The BRIGHT study: Bifocal right ventricular resynchronization therapy: A randomized study
Aims: The BRIGHT study evaluated bifocal right ventricular (RV) (apex and outflow tract) pacing in a single, blind, randomized crossover study in patients eligible for cardiac resynchronization therapy (CRT). Forty-two patients were enrolled with the following characteristics: chronic drug refractory heart failure New York Heart Association (NYHA) class III-IV; ejection fraction (EF)<35%; QRS width ≥ 120 ms; and a left bundle branch block. The aim of the study was to assess an improvement in left ventricular (LV) EF, 6 min walk test, Minnesota quality-of-life score, and NYHA classification. Methods and result: Patients were randomized to receive either bifocal pacing or the control mode, each for a period of 3 months. Parameters were measured prior to randomization and after 3 months of control or bifocal pacing. Eight patients failed to make the 7 month follow-up, three patients died (one prior to randomization at the first month), five patients dropped out, and three patients refused further participation. One patient had a persistent lead problem, which was subsequently replaced with an LV lead, and one patient suffered with persistent atrial fibrillation. Compared with baseline, bifocal pacing improved EF from 26 ± 12% to 36 ± 11% (P < 0.0008), NYHA classification decreased from 2.8 ± 0.4 to 2.3 ± 0.7 (P < 0.007). Furthermore, the 6 min walk test improved from 372 ± 129 m to 453 ± 122 m (P < 0.05), and the Minnesota Living with Heart Failure scores decreased from 33 ± 20 to 24 ± 21 (P < 0.006). In the control group, no significant changes in any parameters were observed. Eight patients did not tolerate reprogramming from DDD BRIGHT to control pacing, with symptoms disappearing in all patients after reprogramming to bifocal pacing. Conclusion: Bifocal RV pacing in patients with a classic indication for CRT shows improvement in all parameters.