Statins have no effect on cholesterol for over 50% of patients
This study is one of the few that looks at the cholesterol/statin correlation directly. And it does so with a substantial sample (N=165,411) so is of considerable interest. As such its conclusions are gloomy for statin use. On half your patients it may do no good at all, assuming that high cholesterol is associated with heart disease. Given the size of the effect, that conclusion is unlikely to be overturned in subsequent research so needs to be taken seriously in patient treatment decisions henceforth
On the other hand, they found that among the "unprotected" group heart disease incidence was marginally higher. In those circumstances (where the effect is weak), limitations of the study must be noted: It must be noted that the sample was not a random one. It was a sample of people who had seen their doctor with some heart problem. And we also should note that the controls for confounding factors were poor -- no demographics!
So with those large reservations, we could say that the present weak results are consistent with previous findings that high levels of cholesterol are problematic for people with pre-existing heart disease only
Sub-optimal cholesterol response to initiation of statins and future risk of cardiovascular disease
Ralph Kwame Akyea et al.
Objective: To assess low-density lipoprotein cholesterol (LDL-C) response in patients after initiation of statins, and future risk of cardiovascular disease (CVD).
Methods: Prospective cohort study of 165 411 primary care patients, from the UK Clinical Practice Research Datalink, who were free of CVD before statin initiation, and had at least one pre-treatment LDL-C within 12 months before, and one post-treatment LDL-C within 24 months after, statin initiation. Based on current national guidelines, <40% reduction in baseline LDL-C within 24 months was classified as a sub-optimal statin response. Cox proportional regression and competing-risks survival regression models were used to determine adjusted hazard ratios (HRs) and sub-HRs for incident CVD outcomes for LDL-C response to statins.
Results: 84 609 (51.2%) patients had a sub-optimal LDL-C response to initiated statin therapy within 24 months. During 1 077 299 person-years of follow-up (median follow-up 6.2 years), there were 22 798 CVD events (12 142 in sub-optimal responders and 10 656 in optimal responders). In sub-optimal responders, compared with optimal responders, the HR for incident CVD was 1.17 (95% CI 1.13 to 1.20) and 1.22 (95% CI 1.19 to 1.25) after adjusting for age and baseline untreated LDL-C. Considering competing risks resulted in lower but similar sub-HRs for both unadjusted (1.13, 95% CI 1.10 to 1.16) and adjusted (1.19, 95% CI 1.16 to 1.23) cumulative incidence function of CVD.
Conclusions: Optimal lowering of LDL-C is not achieved within 2 years in over half of patients in the general population initiated on statin therapy, and these patients will experience significantly increased risk of future CVD.