Efficacy of Cardiac Resynchronization Therapy in Patients with a Narrow QRS Complex

Abstract

Aims. In the guidelines for cardiac resynchronization therapy (CRT), there is a gap between the Japanese Circulation Society (JCS) criteria, which specify a QRS duration of ≥120 ms, and other countries, with a QRS ≥ 130 ms. The efficacy of CRT remains controversial in patients with a narrow QRS <130 ms. The aims of this study are to evaluate the response to CRT in patients with a narrow QRS and to identify predictors of mortality. Methods. We retrospectively studied 212 patients who received CRT. They were divided into narrow QRS (<130 ms) and wide QRS (≥130 ms) groups. We compared CRT response rates and investigated whether age, gender, baseline New York Heart Association (NYHA) class, ischemic etiology, atrial fibrillation, and ventricular arrhythmias are associated with response and also predictive of mortality. Results. The CRT response rate was not significantly different between the wide QRS group and the narrow QRS group (74.6% versus 77.2%, p = 0.6876), and the response rate in the narrow QRS group was as good as that reported worldwide. NYHA class IV was shown to be a predictor of mortality (HR 9.38, 95% CI 5.35–16.3, p < 0.0001). Conclusions. The present study demonstrated that patients with a narrow QRS complex responded well to CRT. Even with QRS <130 ms, CRT should be tried if no other effective treatment is available.

Cardiac resynchronization therapy: Current status and near-future prospects

“…Our study also confirmed that overall survival is significantly better in NYHA class II or III heart failure compared with NYHA IV heart failure ( Fig. 1 ) [10] .…”

CRT Past, Present, and Future Directions: Toward Intelligent Responders Selection and Optimizing Pacing Modalities

“…Critical variables such as global scar burden, scar location, lead position, programmed AV and VV interval, mitral regurgitation, and irreversibly advanced heart failure cases are imperative considerations to improve the outcome [20] Despite the traditional dogma that normal QRS duration is a contraindication for CRT, recent challenging groups suggest that QRS complex <130 ms might benefit from CRT. This response as they describe it, is personalized but having QRS complex <130 ms should not be a reason to withhold the option of CRT in systolic heart failure if no other effective treatment is available [21]. Despite the claim that CRT is under-utilized worldwide, we suggest more wise selections with the advanced criteria for more intelligent selection.…”