CSP offers a physiologic strategy for cardiac resynchronization, yet evidence from randomized trials has been limited compared with BiVP. The CONSYST-CRT trial, published in JACC: Clinical Electrophysiology, directly compared CSP with BiVP in 134 in patients with systolic dysfunction and wide QRS complexes.

At 12 months, the primary composite endpoint included all-cause mortality, cardiac transplantation, heart failure hospitalization, or left ventricular ejection fraction (LVEF) improvement <5%. This outcome occurred in 23.9% of patients treated with CSP and 29.8% of those treated with BiVP, meeting criteria for noninferiority (P=0.02). Echocardiographic response, defined as ≥15% reduction in LV end-systolic volume, was achieved in 66.6% of CSP patients compared with 59.7% with BiVP group (P=0.03 for NI).

CSP further demonstrated significant noninferiority for QRS narrowing and NYHA functional class improvement. However,  LVEF, LV end-systolic volume (LVESV), and septal flash correction were similar between groups but did not reach noninferiority.

These findings support CSP as a clinically valid alternative to BiVP for CRT, though larger multicenter trials are warranted for broader validation.