Review Question - QID 102593

This patient's physical exam findings and history is highly suggestive of scleroderma renal crisis. Angiotensin converting enzyme inhibitors (ACE-I) is the mainstay of treatment to preserve renal function, and improve survival in these patients. ACE-I have been shown to decrease mortality in patients with heart failure.

Scleroderma renal crisis (SRC) is a complication of systemic sclerosis. Patients can present with marked hypertension of abrupt onset, as well as significant rapid impairment of renal function. Pathogenesis of SRC is not well understood. Corticosteroid exposure, especially at high doses, seems to increase the risk of developing SRC. Diffuse skin involvement also seems to represent an important risk factor. Captopril is commonly used to manage these patients. With regards to heart failure, it is important to remember that ACE-I, beta-blockers (i.e., metoprolol, carvedilol), and aldosterone antagonists (i.e., spironolactone) have been shown to decrease mortality in patients with heart failure.

Hinchcliff and Varga present the clinical presentation and treatment of organ involvement in patients with scleroderma. Characteristically, patients with SRC present with accelerated hypertension of sudden onset, which may be accompanied with oliguric renal failure and proteinuria, microangiopathic anemia, as well as microscopic hematuria. SRC was the considered mostly fatal before ACE-I were introduced. ACE inhibitors should be promptly used if SRC is suspected.

Steen et al. explored the outcome of renal crisis in systemic sclerosis before and after ACE-I availability. This was a prospective cohort study. Their data suggests that ACE-I therapy dramatically improved survival in patients with SRC. Along with improved survival, there is a possibility of successful dialysis discontinuation with ACE-I use.

Figure A depicts sclerodactyly, which is characterized by tightening and thickening of the digits. This can lead skin ulceration.

Incorrect Answers
Answer 2: Decreasing bradykinin levels is incorrect. ACE-I would increase bradykinin levels, due to ACE being involved in converting bradykinin into inactive metabolites. This can lead to angioedema.
Answer 3: An increase, not decrease, in renin levels would be expected with ACE-I use.
Answer 4: Calcium channel blockers are not considered first-line for the treatment of SRC. They can be added with ACE-I treatment and can be used to manage Raynaud's.
Answer 5: Having a decrease only in the preload is incorrect. ATII is a powerful vasoconstrictor. ACE-I decrease both the preload and afterload.