This case involves patient with diabetes, cardiovascular problems, and other conditions
A 55-year-old male, R.L., with a history of heart failure (HF), previous myocardial infarction (MI), and Type 2 diabetes is hospitalized for acute renal failure (ARF) following administration of radiocontrast dye. With electrolyte and cardiac stabilization, his renal function has stabilized but is worse than at baseline (SrCr=2.1 mg/dl, BUN=27 mg/dl), BP=135/85, cholesterol 232, LDL=130, A1c=7.1, and his HF is NYHA class III, with ejection fraction l 40%. R.L. is being treated with insulin, metoprolol 25 mg b.i.d., and furosemide 40 mg q.d. His physician is concerned about preserving renal function and is considering adding both an ACE inhibitor (ACE I) and an angiotensin receptor blocker (ARB). Do you agree?
Considering the patient's current medical problems and blood pressure (135/85 mm Hg which is slightly above the goal 130/80 mm Hg established by the JNC-7 for diabetics), use of an ACE I alone is warranted. Keeping financial burden in mind, I would start lisinopril 5 or 10 mg p.o. daily.
Data clearly show morbidity and mortality benefit of ACE I in patients with HF, diabetes, and recent MI. A study comparing valsartan, captopril, or both in patients with recent MI demonstrated that valsartan is as effective as captopril in high-risk patients, but the combination had no added benefit and increased side effects. Additional data have demonstrated a higher mortality risk associated with combination treatment with ACE Is, ARBs, and beta-blockers.
In addition, a meta-analysis has shown renal benefits with ACE I use in patients (including those with diabetes and CHF) with SCr m 3 mg/dl. If the patient needed radiocontrast dye in the future, I would recommend adequate volume expansion prior to dye.
An ACE I plus an ARB will not improve ARF caused by radiocontrast dye. However, there is evidence suggesting an ACE I plus an ARB will decrease proteinuria in Type 2 diabetics. For this patient, I would start with the ACE I alone because adding both agents simultaneously may increase the risk of a hypotensive episode (current BP 135/85 mm Hg).
This patient's diabetes and cardiac profile suggest treatment with an ACE I may be beneficial, provided there are no contraindications to preclude use. I would recommend initiating low-dose captopril at 12.5 mg q 8 hours, slowly increasing the dose every seven days to achieve blood pressure goal of l 130/80 mm Hg, and monitoring BUN, serum creatinine, and electrolytes to reduce the chance of adverse reactions, such as hypovolemia, hyperkalemia, and possibly ARF. Once the maximum dose of the ACE I is attained, the addition of an ARB may be warranted to further decrease proteinuria.
I would also recommend the addition of spironolactone 25 mg q.d. for the NYHA class III HF and a statin to address the elevated LDL. Statins along with an ACE I may decrease the rate of proteinuria in chronic kidney disease; atorvastatin 10 mg q.d. with appropriate clinical follow-up is a logical starting place.
Kathy Hitchens. Clinical Twisters: Benefit of ACE I plus ARB? Drug Topics Dec. 8, 2003;147:HSE8.