The ACCORD study's purpose was to evaluate the efficacy of lowering A1C in long term T2's with poor control through intervention with drug therapy. The study was halted in 2008 before it was completed because subjects were dying at a higher than expected rate.
The initial take on the results was that reducing A1C was dangerous, and some medical professionals started advising their patients against shooting for a too low an A1C. This interpretation was immediately attacked on the grounds that the goal was only to get their A!C's below 7. Also the only intervention was with drugs known to increase heart disease risk, diet and exercise were not included. Finally the subjects had spent many years with poor control.
Further analysis of the data has honed in on where the problem was located. The subjects that died were disproportionately those for whom the intervention had failed, their A1C's were still well above the target of 7. Those who achieved the modest goal of an A1C below 7 had better outcomes after all. Here's a link
describing the study and it's reinterpretation in more detail.
So if you receive advice that trying to get your A1C below 7 is dangerous kindly disregard it. In fact the risk for all complications starts rising at 5.5 and rises exponentially the further above 5.5 you go. The closer you can get to normal the better.