Fresh warning over statin switching
A pharmaceutical company study has reopened the row over statin switching after claiming it substantially increases the risk of death or cardiovascular events.
Moving patients from atorvastatin to simvastatin raised the risk of death or major CVD events by 30%, according to the analysis, conducted by Pfizer and presented at the European Society of Cardiology conference in Vienna.
Researchers examined data from a primary care database of 4.77 million patients, including 2,511 patients who had been switched, comparing each with four unswitched controls.
There were 7% more deaths from all causes in the switched patients than in those un-switched, but this difference was not statistically significant.
But the analysis found significant increases of 42% in major cardiovascular events and 48% in stroke, as well as non-significant increases of about 30% in myocardial infarction and revascularisation.
Dr Berkeley Phillips, cardio-vascular category medical manager at Pfizer UK and one of the researchers, said: 'This study provides further evidence that patients should be switched only on a case-by-case basis, and raises questions against switching as a matter of policy.'
A previous hospital audit comparing periods before and after switching found mortality was 5% on atorvastatin but 14% with simvastatin – but its methodology was criticised.
Dr John Pittard, a member of the Primary Care Cardiovascular Society and a GP in Staines, Middlesex, said: 'The problem is it is usually done in a wholesale mechanistic way, and patients are treated in a one-size-fits-all fashion.'
But Dr Rubin Minhas, a GP in Gillingham and cardiovascular lead for Medway PCT, said: 'This is a poor-quality study susceptible to confounding and bias selection. Switching between equivalent doses of statins is safe, effective and efficient.'