Abstract 19010: Low HDL-C Carries Residual Risk Even at Target LDL-C Among Patients in the Cholesterol Treatment Trialists' Collaboration Studies
Background: For patients treated to reduce lipid-mediated risk, statins are first-line therapy to achieve low levels of LDL-c. Although low HDL-c levels and elevated TGs are associated with higher rates of cardiovascular (CVD) events, the importance of treating these lipid abnormalities in statin-treated men and women has been less certain.
Methods: We examined the importance of any residual risk which might remain relating to persistently low HDL-c or high TG levels in the CTT database of more than 90 000 patients in placebo-controlled trials of statin therapy. Relative risks of CVD events (nonfatal MI, CHD death, stroke, revascularization) were calculated for quintiles of achieved HDL-c at 1 year and according to TG levels (<100, 100-149, 150-199, ≥200 mg/dL) adjusted for LDL-c levels at 1 year, baseline diabetes, sex, prior CVD, and statin or placebo treatment assignment.
Results: The hazard of CVD events correlated inversely with on-study HDL-c level, but only slightly with TG levels after accounting for HDL-c. Compared with TG <100 mg/dL, TG ≥200 mg/dL increased risk by 13% (HR 1.13, 95% CI 1.05-1.21, P=0.001), but only by 2% (P=NS) after HDL-c adjustment. Risks increased by about 70% for diabetes, 100% for prior MI, 30% for male sex, and were 17% lower with statin assignment (all P<0.0001).
Conclusions: Low HDL-c at 1 year remains a risk factor for future CVD events, irrespective of achieved LDL-c level and statin treatment. The risk related to elevated TG is smaller, expecially after accounting for HDL-c. Persistently low HDL-c carries a similar risk to persistently elevated LDL-c (≥130 vs <70 mg/dL). Further risk reductions may be expected by using treatments targeting dyslipidemia even in statin-treated patients at target LDL-c.
- © 2010 by American Heart Association, Inc.