Abstract 3041: Biventricular Pacing in Patients with Severely Reduced LV-function After CABG - The BIVAC-Trial
Background: Biventricular pacing (BIV) has been shown to be highly effective in pts with severely reduced LV function. Pressure volume loop analysis has shown acute perioperative hemodynamic benefits of BIV, the optimal postoperative pacing mode after coronary artery bypass grafting (CABG) in this subset of pts is still unknown.
Hypothesis: BIV is superior to DDD-right ventricular (RV) and AAI-pacing (AAI) in CABG pts with EF <40%.
Methods and Results: 92 pts (mean age 67±9y, mean EF 35 ± 4%) were randomised to either BIV, RV or AAI pacing at 90/min for 96h postoperatively. Duration of intensive care unit (ICU) stay, renal dysfunction, incidence of postoperative AF and VT, inotropic support, NT-pro-BNP level pre-op and 1h, 24h and 96h post-op were evaluated. A composite endpoint of mortality, stroke, intraaortic-balloon-pump usage, myocardial infarction, revascularization and rethoracotomy was defined. Cardiac index (CI), mean pulmonary artery pressure (PAP), mean arterial pressure (MAP) and mixed venous saturation (MVO2) were determined every 4h. Hemodynamic results are shown in table 1⇓. CI, MAP, PAP, MVO2 and cumulative inotropes did not differ significantly between groups for all time points. Neither raw NT-pro-BNP at all time points nor differential values to pre-op values differed significantly between groups. Mean ICU stay did not differ significantly for all pacing modes. The cumulative clinical endpoint was: AAI: 4, RV: 5; BIV: 5 (n.s.). Incidence of postoperative AF was 40% for AAI, 29% for RV and 37% for BIV (n.s.). Cumulative incidence of VT was 11% (n.s.). Glomerular filtration rate (AAI: 83 ± 37; RV: 77 ± 25; BIV 79 ± 35 ml/min) and patients with cumulative RIFLE-Score ≥ 1 (AAI: 17%, RV: 16%; BIV: 26%) did not differ significantly.
Conclusion: BIV is safe and feasible in CABG patients with severly reduced EF. However, the short-term hemodynamic benefits of BIV do not translate into improved postoperative hemodynamics or clinical outcomes compared to RV and AAI