Baseline left ventricular dP/dtmax rather than the acute improvement in dP/dtmax predicts clinical outcome in patients with cardiac resynchronization therapy

Abstract

The maximum rate of left ventricular (LV) pressure rise (dP/dt(max)) has been used to assess the acute haemodynamic effect of cardiac resynchronization therapy (CRT). We tested the hypothesis that LV dP/dt(max) predicts long-term clinical outcome after initiation of CRT. This was a retrospective observational multicentre study in 285 patients in whom dP/dt(max) was measured invasively following implantation of a CRT device. The minimum required follow-up was 1 year. We analysed the relationship between dP/dt(max) and time to the composite endpoint, consisting of all-cause mortality, heart transplantation (HTX), or LV assist device (LVAD) implantation within the first year of CRT. Thirty-four events occurred after a mean follow-up of 160 days (range 21-359). Patients with an event had lower dP/dt(max) than patients without an event both at baseline (705 ± 194 vs. 800 ± 222 mmHg/s, P= 0.018) and during CRT (894 ± 224 vs. 985 ± 244 mmHg/s, P= 0.033), but the acute increase in dP/dt(max) was similar in patients with and without an event (190 ± 133 vs. 185 ± 115 mmHg/s, P= n.s.). Left ventricular dP/dt(max)-level at baseline and during CRT both predicted the clinical outcome after adjustment for gender, aetiology and New York Heart Association class: hazard ratio (HR) 0.791 [95% confidence interval (CI) 0.658-0.950, P= 0.012] and HR 0.846 (95% CI 0.723-0.991, P= 0.038), respectively. Left ventricular dP/dt(max) measured at baseline and during CRT are predictors of 1-year survival free from all-cause mortality, HTX, or LVAD implantation, but the acute improvement in dP/dt(max) is not correlated to clinical outcome.