Change from Medtronic 670G to Tandem

My 670G warranty is expiring in the next few months and I am considering the Tandem/Decom combination (tSlim X2). The consensus is for the tSlim but has anyone had negative experiences with this device?

Hi @don . I’ve been a Tandem user for over 10 years and am very happy with it. There have been comments on the forum from people who did not like it - I’ll let them share their own details, but two things people have a hard time adjusting to in the switch from Medtronic to Tandem are

  1. Tandem charges with a power cord rather than using batteries. I plug in randomly while I’m at my desk, watching TV or riding in the car, and it’s a quick process to charge fully, even with a portable charger. However some people do have concerns about power failures.
  2. People find Tandem’s full process cumbersome. I’ve been doing it so long it comes naturally and goes quickly, but since it uses a syringe rather than an adapter it may take some getting used to.

Just a couple of observations so you go in with your eyes wide open. I think you can take a “test drive” before you commit so check with Tandem on that. Hopefully you’ll get comparative feedback soon but no problems or regrets here.

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Welcome. We’ve got a bunch of threads where people have discussed their experiences with this exact thing. Searching the forum for “Tandem Medtronic” brings up:

You might find some good info browsing there.

For myself, the switch from 670G to t:slim x2 has been great. I’ve got better control, much better sensor, fewer alarms, and a generally more relaxed experience. It’s also neat to have the pump automatically send data to my phone via Bluetooth, so I can always see my current glucose reading, recent graphs, easily scroll through recent boluses, and double check settings. As a bonus, the phone then automatically relays that data to Tandem and Dexcom’s servers, so my doctor can access it and view reports without my having to manually upload the data. Besides adjusting your basal rate based on CGM readings, the pump will also (unless you’re in sleep mode) give you an automatic correction bolus if you’re running high it’s been at least an hour since your last bolus, and the basal increase hasn’t been enough.

As Dorie said, recharging is easy. Doesn’t take long, and it’s less wasteful than using AA batteries. (I used rechargeable AAs in my 670g anyway, but that meant carrying a couple of spares around with me.)

It also automatically gets software updates when they’re released (which hasn’t happened since I made the switch at the beginning of the year).

The fill process, as Dorie said, is a bit more cumbersome, but not too bad, and you do get used to it. Likewise, having the extra connector in the tubing bothers some people, but it is kind of nice that it helps remove air bubbles that may have gotten through the fill process.

The user menus are different. Tandem uses a touchscreen interface, which is nice, but it can be a little annoying when the pump locks on you because you didn’t hit exactly the right spot on the screen. Still, the menus are better organized. The bolus button is right on the home screen, and you don’t need to navigate through multiple sub-menus to get to other common settings.

The bolus process can be a pain. It’s really nice that the pump implicitly trusts the Dexcom’s accuracy and automatically factors that in to the calculations, rather than you having to manually enter a BG value. But it’s kind of ridiculous how many times it asks you to confirm everything as you go along. Especially if you’re doing an extended bolus.

Otherwise, making the switch should be fairly straightforward. You’re already used to filling the pump, changing your infusion set, inserting your CGM, programming boluses, letting the pump adjust your basal, etc. Most of the experience is very similar.

Hi @wadarabbit and thanks much for your thoughts. This pretty ,uch
confirms things. The 670G is cumbersome, not terribly accurate (Guardian
sensors) and not intuitive. While it has helped my control immeasurably,
Tandem looks like the next big thing for me. Medtronic seems more like
just another big business selling stuff and I get that from an investor
standpoint just not from a user perspective!


I started pumping in the mid 90s and my first were Medtronic Minimeds. There may have been four our five brands to choose from at the time (Tandem was not among them) and my doctor felt Medtronic was the best. The others are no longer available in the US although some may be in other countries. At the time I switched to Tandem it was pretty much neck in neck with Medtronic as far as bells and whistles although some with features were expected down the line. While those were exciting I switched because all other things being equal at the time, I really preferred Tandem’s sleek profile.
I think I switched before Medtronic’s CGM came out so never used it much less Medtronic’s closed loop, but have always been happy with Dexcom’s “plain old” CGM and now their loop. I hope you feel the same. I would also hope Medtronic does some product improvement so their users overall can have the same level of confidence and positive their with their CGM and loop that Tandem/Dexcom users have. From what I’ve read in the forum there are more complaints about Medtronic and users who have switched to Tandem with Dexcom, than vice versa. Given the nature of the devices you would hope they would be close equal in accuracy and ease of use.
Anyway, I would encourage you to try before you buy if that’s an option. Although you already use a CGM you have to do online training before switching to Basal IQ or Control IQ so keep that in mind.

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I began in 1998 with I believe was the Medtronic 470? Moved through the years to the different upgraded systems of medtronic and have always been pleased with their products. In September of 2019, my warrantee had expired and i needed to upgrade. I was also going through a bout with an infected Bursa that kept me in the hospital for several days and a 3 week stay in a care home for 24/7 IV’s to fight Mrsa. So I had given my wife power of attorney as far as what I could be spending. I called Medtronic’s asking for a closed loop system, and he said that their product would not be covered by Medicare so it probably woulldn’t work for me. A few days later, the Tandem rep came in and more or less rambed their product down my throat. Their much smaller pump is nice for a teen aged girl in a bikini, but for a old man with large arthritic hands, it is just so much easier to drop. And I really like the fact that you don’t have to hold buttons down like the Medtronic. Instead, I may have to push up to 17 different buttons to take a simple bolus… Thanks for making it easy.
As far as the two pumps are concerned, I would say that they both can do their job equally well. Medtronic has Tandem beet as far as infusion sets and other supplies. Tandem infusion sets are junk in comparison to Medtronic and they must get kickbacks from the garbage companies for the amount of waste byproduct that we the consumers must dispose of.
I sometimes think that four shots a day and test strips were easier (I still have 1 of my 2 original glass syringes). My HBA1C in those days was 6.8 to 7.2 compared to 6.5 today. I was first diagnosed in 1957.

@Don, check out the Tandem CIQ groups on Facebook. There is about a 1-2% negative on two groups I watch. Look for Tandem X2 and Tandem CIQ for the groups.

If you make the jump, it is like going from a single engine private aircraft to a 400 passenger multi-engine with autopilot. Imagine landing with hands off.

this is how CIQ works. I have been on CIQ since 1/20 and would not go back.

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