  The progenitors of the high-mass black-hole mergers observed by LIGO and
Virgo are potential LISA sources and promising candidates for multiband GW
observations. In this letter, we consider the minimum signal-to-noise ratio
these sources must have to be detected by LISA. Our revised threshold of
$\rho_{\rm thr}\sim 15$ is higher than previous estimates, which significantly
reduces the expected number of events. We also point out the importance of the
detector performance at high-frequencies and the duration of the LISA mission,
which both influence the event rate substantially.

High Energy Astrophysical Phenomena;General Relativity and Quantum Cosmology