WASHINGTON – Exposure to angiotensin-converting enzyme inhibitors prior to the onset of renal crisis in patients with scleroderma increases the risk of death, according to 1-year findings from the prospective observational International Scleroderma Renal Crisis Survey.
The findings, which contrast with those from a preliminary analysis reported last year, suggest that clinicians caring for patients with systemic scleroderma should exercise caution when prescribing angiotensin-converting enzyme (ACE) inhibitors, Dr. Marie Hudson said at the annual meeting of the American College of Rheumatology, where she reported the survey results.
Of 75 patients who experienced scleroderma renal crisis (SRC) in the course of the study, 16 were taking an ACE inhibitor prior to onset of SRC. At the 1-year follow-up, 27 (36%) of the patients had died and 25% remained on dialysis. After adjusting for differences in prednisone exposure and history of systemic hypertension, ACE inhibitor exposure prior to SRC, compared with no such exposure, was associated with significantly increased risk of death (adjusted hazard ratio, 2.52), said Dr. Hudson of the division of rheumatology at McGill University, Montreal.
SRC is a rare but life-threatening complication of systemic sclerosis that typically presents with malignant hypertension and acute renal failure.
"Prior to the advent of ACE inhibitors, it was almost a universally deadly complication of scleroderma, but since the advent of ACE inhibitors, the outcomes of patients with scleroderma renal crisis have improved tremendously," Dr. Hudson said, noting also that some evidence suggest that the incidence of SRC has decreased over the past two decades as well – due, perhaps, to more liberal use of ACE inhibitors.
"So, given the benefits of ACE inhibitors to treat SRC along with this perceived decrease in the incidence of SRC, the prophylactic use of ACE inhibitors to prevent SRC has been considered. However, some would argue that there’s no clear physiologic rationale for this," she said, explaining that most patients with SRC are not hyperreninemic prior to renal crisis and that prophylactic treatment could mask hypertension and delay diagnosis, thus leading to worse outcomes in those who develop SRC.
In fact, recent retrospective data support the idea that those exposed prior to SRC may have worse outcomes, she noted.
The findings of this survey, which are important given the widespread availability of ACE inhibitors, confirm that, she said.
Patients included in the study were identified by physicians from numerous practices around the world who had agreed to participate in the survey. A total of 589 physicians were asked biweekly if they had made a diagnosis of SRC, and if so, they filled out a short case report form at that time and then submitted another 1 year later.
The patients had a mean age of 52 years, and 67% were women. Most (76%) had diffuse systemic scleroderma with a median disease duration of 1.5 years. SRC was hypertensive in 71 patients; only 5 patients had normotensive SRC, she noted.
The rate of prednisone use was surprisingly high at nearly 50% overall, but, more importantly, the mean daily dose was twice as high in the group of patients who were not exposed to ACE inhibitors prior to SRC (mean dose of 18 mg/day vs. 9 mg/day in the exposed group), Dr. Hudson said.
However, even after adjusting for prednisone use, the risk of death in exposed patients was more than twice that of nonexposed patients, and the difference was statistically significant, she said.
Although the precise risk of death after SRC remains uncertain, it does appear that caution when using ACE inhibitors in these patients is warranted, especially early in disease when the risk of SRC is the greatest, she said.
Dr. Hudson had no disclosures to report.