Midfielder Sissoko was suspended for Saturday's encounter at the Emirates Stadium and the Newcastle engine room suffered without the France international, as Arsenal dominated in a largely one-sided affair.
Olivier Giroud and Santi Cazorla were both on target twice for the north London club, with Ayoze Perez's 63rd-minute strike a mere consolation for Newcastle.
Pardew felt that Newcastle missed Sissoko, and he accepted that his team selection was one of the reasons for their heavy defeat.
"You know with Arsenal there's going to be a chance but it wasn't to be," Pardew was quoted as saying by BBC Sport.
"We didn't play well today and they played well. I don't think many teams would have coped with them.
"We were sloppy with our passing, but we've been on a fantastic run and this was always going to be a tough game and it didn't work out for us.
"We play a lot better than that usually. We missed Sissoko and I must look at myself in terms of selection of the team.
"We need to cope without him because he's not going to play every week. We tried to be ambitious and if that's a fault we have to accept that."
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