Preparing for an angiogram starts several days before the procedure and involves fasting, adjusting medications, arranging a ride home, and knowing what to expect so you’re not caught off guard. Most of the preparation is straightforward, but the details matter, especially around food and drink timing, kidney protection, and planning for recovery at home.
Fasting Before the Procedure
Current guidelines call for fasting from solid food for at least 6 hours before a coronary angiogram and from liquids for at least 2 hours. In practice, most hospitals will tell you to stop eating after midnight if your procedure is in the morning. Clear liquids like water are usually permitted up to 2 hours beforehand, but check with your specific hospital since instructions can vary slightly.
This fasting window exists because sedation is used during the procedure, and having food in your stomach raises the risk of nausea or aspiration. If your angiogram is scheduled for the afternoon, you may be allowed a light, early breakfast, but confirm this with your care team rather than assuming.
Medications to Discuss With Your Doctor
Some medications need to be paused or adjusted before an angiogram. Blood thinners are the most common concern. Your doctor will give you specific instructions about when to stop taking them, which could be anywhere from one to several days before the procedure depending on the type.
If you take diabetes medication, you’ll likely need modified dosing since you’ll be fasting. Metformin in particular is often paused around the time of the procedure because of how it interacts with the contrast dye used during imaging. Blood pressure medications are typically continued, sometimes with a small sip of water on the morning of the procedure, but again, your doctor’s specific instructions take priority.
Protecting Your Kidneys From Contrast Dye
The dye injected during an angiogram is processed by your kidneys, which means staying well hydrated in the days leading up to the procedure is genuinely important. For most people, drinking plenty of water in the 24 hours before (up until the fasting cutoff) is sufficient.
If you have reduced kidney function, your medical team will take extra precautions. Patients with mildly reduced kidney filtration rates are typically asked to drink around 500 mL of water before the procedure. Those with more significant kidney impairment may receive intravenous fluids, usually a small saline infusion before and after imaging. Your pre-procedure blood work, which checks how well your kidneys and liver are functioning, determines which category you fall into.
If You Have a Contrast Dye Allergy
Let your doctor know well in advance if you’ve ever had a reaction to contrast dye, iodine, or shellfish. Patients with a history of allergic reactions to contrast are given a premedication regimen that typically starts 12 to 13 hours before the procedure. This involves a steroid taken at timed intervals (often the night before and again a few hours before the angiogram) along with an antihistamine about an hour beforehand. The exact drugs and timing vary between hospitals, so this needs to be coordinated days ahead, not the morning of.
Pre-Procedure Blood Work and Testing
You’ll have blood drawn before the procedure if it hasn’t been done recently. These tests check your kidney and liver function, your blood’s ability to clot, and your basic blood cell counts. Kidney function results are especially critical because they determine whether you need extra hydration or dye precautions. Some hospitals do this blood work a few days before the angiogram at a separate appointment; others handle it on the day of the procedure. Either way, expect a needle stick.
You may also have an ECG (a quick heart rhythm recording) done beforehand if one isn’t already on file.
What to Bring to the Hospital
Pack light. The essentials are:
- Photo ID such as a driver’s license or state ID
- Insurance card(s)
- All your medications in their bottles, or at minimum a written list with exact dosages
- Comfortable, loose clothing for going home, particularly pants that won’t press tightly against your groin if that’s where the catheter will be inserted
Leave jewelry, watches, and valuables at home. You’ll be asked to remove them anyway, and hospitals aren’t responsible for lost items. Your phone and a charger are fine to bring since there can be waiting time before and after the procedure.
Don’t Shave the Insertion Site
The catheter used during an angiogram is inserted either through your wrist (radial access) or your groin (femoral access). You might assume you should shave the area beforehand, but don’t. Hospital staff will handle any necessary hair removal with sterile equipment. Shaving at home creates tiny nicks in the skin that can increase infection risk at the insertion site.
Arrange Your Ride and Your First Day Home
You will not be allowed to drive yourself home. The sedation used during the procedure impairs your reflexes and judgment even after you feel normal, so you need someone to pick you up. For the first 24 hours after the angiogram, you should not drive or operate any equipment.
It helps to have someone stay with you at home for the rest of that day. Not because complications are common, but because you’ll be groggy and need to keep the insertion site still. If the catheter went through your groin, you’ll want to avoid walking up stairs for the first couple of days. Plan to have everything you need on one floor: food, water, phone charger, entertainment.
Preparing Your Home for Recovery
Recovery from a diagnostic angiogram is relatively quick, but the first few days require some restrictions. The insertion site will have a small bandage that stays on for one to two days and typically falls off on its own. You won’t need special wound care supplies.
What you do need to plan around is the activity restriction. No strenuous exercise, and no lifting, pulling, or pushing anything heavy for several days. If you live alone, stock your fridge beforehand, move laundry baskets and heavy items to accessible spots, and handle any errands that involve carrying bags or bending. Think of it like preparing for a few quiet days where you avoid anything that would strain your core or raise your blood pressure.
Be Prepared for More Than a Diagnostic Test
A standard angiogram is diagnostic, meaning its purpose is to take pictures of your coronary arteries and look for blockages. But if your doctor finds a significant blockage during the procedure, they may recommend treating it right then with angioplasty and a stent rather than scheduling a second procedure. This means a diagnostic angiogram that was expected to take 30 to 60 minutes could turn into a longer intervention.
Ask your doctor ahead of time whether same-session treatment is a possibility in your case. If it is, your hospital stay will be longer, potentially overnight instead of same-day discharge. Knowing this in advance lets you pack an overnight bag, arrange for extended childcare or pet care, and mentally prepare for either outcome. Having that conversation before the procedure removes a layer of stress on the day itself.