  We show that the spectral lineshape of superconducting
La$_{2-x}$Sr$_x$CuO$_4$ (LSCO) and Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$ (Bi2212)
can be well described by the coupling of the charge carriers to collective
incommensurate charge-density wave (CDW) excitations. Our results imply that
besides antiferromagnetic (AF) fluctuations also low-energy CDW modes can
contribute to the observed dip-hump structure in the Bi2212 photoemission
spectra. In case of underdoped LSCO we propose a possible interpretation of
ARPES data in terms of a grid pattern of fluctuating stripes where the charge
and spin scattering directions deviate by $\alpha=\pi/4$. Within this scenario
we find that the spectral intensity along $(0,0) \to (\pi,\pi)$ is strongly
suppressed consistent with recent photoemission experiments. In addition the
incommensurate charge-density wave scattering leads to a significant broadening
of the quasiparticle-peak around $(\pi,0)$.
