Early news reports of fatalities in China from coronavirus strongly implied that hypertension was an independent risk factor for severe disease and death.
Bloomberg and many other seemingly reliable news sources relied on one Chinese doctor’s anecdotal statements along with a Lancet article to make this claim:
“A top Chinese intensive care doctor told Bloomberg that of 170 patients who died in January in Wuhan, nearly half had hypertension, and anecdotally he said that he and other doctors have noticed hypertension is prevalent in those who die.”
However the actual Lancet report on 191 patients published March 11, 2020 , entitled Clinical course and risk factors for mortality of adult inpatients with COVID-19 in Wuhan, China: a retrospective cohort study did not find hypertension or heart disease to be an independent risk factor for severe respiratory disease or death.
Of the 191 patients, 137 were discharged and 54 died in hospital. 91 (48%) patients had a comorbidity, with hypertension being the most common (58 [30%] patients), followed by diabetes (36 [19%] patients) and coronary heart disease (15 [8%] patients).
Although patients with hypertension were more likely to die than those without hypertension this does not prove hypertension is an independent risk factor
Age was by far the most significant risk factor and the older patients also had more hypertension. When all variables were factored into an analysis, hypertension and heart disease were not significantly related to death:
Multivariable regression showed increasing odds of in-hospital death associated with older age (odds ratio 1·10, 95% CI 1·03–1·17, per year increase; p=0·0043), higher Sequential Organ Failure Assessment (SOFA) score (5·65, 2·61–12·23; p<0·0001), and d-dimer greater than 1 μg/mL (18·42, 2·64–128·55; p=0·0033) on admission
Heart disease and hypertension were not significant factors after accounting for age.
Nephrology Journal Club (NephJC) has an excellent discussion (frequently updated and well-reference) on this topic here. After looking at all current publications in this area they agree with me that the current data do not support the idea that hypertension is an independent risk factor for either getting SARS-CoV2 or having a more serious illness from it.
Among the patients with COVID-19, it seems the prevalence of prior h/o HT is higher in those who develop severe disease than those who do not. Same applies for development of ARDS or death – but mostly in unadjusted analysis. See table below for more. The last two rows are the best quality data so far, and suggest the association between COVID-19 severity and hypertension is attenuated after adjustment.
Sources: Guan et al, NEJM; Huang et al, Lancet; Wang et al, JAMA; Zhang et al, Allergy; Zhou et al, Lancet; Wu et al, JAMA IM; Italian report (PDF); Chen et al, BMJ; Shi et al, JAMA Cardiol; McMichael et al, NEJM; Guo et al, JAMA Cardiol; Bean et al, MedRxiv 2020; Petrilli et al, MedRXiv 2020
As can be seen, most of the studies except the last two, did not adjust for age. Even age-stratified association of hypertension would have been a more useful way to see these data to understand this issue a bit better. We hope more data in coming days will clarify this relationship. Unlike what we stated earlier, the Zhou et al study did not adjust for hypertension.
As can be seen above, hypertension in the general population closely associates with increasing age, hence any association with hypertension may merely represent confounding due to age, and should be interpreted after careful analysis.
The Question Is Definitively Answered
- Hypertension does not put you at a higher risk of serious illness or death due to Covid-19.
- As discussed in previous posts (see here and here), there is no reason to stop taking your ACE inhibitor or angiotensin receptor blocker (ARB) blood pressure medication during this pandemic. (Also don’t start demanding you be put on an ACE inhibitor-the protective association seen in one study does not prove causality, we need randomized trials to show drugs safety and effectiveness!)
- Be very skeptical of early anecdotal reports and small trials rushed to publication (especially “preprints” which have not been peer-reviewed) during Covid-19. The poorly substantiated claims that hypertension was a major risk factor for death and that ACE inhibitors increased patient’s risk during Covid-19 have proven false. As better data emerges regarding hydroxychloroquine, despite enthusiastic anecdotal reports from some physicians, this drug has not been proven safe and/or effective for Covid-19 treatment.