulatory class IV and normal sinus rhythm, who had complete left bundle branch block and were treated with CRT were included in this study. Patients were classified as "CRT responders" and "CRT non responders" according to their LVEF improvement. The frontal QRS-T angle was calculated as the absolute value of the difference between the QRS and T wave axes [frontal QRS-T angle = (QRS axis-T axis)].

RESULTS

The mean age of the patients was 64.5 ± 9.1 years, and the average follow-up was 28 (12-47) months. The post-implantation LVEF was higher in the patients CRT responders group (p < 0.001). Post-implantation frontal QRS-T angle (p = 0.003), QRS duration (p = 0.008) and cQT interval (p = 0.012) values were much shorter in the CRT responder group. Multivariable regression analyses showed that the frontal QRS-T angle and age were independent risk factors for CRT response (p = 0.009). The results of the receiver operating characteristic curve analyses (ROC) showed that the predictive optimal cut-off value of CRT response for the frontal QRS-T angle was <135 degrees (AUC: 0.69, 95% CI 0.575-0.814, p = 0.004).

CONCLUSION

The narrowed frontal QRS-T angle (<135 degrees), QRS duration and cQT interval were associated with CRT response in heart failure patients. The frontal QRS-T angle can be an independent predictor of CRT response.

Risk of ventricular arrhythmia in cardiac resynchronization therapy responders and super-responders: a systematic review and meta-analysis

AIMS

Response to cardiac resynchronization therapy (CRT) is associated with improved survival, and reduction in heart failure hospitalization, and ventricular arrhythmia (VA) risk. However, the impact of CRT super-response [CRT-SR, increase in left ventricular ejection fraction (LVEF) to ≥ 50%] on VA remains unclear.

METHODS AND RESULTS

We undertook a meta-analysis aimed at determining the impact of CRT response and CRT-SR on risk of VA and all-cause mortality. Systematic search of PubMed, EMBASE, and Cochrane databases, identifying all relevant English articles published until 31 December 2019. A total of 34 studies (7605 patients for VA and 5874 patients for all-cause mortality) were retained for the meta-analysis. The pooled cumulative incidence of appropriate implantable cardioverter-defibrillator therapy for VA was significantly lower at 13.0% (4.5% per annum) in CRT-responders, vs. 29.0% (annualized rate of 10.0%) in CRT non-responders, relative risk (RR) 0.47 [95% confidence interval (CI) 0.39-0.56, P < 0.0001]; all-cause mortality 3.5% vs. 9.1% per annum, RR of 0.38 (95% CI 0.30-0.49, P < 0.0001). The pooled incidence of VA was significantly lower in CRT-SR compared with CRT non-super-responders (non-responders + responders) at 0.9% vs. 3.8% per annum, respectively, RR 0.22 (95% CI 0.12-0.40, P < 0.0001); as well as all-cause mortality at 2.0% vs. 4.3%, respectively, RR 0.47 (95% CI 0.33-0.66, P < 0.0001).

CONCLUSIONS

Cardiac resynchronization therapy super-responders have low absolute risk of VA and all-cause mortality. However, there remains a non-trivial residual absolute risk of these adverse outcomes in CRT responders. These findings suggest that among CRT responders, there may be a continued clinical benefit of defibrillators.

Biventricular Pacing Going Along with Acute Hemodynamic Response in a Patient with Huge Anterior Wall Aneurysm - Importance of Pacing Viable Myocardium

Patient: Female, 85

Final Diagnosis: Ischemic cardiomyopathy with electrical storm

Symptoms: Dyspnea

Medication: —

Clinical Procedure: Ablation of ventricular tachycardia

Specialty: Cardiology