  Debris disk stars are good targets for high contrast imaging searches for
planetary systems, since debris disks have been shown to have a tentative
correlation with giant planets. We selected 20 stars identified as debris disk
hosts by the WSIE mission, with particularly high levels of warm dust. We
observed these with the VLT/SPHERE high contrast imaging instrument with the
goal of finding planets and imaging the disks in scattered light. Our survey
reaches a median 5$\sigma$~sensitivity of 10.4Mj at 25au and 5.9Mj at 100au. We
identified three new stellar companions (HD18378B, HD19257B and HD133778B): two
are mid-M type stars and one is late-K or early-M star. Three additional stars
have very widely separated stellar companions (all at $>$2000au) identified in
the Gaia catalog. The stars hosting the three SPHERE-identified companions are
all older ($\gtrsim$700Myr), with one having recently left the main sequence
and one a giant star. We infer that the high volumes of dust observed around
these stars might have been caused by a recent collision between the planets
and planetesimal belts in the system, although for the most evolved star, mass
loss could also be responsible for the infrared excess. Future mid-IR
spectroscopy or polarimetric imaging may allow the positions and spatial extent
of these dust belts to be constrained, thereby providing evidence as to the
true cause of the elevated levels of dust around these old systems. None of the
disks in this survey are resolved in scattered light.
