The only meaningful amendment was the one including congressional members in the law.

"When the ACA was making its way through Congress, former President Barack Obama made a similar statement in September 2009. During a joint address to Congress, he said that his plan incorporated the ideas of both Republicans and Democrats. We rated that claim Mostly False, because many of the amendments Republicans introduced were technical in nature"

http://www.politifact.com/truth-o-meter/statements/2017/mar/16/luis-gutierrez/rep-gutierrez-says-hundreds-republican-amendments-/

The bill the Republicans attempted to pass only addressed the spending and taxing portion of Obamacare. Even if it passed it would still have to go through committee and be reconciled. The Democrats had flat out refuse to participate in anything designed to repeal Obamacare so they weren't invited. The next step in the replacement process was going to take 60 votes so Democrats would be included