Effect of Preoperative Ejection Fraction

Ninety-three patients with aortic valve disease were evaluated to determine the effect of the preoperative left ventricular ejection fraction (EF) on the results of aortic valve replacement (AVR). Forty-six patients had aortic stenosis (AS), 16 had aortic insufficiency (Al), and 31 had mixed aortic stenosis and insufficiency (MX). Immediate and long-term survival curves in AS and MX, and in AS patients with adequate preoperative EF (' 0.50) and those with depressed preoperative EF (< 0.50), were compared. There was a trend toward a greater early mortality rate (0-1 month after AVR), but this difference did not reach the level of statistical significance (P > 0.05). In patients surviving the one-month preoperative period there was no significant difference in the long-term survival between the EF groups. Thirty-two surviving patients, 18 with EF > 0.50 and 14 with EF < 0.50, were further evaluated clinically and hemodynamically at an average interval of 29 months (range 9-66 months) after surgery. All AS and MX patients stayed at or improved to New York Heart Association (NYHA) class I or II. Six of the AS or MX patients with depressed EF had distinctly abnormal arteriovenous oxygen (A-VO,) difference (> 6 vol%) preoperatively. Surgery resulted in normalization of the A-VO, difference in four. The preoperative mean pulmonary arterial (PA) pressure was elevated to > 20 mm Hg in five of the AS orMX patients with depressed EF. Postoperatively, four of the five showed significant decreases (> 10 mm Hg) in the mean PA pressure, but most (four-fifths) of the patients remained abnormal (mean PA > 20 mm Hg). Hemodynamics obtained during 300 kg-m/min exercise showed gross abnormalities of pressure and flow in seven of eight patients with depressed EF. Stress-induced hemodynamic abnormalities were also present in six of 12 with EF 0.50, but the abnormality was limited to moderate rises in the mean PA pressure in five of the six. Similar clinical and hemodynamic changes were seen in the eight restudied patients with Al, except that two patients with depressed EF were not improved clinically (remained NYHA class III postoperatively) and continued to have marked hemodynamic abnormalities postoperatively. We conclude that a depressed preoperative EF may cause a moderate increase in the perioperative mortality rate, with little effect on subsequent long-term survival in patients with AS or MX undergoing AVR. Resting hemodynamic abnormalities seen in the depressed EF group often show significant improvement after