Inducible left ventricular outflow tract gradient during dobutamine stress echocardiography: an association with intraoperative hypotension but not a contraindication to liver transplantation.

BACKGROUND: Dobutamine stress echocardiography (DSE) is frequently used in the evaluation of cardiac risk prior to orthotopic liver transplantation (OLT). In the general cardiac population, an inducible left ventricular outflow tract gradient (LVOT Delta) during DSE has variable prognostic importance. The purpose of this study was to determine the prevalence and clinical significance of LVOT Delta in patients undergoing OLT during DSE.
METHODS: Consecutive medical records of 106 patients who had undergone OLT at our institution from January 1997 until January 2002 were retrospectively analyzed and divided into two groups based on the presence (Group I, LVOT Delta >36 mmHg) or absence (Group II, LVOT Delta< or = 36 mmHg) of a significant LVOT Delta measured during DSE. We determined any outcome differences between these two groups with regard to intraoperative hypotension, cardiac mortality, length of hospital stay, graft function, and renal function post-OLT.
RESULTS: Forty-six patients had an LVOT Delta > 36 mmHg (Group I) and 60 patients had LVOT Delta< or = 36 mmHg (Group II). Baseline demographics were similar in both groups. There was no significant overall difference in cardiac mortality between Group I versus Group II patients (0 versus 1 patient, respectively, P=0.57). Intraoperative hypotension occurred in 4 patients in Group I versus 0 patient in Group II (P=0.03). Length of stay, graft function, and postoperative renal function were similar in both groups.
CONCLUSION: A significant LVOT Delta >36 mmHg is a frequent finding occurring in 46/106 (43%) of patients who have DSE pre-OLT. Intraoperative hypotension is associated with patients having an LVOT Delta. However, post-OLT patients with significant LVOT Delta have a similar in-hospital outcome compared to patients without significant LVOT Delta.