At 6 months ' follow-up , there was a significant improvement in rest myocardial perfusion scores ( 6.3 5.8 vs 3.1 4.3 ; P < .001 ) , LVEF ( 25 7 % vs 29 8 % ; P = .005 ) , and 6-minute walking distance ( 354 71 m vs 404 91 m ; P < .001 ) .