A subsea wellhead assembly allows communication between a production tubing annulus and a conduit in fluid communication with a platform above. The wellhead assembly has a tubing hanger that is held relative to a tubular wellhead member of a subsea well by a tubing hanger support. A string of tubing extends from the tubing hanger into the well, defining an annulus around the tubing. The conduit communicates with the tubing annulus through a tubing annulus passage. The tubing annulus passage has a portion extending through the tubing hanger support. The wellhead member supports a valve block located between the tubing hanger support and the riser. The tubing annulus passage has another portion that registers with the portion of the passage in the tubing hanger support. The conduit stabs into valve block portion of the tubing annulus passage when the riser connects to the upper end of the valve block.