COVID-19: Hypertension Doubles Risk of Death

Hypertension is associated with significantly increased mortality in patients with COVID-19, new research shows.

Investigators examined the medical records of patients with COVID-19 and found a twofold increase in the relative risk of mortality among patients with hypertension, compared with normotensive patients.

Among patients with COVID-19 and hypertension, untreated hypertension was associated with an approximately twofold increase in mortality, compared with treated hypertension.

Importantly, investigators did not find a significant difference in mortality between patients who took renin-angiotensin-aldosterone system (RAAS) inhibitors and those who took another class of antihypertensive medication - a finding that surprised the investigators.

The study was published online June 4 in European Heart Journal.

Previous epidemiologic research suggests hypertension is associated with increased mortality among patients with COVID-19. However, these studies did not adjust for potential confounders such as age, which is emerging as the strongest predictor of COVID-19 related death.

Angiotensin-converting enzyme 2 (ACE2) is needed for SARS-CoV-2 to enter the body. Reports suggest that ACE inhibitors and angiotensin receptor blockers, the two RAAS inhibitors used as antihypertensive treatments, increase the expression of ACE2.

The researchers conducted the retrospective observational study to analyze whether the treatment of hypertension influences mortality among patients with COVID-19. The study population included all patients with confirmed COVID-19 who were admitted to Huo Shen Shan Hospital in Wuhan, China, from February 5 to March 15.

They collected patients' demographic and clinical data from electronic medical records. Diagnoses of hypertension were made before infection with SARS-CoV-2. The study's primary endpoint was all-cause mortality during hospitalization.

A total of 2877 consecutive patients were included in the analysis. The population's mean age was approximately 60 years, and about 51% of patients were male.

Overall, 29.5% of patients had a history of hypertension. Patients with hypertension were older and more likely to have a history of diabetes, angina, stroke, renal failure, or previous revascularization, compared with patients without hypertension.

In addition, 83.5% of patients with hypertension were taking antihypertensive medications. Of this group, 25.7% were treated with RAAS inhibitors, and 74.2% were treated with non-RAAS inhibitors such as beta blockers or diuretics.

The mortality rate was 4.0% among patients with hypertension and 1.1% among normotensive patients. The unadjusted hazard ratio (HR) of mortality was 3.75 among patients with hypertension, compared with normotensive patients. After adjustment for potential confounders, the HR was 2.12.

Among patients with hypertension, the unadjusted mortality rate was significantly higher for those without antihypertensive treatment (7.9% vs 3.2%; HR, 2.52). Adjustment for potential confounders did not change the character of this observed relationship (HR, 2.17).

The difference in mortality between patients treated with RAAS inhibitors and those treated with non-RAAS inhibitors was not significant before or after data adjustment. Contrary to the investigators' hypothesis, RAAS inhibitors were associated with a lower mortality rate than non-RAAS inhibitors (2.2% vs 3.6%; adjusted HR, 0.85). The small sample sizes of the two groups suggest that the finding could result from chance.