Probably not. This is a good question for your own doctor. In general, the short answer is: your arthritis may just get worse and worse without medicines. The longer answer is that studies are starting to show that improved treatment of RA lowers risk of heart attack and possibly risk of death. Medicines have various risks but most people do well when monitored appropriately.
Shorter life. Untreated rheumatoid arthritis shortens lives. The effect on the lifespan depends on the severity of the disease and the amount of inflammation. Stopping RA medications rarely causes immediate death but untreated RA is potentially very serious.