GDMT Management Before Cardiac Catheterization in CKD Patients
In patients with eGFR 30-60 mL/min/1.73m² undergoing cardiac catheterization, metformin must be discontinued at the time of or prior to the procedure, with most other GDMT medications continued through the periprocedural period, as the cardiovascular benefits of maintaining GDMT typically outweigh procedural risks.
Metformin - MANDATORY Hold
Metformin must be stopped at the time of, or prior to, iodinated contrast imaging procedures in patients with eGFR between 30-60 mL/min/1.73m² 1. This is an FDA-mandated requirement, not optional 1.
Timing and Restart Protocol:
- Discontinue: At the time of or immediately before the procedure 1
- Duration of hold: Until 48 hours post-procedure 1
- Restart criteria: Only after re-evaluating eGFR at 48 hours and confirming stable renal function 1
- Rationale: Prevents metformin accumulation and lactic acidosis risk if contrast-induced AKI develops 1
RAAS Inhibitors (ACE-I/ARB/ARNI) - Generally CONTINUE
RAAS inhibitors should typically be continued through cardiac catheterization 2, 3. The 2023 AHA/ACC guidelines emphasize that when PCI is clinically needed, the risk of contrast-induced AKI should not be a reason to withhold necessary procedures in most CKD patients 2.
Key Evidence:
- Early GDMT (including RAAS inhibitors) in ACS patients with advanced renal dysfunction (eGFR <30) reduced in-hospital mortality by 38% (RR: 0.62,95% CI: 0.47-0.81) 3
- In MI patients specifically, GDMT reduced mortality by 61% (RR: 0.39,95% CI: 0.27-0.58) 3
- Temporary hold consideration: Only if patient is hemodynamically unstable, volume depleted, or has acute kidney injury 2
Beta-Blockers - CONTINUE
Beta-blockers should be continued perioperatively 2, 3. These medications provide critical cardioprotection and are part of the mortality-reducing GDMT regimen 2.
Supporting Evidence:
- Beta-blockers reduce sympathetic nervous system activation and prevent harmful cardiac remodeling 2
- Discontinuation increases risk of perioperative cardiac events 3
- No routine holding required for catheterization procedures 2, 3
Mineralocorticoid Receptor Antagonists (MRAs) - CONTINUE with Monitoring
MRAs should generally be continued but require careful potassium monitoring 2.
Management Protocol:
- Continue through procedure if baseline potassium ≤5.0 mEq/L 2
- Check potassium within 24-48 hours post-procedure 2
- Hold temporarily if potassium >5.0 mEq/L or acute kidney injury develops 2
- Dosing in eGFR 30-49: Consider 25 mg every other day for eplerenone or 12.5 mg daily/every other day for spironolactone 2
SGLT2 Inhibitors - CONTINUE
SGLT2 inhibitors should be continued perioperatively 2. These agents provide both cardiovascular and renal protection 2.
Rationale:
- Enhance diuretic efficacy and decongestion 2
- Provide direct cardioprotective effects through metabolic shifts 2
- Prevent glomerular hyperfiltration and offer kidney protection 2
- No evidence requiring discontinuation for contrast procedures 2
Antiplatelet Therapy - CONTINUE
Dual antiplatelet therapy must be continued, especially in ACS patients 3, 4.
Critical Points:
- GDMT including dual antiplatelet therapy reduced 1-year MACE by 32% (adjusted HR 0.68,95% CI 0.58-0.80) 4
- Never hold aspirin or P2Y12 inhibitors before diagnostic or interventional catheterization 3, 4
- Bleeding risk from holding antiplatelet therapy exceeds bleeding risk from continuation 4
Statins - CONTINUE and Consider High-Dose Loading
Statins should be continued, and high-dose statin therapy before the procedure may reduce contrast-induced AKI 2, 5, 6.
Optimal Protocol:
- Continue baseline statin through procedure 4
- Consider loading: Rosuvastatin 40/20 mg, atorvastatin 80 mg, or simvastatin 80 mg before procedure (Class IIa, Level A) 5, 6
- High-dose statins reduce contrast-induced AKI occurrence 2, 6
Diuretics - INDIVIDUALIZED Approach
Loop diuretics require case-by-case assessment based on volume status 2.
Decision Algorithm:
- Euvolemic patients: Continue usual dose 2
- Volume overloaded: Continue or increase dose; decongestion improves outcomes 2
- Volume depleted or hypotensive: Hold temporarily and provide adequate hydration 5, 6
- Thiazides: Generally continue unless volume depleted 2
Nephrotoxic Medications - HOLD
NSAIDs and other nephrotoxic agents must be discontinued 5, 6.
Medications to Hold:
- NSAIDs: Stop at least 24-48 hours before procedure 5, 6
- Aminoglycosides: Discontinue if possible 5
- Other nephrotoxins: Review and hold when feasible 5, 6
Critical Contrast Nephropathy Prevention Bundle
Beyond medication management, implement these evidence-based strategies 2, 5, 6:
Hydration Protocol (Class I, Level A):
- Isotonic saline 1.0-1.5 mL/kg/hour starting 3-12 hours before and continuing 6-24 hours after contrast 5, 6
- For severe CKD: Consider 1000 mL/h fluid replacement rate continued for 24 hours post-procedure 5
Contrast Minimization:
- Use low-osmolar or iso-osmolar contrast media exclusively 2, 5, 6
- Minimize volume: Keep <350 mL or <4 mL/kg 5
- Apply contrast volume/eGFR ratio <3.4 rule 5, 6
Procedural Considerations:
- Radial access preferred over femoral to reduce AKI risk 2, 6
- If CABG planned after angiography, delay >24 hours when clinically feasible 2
Common Pitfalls to Avoid
- Failing to hold metformin: This is an FDA-mandated requirement with serious consequences 1
- Unnecessarily discontinuing RAAS inhibitors: The mortality benefit of continuing GDMT outweighs theoretical AKI risk in stable patients 3
- Inadequate hydration duration: Must extend 6-24 hours post-procedure, not just pre-procedure 5, 6
- Using serum creatinine alone: Always calculate eGFR, as creatinine underestimates dysfunction in elderly and low muscle mass patients 6
- Forgetting to restart metformin: Requires active 48-hour eGFR check and documentation of stable renal function 1