Patients with raised blood pressure have a two-fold increased risk of dying from the coronavirus (Covid-19) compared to patients without high blood pressure, warn researchers.
In addition, the study, published in the European Heart Journal, found that patients with high blood pressure who were not taking medication to control the condition were at even greater risk of dying from Covid-19.
"It is important that patients with high blood pressure realise that they are at increased risk of dying from Covid-19," said study author Fei Li from Xijing Hospital China.
"They should take good care of themselves during this pandemic and they need more attention if they are infected with the coronavirus," Li added.
For the findings, researchers in China and Ireland analysed data from 2866 patients with Covid-19 who were admitted to Huo Shen Shan hospital in Wuhan, China, between 5 February and 15 March 2020.
Of these patients, 29.5 per cent (850) had a medical history of high blood pressure (hypertension).The study found four per cent high blood pressure patients with coronavirus died compared to 1.1 per cent patients without hypertension - a 2.12-fold increased risk after adjustment for factors that could affect the results, such as age, sex and other medical conditions.
In a separate meta-analysis of three other studies covering 2,300 Covid-19 patients from the same hospital, the research team investigated the death rates in patients being treated with drugs to control blood pressure levels by targeting the renin-angiotensin-aldosterone system (RAAS).
The findings showed a lower risk of death among the 183 patients treated with RAAS inhibitors) than in 527 patients treated with other non- RAAS heart drugs. RAAS drugs include angiotensin-converting enzyme (ACE) inhibitors, or angiotensin receptor blockers (ARBs). Non-RAAS inhibiting drugs used for treating high blood pressure include beta-blockers, calcium channel blockers (CCBs) or diuretics.
However, the researchers say this result should be treated with caution as the number of patients in this analysis was small and so it could be due to chance.
"We found that RAAS inhibitors, such as ACE inhibitors or angiotensin receptor blockers, were not linked to an increased risk of dying from Covid-19 and, in fact, maybe protective," said study co-author Ling Tao.
"Therefore, we suggest that patients should not discontinue or change their usual antihypertensive treatment unless instructed by a physician," Tao added.
As this was a study that looked at data from observations in the hospital, the researchers say it is too early to make clinical recommendations based on these results, and that results from randomised controlled clinical trials are needed to look, in particular, at the role played by RAAS inhibitors.