151 Impact of left ventricular-vascular interaction on long-term outcome after heart transplantation

Background and aim In heart transplant (HT) recipients, early alterations of graft function are often asymptomatic and, therefore, underrecognized. The investigation of ventricular-vascular interaction could identify poor outcomes in HT recipients with normal left ventricular ejection fraction (LVEF). We compared pressure-volume (PV) derivative variables between HT patients and healthy controls. Additionally, we assessed the influence of ventricular-arterial coupling (VAC) and its components on long-term outcome. Methods in this single-center retrospective observational cohort study, HT patients surviving their first post-HT year with LVEF ≥50%, absence of allograft vasculopathy and acute rejection were enrolled. VAC and other PV derived parameters were measured by transthoracic Doppler echocardiography and then compared with healthy controls, matched for age and sex. The endpoint was cardiovascular mortality after the first year from HT. Results: from 1985 to 2015, 345 patients were enrolled. Arterial elastance (Ea) and ventricular elastance (Ees) were higher in HT recipients than in healthy controls (4.03 vs. 1.65, p<;0.0001 and 6.75 vs 2.47, p<0.0001, respectively), while VAC was similar between the two groups (0.66 vs. 0.59, p=0.105). Cardiac energetic parameters (stroke work, potential energy, PV area) were significantly reduced in HT patients. After a median of 11.3-year follow-up, 59 (17%) HT recipients died. VAC was not significantly associated with cardiac mortality (p=0.074). Conversely, survival was lower in HT recipients with Ea<4 mmHg/mL and Ees≤6.75 mmHg/mL, and both were independently associated with mortality risk after adjustment (Ea > 4 mmHg/mL: HR 2.25 [95% CI 1.38–3.66], p = 0.013; Ees ≤ 6.75 mmHg/mL: HR 3.70 [95% CI 1.95–7.06], p = 0.001). Conclusions In HT recipients with normal LVEF, high Ea and low Ees values were independently associated with poorer outcomes in a long-term follow up. Conflict of Interest None