Prognostic implications of invasive hemodynamics during cardiac resynchronization therapy: Stroke work outperforms dP/dt_max

Background Invasive measurements of left ventricular (LV) hemodynamic performance can evaluate acute response to cardiac resynchronization therapy (CRT).Objective The study sought to determine which metric, maximum rate of LV pressure rise (LV dP/dt(max)) or LV stroke work (LVSW), is more strongly associated with long-term prognosis.Methods CRT patients were prospectively included from 3 academic centers. Invasive pressure-volume loop measurements during implantation were performed, and LV dP/dt(max) and LVSW were determined at baseline and during biventricular pacing (BVP) as well as their relative increase (%Delta). Hazard ratios (HRs) for the primary outcome of 8-year all-cause mortality were derived using Cox proportional hazards. The secondary endpoint was echocardiographic response, defined as 6-month LV end-systolic volume reduction >= 15%.Results Paired data from 82 patients were analyzed (67% male; age 66 +/- 9 years; QRS duration 158 +/- 22 ms, median survival time 72 months). Survival was better when LVSW during BVP was >= 4400 mL center dot mm Hg (HR 0.21, 95% CI 0.08-0.58, P < .003) or when Delta LVSW% was >= 10% (HR 0.22, 95% CI 0.08-0.65, P = .006). In multivariate analysis, following direct comparison of continuous measures of acute Delta LV dP/dt(max)% and Delta LVSW%, only Delta LVSW% remained associated with the primary endpoint (HR 0.982 per percentage point, P = .028). In contrast to LV dP/dt(max) (all P > .05), significant associations with echocardiographic response were found for stroke work during BVP (area under the receiver-operating characteristic curve 0.745, P = .001) and Delta LVSW% (area under the receiver-operating characteristic curve 0.803, P < .001).Conclusion Stroke work, but not LV dP/dt(max,) is consistently associated with long-term prognosis and response after CRT. Our results therefore favor the use of stroke work as the hemodynamic parameter to predict long-term outcome after CRT.