agb2002: The material is identical.
The black bishop does not control e6 at the moment. This suggests 43.Rxd5, to divert the pawn on e6 and enable the pawn thrust 44.e6:
A) 43... exd5 44.e6
A.1) 44... fxe6 45.Rxe6
A.1.a) 45... Qf8 46.Rf6
A.1.a.i) 46... Nxf6 47.Nxf6+
A.1.a.i.1) 47... Kh8 48.Qc7
A.1.a.i.1.a) 48... Ne7 49.Qd8 followed by Nf7#.
A.1.a.i.1.b) 48... Qe7 49.Qxe7 Nxe7 50.Nf7#.
A.1.a.i.1.c) 48... Qxf6 49.Qxh7#.
A.1.a.i.1.d) 48... Qxh6 49.Nf7+ Kg7 50.Nxh6+ Kxf6 (50... Kxh6 51.Qxh7+ Kg5 52.Qh4+ Kf5 53.Bh3+ Ke5 54.Qf4#) 51.Ng8+ Kf5 (51... Ke6 52.Bh3#; 51... Kg5 52.Qf4+ Kh5 53.Nf6#) 52.Bh3+ Ke4 53.Qf4#.
A.1.a.i.1.e) 48... Qxh6 49.Nf7+ Kg7 50.Nxh6+ Bd7 51.Qxd7+ with material advantage and attack.
A.1.a.i.2) 47... Qxf6 48.Qxf6 Ra7 49.Bg2 Rc5 (49... Ne7 50.Qg7#) 50.Qd6 looks winning.
A.1.a.ii) 46... Qd8 47.Rxg6+ and mate in two.
A.1.a.iii) 46... Qe8 47.Rf7 seems to win (47... Qd8 48.Rg7+ Kh8 49.Nf7#; 47... Ra7 48.Rg7+ Kh8 49.Nf7+ Qxf7 50.Qxf7 + -).
A.1.a.iv) 46... Qe7 47.Rf7 Rf3 (47... Qxg5 48.Rg7+ Kh8 49.Rxh7+ and mate in two) 48.Qxf3 Qxg5 49.Rg7+ and mate in three as in the previous subline.
A.1.b) 45... Qd8 46.Qf7+ and mate next.
A.1.c) 45... Rf3 46.Qxf3 with a winning attack (46... Qxg5 47.Re8+ and mate next).
A.2) 44... Nde5 45.exf7+
A.2.a) 45... Kf8 46.Nxh7#.
A.2.b) 45... Kh8 46.f8=Q+ Qxf8 47.Qxf8#.
A.2.c) 45... Nxf7 46.Rxe7 wins.
A.2.d) 45.... Qxf7 46.Qxf7+ Nxf7 47.Re8#.
A.3) 44... Nce5 45.exf7+
A.3.a) 45... Kf8 46.Nxh7#.
A.3.b) 45... Kh8 46.Rxe5 looks winning.
A.3.c) 45... Nxf7 46.Rxe7 wins.
A.3.d) 45... Qxf7 46.Qxf7+ Nxf7 47.Re8+ Nf8 48.Nf6+ and mate next.
A.4) 44... Qf8 45.exf7+ Kh8 46.Re8 looks crushing.
A.5) 44... f5 45.exd7
A.5.a) 45... Qxe1 46.Nf6+ Kf8 (46... Kh8 47.Nf7#) 47.Qd6+ Qe7 (47... Ne7 48.d8=Q#) 48.Nfxh7+ Kg8 49.Qxe7 Nxe7 50.d8=Q(R)#.
A.5.b) 45... Qxd7 46.Nf6+ and 47.Nxd7 wins.
A.6) 44... f6 45.exd7 looks similar to A.5.