Cardiologists have poured cold water on claims that the anti-inflammatory effects of statins may have a protective effect in people hospitalised with COVID-19 .
A Chinese study has found an association between statin use and lower rates of death and need for ICU ventilation in people hospitalised with COVID-19, but that does not prove causality, according to other commentators.
An analysis of 13,981 COVID-19 patients admitted to hospital in Hubei, China found that those taking statins (n = 1,219) had a 5.5% mortality rate at one month, compared to 6.8% in patients who did not use statins.
The retrospective observational study showed a larger – 45% – decrease in mortality, from 9.4% to 5.2%, when comparing matched cohorts of statin users and non users who were otherwise similar. Statin use was also associated with lower levels of inflammation biomarkers, a lower incidence of acute respiratory distress syndrome and lower rates of admission to intensive care units.
In a matched cohort with 204 patients in each group, the use of statins combined with ACE inhibitors or ARBs versus other antihypertensive drugs was associated with a 65% drop in the death rate (3.4% versus 9.8%) and a lower incidence of heart injury and acute respiratory distress syndrome, according to the findings published in Cell Metabolism
“These results support the safety and potential benefits of statin therapy in hospitalised patients with COVID-19 and provide a rationale for prospective studies to determine whether statins confer protection against COVID-19-associated mortality,” said lead study author Dr Li Hongliang of Wuhan University.
But Dr Riyaz Patel, Associate Professor of Cardiology, UCL, London said that as with all observational studies it was difficult to be sure whether the differences seen with statin use were due to confounding or affected by specific biases.
“Statins are frequently given to very specific groups and this observation may be related to other unmeasured factors that could give a favourable outcome like being more wealthy or having regular access to preventative healthcare,” he said.
“Some people may be too sick with cancer or other conditions and may not be given statins at all. It is also possible those taking statins were admitted because their co-morbidities made them higher risk, while those without these comorbidities and therefore not taking statins were admitted because of more severe viral features, which would lead to an appearance that statin use was in fact protective.”
The authors have tried to address some of these challenges, but such biases were very difficult to resolve, said Dr Patel.
“The study will be of interest especially as so many people take statins. However the findings should be interpreted with significant caution and only a randomised clinical trial, such as the dexamethasone study recently, can demonstrate if treatment with statins is beneficial in the context of COVID infection,” he added.
Prof Kevin McConway, Emeritus Professor of Applied Statistics, The Open University, said the study provided some evidence on the safety of ACE inhibitors and ARBs in COVID-19 patients.
“Just as with the comparison between statin users and non-users, however, it can’t be clear what is causing what here, because it is an observational study, and the number of patients involved in the ACE inhibitor and ARBs study was relatively small. But this result, like the results of some other studies on these drugs, does provide a certain amount of reassurance that they are unlikely to be harmful in COVID-19 patients,” he said.