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 determined in 19 patients who underwent cardiomyoplasty for treatment of refractory heart failure (New York Heart Association [NYHA] functional class III) before (pre) acid at 6-month follow-up (post) maximum oxygen consumption (peak Vo(2)), NYHA functional class, and resting left ventricular ejection fraction (LVEF) (MUGA). We analyzed the results according 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 and post-peak Vo(2) values were 15.9+/-4.4 and 18.6+/-6.4 mL/kg per minute, 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 seconds (P<.04). For the subgroup with preoperative peak Vo(2) < 14 mL/kg per minute, exercise time improved from 585+/-76.9 to 825+/-186.3 seconds (P<.01). In the subgroup with preoperative Vo(2) > 14 mL/kg per minute, 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 II. 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) cardiomyoplasty. A weak correlation was observed between the changes in absolute values of peak Vo(2) and LVEF from the preoperative to the postoperative period (r=.48, P=.048). Conclusions Cardiomyoplasty is a useful method 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 capacity after surgery. The effects of cardiomyoplasty on LVEF appear to be partially associated with maximum exercise capacity changes.