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FOCUS ON NEPHROLOGIC
DISORDERS
Edward F. Foote, Section Advisor
Effects of statins in patients with and without CKD
Key point: A post-hoc analysis of data from the Air
Force/Texas Coronary Atherosclerosis Prevention Study (AFCAPS/TexCAPS)
showed that use of lovastatin for approximately 5 years reduced the
incidence of cardiovascular events in patients with mild chronic kidney
disease (CKD); however, the drug had no effect on preventing kidney
function loss in patients with or without CKD.
Finer points: Jessica Kendrick, MD, and colleagues
conducted a post-hoc analysis of data from 6,604 patients enrolled in
the AFCAPS/TexCAPS to determine the effects of long-term lovastatin
therapy on primary prevention of cardiovascular events and prevention of
kidney function loss. Men aged 50 to 73 years and postmenopausal women
aged 55 to 73 years with mild to moderate dyslipidemia were enrolled.
Patients were otherwise healthy since those with a history of CVD,
uncontrolled hypertension, or diabetes were excluded. Of the 6,604
patients, 6,300 had a baseline glomerular filtration rate (GFR) of 60
mL/min/1.73 m2 or greater; the remaining 304 patients were classified as
having CKD. Investigators compared differences between the kidney
function groups with respect to the effect of lovastatin therapy.
The investigators reported that use of lovastatin 20 mg/d for a mean
duration of 5.3 years resulted in a lower rate of cardiovascular events
in patients with CKD compared with use of placebo. Significant
differences in favor of lovastatin were noted for fatal and nonfatal
coronary events (relative risk 0.35 [95% CI 0.13–0.93], P = 0.03),
fatal and nonfatal cardiovascular events (0.39 [0.16–0.93], P =
0.03), and coronary revascularization procedures (0.23
[0.07–0.77], P = 0.01). Similar benefits with lovastatin therapy
were also seen in patients without CKD. When assessing kidney function
loss over time, no differences were noted between the lovastatin and
placebo groups in terms of yearly changes (decreases) in estimated GFR
for patients with and without CKD or for the risk of incident CKD in
patients without CKD at baseline.
What you need to know: Given the preponderance of
evidence on the benefits of statin therapy in patients with normal
kidney function, the beneficial results on CV outcomes in patients with
mild CKD, although a new finding, is not unexpected. However, the
current trial was unable to show a benefit in terms of renoprotective
effects. Data from this trial are difficult to generalize to the
population since subjects in this trial were overwhelmingly white males
and, by study design, did not include important comorbities such as
diabetes. In addition, although the trial as a whole was very large, the
number of patients with CKD was quite small and the degree of kidney
dysfunction was mild. Other studies which examined the effect of statin
therapy on kidney dysfunction have yielded conflicting results. This may
be due to differences in study design such as etiology or stage of CKD
studied. Results from well-designed prospective studies such as PLANET
(Prospective Evaluation of Proteinuria and Renal Function in Diabetic
Patients with Progressive Renal Disease Trial) and SHARP (Study of Heart
and Renal Protection) are needed to determine the effects of statin
therapy on kidney function outcomes.
What your patients need to know: Educate patients
with and without CKD that statins are effective for prevention of
cardiovascular events. Although statin therapy may have some beneficial
effects on kidney function; this is not yet proven and requires further
study.
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