PEAK OXYGEN-CONSUMPTION AND RESTING LEFT-VENTRICULAR EJECTION FRACTION CHANGES AFTER CARDIOMYOPLASTY AT 6-MONTH FOLLOW-UP

Background The effects of cardiomyoplasty on cardiopulmonary exercise test characteristics are not fully known. Methods and Results We deter mined in 19 patients who underwent cardiomyoplasty for treatment of re fractory heart failure (New York Heart Association [NYHA] functional c lass III) before (pre) acid at 6-month follow-up (post) maximum oxygen consumption (peak Vo(2)), NYHA functional class, and resting left ven tricular ejection fraction (LVEF) (MUGA). We analyzed the results acco rding to pre peak Vo(2) < or > 14 mL/kg per minute and the correlation between the changes in absolute values of LVEF and peak Vo(2). Pre an d post-peak Vo(2) values were 15.9+/-4.4 and 18.6+/-6.4 mL/kg per minu te, respectively (P=.059). In the subgroup with pre-peak Vo(2) < 14 mL /kg per minute, the peak Vo(2) increased from 11.1+/-1.9 to 16.4+/-6.2 mL/kg per minute (P=.02). The subgroup with peak Vo(2) > 14 mL/kg per minute showed pre- and post-peak Vo(2) of 19.2+/-2.6 and of 20.1+/-7 mL/kg per minute, respectively (P=.06). The pre-total exercise time of the entire group increased from 688.4+/-222.1 to 833.7+/-241.6 second s (P<.04). For the subgroup with preoperative peak Vo(2) < 14 mL/kg pe r minute, exercise time improved from 585+/-76.9 to 825+/-186.3 second s (P<.01). In the subgroup with preoperative Vo(2) > 14 mL/kg per minu te, the preexercise and postexercise time was 763.6+/-264.4 and 840+/- 282 seconds, respectively (P=.4). Pre-LVEF increased from 20.6+/-3.3% to 24.2+/-7.8% at 6 months of follow-up (P=.02). At 6 months of follow -up, 9 patients were in NYHA functional class I and 10 were in class I I. There was no correlation between LVEF values and absolute values of peak Vo(2) before (r=.123, P=.6) and after (r=.27, P=.2) cardiomyopla sty. A weak correlation was observed between the changes in absolute v alues of peak Vo(2) and LVEF from the preoperative to the postoperativ e period (r=.48, P=.048). Conclusions Cardiomyoplasty is a useful meth od for improving NYHA functional class and LVEF in patients with heart failure. Peak Vo(2) < 14 mL/kg per minute before cardiomyoplasty may be a selection criterion with which to determine improved exercise cap acity after surgery. The effects of cardiomyoplasty on LVEF appear to be partially associated with maximum exercise capacity changes.